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perf: Rename perf-examples.txt to examples.txt
[linux-2.6/mini2440.git] / fs / btrfs / volumes.c
blob5dbefd11b4af524f969c21b857067281eab0dc71
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 batch_run = 0;
165 unsigned long limit;
166 unsigned long last_waited = 0;
167 int force_reg = 0;
168
169 bdi = blk_get_backing_dev_info(device->bdev);
170 fs_info = device->dev_root->fs_info;
171 limit = btrfs_async_submit_limit(fs_info);
172 limit = limit * 2 / 3;
173
174 /* we want to make sure that every time we switch from the sync
175 * list to the normal list, we unplug
176 */
177 num_sync_run = 0;
178
179 loop:
180 spin_lock(&device->io_lock);
181
182 loop_lock:
183 num_run = 0;
184
185 /* take all the bios off the list at once and process them
186 * later on (without the lock held). But, remember the
187 * tail and other pointers so the bios can be properly reinserted
188 * into the list if we hit congestion
189 */
190 if (!force_reg && device->pending_sync_bios.head) {
191 pending_bios = &device->pending_sync_bios;
192 force_reg = 1;
193 } else {
194 pending_bios = &device->pending_bios;
195 force_reg = 0;
196 }
197
198 pending = pending_bios->head;
199 tail = pending_bios->tail;
200 WARN_ON(pending && !tail);
201
202 /*
203 * if pending was null this time around, no bios need processing
204 * at all and we can stop. Otherwise it'll loop back up again
205 * and do an additional check so no bios are missed.
206 *
207 * device->running_pending is used to synchronize with the
208 * schedule_bio code.
209 */
210 if (device->pending_sync_bios.head == NULL &&
211 device->pending_bios.head == NULL) {
212 again = 0;
213 device->running_pending = 0;
214 } else {
215 again = 1;
216 device->running_pending = 1;
217 }
218
219 pending_bios->head = NULL;
220 pending_bios->tail = NULL;
221
222 spin_unlock(&device->io_lock);
223
224 /*
225 * if we're doing the regular priority list, make sure we unplug
226 * for any high prio bios we've sent down
227 */
228 if (pending_bios == &device->pending_bios && num_sync_run > 0) {
229 num_sync_run = 0;
230 blk_run_backing_dev(bdi, NULL);
231 }
232
233 while (pending) {
234
235 rmb();
236 /* we want to work on both lists, but do more bios on the
237 * sync list than the regular list
238 */
239 if ((num_run > 32 &&
240 pending_bios != &device->pending_sync_bios &&
241 device->pending_sync_bios.head) ||
242 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
243 device->pending_bios.head)) {
244 spin_lock(&device->io_lock);
245 requeue_list(pending_bios, pending, tail);
246 goto loop_lock;
247 }
248
249 cur = pending;
250 pending = pending->bi_next;
251 cur->bi_next = NULL;
252 atomic_dec(&fs_info->nr_async_bios);
253
254 if (atomic_read(&fs_info->nr_async_bios) < limit &&
255 waitqueue_active(&fs_info->async_submit_wait))
256 wake_up(&fs_info->async_submit_wait);
257
258 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
259 submit_bio(cur->bi_rw, cur);
260 num_run++;
261 batch_run++;
262
263 if (bio_sync(cur))
264 num_sync_run++;
265
266 if (need_resched()) {
267 if (num_sync_run) {
268 blk_run_backing_dev(bdi, NULL);
269 num_sync_run = 0;
270 }
271 cond_resched();
272 }
273
274 /*
275 * we made progress, there is more work to do and the bdi
276 * is now congested. Back off and let other work structs
277 * run instead
278 */
279 if (pending && bdi_write_congested(bdi) && batch_run > 32 &&
280 fs_info->fs_devices->open_devices > 1) {
281 struct io_context *ioc;
282
283 ioc = current->io_context;
284
285 /*
286 * the main goal here is that we don't want to
287 * block if we're going to be able to submit
288 * more requests without blocking.
289 *
290 * This code does two great things, it pokes into
291 * the elevator code from a filesystem _and_
292 * it makes assumptions about how batching works.
293 */
294 if (ioc && ioc->nr_batch_requests > 0 &&
295 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
296 (last_waited == 0 ||
297 ioc->last_waited == last_waited)) {
298 /*
299 * we want to go through our batch of
300 * requests and stop. So, we copy out
301 * the ioc->last_waited time and test
302 * against it before looping
303 */
304 last_waited = ioc->last_waited;
305 if (need_resched()) {
306 if (num_sync_run) {
307 blk_run_backing_dev(bdi, NULL);
308 num_sync_run = 0;
309 }
310 cond_resched();
311 }
312 continue;
313 }
314 spin_lock(&device->io_lock);
315 requeue_list(pending_bios, pending, tail);
316 device->running_pending = 1;
317
318 spin_unlock(&device->io_lock);
319 btrfs_requeue_work(&device->work);
320 goto done;
321 }
322 }
323
324 if (num_sync_run) {
325 num_sync_run = 0;
326 blk_run_backing_dev(bdi, NULL);
327 }
328
329 cond_resched();
330 if (again)
331 goto loop;
332
333 spin_lock(&device->io_lock);
334 if (device->pending_bios.head || device->pending_sync_bios.head)
335 goto loop_lock;
336 spin_unlock(&device->io_lock);
337
338 /*
339 * IO has already been through a long path to get here. Checksumming,
340 * async helper threads, perhaps compression. We've done a pretty
341 * good job of collecting a batch of IO and should just unplug
342 * the device right away.
343 *
344 * This will help anyone who is waiting on the IO, they might have
345 * already unplugged, but managed to do so before the bio they
346 * cared about found its way down here.
347 */
348 blk_run_backing_dev(bdi, NULL);
349 done:
350 return 0;
351 }
352
353 static void pending_bios_fn(struct btrfs_work *work)
354 {
355 struct btrfs_device *device;
356
357 device = container_of(work, struct btrfs_device, work);
358 run_scheduled_bios(device);
359 }
360
361 static noinline int device_list_add(const char *path,
362 struct btrfs_super_block *disk_super,
363 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
364 {
365 struct btrfs_device *device;
366 struct btrfs_fs_devices *fs_devices;
367 u64 found_transid = btrfs_super_generation(disk_super);
368
369 fs_devices = find_fsid(disk_super->fsid);
370 if (!fs_devices) {
371 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
372 if (!fs_devices)
373 return -ENOMEM;
374 INIT_LIST_HEAD(&fs_devices->devices);
375 INIT_LIST_HEAD(&fs_devices->alloc_list);
376 list_add(&fs_devices->list, &fs_uuids);
377 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
378 fs_devices->latest_devid = devid;
379 fs_devices->latest_trans = found_transid;
380 mutex_init(&fs_devices->device_list_mutex);
381 device = NULL;
382 } else {
383 device = __find_device(&fs_devices->devices, devid,
384 disk_super->dev_item.uuid);
385 }
386 if (!device) {
387 if (fs_devices->opened)
388 return -EBUSY;
389
390 device = kzalloc(sizeof(*device), GFP_NOFS);
391 if (!device) {
392 /* we can safely leave the fs_devices entry around */
393 return -ENOMEM;
394 }
395 device->devid = devid;
396 device->work.func = pending_bios_fn;
397 memcpy(device->uuid, disk_super->dev_item.uuid,
398 BTRFS_UUID_SIZE);
399 device->barriers = 1;
400 spin_lock_init(&device->io_lock);
401 device->name = kstrdup(path, GFP_NOFS);
402 if (!device->name) {
403 kfree(device);
404 return -ENOMEM;
405 }
406 INIT_LIST_HEAD(&device->dev_alloc_list);
407
408 mutex_lock(&fs_devices->device_list_mutex);
409 list_add(&device->dev_list, &fs_devices->devices);
410 mutex_unlock(&fs_devices->device_list_mutex);
411
412 device->fs_devices = fs_devices;
413 fs_devices->num_devices++;
414 }
415
416 if (found_transid > fs_devices->latest_trans) {
417 fs_devices->latest_devid = devid;
418 fs_devices->latest_trans = found_transid;
419 }
420 *fs_devices_ret = fs_devices;
421 return 0;
422 }
423
424 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
425 {
426 struct btrfs_fs_devices *fs_devices;
427 struct btrfs_device *device;
428 struct btrfs_device *orig_dev;
429
430 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
431 if (!fs_devices)
432 return ERR_PTR(-ENOMEM);
433
434 INIT_LIST_HEAD(&fs_devices->devices);
435 INIT_LIST_HEAD(&fs_devices->alloc_list);
436 INIT_LIST_HEAD(&fs_devices->list);
437 mutex_init(&fs_devices->device_list_mutex);
438 fs_devices->latest_devid = orig->latest_devid;
439 fs_devices->latest_trans = orig->latest_trans;
440 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
441
442 mutex_lock(&orig->device_list_mutex);
443 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
444 device = kzalloc(sizeof(*device), GFP_NOFS);
445 if (!device)
446 goto error;
447
448 device->name = kstrdup(orig_dev->name, GFP_NOFS);
449 if (!device->name)
450 goto error;
451
452 device->devid = orig_dev->devid;
453 device->work.func = pending_bios_fn;
454 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
455 device->barriers = 1;
456 spin_lock_init(&device->io_lock);
457 INIT_LIST_HEAD(&device->dev_list);
458 INIT_LIST_HEAD(&device->dev_alloc_list);
459
460 list_add(&device->dev_list, &fs_devices->devices);
461 device->fs_devices = fs_devices;
462 fs_devices->num_devices++;
463 }
464 mutex_unlock(&orig->device_list_mutex);
465 return fs_devices;
466 error:
467 mutex_unlock(&orig->device_list_mutex);
468 free_fs_devices(fs_devices);
469 return ERR_PTR(-ENOMEM);
470 }
471
472 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
473 {
474 struct btrfs_device *device, *next;
475
476 mutex_lock(&uuid_mutex);
477 again:
478 mutex_lock(&fs_devices->device_list_mutex);
479 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
480 if (device->in_fs_metadata)
481 continue;
482
483 if (device->bdev) {
484 close_bdev_exclusive(device->bdev, device->mode);
485 device->bdev = NULL;
486 fs_devices->open_devices--;
487 }
488 if (device->writeable) {
489 list_del_init(&device->dev_alloc_list);
490 device->writeable = 0;
491 fs_devices->rw_devices--;
492 }
493 list_del_init(&device->dev_list);
494 fs_devices->num_devices--;
495 kfree(device->name);
496 kfree(device);
497 }
498 mutex_unlock(&fs_devices->device_list_mutex);
499
500 if (fs_devices->seed) {
501 fs_devices = fs_devices->seed;
502 goto again;
503 }
504
505 mutex_unlock(&uuid_mutex);
506 return 0;
507 }
508
509 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
510 {
511 struct btrfs_device *device;
512
513 if (--fs_devices->opened > 0)
514 return 0;
515
516 list_for_each_entry(device, &fs_devices->devices, dev_list) {
517 if (device->bdev) {
518 close_bdev_exclusive(device->bdev, device->mode);
519 fs_devices->open_devices--;
520 }
521 if (device->writeable) {
522 list_del_init(&device->dev_alloc_list);
523 fs_devices->rw_devices--;
524 }
525
526 device->bdev = NULL;
527 device->writeable = 0;
528 device->in_fs_metadata = 0;
529 }
530 WARN_ON(fs_devices->open_devices);
531 WARN_ON(fs_devices->rw_devices);
532 fs_devices->opened = 0;
533 fs_devices->seeding = 0;
534
535 return 0;
536 }
537
538 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
539 {
540 struct btrfs_fs_devices *seed_devices = NULL;
541 int ret;
542
543 mutex_lock(&uuid_mutex);
544 ret = __btrfs_close_devices(fs_devices);
545 if (!fs_devices->opened) {
546 seed_devices = fs_devices->seed;
547 fs_devices->seed = NULL;
548 }
549 mutex_unlock(&uuid_mutex);
550
551 while (seed_devices) {
552 fs_devices = seed_devices;
553 seed_devices = fs_devices->seed;
554 __btrfs_close_devices(fs_devices);
555 free_fs_devices(fs_devices);
556 }
557 return ret;
558 }
559
560 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
561 fmode_t flags, void *holder)
562 {
563 struct block_device *bdev;
564 struct list_head *head = &fs_devices->devices;
565 struct btrfs_device *device;
566 struct block_device *latest_bdev = NULL;
567 struct buffer_head *bh;
568 struct btrfs_super_block *disk_super;
569 u64 latest_devid = 0;
570 u64 latest_transid = 0;
571 u64 devid;
572 int seeding = 1;
573 int ret = 0;
574
575 list_for_each_entry(device, head, dev_list) {
576 if (device->bdev)
577 continue;
578 if (!device->name)
579 continue;
580
581 bdev = open_bdev_exclusive(device->name, flags, holder);
582 if (IS_ERR(bdev)) {
583 printk(KERN_INFO "open %s failed\n", device->name);
584 goto error;
585 }
586 set_blocksize(bdev, 4096);
587
588 bh = btrfs_read_dev_super(bdev);
589 if (!bh)
590 goto error_close;
591
592 disk_super = (struct btrfs_super_block *)bh->b_data;
593 devid = le64_to_cpu(disk_super->dev_item.devid);
594 if (devid != device->devid)
595 goto error_brelse;
596
597 if (memcmp(device->uuid, disk_super->dev_item.uuid,
598 BTRFS_UUID_SIZE))
599 goto error_brelse;
600
601 device->generation = btrfs_super_generation(disk_super);
602 if (!latest_transid || device->generation > latest_transid) {
603 latest_devid = devid;
604 latest_transid = device->generation;
605 latest_bdev = bdev;
606 }
607
608 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
609 device->writeable = 0;
610 } else {
611 device->writeable = !bdev_read_only(bdev);
612 seeding = 0;
613 }
614
615 device->bdev = bdev;
616 device->in_fs_metadata = 0;
617 device->mode = flags;
618
619 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
620 fs_devices->rotating = 1;
621
622 fs_devices->open_devices++;
623 if (device->writeable) {
624 fs_devices->rw_devices++;
625 list_add(&device->dev_alloc_list,
626 &fs_devices->alloc_list);
627 }
628 continue;
629
630 error_brelse:
631 brelse(bh);
632 error_close:
633 close_bdev_exclusive(bdev, FMODE_READ);
634 error:
635 continue;
636 }
637 if (fs_devices->open_devices == 0) {
638 ret = -EIO;
639 goto out;
640 }
641 fs_devices->seeding = seeding;
642 fs_devices->opened = 1;
643 fs_devices->latest_bdev = latest_bdev;
644 fs_devices->latest_devid = latest_devid;
645 fs_devices->latest_trans = latest_transid;
646 fs_devices->total_rw_bytes = 0;
647 out:
648 return ret;
649 }
650
651 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
652 fmode_t flags, void *holder)
653 {
654 int ret;
655
656 mutex_lock(&uuid_mutex);
657 if (fs_devices->opened) {
658 fs_devices->opened++;
659 ret = 0;
660 } else {
661 ret = __btrfs_open_devices(fs_devices, flags, holder);
662 }
663 mutex_unlock(&uuid_mutex);
664 return ret;
665 }
666
667 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
668 struct btrfs_fs_devices **fs_devices_ret)
669 {
670 struct btrfs_super_block *disk_super;
671 struct block_device *bdev;
672 struct buffer_head *bh;
673 int ret;
674 u64 devid;
675 u64 transid;
676
677 mutex_lock(&uuid_mutex);
678
679 bdev = open_bdev_exclusive(path, flags, holder);
680
681 if (IS_ERR(bdev)) {
682 ret = PTR_ERR(bdev);
683 goto error;
684 }
685
686 ret = set_blocksize(bdev, 4096);
687 if (ret)
688 goto error_close;
689 bh = btrfs_read_dev_super(bdev);
690 if (!bh) {
691 ret = -EIO;
692 goto error_close;
693 }
694 disk_super = (struct btrfs_super_block *)bh->b_data;
695 devid = le64_to_cpu(disk_super->dev_item.devid);
696 transid = btrfs_super_generation(disk_super);
697 if (disk_super->label[0])
698 printk(KERN_INFO "device label %s ", disk_super->label);
699 else {
700 /* FIXME, make a readl uuid parser */
701 printk(KERN_INFO "device fsid %llx-%llx ",
702 *(unsigned long long *)disk_super->fsid,
703 *(unsigned long long *)(disk_super->fsid + 8));
704 }
705 printk(KERN_CONT "devid %llu transid %llu %s\n",
706 (unsigned long long)devid, (unsigned long long)transid, path);
707 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
708
709 brelse(bh);
710 error_close:
711 close_bdev_exclusive(bdev, flags);
712 error:
713 mutex_unlock(&uuid_mutex);
714 return ret;
715 }
716
717 /*
718 * this uses a pretty simple search, the expectation is that it is
719 * called very infrequently and that a given device has a small number
720 * of extents
721 */
722 static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans,
723 struct btrfs_device *device,
724 u64 num_bytes, u64 *start,
725 u64 *max_avail)
726 {
727 struct btrfs_key key;
728 struct btrfs_root *root = device->dev_root;
729 struct btrfs_dev_extent *dev_extent = NULL;
730 struct btrfs_path *path;
731 u64 hole_size = 0;
732 u64 last_byte = 0;
733 u64 search_start = 0;
734 u64 search_end = device->total_bytes;
735 int ret;
736 int slot = 0;
737 int start_found;
738 struct extent_buffer *l;
739
740 path = btrfs_alloc_path();
741 if (!path)
742 return -ENOMEM;
743 path->reada = 2;
744 start_found = 0;
745
746 /* FIXME use last free of some kind */
747
748 /* we don't want to overwrite the superblock on the drive,
749 * so we make sure to start at an offset of at least 1MB
750 */
751 search_start = max((u64)1024 * 1024, search_start);
752
753 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
754 search_start = max(root->fs_info->alloc_start, search_start);
755
756 key.objectid = device->devid;
757 key.offset = search_start;
758 key.type = BTRFS_DEV_EXTENT_KEY;
759 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
760 if (ret < 0)
761 goto error;
762 if (ret > 0) {
763 ret = btrfs_previous_item(root, path, key.objectid, key.type);
764 if (ret < 0)
765 goto error;
766 if (ret > 0)
767 start_found = 1;
768 }
769 l = path->nodes[0];
770 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
771 while (1) {
772 l = path->nodes[0];
773 slot = path->slots[0];
774 if (slot >= btrfs_header_nritems(l)) {
775 ret = btrfs_next_leaf(root, path);
776 if (ret == 0)
777 continue;
778 if (ret < 0)
779 goto error;
780 no_more_items:
781 if (!start_found) {
782 if (search_start >= search_end) {
783 ret = -ENOSPC;
784 goto error;
785 }
786 *start = search_start;
787 start_found = 1;
788 goto check_pending;
789 }
790 *start = last_byte > search_start ?
791 last_byte : search_start;
792 if (search_end <= *start) {
793 ret = -ENOSPC;
794 goto error;
795 }
796 goto check_pending;
797 }
798 btrfs_item_key_to_cpu(l, &key, slot);
799
800 if (key.objectid < device->devid)
801 goto next;
802
803 if (key.objectid > device->devid)
804 goto no_more_items;
805
806 if (key.offset >= search_start && key.offset > last_byte &&
807 start_found) {
808 if (last_byte < search_start)
809 last_byte = search_start;
810 hole_size = key.offset - last_byte;
811
812 if (hole_size > *max_avail)
813 *max_avail = hole_size;
814
815 if (key.offset > last_byte &&
816 hole_size >= num_bytes) {
817 *start = last_byte;
818 goto check_pending;
819 }
820 }
821 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
822 goto next;
823
824 start_found = 1;
825 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
826 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
827 next:
828 path->slots[0]++;
829 cond_resched();
830 }
831 check_pending:
832 /* we have to make sure we didn't find an extent that has already
833 * been allocated by the map tree or the original allocation
834 */
835 BUG_ON(*start < search_start);
836
837 if (*start + num_bytes > search_end) {
838 ret = -ENOSPC;
839 goto error;
840 }
841 /* check for pending inserts here */
842 ret = 0;
843
844 error:
845 btrfs_free_path(path);
846 return ret;
847 }
848
849 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
850 struct btrfs_device *device,
851 u64 start)
852 {
853 int ret;
854 struct btrfs_path *path;
855 struct btrfs_root *root = device->dev_root;
856 struct btrfs_key key;
857 struct btrfs_key found_key;
858 struct extent_buffer *leaf = NULL;
859 struct btrfs_dev_extent *extent = NULL;
860
861 path = btrfs_alloc_path();
862 if (!path)
863 return -ENOMEM;
864
865 key.objectid = device->devid;
866 key.offset = start;
867 key.type = BTRFS_DEV_EXTENT_KEY;
868
869 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
870 if (ret > 0) {
871 ret = btrfs_previous_item(root, path, key.objectid,
872 BTRFS_DEV_EXTENT_KEY);
873 BUG_ON(ret);
874 leaf = path->nodes[0];
875 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
876 extent = btrfs_item_ptr(leaf, path->slots[0],
877 struct btrfs_dev_extent);
878 BUG_ON(found_key.offset > start || found_key.offset +
879 btrfs_dev_extent_length(leaf, extent) < start);
880 ret = 0;
881 } else if (ret == 0) {
882 leaf = path->nodes[0];
883 extent = btrfs_item_ptr(leaf, path->slots[0],
884 struct btrfs_dev_extent);
885 }
886 BUG_ON(ret);
887
888 if (device->bytes_used > 0)
889 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
890 ret = btrfs_del_item(trans, root, path);
891 BUG_ON(ret);
892
893 btrfs_free_path(path);
894 return ret;
895 }
896
897 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
898 struct btrfs_device *device,
899 u64 chunk_tree, u64 chunk_objectid,
900 u64 chunk_offset, u64 start, u64 num_bytes)
901 {
902 int ret;
903 struct btrfs_path *path;
904 struct btrfs_root *root = device->dev_root;
905 struct btrfs_dev_extent *extent;
906 struct extent_buffer *leaf;
907 struct btrfs_key key;
908
909 WARN_ON(!device->in_fs_metadata);
910 path = btrfs_alloc_path();
911 if (!path)
912 return -ENOMEM;
913
914 key.objectid = device->devid;
915 key.offset = start;
916 key.type = BTRFS_DEV_EXTENT_KEY;
917 ret = btrfs_insert_empty_item(trans, root, path, &key,
918 sizeof(*extent));
919 BUG_ON(ret);
920
921 leaf = path->nodes[0];
922 extent = btrfs_item_ptr(leaf, path->slots[0],
923 struct btrfs_dev_extent);
924 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
925 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
926 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
927
928 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
929 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
930 BTRFS_UUID_SIZE);
931
932 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
933 btrfs_mark_buffer_dirty(leaf);
934 btrfs_free_path(path);
935 return ret;
936 }
937
938 static noinline int find_next_chunk(struct btrfs_root *root,
939 u64 objectid, u64 *offset)
940 {
941 struct btrfs_path *path;
942 int ret;
943 struct btrfs_key key;
944 struct btrfs_chunk *chunk;
945 struct btrfs_key found_key;
946
947 path = btrfs_alloc_path();
948 BUG_ON(!path);
949
950 key.objectid = objectid;
951 key.offset = (u64)-1;
952 key.type = BTRFS_CHUNK_ITEM_KEY;
953
954 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
955 if (ret < 0)
956 goto error;
957
958 BUG_ON(ret == 0);
959
960 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
961 if (ret) {
962 *offset = 0;
963 } else {
964 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
965 path->slots[0]);
966 if (found_key.objectid != objectid)
967 *offset = 0;
968 else {
969 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
970 struct btrfs_chunk);
971 *offset = found_key.offset +
972 btrfs_chunk_length(path->nodes[0], chunk);
973 }
974 }
975 ret = 0;
976 error:
977 btrfs_free_path(path);
978 return ret;
979 }
980
981 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
982 {
983 int ret;
984 struct btrfs_key key;
985 struct btrfs_key found_key;
986 struct btrfs_path *path;
987
988 root = root->fs_info->chunk_root;
989
990 path = btrfs_alloc_path();
991 if (!path)
992 return -ENOMEM;
993
994 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
995 key.type = BTRFS_DEV_ITEM_KEY;
996 key.offset = (u64)-1;
997
998 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
999 if (ret < 0)
1000 goto error;
1001
1002 BUG_ON(ret == 0);
1003
1004 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1005 BTRFS_DEV_ITEM_KEY);
1006 if (ret) {
1007 *objectid = 1;
1008 } else {
1009 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1010 path->slots[0]);
1011 *objectid = found_key.offset + 1;
1012 }
1013 ret = 0;
1014 error:
1015 btrfs_free_path(path);
1016 return ret;
1017 }
1018
1019 /*
1020 * the device information is stored in the chunk root
1021 * the btrfs_device struct should be fully filled in
1022 */
1023 int btrfs_add_device(struct btrfs_trans_handle *trans,
1024 struct btrfs_root *root,
1025 struct btrfs_device *device)
1026 {
1027 int ret;
1028 struct btrfs_path *path;
1029 struct btrfs_dev_item *dev_item;
1030 struct extent_buffer *leaf;
1031 struct btrfs_key key;
1032 unsigned long ptr;
1033
1034 root = root->fs_info->chunk_root;
1035
1036 path = btrfs_alloc_path();
1037 if (!path)
1038 return -ENOMEM;
1039
1040 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1041 key.type = BTRFS_DEV_ITEM_KEY;
1042 key.offset = device->devid;
1043
1044 ret = btrfs_insert_empty_item(trans, root, path, &key,
1045 sizeof(*dev_item));
1046 if (ret)
1047 goto out;
1048
1049 leaf = path->nodes[0];
1050 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1051
1052 btrfs_set_device_id(leaf, dev_item, device->devid);
1053 btrfs_set_device_generation(leaf, dev_item, 0);
1054 btrfs_set_device_type(leaf, dev_item, device->type);
1055 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1056 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1057 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1058 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1059 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1060 btrfs_set_device_group(leaf, dev_item, 0);
1061 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1062 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1063 btrfs_set_device_start_offset(leaf, dev_item, 0);
1064
1065 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1066 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1067 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1068 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1069 btrfs_mark_buffer_dirty(leaf);
1070
1071 ret = 0;
1072 out:
1073 btrfs_free_path(path);
1074 return ret;
1075 }
1076
1077 static int btrfs_rm_dev_item(struct btrfs_root *root,
1078 struct btrfs_device *device)
1079 {
1080 int ret;
1081 struct btrfs_path *path;
1082 struct btrfs_key key;
1083 struct btrfs_trans_handle *trans;
1084
1085 root = root->fs_info->chunk_root;
1086
1087 path = btrfs_alloc_path();
1088 if (!path)
1089 return -ENOMEM;
1090
1091 trans = btrfs_start_transaction(root, 1);
1092 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1093 key.type = BTRFS_DEV_ITEM_KEY;
1094 key.offset = device->devid;
1095 lock_chunks(root);
1096
1097 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1098 if (ret < 0)
1099 goto out;
1100
1101 if (ret > 0) {
1102 ret = -ENOENT;
1103 goto out;
1104 }
1105
1106 ret = btrfs_del_item(trans, root, path);
1107 if (ret)
1108 goto out;
1109 out:
1110 btrfs_free_path(path);
1111 unlock_chunks(root);
1112 btrfs_commit_transaction(trans, root);
1113 return ret;
1114 }
1115
1116 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1117 {
1118 struct btrfs_device *device;
1119 struct btrfs_device *next_device;
1120 struct block_device *bdev;
1121 struct buffer_head *bh = NULL;
1122 struct btrfs_super_block *disk_super;
1123 u64 all_avail;
1124 u64 devid;
1125 u64 num_devices;
1126 u8 *dev_uuid;
1127 int ret = 0;
1128
1129 mutex_lock(&uuid_mutex);
1130 mutex_lock(&root->fs_info->volume_mutex);
1131
1132 all_avail = root->fs_info->avail_data_alloc_bits |
1133 root->fs_info->avail_system_alloc_bits |
1134 root->fs_info->avail_metadata_alloc_bits;
1135
1136 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1137 root->fs_info->fs_devices->rw_devices <= 4) {
1138 printk(KERN_ERR "btrfs: unable to go below four devices "
1139 "on raid10\n");
1140 ret = -EINVAL;
1141 goto out;
1142 }
1143
1144 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1145 root->fs_info->fs_devices->rw_devices <= 2) {
1146 printk(KERN_ERR "btrfs: unable to go below two "
1147 "devices on raid1\n");
1148 ret = -EINVAL;
1149 goto out;
1150 }
1151
1152 if (strcmp(device_path, "missing") == 0) {
1153 struct list_head *devices;
1154 struct btrfs_device *tmp;
1155
1156 device = NULL;
1157 devices = &root->fs_info->fs_devices->devices;
1158 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1159 list_for_each_entry(tmp, devices, dev_list) {
1160 if (tmp->in_fs_metadata && !tmp->bdev) {
1161 device = tmp;
1162 break;
1163 }
1164 }
1165 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1166 bdev = NULL;
1167 bh = NULL;
1168 disk_super = NULL;
1169 if (!device) {
1170 printk(KERN_ERR "btrfs: no missing devices found to "
1171 "remove\n");
1172 goto out;
1173 }
1174 } else {
1175 bdev = open_bdev_exclusive(device_path, FMODE_READ,
1176 root->fs_info->bdev_holder);
1177 if (IS_ERR(bdev)) {
1178 ret = PTR_ERR(bdev);
1179 goto out;
1180 }
1181
1182 set_blocksize(bdev, 4096);
1183 bh = btrfs_read_dev_super(bdev);
1184 if (!bh) {
1185 ret = -EIO;
1186 goto error_close;
1187 }
1188 disk_super = (struct btrfs_super_block *)bh->b_data;
1189 devid = le64_to_cpu(disk_super->dev_item.devid);
1190 dev_uuid = disk_super->dev_item.uuid;
1191 device = btrfs_find_device(root, devid, dev_uuid,
1192 disk_super->fsid);
1193 if (!device) {
1194 ret = -ENOENT;
1195 goto error_brelse;
1196 }
1197 }
1198
1199 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1200 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1201 "device\n");
1202 ret = -EINVAL;
1203 goto error_brelse;
1204 }
1205
1206 if (device->writeable) {
1207 list_del_init(&device->dev_alloc_list);
1208 root->fs_info->fs_devices->rw_devices--;
1209 }
1210
1211 ret = btrfs_shrink_device(device, 0);
1212 if (ret)
1213 goto error_brelse;
1214
1215 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1216 if (ret)
1217 goto error_brelse;
1218
1219 device->in_fs_metadata = 0;
1220
1221 /*
1222 * the device list mutex makes sure that we don't change
1223 * the device list while someone else is writing out all
1224 * the device supers.
1225 */
1226 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1227 list_del_init(&device->dev_list);
1228 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1229
1230 device->fs_devices->num_devices--;
1231
1232 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1233 struct btrfs_device, dev_list);
1234 if (device->bdev == root->fs_info->sb->s_bdev)
1235 root->fs_info->sb->s_bdev = next_device->bdev;
1236 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1237 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1238
1239 if (device->bdev) {
1240 close_bdev_exclusive(device->bdev, device->mode);
1241 device->bdev = NULL;
1242 device->fs_devices->open_devices--;
1243 }
1244
1245 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1246 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1247
1248 if (device->fs_devices->open_devices == 0) {
1249 struct btrfs_fs_devices *fs_devices;
1250 fs_devices = root->fs_info->fs_devices;
1251 while (fs_devices) {
1252 if (fs_devices->seed == device->fs_devices)
1253 break;
1254 fs_devices = fs_devices->seed;
1255 }
1256 fs_devices->seed = device->fs_devices->seed;
1257 device->fs_devices->seed = NULL;
1258 __btrfs_close_devices(device->fs_devices);
1259 free_fs_devices(device->fs_devices);
1260 }
1261
1262 /*
1263 * at this point, the device is zero sized. We want to
1264 * remove it from the devices list and zero out the old super
1265 */
1266 if (device->writeable) {
1267 /* make sure this device isn't detected as part of
1268 * the FS anymore
1269 */
1270 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1271 set_buffer_dirty(bh);
1272 sync_dirty_buffer(bh);
1273 }
1274
1275 kfree(device->name);
1276 kfree(device);
1277 ret = 0;
1278
1279 error_brelse:
1280 brelse(bh);
1281 error_close:
1282 if (bdev)
1283 close_bdev_exclusive(bdev, FMODE_READ);
1284 out:
1285 mutex_unlock(&root->fs_info->volume_mutex);
1286 mutex_unlock(&uuid_mutex);
1287 return ret;
1288 }
1289
1290 /*
1291 * does all the dirty work required for changing file system's UUID.
1292 */
1293 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1294 struct btrfs_root *root)
1295 {
1296 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1297 struct btrfs_fs_devices *old_devices;
1298 struct btrfs_fs_devices *seed_devices;
1299 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1300 struct btrfs_device *device;
1301 u64 super_flags;
1302
1303 BUG_ON(!mutex_is_locked(&uuid_mutex));
1304 if (!fs_devices->seeding)
1305 return -EINVAL;
1306
1307 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1308 if (!seed_devices)
1309 return -ENOMEM;
1310
1311 old_devices = clone_fs_devices(fs_devices);
1312 if (IS_ERR(old_devices)) {
1313 kfree(seed_devices);
1314 return PTR_ERR(old_devices);
1315 }
1316
1317 list_add(&old_devices->list, &fs_uuids);
1318
1319 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1320 seed_devices->opened = 1;
1321 INIT_LIST_HEAD(&seed_devices->devices);
1322 INIT_LIST_HEAD(&seed_devices->alloc_list);
1323 mutex_init(&seed_devices->device_list_mutex);
1324 list_splice_init(&fs_devices->devices, &seed_devices->devices);
1325 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1326 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1327 device->fs_devices = seed_devices;
1328 }
1329
1330 fs_devices->seeding = 0;
1331 fs_devices->num_devices = 0;
1332 fs_devices->open_devices = 0;
1333 fs_devices->seed = seed_devices;
1334
1335 generate_random_uuid(fs_devices->fsid);
1336 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1337 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1338 super_flags = btrfs_super_flags(disk_super) &
1339 ~BTRFS_SUPER_FLAG_SEEDING;
1340 btrfs_set_super_flags(disk_super, super_flags);
1341
1342 return 0;
1343 }
1344
1345 /*
1346 * strore the expected generation for seed devices in device items.
1347 */
1348 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1349 struct btrfs_root *root)
1350 {
1351 struct btrfs_path *path;
1352 struct extent_buffer *leaf;
1353 struct btrfs_dev_item *dev_item;
1354 struct btrfs_device *device;
1355 struct btrfs_key key;
1356 u8 fs_uuid[BTRFS_UUID_SIZE];
1357 u8 dev_uuid[BTRFS_UUID_SIZE];
1358 u64 devid;
1359 int ret;
1360
1361 path = btrfs_alloc_path();
1362 if (!path)
1363 return -ENOMEM;
1364
1365 root = root->fs_info->chunk_root;
1366 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1367 key.offset = 0;
1368 key.type = BTRFS_DEV_ITEM_KEY;
1369
1370 while (1) {
1371 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1372 if (ret < 0)
1373 goto error;
1374
1375 leaf = path->nodes[0];
1376 next_slot:
1377 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1378 ret = btrfs_next_leaf(root, path);
1379 if (ret > 0)
1380 break;
1381 if (ret < 0)
1382 goto error;
1383 leaf = path->nodes[0];
1384 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1385 btrfs_release_path(root, path);
1386 continue;
1387 }
1388
1389 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1390 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1391 key.type != BTRFS_DEV_ITEM_KEY)
1392 break;
1393
1394 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1395 struct btrfs_dev_item);
1396 devid = btrfs_device_id(leaf, dev_item);
1397 read_extent_buffer(leaf, dev_uuid,
1398 (unsigned long)btrfs_device_uuid(dev_item),
1399 BTRFS_UUID_SIZE);
1400 read_extent_buffer(leaf, fs_uuid,
1401 (unsigned long)btrfs_device_fsid(dev_item),
1402 BTRFS_UUID_SIZE);
1403 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1404 BUG_ON(!device);
1405
1406 if (device->fs_devices->seeding) {
1407 btrfs_set_device_generation(leaf, dev_item,
1408 device->generation);
1409 btrfs_mark_buffer_dirty(leaf);
1410 }
1411
1412 path->slots[0]++;
1413 goto next_slot;
1414 }
1415 ret = 0;
1416 error:
1417 btrfs_free_path(path);
1418 return ret;
1419 }
1420
1421 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1422 {
1423 struct btrfs_trans_handle *trans;
1424 struct btrfs_device *device;
1425 struct block_device *bdev;
1426 struct list_head *devices;
1427 struct super_block *sb = root->fs_info->sb;
1428 u64 total_bytes;
1429 int seeding_dev = 0;
1430 int ret = 0;
1431
1432 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1433 return -EINVAL;
1434
1435 bdev = open_bdev_exclusive(device_path, 0, root->fs_info->bdev_holder);
1436 if (!bdev)
1437 return -EIO;
1438
1439 if (root->fs_info->fs_devices->seeding) {
1440 seeding_dev = 1;
1441 down_write(&sb->s_umount);
1442 mutex_lock(&uuid_mutex);
1443 }
1444
1445 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1446 mutex_lock(&root->fs_info->volume_mutex);
1447
1448 devices = &root->fs_info->fs_devices->devices;
1449 /*
1450 * we have the volume lock, so we don't need the extra
1451 * device list mutex while reading the list here.
1452 */
1453 list_for_each_entry(device, devices, dev_list) {
1454 if (device->bdev == bdev) {
1455 ret = -EEXIST;
1456 goto error;
1457 }
1458 }
1459
1460 device = kzalloc(sizeof(*device), GFP_NOFS);
1461 if (!device) {
1462 /* we can safely leave the fs_devices entry around */
1463 ret = -ENOMEM;
1464 goto error;
1465 }
1466
1467 device->name = kstrdup(device_path, GFP_NOFS);
1468 if (!device->name) {
1469 kfree(device);
1470 ret = -ENOMEM;
1471 goto error;
1472 }
1473
1474 ret = find_next_devid(root, &device->devid);
1475 if (ret) {
1476 kfree(device);
1477 goto error;
1478 }
1479
1480 trans = btrfs_start_transaction(root, 1);
1481 lock_chunks(root);
1482
1483 device->barriers = 1;
1484 device->writeable = 1;
1485 device->work.func = pending_bios_fn;
1486 generate_random_uuid(device->uuid);
1487 spin_lock_init(&device->io_lock);
1488 device->generation = trans->transid;
1489 device->io_width = root->sectorsize;
1490 device->io_align = root->sectorsize;
1491 device->sector_size = root->sectorsize;
1492 device->total_bytes = i_size_read(bdev->bd_inode);
1493 device->disk_total_bytes = device->total_bytes;
1494 device->dev_root = root->fs_info->dev_root;
1495 device->bdev = bdev;
1496 device->in_fs_metadata = 1;
1497 device->mode = 0;
1498 set_blocksize(device->bdev, 4096);
1499
1500 if (seeding_dev) {
1501 sb->s_flags &= ~MS_RDONLY;
1502 ret = btrfs_prepare_sprout(trans, root);
1503 BUG_ON(ret);
1504 }
1505
1506 device->fs_devices = root->fs_info->fs_devices;
1507
1508 /*
1509 * we don't want write_supers to jump in here with our device
1510 * half setup
1511 */
1512 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1513 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1514 list_add(&device->dev_alloc_list,
1515 &root->fs_info->fs_devices->alloc_list);
1516 root->fs_info->fs_devices->num_devices++;
1517 root->fs_info->fs_devices->open_devices++;
1518 root->fs_info->fs_devices->rw_devices++;
1519 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1520
1521 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1522 root->fs_info->fs_devices->rotating = 1;
1523
1524 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1525 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1526 total_bytes + device->total_bytes);
1527
1528 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1529 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1530 total_bytes + 1);
1531 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1532
1533 if (seeding_dev) {
1534 ret = init_first_rw_device(trans, root, device);
1535 BUG_ON(ret);
1536 ret = btrfs_finish_sprout(trans, root);
1537 BUG_ON(ret);
1538 } else {
1539 ret = btrfs_add_device(trans, root, device);
1540 }
1541
1542 /*
1543 * we've got more storage, clear any full flags on the space
1544 * infos
1545 */
1546 btrfs_clear_space_info_full(root->fs_info);
1547
1548 unlock_chunks(root);
1549 btrfs_commit_transaction(trans, root);
1550
1551 if (seeding_dev) {
1552 mutex_unlock(&uuid_mutex);
1553 up_write(&sb->s_umount);
1554
1555 ret = btrfs_relocate_sys_chunks(root);
1556 BUG_ON(ret);
1557 }
1558 out:
1559 mutex_unlock(&root->fs_info->volume_mutex);
1560 return ret;
1561 error:
1562 close_bdev_exclusive(bdev, 0);
1563 if (seeding_dev) {
1564 mutex_unlock(&uuid_mutex);
1565 up_write(&sb->s_umount);
1566 }
1567 goto out;
1568 }
1569
1570 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1571 struct btrfs_device *device)
1572 {
1573 int ret;
1574 struct btrfs_path *path;
1575 struct btrfs_root *root;
1576 struct btrfs_dev_item *dev_item;
1577 struct extent_buffer *leaf;
1578 struct btrfs_key key;
1579
1580 root = device->dev_root->fs_info->chunk_root;
1581
1582 path = btrfs_alloc_path();
1583 if (!path)
1584 return -ENOMEM;
1585
1586 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1587 key.type = BTRFS_DEV_ITEM_KEY;
1588 key.offset = device->devid;
1589
1590 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1591 if (ret < 0)
1592 goto out;
1593
1594 if (ret > 0) {
1595 ret = -ENOENT;
1596 goto out;
1597 }
1598
1599 leaf = path->nodes[0];
1600 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1601
1602 btrfs_set_device_id(leaf, dev_item, device->devid);
1603 btrfs_set_device_type(leaf, dev_item, device->type);
1604 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1605 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1606 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1607 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1608 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1609 btrfs_mark_buffer_dirty(leaf);
1610
1611 out:
1612 btrfs_free_path(path);
1613 return ret;
1614 }
1615
1616 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1617 struct btrfs_device *device, u64 new_size)
1618 {
1619 struct btrfs_super_block *super_copy =
1620 &device->dev_root->fs_info->super_copy;
1621 u64 old_total = btrfs_super_total_bytes(super_copy);
1622 u64 diff = new_size - device->total_bytes;
1623
1624 if (!device->writeable)
1625 return -EACCES;
1626 if (new_size <= device->total_bytes)
1627 return -EINVAL;
1628
1629 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1630 device->fs_devices->total_rw_bytes += diff;
1631
1632 device->total_bytes = new_size;
1633 device->disk_total_bytes = new_size;
1634 btrfs_clear_space_info_full(device->dev_root->fs_info);
1635
1636 return btrfs_update_device(trans, device);
1637 }
1638
1639 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1640 struct btrfs_device *device, u64 new_size)
1641 {
1642 int ret;
1643 lock_chunks(device->dev_root);
1644 ret = __btrfs_grow_device(trans, device, new_size);
1645 unlock_chunks(device->dev_root);
1646 return ret;
1647 }
1648
1649 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1650 struct btrfs_root *root,
1651 u64 chunk_tree, u64 chunk_objectid,
1652 u64 chunk_offset)
1653 {
1654 int ret;
1655 struct btrfs_path *path;
1656 struct btrfs_key key;
1657
1658 root = root->fs_info->chunk_root;
1659 path = btrfs_alloc_path();
1660 if (!path)
1661 return -ENOMEM;
1662
1663 key.objectid = chunk_objectid;
1664 key.offset = chunk_offset;
1665 key.type = BTRFS_CHUNK_ITEM_KEY;
1666
1667 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1668 BUG_ON(ret);
1669
1670 ret = btrfs_del_item(trans, root, path);
1671 BUG_ON(ret);
1672
1673 btrfs_free_path(path);
1674 return 0;
1675 }
1676
1677 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1678 chunk_offset)
1679 {
1680 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1681 struct btrfs_disk_key *disk_key;
1682 struct btrfs_chunk *chunk;
1683 u8 *ptr;
1684 int ret = 0;
1685 u32 num_stripes;
1686 u32 array_size;
1687 u32 len = 0;
1688 u32 cur;
1689 struct btrfs_key key;
1690
1691 array_size = btrfs_super_sys_array_size(super_copy);
1692
1693 ptr = super_copy->sys_chunk_array;
1694 cur = 0;
1695
1696 while (cur < array_size) {
1697 disk_key = (struct btrfs_disk_key *)ptr;
1698 btrfs_disk_key_to_cpu(&key, disk_key);
1699
1700 len = sizeof(*disk_key);
1701
1702 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1703 chunk = (struct btrfs_chunk *)(ptr + len);
1704 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1705 len += btrfs_chunk_item_size(num_stripes);
1706 } else {
1707 ret = -EIO;
1708 break;
1709 }
1710 if (key.objectid == chunk_objectid &&
1711 key.offset == chunk_offset) {
1712 memmove(ptr, ptr + len, array_size - (cur + len));
1713 array_size -= len;
1714 btrfs_set_super_sys_array_size(super_copy, array_size);
1715 } else {
1716 ptr += len;
1717 cur += len;
1718 }
1719 }
1720 return ret;
1721 }
1722
1723 static int btrfs_relocate_chunk(struct btrfs_root *root,
1724 u64 chunk_tree, u64 chunk_objectid,
1725 u64 chunk_offset)
1726 {
1727 struct extent_map_tree *em_tree;
1728 struct btrfs_root *extent_root;
1729 struct btrfs_trans_handle *trans;
1730 struct extent_map *em;
1731 struct map_lookup *map;
1732 int ret;
1733 int i;
1734
1735 root = root->fs_info->chunk_root;
1736 extent_root = root->fs_info->extent_root;
1737 em_tree = &root->fs_info->mapping_tree.map_tree;
1738
1739 /* step one, relocate all the extents inside this chunk */
1740 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1741 BUG_ON(ret);
1742
1743 trans = btrfs_start_transaction(root, 1);
1744 BUG_ON(!trans);
1745
1746 lock_chunks(root);
1747
1748 /*
1749 * step two, delete the device extents and the
1750 * chunk tree entries
1751 */
1752 spin_lock(&em_tree->lock);
1753 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1754 spin_unlock(&em_tree->lock);
1755
1756 BUG_ON(em->start > chunk_offset ||
1757 em->start + em->len < chunk_offset);
1758 map = (struct map_lookup *)em->bdev;
1759
1760 for (i = 0; i < map->num_stripes; i++) {
1761 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1762 map->stripes[i].physical);
1763 BUG_ON(ret);
1764
1765 if (map->stripes[i].dev) {
1766 ret = btrfs_update_device(trans, map->stripes[i].dev);
1767 BUG_ON(ret);
1768 }
1769 }
1770 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1771 chunk_offset);
1772
1773 BUG_ON(ret);
1774
1775 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1776 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1777 BUG_ON(ret);
1778 }
1779
1780 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1781 BUG_ON(ret);
1782
1783 spin_lock(&em_tree->lock);
1784 remove_extent_mapping(em_tree, em);
1785 spin_unlock(&em_tree->lock);
1786
1787 kfree(map);
1788 em->bdev = NULL;
1789
1790 /* once for the tree */
1791 free_extent_map(em);
1792 /* once for us */
1793 free_extent_map(em);
1794
1795 unlock_chunks(root);
1796 btrfs_end_transaction(trans, root);
1797 return 0;
1798 }
1799
1800 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1801 {
1802 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1803 struct btrfs_path *path;
1804 struct extent_buffer *leaf;
1805 struct btrfs_chunk *chunk;
1806 struct btrfs_key key;
1807 struct btrfs_key found_key;
1808 u64 chunk_tree = chunk_root->root_key.objectid;
1809 u64 chunk_type;
1810 int ret;
1811
1812 path = btrfs_alloc_path();
1813 if (!path)
1814 return -ENOMEM;
1815
1816 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1817 key.offset = (u64)-1;
1818 key.type = BTRFS_CHUNK_ITEM_KEY;
1819
1820 while (1) {
1821 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1822 if (ret < 0)
1823 goto error;
1824 BUG_ON(ret == 0);
1825
1826 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1827 key.type);
1828 if (ret < 0)
1829 goto error;
1830 if (ret > 0)
1831 break;
1832
1833 leaf = path->nodes[0];
1834 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1835
1836 chunk = btrfs_item_ptr(leaf, path->slots[0],
1837 struct btrfs_chunk);
1838 chunk_type = btrfs_chunk_type(leaf, chunk);
1839 btrfs_release_path(chunk_root, path);
1840
1841 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1842 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1843 found_key.objectid,
1844 found_key.offset);
1845 BUG_ON(ret);
1846 }
1847
1848 if (found_key.offset == 0)
1849 break;
1850 key.offset = found_key.offset - 1;
1851 }
1852 ret = 0;
1853 error:
1854 btrfs_free_path(path);
1855 return ret;
1856 }
1857
1858 static u64 div_factor(u64 num, int factor)
1859 {
1860 if (factor == 10)
1861 return num;
1862 num *= factor;
1863 do_div(num, 10);
1864 return num;
1865 }
1866
1867 int btrfs_balance(struct btrfs_root *dev_root)
1868 {
1869 int ret;
1870 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1871 struct btrfs_device *device;
1872 u64 old_size;
1873 u64 size_to_free;
1874 struct btrfs_path *path;
1875 struct btrfs_key key;
1876 struct btrfs_chunk *chunk;
1877 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1878 struct btrfs_trans_handle *trans;
1879 struct btrfs_key found_key;
1880
1881 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
1882 return -EROFS;
1883
1884 mutex_lock(&dev_root->fs_info->volume_mutex);
1885 dev_root = dev_root->fs_info->dev_root;
1886
1887 /* step one make some room on all the devices */
1888 list_for_each_entry(device, devices, dev_list) {
1889 old_size = device->total_bytes;
1890 size_to_free = div_factor(old_size, 1);
1891 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
1892 if (!device->writeable ||
1893 device->total_bytes - device->bytes_used > size_to_free)
1894 continue;
1895
1896 ret = btrfs_shrink_device(device, old_size - size_to_free);
1897 BUG_ON(ret);
1898
1899 trans = btrfs_start_transaction(dev_root, 1);
1900 BUG_ON(!trans);
1901
1902 ret = btrfs_grow_device(trans, device, old_size);
1903 BUG_ON(ret);
1904
1905 btrfs_end_transaction(trans, dev_root);
1906 }
1907
1908 /* step two, relocate all the chunks */
1909 path = btrfs_alloc_path();
1910 BUG_ON(!path);
1911
1912 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1913 key.offset = (u64)-1;
1914 key.type = BTRFS_CHUNK_ITEM_KEY;
1915
1916 while (1) {
1917 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1918 if (ret < 0)
1919 goto error;
1920
1921 /*
1922 * this shouldn't happen, it means the last relocate
1923 * failed
1924 */
1925 if (ret == 0)
1926 break;
1927
1928 ret = btrfs_previous_item(chunk_root, path, 0,
1929 BTRFS_CHUNK_ITEM_KEY);
1930 if (ret)
1931 break;
1932
1933 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1934 path->slots[0]);
1935 if (found_key.objectid != key.objectid)
1936 break;
1937
1938 chunk = btrfs_item_ptr(path->nodes[0],
1939 path->slots[0],
1940 struct btrfs_chunk);
1941 key.offset = found_key.offset;
1942 /* chunk zero is special */
1943 if (key.offset == 0)
1944 break;
1945
1946 btrfs_release_path(chunk_root, path);
1947 ret = btrfs_relocate_chunk(chunk_root,
1948 chunk_root->root_key.objectid,
1949 found_key.objectid,
1950 found_key.offset);
1951 BUG_ON(ret);
1952 }
1953 ret = 0;
1954 error:
1955 btrfs_free_path(path);
1956 mutex_unlock(&dev_root->fs_info->volume_mutex);
1957 return ret;
1958 }
1959
1960 /*
1961 * shrinking a device means finding all of the device extents past
1962 * the new size, and then following the back refs to the chunks.
1963 * The chunk relocation code actually frees the device extent
1964 */
1965 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
1966 {
1967 struct btrfs_trans_handle *trans;
1968 struct btrfs_root *root = device->dev_root;
1969 struct btrfs_dev_extent *dev_extent = NULL;
1970 struct btrfs_path *path;
1971 u64 length;
1972 u64 chunk_tree;
1973 u64 chunk_objectid;
1974 u64 chunk_offset;
1975 int ret;
1976 int slot;
1977 struct extent_buffer *l;
1978 struct btrfs_key key;
1979 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1980 u64 old_total = btrfs_super_total_bytes(super_copy);
1981 u64 diff = device->total_bytes - new_size;
1982
1983 if (new_size >= device->total_bytes)
1984 return -EINVAL;
1985
1986 path = btrfs_alloc_path();
1987 if (!path)
1988 return -ENOMEM;
1989
1990 trans = btrfs_start_transaction(root, 1);
1991 if (!trans) {
1992 ret = -ENOMEM;
1993 goto done;
1994 }
1995
1996 path->reada = 2;
1997
1998 lock_chunks(root);
1999
2000 device->total_bytes = new_size;
2001 if (device->writeable)
2002 device->fs_devices->total_rw_bytes -= diff;
2003 unlock_chunks(root);
2004 btrfs_end_transaction(trans, root);
2005
2006 key.objectid = device->devid;
2007 key.offset = (u64)-1;
2008 key.type = BTRFS_DEV_EXTENT_KEY;
2009
2010 while (1) {
2011 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2012 if (ret < 0)
2013 goto done;
2014
2015 ret = btrfs_previous_item(root, path, 0, key.type);
2016 if (ret < 0)
2017 goto done;
2018 if (ret) {
2019 ret = 0;
2020 break;
2021 }
2022
2023 l = path->nodes[0];
2024 slot = path->slots[0];
2025 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2026
2027 if (key.objectid != device->devid)
2028 break;
2029
2030 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2031 length = btrfs_dev_extent_length(l, dev_extent);
2032
2033 if (key.offset + length <= new_size)
2034 break;
2035
2036 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2037 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2038 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2039 btrfs_release_path(root, path);
2040
2041 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2042 chunk_offset);
2043 if (ret)
2044 goto done;
2045 }
2046
2047 /* Shrinking succeeded, else we would be at "done". */
2048 trans = btrfs_start_transaction(root, 1);
2049 if (!trans) {
2050 ret = -ENOMEM;
2051 goto done;
2052 }
2053 lock_chunks(root);
2054
2055 device->disk_total_bytes = new_size;
2056 /* Now btrfs_update_device() will change the on-disk size. */
2057 ret = btrfs_update_device(trans, device);
2058 if (ret) {
2059 unlock_chunks(root);
2060 btrfs_end_transaction(trans, root);
2061 goto done;
2062 }
2063 WARN_ON(diff > old_total);
2064 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2065 unlock_chunks(root);
2066 btrfs_end_transaction(trans, root);
2067 done:
2068 btrfs_free_path(path);
2069 return ret;
2070 }
2071
2072 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2073 struct btrfs_root *root,
2074 struct btrfs_key *key,
2075 struct btrfs_chunk *chunk, int item_size)
2076 {
2077 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2078 struct btrfs_disk_key disk_key;
2079 u32 array_size;
2080 u8 *ptr;
2081
2082 array_size = btrfs_super_sys_array_size(super_copy);
2083 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2084 return -EFBIG;
2085
2086 ptr = super_copy->sys_chunk_array + array_size;
2087 btrfs_cpu_key_to_disk(&disk_key, key);
2088 memcpy(ptr, &disk_key, sizeof(disk_key));
2089 ptr += sizeof(disk_key);
2090 memcpy(ptr, chunk, item_size);
2091 item_size += sizeof(disk_key);
2092 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2093 return 0;
2094 }
2095
2096 static noinline u64 chunk_bytes_by_type(u64 type, u64 calc_size,
2097 int num_stripes, int sub_stripes)
2098 {
2099 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
2100 return calc_size;
2101 else if (type & BTRFS_BLOCK_GROUP_RAID10)
2102 return calc_size * (num_stripes / sub_stripes);
2103 else
2104 return calc_size * num_stripes;
2105 }
2106
2107 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2108 struct btrfs_root *extent_root,
2109 struct map_lookup **map_ret,
2110 u64 *num_bytes, u64 *stripe_size,
2111 u64 start, u64 type)
2112 {
2113 struct btrfs_fs_info *info = extent_root->fs_info;
2114 struct btrfs_device *device = NULL;
2115 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2116 struct list_head *cur;
2117 struct map_lookup *map = NULL;
2118 struct extent_map_tree *em_tree;
2119 struct extent_map *em;
2120 struct list_head private_devs;
2121 int min_stripe_size = 1 * 1024 * 1024;
2122 u64 calc_size = 1024 * 1024 * 1024;
2123 u64 max_chunk_size = calc_size;
2124 u64 min_free;
2125 u64 avail;
2126 u64 max_avail = 0;
2127 u64 dev_offset;
2128 int num_stripes = 1;
2129 int min_stripes = 1;
2130 int sub_stripes = 0;
2131 int looped = 0;
2132 int ret;
2133 int index;
2134 int stripe_len = 64 * 1024;
2135
2136 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2137 (type & BTRFS_BLOCK_GROUP_DUP)) {
2138 WARN_ON(1);
2139 type &= ~BTRFS_BLOCK_GROUP_DUP;
2140 }
2141 if (list_empty(&fs_devices->alloc_list))
2142 return -ENOSPC;
2143
2144 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2145 num_stripes = fs_devices->rw_devices;
2146 min_stripes = 2;
2147 }
2148 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2149 num_stripes = 2;
2150 min_stripes = 2;
2151 }
2152 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2153 num_stripes = min_t(u64, 2, fs_devices->rw_devices);
2154 if (num_stripes < 2)
2155 return -ENOSPC;
2156 min_stripes = 2;
2157 }
2158 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2159 num_stripes = fs_devices->rw_devices;
2160 if (num_stripes < 4)
2161 return -ENOSPC;
2162 num_stripes &= ~(u32)1;
2163 sub_stripes = 2;
2164 min_stripes = 4;
2165 }
2166
2167 if (type & BTRFS_BLOCK_GROUP_DATA) {
2168 max_chunk_size = 10 * calc_size;
2169 min_stripe_size = 64 * 1024 * 1024;
2170 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2171 max_chunk_size = 4 * calc_size;
2172 min_stripe_size = 32 * 1024 * 1024;
2173 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2174 calc_size = 8 * 1024 * 1024;
2175 max_chunk_size = calc_size * 2;
2176 min_stripe_size = 1 * 1024 * 1024;
2177 }
2178
2179 /* we don't want a chunk larger than 10% of writeable space */
2180 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2181 max_chunk_size);
2182
2183 again:
2184 max_avail = 0;
2185 if (!map || map->num_stripes != num_stripes) {
2186 kfree(map);
2187 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2188 if (!map)
2189 return -ENOMEM;
2190 map->num_stripes = num_stripes;
2191 }
2192
2193 if (calc_size * num_stripes > max_chunk_size) {
2194 calc_size = max_chunk_size;
2195 do_div(calc_size, num_stripes);
2196 do_div(calc_size, stripe_len);
2197 calc_size *= stripe_len;
2198 }
2199 /* we don't want tiny stripes */
2200 calc_size = max_t(u64, min_stripe_size, calc_size);
2201
2202 do_div(calc_size, stripe_len);
2203 calc_size *= stripe_len;
2204
2205 cur = fs_devices->alloc_list.next;
2206 index = 0;
2207
2208 if (type & BTRFS_BLOCK_GROUP_DUP)
2209 min_free = calc_size * 2;
2210 else
2211 min_free = calc_size;
2212
2213 /*
2214 * we add 1MB because we never use the first 1MB of the device, unless
2215 * we've looped, then we are likely allocating the maximum amount of
2216 * space left already
2217 */
2218 if (!looped)
2219 min_free += 1024 * 1024;
2220
2221 INIT_LIST_HEAD(&private_devs);
2222 while (index < num_stripes) {
2223 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2224 BUG_ON(!device->writeable);
2225 if (device->total_bytes > device->bytes_used)
2226 avail = device->total_bytes - device->bytes_used;
2227 else
2228 avail = 0;
2229 cur = cur->next;
2230
2231 if (device->in_fs_metadata && avail >= min_free) {
2232 ret = find_free_dev_extent(trans, device,
2233 min_free, &dev_offset,
2234 &max_avail);
2235 if (ret == 0) {
2236 list_move_tail(&device->dev_alloc_list,
2237 &private_devs);
2238 map->stripes[index].dev = device;
2239 map->stripes[index].physical = dev_offset;
2240 index++;
2241 if (type & BTRFS_BLOCK_GROUP_DUP) {
2242 map->stripes[index].dev = device;
2243 map->stripes[index].physical =
2244 dev_offset + calc_size;
2245 index++;
2246 }
2247 }
2248 } else if (device->in_fs_metadata && avail > max_avail)
2249 max_avail = avail;
2250 if (cur == &fs_devices->alloc_list)
2251 break;
2252 }
2253 list_splice(&private_devs, &fs_devices->alloc_list);
2254 if (index < num_stripes) {
2255 if (index >= min_stripes) {
2256 num_stripes = index;
2257 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2258 num_stripes /= sub_stripes;
2259 num_stripes *= sub_stripes;
2260 }
2261 looped = 1;
2262 goto again;
2263 }
2264 if (!looped && max_avail > 0) {
2265 looped = 1;
2266 calc_size = max_avail;
2267 goto again;
2268 }
2269 kfree(map);
2270 return -ENOSPC;
2271 }
2272 map->sector_size = extent_root->sectorsize;
2273 map->stripe_len = stripe_len;
2274 map->io_align = stripe_len;
2275 map->io_width = stripe_len;
2276 map->type = type;
2277 map->num_stripes = num_stripes;
2278 map->sub_stripes = sub_stripes;
2279
2280 *map_ret = map;
2281 *stripe_size = calc_size;
2282 *num_bytes = chunk_bytes_by_type(type, calc_size,
2283 num_stripes, sub_stripes);
2284
2285 em = alloc_extent_map(GFP_NOFS);
2286 if (!em) {
2287 kfree(map);
2288 return -ENOMEM;
2289 }
2290 em->bdev = (struct block_device *)map;
2291 em->start = start;
2292 em->len = *num_bytes;
2293 em->block_start = 0;
2294 em->block_len = em->len;
2295
2296 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2297 spin_lock(&em_tree->lock);
2298 ret = add_extent_mapping(em_tree, em);
2299 spin_unlock(&em_tree->lock);
2300 BUG_ON(ret);
2301 free_extent_map(em);
2302
2303 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2304 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2305 start, *num_bytes);
2306 BUG_ON(ret);
2307
2308 index = 0;
2309 while (index < map->num_stripes) {
2310 device = map->stripes[index].dev;
2311 dev_offset = map->stripes[index].physical;
2312
2313 ret = btrfs_alloc_dev_extent(trans, device,
2314 info->chunk_root->root_key.objectid,
2315 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2316 start, dev_offset, calc_size);
2317 BUG_ON(ret);
2318 index++;
2319 }
2320
2321 return 0;
2322 }
2323
2324 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2325 struct btrfs_root *extent_root,
2326 struct map_lookup *map, u64 chunk_offset,
2327 u64 chunk_size, u64 stripe_size)
2328 {
2329 u64 dev_offset;
2330 struct btrfs_key key;
2331 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2332 struct btrfs_device *device;
2333 struct btrfs_chunk *chunk;
2334 struct btrfs_stripe *stripe;
2335 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2336 int index = 0;
2337 int ret;
2338
2339 chunk = kzalloc(item_size, GFP_NOFS);
2340 if (!chunk)
2341 return -ENOMEM;
2342
2343 index = 0;
2344 while (index < map->num_stripes) {
2345 device = map->stripes[index].dev;
2346 device->bytes_used += stripe_size;
2347 ret = btrfs_update_device(trans, device);
2348 BUG_ON(ret);
2349 index++;
2350 }
2351
2352 index = 0;
2353 stripe = &chunk->stripe;
2354 while (index < map->num_stripes) {
2355 device = map->stripes[index].dev;
2356 dev_offset = map->stripes[index].physical;
2357
2358 btrfs_set_stack_stripe_devid(stripe, device->devid);
2359 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2360 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2361 stripe++;
2362 index++;
2363 }
2364
2365 btrfs_set_stack_chunk_length(chunk, chunk_size);
2366 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2367 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2368 btrfs_set_stack_chunk_type(chunk, map->type);
2369 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2370 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2371 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2372 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2373 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2374
2375 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2376 key.type = BTRFS_CHUNK_ITEM_KEY;
2377 key.offset = chunk_offset;
2378
2379 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2380 BUG_ON(ret);
2381
2382 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2383 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2384 item_size);
2385 BUG_ON(ret);
2386 }
2387 kfree(chunk);
2388 return 0;
2389 }
2390
2391 /*
2392 * Chunk allocation falls into two parts. The first part does works
2393 * that make the new allocated chunk useable, but not do any operation
2394 * that modifies the chunk tree. The second part does the works that
2395 * require modifying the chunk tree. This division is important for the
2396 * bootstrap process of adding storage to a seed btrfs.
2397 */
2398 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2399 struct btrfs_root *extent_root, u64 type)
2400 {
2401 u64 chunk_offset;
2402 u64 chunk_size;
2403 u64 stripe_size;
2404 struct map_lookup *map;
2405 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2406 int ret;
2407
2408 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2409 &chunk_offset);
2410 if (ret)
2411 return ret;
2412
2413 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2414 &stripe_size, chunk_offset, type);
2415 if (ret)
2416 return ret;
2417
2418 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2419 chunk_size, stripe_size);
2420 BUG_ON(ret);
2421 return 0;
2422 }
2423
2424 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2425 struct btrfs_root *root,
2426 struct btrfs_device *device)
2427 {
2428 u64 chunk_offset;
2429 u64 sys_chunk_offset;
2430 u64 chunk_size;
2431 u64 sys_chunk_size;
2432 u64 stripe_size;
2433 u64 sys_stripe_size;
2434 u64 alloc_profile;
2435 struct map_lookup *map;
2436 struct map_lookup *sys_map;
2437 struct btrfs_fs_info *fs_info = root->fs_info;
2438 struct btrfs_root *extent_root = fs_info->extent_root;
2439 int ret;
2440
2441 ret = find_next_chunk(fs_info->chunk_root,
2442 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2443 BUG_ON(ret);
2444
2445 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2446 (fs_info->metadata_alloc_profile &
2447 fs_info->avail_metadata_alloc_bits);
2448 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2449
2450 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2451 &stripe_size, chunk_offset, alloc_profile);
2452 BUG_ON(ret);
2453
2454 sys_chunk_offset = chunk_offset + chunk_size;
2455
2456 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2457 (fs_info->system_alloc_profile &
2458 fs_info->avail_system_alloc_bits);
2459 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2460
2461 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2462 &sys_chunk_size, &sys_stripe_size,
2463 sys_chunk_offset, alloc_profile);
2464 BUG_ON(ret);
2465
2466 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2467 BUG_ON(ret);
2468
2469 /*
2470 * Modifying chunk tree needs allocating new blocks from both
2471 * system block group and metadata block group. So we only can
2472 * do operations require modifying the chunk tree after both
2473 * block groups were created.
2474 */
2475 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2476 chunk_size, stripe_size);
2477 BUG_ON(ret);
2478
2479 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2480 sys_chunk_offset, sys_chunk_size,
2481 sys_stripe_size);
2482 BUG_ON(ret);
2483 return 0;
2484 }
2485
2486 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2487 {
2488 struct extent_map *em;
2489 struct map_lookup *map;
2490 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2491 int readonly = 0;
2492 int i;
2493
2494 spin_lock(&map_tree->map_tree.lock);
2495 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2496 spin_unlock(&map_tree->map_tree.lock);
2497 if (!em)
2498 return 1;
2499
2500 map = (struct map_lookup *)em->bdev;
2501 for (i = 0; i < map->num_stripes; i++) {
2502 if (!map->stripes[i].dev->writeable) {
2503 readonly = 1;
2504 break;
2505 }
2506 }
2507 free_extent_map(em);
2508 return readonly;
2509 }
2510
2511 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2512 {
2513 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
2514 }
2515
2516 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2517 {
2518 struct extent_map *em;
2519
2520 while (1) {
2521 spin_lock(&tree->map_tree.lock);
2522 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2523 if (em)
2524 remove_extent_mapping(&tree->map_tree, em);
2525 spin_unlock(&tree->map_tree.lock);
2526 if (!em)
2527 break;
2528 kfree(em->bdev);
2529 /* once for us */
2530 free_extent_map(em);
2531 /* once for the tree */
2532 free_extent_map(em);
2533 }
2534 }
2535
2536 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2537 {
2538 struct extent_map *em;
2539 struct map_lookup *map;
2540 struct extent_map_tree *em_tree = &map_tree->map_tree;
2541 int ret;
2542
2543 spin_lock(&em_tree->lock);
2544 em = lookup_extent_mapping(em_tree, logical, len);
2545 spin_unlock(&em_tree->lock);
2546 BUG_ON(!em);
2547
2548 BUG_ON(em->start > logical || em->start + em->len < logical);
2549 map = (struct map_lookup *)em->bdev;
2550 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2551 ret = map->num_stripes;
2552 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2553 ret = map->sub_stripes;
2554 else
2555 ret = 1;
2556 free_extent_map(em);
2557 return ret;
2558 }
2559
2560 static int find_live_mirror(struct map_lookup *map, int first, int num,
2561 int optimal)
2562 {
2563 int i;
2564 if (map->stripes[optimal].dev->bdev)
2565 return optimal;
2566 for (i = first; i < first + num; i++) {
2567 if (map->stripes[i].dev->bdev)
2568 return i;
2569 }
2570 /* we couldn't find one that doesn't fail. Just return something
2571 * and the io error handling code will clean up eventually
2572 */
2573 return optimal;
2574 }
2575
2576 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2577 u64 logical, u64 *length,
2578 struct btrfs_multi_bio **multi_ret,
2579 int mirror_num, struct page *unplug_page)
2580 {
2581 struct extent_map *em;
2582 struct map_lookup *map;
2583 struct extent_map_tree *em_tree = &map_tree->map_tree;
2584 u64 offset;
2585 u64 stripe_offset;
2586 u64 stripe_nr;
2587 int stripes_allocated = 8;
2588 int stripes_required = 1;
2589 int stripe_index;
2590 int i;
2591 int num_stripes;
2592 int max_errors = 0;
2593 struct btrfs_multi_bio *multi = NULL;
2594
2595 if (multi_ret && !(rw & (1 << BIO_RW)))
2596 stripes_allocated = 1;
2597 again:
2598 if (multi_ret) {
2599 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2600 GFP_NOFS);
2601 if (!multi)
2602 return -ENOMEM;
2603
2604 atomic_set(&multi->error, 0);
2605 }
2606
2607 spin_lock(&em_tree->lock);
2608 em = lookup_extent_mapping(em_tree, logical, *length);
2609 spin_unlock(&em_tree->lock);
2610
2611 if (!em && unplug_page)
2612 return 0;
2613
2614 if (!em) {
2615 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2616 (unsigned long long)logical,
2617 (unsigned long long)*length);
2618 BUG();
2619 }
2620
2621 BUG_ON(em->start > logical || em->start + em->len < logical);
2622 map = (struct map_lookup *)em->bdev;
2623 offset = logical - em->start;
2624
2625 if (mirror_num > map->num_stripes)
2626 mirror_num = 0;
2627
2628 /* if our multi bio struct is too small, back off and try again */
2629 if (rw & (1 << BIO_RW)) {
2630 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2631 BTRFS_BLOCK_GROUP_DUP)) {
2632 stripes_required = map->num_stripes;
2633 max_errors = 1;
2634 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2635 stripes_required = map->sub_stripes;
2636 max_errors = 1;
2637 }
2638 }
2639 if (multi_ret && (rw & (1 << BIO_RW)) &&
2640 stripes_allocated < stripes_required) {
2641 stripes_allocated = map->num_stripes;
2642 free_extent_map(em);
2643 kfree(multi);
2644 goto again;
2645 }
2646 stripe_nr = offset;
2647 /*
2648 * stripe_nr counts the total number of stripes we have to stride
2649 * to get to this block
2650 */
2651 do_div(stripe_nr, map->stripe_len);
2652
2653 stripe_offset = stripe_nr * map->stripe_len;
2654 BUG_ON(offset < stripe_offset);
2655
2656 /* stripe_offset is the offset of this block in its stripe*/
2657 stripe_offset = offset - stripe_offset;
2658
2659 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2660 BTRFS_BLOCK_GROUP_RAID10 |
2661 BTRFS_BLOCK_GROUP_DUP)) {
2662 /* we limit the length of each bio to what fits in a stripe */
2663 *length = min_t(u64, em->len - offset,
2664 map->stripe_len - stripe_offset);
2665 } else {
2666 *length = em->len - offset;
2667 }
2668
2669 if (!multi_ret && !unplug_page)
2670 goto out;
2671
2672 num_stripes = 1;
2673 stripe_index = 0;
2674 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2675 if (unplug_page || (rw & (1 << BIO_RW)))
2676 num_stripes = map->num_stripes;
2677 else if (mirror_num)
2678 stripe_index = mirror_num - 1;
2679 else {
2680 stripe_index = find_live_mirror(map, 0,
2681 map->num_stripes,
2682 current->pid % map->num_stripes);
2683 }
2684
2685 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2686 if (rw & (1 << BIO_RW))
2687 num_stripes = map->num_stripes;
2688 else if (mirror_num)
2689 stripe_index = mirror_num - 1;
2690
2691 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2692 int factor = map->num_stripes / map->sub_stripes;
2693
2694 stripe_index = do_div(stripe_nr, factor);
2695 stripe_index *= map->sub_stripes;
2696
2697 if (unplug_page || (rw & (1 << BIO_RW)))
2698 num_stripes = map->sub_stripes;
2699 else if (mirror_num)
2700 stripe_index += mirror_num - 1;
2701 else {
2702 stripe_index = find_live_mirror(map, stripe_index,
2703 map->sub_stripes, stripe_index +
2704 current->pid % map->sub_stripes);
2705 }
2706 } else {
2707 /*
2708 * after this do_div call, stripe_nr is the number of stripes
2709 * on this device we have to walk to find the data, and
2710 * stripe_index is the number of our device in the stripe array
2711 */
2712 stripe_index = do_div(stripe_nr, map->num_stripes);
2713 }
2714 BUG_ON(stripe_index >= map->num_stripes);
2715
2716 for (i = 0; i < num_stripes; i++) {
2717 if (unplug_page) {
2718 struct btrfs_device *device;
2719 struct backing_dev_info *bdi;
2720
2721 device = map->stripes[stripe_index].dev;
2722 if (device->bdev) {
2723 bdi = blk_get_backing_dev_info(device->bdev);
2724 if (bdi->unplug_io_fn)
2725 bdi->unplug_io_fn(bdi, unplug_page);
2726 }
2727 } else {
2728 multi->stripes[i].physical =
2729 map->stripes[stripe_index].physical +
2730 stripe_offset + stripe_nr * map->stripe_len;
2731 multi->stripes[i].dev = map->stripes[stripe_index].dev;
2732 }
2733 stripe_index++;
2734 }
2735 if (multi_ret) {
2736 *multi_ret = multi;
2737 multi->num_stripes = num_stripes;
2738 multi->max_errors = max_errors;
2739 }
2740 out:
2741 free_extent_map(em);
2742 return 0;
2743 }
2744
2745 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2746 u64 logical, u64 *length,
2747 struct btrfs_multi_bio **multi_ret, int mirror_num)
2748 {
2749 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
2750 mirror_num, NULL);
2751 }
2752
2753 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
2754 u64 chunk_start, u64 physical, u64 devid,
2755 u64 **logical, int *naddrs, int *stripe_len)
2756 {
2757 struct extent_map_tree *em_tree = &map_tree->map_tree;
2758 struct extent_map *em;
2759 struct map_lookup *map;
2760 u64 *buf;
2761 u64 bytenr;
2762 u64 length;
2763 u64 stripe_nr;
2764 int i, j, nr = 0;
2765
2766 spin_lock(&em_tree->lock);
2767 em = lookup_extent_mapping(em_tree, chunk_start, 1);
2768 spin_unlock(&em_tree->lock);
2769
2770 BUG_ON(!em || em->start != chunk_start);
2771 map = (struct map_lookup *)em->bdev;
2772
2773 length = em->len;
2774 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2775 do_div(length, map->num_stripes / map->sub_stripes);
2776 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
2777 do_div(length, map->num_stripes);
2778
2779 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
2780 BUG_ON(!buf);
2781
2782 for (i = 0; i < map->num_stripes; i++) {
2783 if (devid && map->stripes[i].dev->devid != devid)
2784 continue;
2785 if (map->stripes[i].physical > physical ||
2786 map->stripes[i].physical + length <= physical)
2787 continue;
2788
2789 stripe_nr = physical - map->stripes[i].physical;
2790 do_div(stripe_nr, map->stripe_len);
2791
2792 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2793 stripe_nr = stripe_nr * map->num_stripes + i;
2794 do_div(stripe_nr, map->sub_stripes);
2795 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2796 stripe_nr = stripe_nr * map->num_stripes + i;
2797 }
2798 bytenr = chunk_start + stripe_nr * map->stripe_len;
2799 WARN_ON(nr >= map->num_stripes);
2800 for (j = 0; j < nr; j++) {
2801 if (buf[j] == bytenr)
2802 break;
2803 }
2804 if (j == nr) {
2805 WARN_ON(nr >= map->num_stripes);
2806 buf[nr++] = bytenr;
2807 }
2808 }
2809
2810 *logical = buf;
2811 *naddrs = nr;
2812 *stripe_len = map->stripe_len;
2813
2814 free_extent_map(em);
2815 return 0;
2816 }
2817
2818 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
2819 u64 logical, struct page *page)
2820 {
2821 u64 length = PAGE_CACHE_SIZE;
2822 return __btrfs_map_block(map_tree, READ, logical, &length,
2823 NULL, 0, page);
2824 }
2825
2826 static void end_bio_multi_stripe(struct bio *bio, int err)
2827 {
2828 struct btrfs_multi_bio *multi = bio->bi_private;
2829 int is_orig_bio = 0;
2830
2831 if (err)
2832 atomic_inc(&multi->error);
2833
2834 if (bio == multi->orig_bio)
2835 is_orig_bio = 1;
2836
2837 if (atomic_dec_and_test(&multi->stripes_pending)) {
2838 if (!is_orig_bio) {
2839 bio_put(bio);
2840 bio = multi->orig_bio;
2841 }
2842 bio->bi_private = multi->private;
2843 bio->bi_end_io = multi->end_io;
2844 /* only send an error to the higher layers if it is
2845 * beyond the tolerance of the multi-bio
2846 */
2847 if (atomic_read(&multi->error) > multi->max_errors) {
2848 err = -EIO;
2849 } else if (err) {
2850 /*
2851 * this bio is actually up to date, we didn't
2852 * go over the max number of errors
2853 */
2854 set_bit(BIO_UPTODATE, &bio->bi_flags);
2855 err = 0;
2856 }
2857 kfree(multi);
2858
2859 bio_endio(bio, err);
2860 } else if (!is_orig_bio) {
2861 bio_put(bio);
2862 }
2863 }
2864
2865 struct async_sched {
2866 struct bio *bio;
2867 int rw;
2868 struct btrfs_fs_info *info;
2869 struct btrfs_work work;
2870 };
2871
2872 /*
2873 * see run_scheduled_bios for a description of why bios are collected for
2874 * async submit.
2875 *
2876 * This will add one bio to the pending list for a device and make sure
2877 * the work struct is scheduled.
2878 */
2879 static noinline int schedule_bio(struct btrfs_root *root,
2880 struct btrfs_device *device,
2881 int rw, struct bio *bio)
2882 {
2883 int should_queue = 1;
2884 struct btrfs_pending_bios *pending_bios;
2885
2886 /* don't bother with additional async steps for reads, right now */
2887 if (!(rw & (1 << BIO_RW))) {
2888 bio_get(bio);
2889 submit_bio(rw, bio);
2890 bio_put(bio);
2891 return 0;
2892 }
2893
2894 /*
2895 * nr_async_bios allows us to reliably return congestion to the
2896 * higher layers. Otherwise, the async bio makes it appear we have
2897 * made progress against dirty pages when we've really just put it
2898 * on a queue for later
2899 */
2900 atomic_inc(&root->fs_info->nr_async_bios);
2901 WARN_ON(bio->bi_next);
2902 bio->bi_next = NULL;
2903 bio->bi_rw |= rw;
2904
2905 spin_lock(&device->io_lock);
2906 if (bio_sync(bio))
2907 pending_bios = &device->pending_sync_bios;
2908 else
2909 pending_bios = &device->pending_bios;
2910
2911 if (pending_bios->tail)
2912 pending_bios->tail->bi_next = bio;
2913
2914 pending_bios->tail = bio;
2915 if (!pending_bios->head)
2916 pending_bios->head = bio;
2917 if (device->running_pending)
2918 should_queue = 0;
2919
2920 spin_unlock(&device->io_lock);
2921
2922 if (should_queue)
2923 btrfs_queue_worker(&root->fs_info->submit_workers,
2924 &device->work);
2925 return 0;
2926 }
2927
2928 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
2929 int mirror_num, int async_submit)
2930 {
2931 struct btrfs_mapping_tree *map_tree;
2932 struct btrfs_device *dev;
2933 struct bio *first_bio = bio;
2934 u64 logical = (u64)bio->bi_sector << 9;
2935 u64 length = 0;
2936 u64 map_length;
2937 struct btrfs_multi_bio *multi = NULL;
2938 int ret;
2939 int dev_nr = 0;
2940 int total_devs = 1;
2941
2942 length = bio->bi_size;
2943 map_tree = &root->fs_info->mapping_tree;
2944 map_length = length;
2945
2946 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
2947 mirror_num);
2948 BUG_ON(ret);
2949
2950 total_devs = multi->num_stripes;
2951 if (map_length < length) {
2952 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
2953 "len %llu\n", (unsigned long long)logical,
2954 (unsigned long long)length,
2955 (unsigned long long)map_length);
2956 BUG();
2957 }
2958 multi->end_io = first_bio->bi_end_io;
2959 multi->private = first_bio->bi_private;
2960 multi->orig_bio = first_bio;
2961 atomic_set(&multi->stripes_pending, multi->num_stripes);
2962
2963 while (dev_nr < total_devs) {
2964 if (total_devs > 1) {
2965 if (dev_nr < total_devs - 1) {
2966 bio = bio_clone(first_bio, GFP_NOFS);
2967 BUG_ON(!bio);
2968 } else {
2969 bio = first_bio;
2970 }
2971 bio->bi_private = multi;
2972 bio->bi_end_io = end_bio_multi_stripe;
2973 }
2974 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
2975 dev = multi->stripes[dev_nr].dev;
2976 BUG_ON(rw == WRITE && !dev->writeable);
2977 if (dev && dev->bdev) {
2978 bio->bi_bdev = dev->bdev;
2979 if (async_submit)
2980 schedule_bio(root, dev, rw, bio);
2981 else
2982 submit_bio(rw, bio);
2983 } else {
2984 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
2985 bio->bi_sector = logical >> 9;
2986 bio_endio(bio, -EIO);
2987 }
2988 dev_nr++;
2989 }
2990 if (total_devs == 1)
2991 kfree(multi);
2992 return 0;
2993 }
2994
2995 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
2996 u8 *uuid, u8 *fsid)
2997 {
2998 struct btrfs_device *device;
2999 struct btrfs_fs_devices *cur_devices;
3000
3001 cur_devices = root->fs_info->fs_devices;
3002 while (cur_devices) {
3003 if (!fsid ||
3004 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3005 device = __find_device(&cur_devices->devices,
3006 devid, uuid);
3007 if (device)
3008 return device;
3009 }
3010 cur_devices = cur_devices->seed;
3011 }
3012 return NULL;
3013 }
3014
3015 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3016 u64 devid, u8 *dev_uuid)
3017 {
3018 struct btrfs_device *device;
3019 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3020
3021 device = kzalloc(sizeof(*device), GFP_NOFS);
3022 if (!device)
3023 return NULL;
3024 list_add(&device->dev_list,
3025 &fs_devices->devices);
3026 device->barriers = 1;
3027 device->dev_root = root->fs_info->dev_root;
3028 device->devid = devid;
3029 device->work.func = pending_bios_fn;
3030 device->fs_devices = fs_devices;
3031 fs_devices->num_devices++;
3032 spin_lock_init(&device->io_lock);
3033 INIT_LIST_HEAD(&device->dev_alloc_list);
3034 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3035 return device;
3036 }
3037
3038 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3039 struct extent_buffer *leaf,
3040 struct btrfs_chunk *chunk)
3041 {
3042 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3043 struct map_lookup *map;
3044 struct extent_map *em;
3045 u64 logical;
3046 u64 length;
3047 u64 devid;
3048 u8 uuid[BTRFS_UUID_SIZE];
3049 int num_stripes;
3050 int ret;
3051 int i;
3052
3053 logical = key->offset;
3054 length = btrfs_chunk_length(leaf, chunk);
3055
3056 spin_lock(&map_tree->map_tree.lock);
3057 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3058 spin_unlock(&map_tree->map_tree.lock);
3059
3060 /* already mapped? */
3061 if (em && em->start <= logical && em->start + em->len > logical) {
3062 free_extent_map(em);
3063 return 0;
3064 } else if (em) {
3065 free_extent_map(em);
3066 }
3067
3068 em = alloc_extent_map(GFP_NOFS);
3069 if (!em)
3070 return -ENOMEM;
3071 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3072 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3073 if (!map) {
3074 free_extent_map(em);
3075 return -ENOMEM;
3076 }
3077
3078 em->bdev = (struct block_device *)map;
3079 em->start = logical;
3080 em->len = length;
3081 em->block_start = 0;
3082 em->block_len = em->len;
3083
3084 map->num_stripes = num_stripes;
3085 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3086 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3087 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3088 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3089 map->type = btrfs_chunk_type(leaf, chunk);
3090 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3091 for (i = 0; i < num_stripes; i++) {
3092 map->stripes[i].physical =
3093 btrfs_stripe_offset_nr(leaf, chunk, i);
3094 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3095 read_extent_buffer(leaf, uuid, (unsigned long)
3096 btrfs_stripe_dev_uuid_nr(chunk, i),
3097 BTRFS_UUID_SIZE);
3098 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3099 NULL);
3100 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3101 kfree(map);
3102 free_extent_map(em);
3103 return -EIO;
3104 }
3105 if (!map->stripes[i].dev) {
3106 map->stripes[i].dev =
3107 add_missing_dev(root, devid, uuid);
3108 if (!map->stripes[i].dev) {
3109 kfree(map);
3110 free_extent_map(em);
3111 return -EIO;
3112 }
3113 }
3114 map->stripes[i].dev->in_fs_metadata = 1;
3115 }
3116
3117 spin_lock(&map_tree->map_tree.lock);
3118 ret = add_extent_mapping(&map_tree->map_tree, em);
3119 spin_unlock(&map_tree->map_tree.lock);
3120 BUG_ON(ret);
3121 free_extent_map(em);
3122
3123 return 0;
3124 }
3125
3126 static int fill_device_from_item(struct extent_buffer *leaf,
3127 struct btrfs_dev_item *dev_item,
3128 struct btrfs_device *device)
3129 {
3130 unsigned long ptr;
3131
3132 device->devid = btrfs_device_id(leaf, dev_item);
3133 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3134 device->total_bytes = device->disk_total_bytes;
3135 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3136 device->type = btrfs_device_type(leaf, dev_item);
3137 device->io_align = btrfs_device_io_align(leaf, dev_item);
3138 device->io_width = btrfs_device_io_width(leaf, dev_item);
3139 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3140
3141 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3142 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3143
3144 return 0;
3145 }
3146
3147 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3148 {
3149 struct btrfs_fs_devices *fs_devices;
3150 int ret;
3151
3152 mutex_lock(&uuid_mutex);
3153
3154 fs_devices = root->fs_info->fs_devices->seed;
3155 while (fs_devices) {
3156 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3157 ret = 0;
3158 goto out;
3159 }
3160 fs_devices = fs_devices->seed;
3161 }
3162
3163 fs_devices = find_fsid(fsid);
3164 if (!fs_devices) {
3165 ret = -ENOENT;
3166 goto out;
3167 }
3168
3169 fs_devices = clone_fs_devices(fs_devices);
3170 if (IS_ERR(fs_devices)) {
3171 ret = PTR_ERR(fs_devices);
3172 goto out;
3173 }
3174
3175 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3176 root->fs_info->bdev_holder);
3177 if (ret)
3178 goto out;
3179
3180 if (!fs_devices->seeding) {
3181 __btrfs_close_devices(fs_devices);
3182 free_fs_devices(fs_devices);
3183 ret = -EINVAL;
3184 goto out;
3185 }
3186
3187 fs_devices->seed = root->fs_info->fs_devices->seed;
3188 root->fs_info->fs_devices->seed = fs_devices;
3189 out:
3190 mutex_unlock(&uuid_mutex);
3191 return ret;
3192 }
3193
3194 static int read_one_dev(struct btrfs_root *root,
3195 struct extent_buffer *leaf,
3196 struct btrfs_dev_item *dev_item)
3197 {
3198 struct btrfs_device *device;
3199 u64 devid;
3200 int ret;
3201 u8 fs_uuid[BTRFS_UUID_SIZE];
3202 u8 dev_uuid[BTRFS_UUID_SIZE];
3203
3204 devid = btrfs_device_id(leaf, dev_item);
3205 read_extent_buffer(leaf, dev_uuid,
3206 (unsigned long)btrfs_device_uuid(dev_item),
3207 BTRFS_UUID_SIZE);
3208 read_extent_buffer(leaf, fs_uuid,
3209 (unsigned long)btrfs_device_fsid(dev_item),
3210 BTRFS_UUID_SIZE);
3211
3212 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3213 ret = open_seed_devices(root, fs_uuid);
3214 if (ret && !btrfs_test_opt(root, DEGRADED))
3215 return ret;
3216 }
3217
3218 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3219 if (!device || !device->bdev) {
3220 if (!btrfs_test_opt(root, DEGRADED))
3221 return -EIO;
3222
3223 if (!device) {
3224 printk(KERN_WARNING "warning devid %llu missing\n",
3225 (unsigned long long)devid);
3226 device = add_missing_dev(root, devid, dev_uuid);
3227 if (!device)
3228 return -ENOMEM;
3229 }
3230 }
3231
3232 if (device->fs_devices != root->fs_info->fs_devices) {
3233 BUG_ON(device->writeable);
3234 if (device->generation !=
3235 btrfs_device_generation(leaf, dev_item))
3236 return -EINVAL;
3237 }
3238
3239 fill_device_from_item(leaf, dev_item, device);
3240 device->dev_root = root->fs_info->dev_root;
3241 device->in_fs_metadata = 1;
3242 if (device->writeable)
3243 device->fs_devices->total_rw_bytes += device->total_bytes;
3244 ret = 0;
3245 return ret;
3246 }
3247
3248 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
3249 {
3250 struct btrfs_dev_item *dev_item;
3251
3252 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
3253 dev_item);
3254 return read_one_dev(root, buf, dev_item);
3255 }
3256
3257 int btrfs_read_sys_array(struct btrfs_root *root)
3258 {
3259 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3260 struct extent_buffer *sb;
3261 struct btrfs_disk_key *disk_key;
3262 struct btrfs_chunk *chunk;
3263 u8 *ptr;
3264 unsigned long sb_ptr;
3265 int ret = 0;
3266 u32 num_stripes;
3267 u32 array_size;
3268 u32 len = 0;
3269 u32 cur;
3270 struct btrfs_key key;
3271
3272 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3273 BTRFS_SUPER_INFO_SIZE);
3274 if (!sb)
3275 return -ENOMEM;
3276 btrfs_set_buffer_uptodate(sb);
3277 btrfs_set_buffer_lockdep_class(sb, 0);
3278
3279 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3280 array_size = btrfs_super_sys_array_size(super_copy);
3281
3282 ptr = super_copy->sys_chunk_array;
3283 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3284 cur = 0;
3285
3286 while (cur < array_size) {
3287 disk_key = (struct btrfs_disk_key *)ptr;
3288 btrfs_disk_key_to_cpu(&key, disk_key);
3289
3290 len = sizeof(*disk_key); ptr += len;
3291 sb_ptr += len;
3292 cur += len;
3293
3294 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3295 chunk = (struct btrfs_chunk *)sb_ptr;
3296 ret = read_one_chunk(root, &key, sb, chunk);
3297 if (ret)
3298 break;
3299 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3300 len = btrfs_chunk_item_size(num_stripes);
3301 } else {
3302 ret = -EIO;
3303 break;
3304 }
3305 ptr += len;
3306 sb_ptr += len;
3307 cur += len;
3308 }
3309 free_extent_buffer(sb);
3310 return ret;
3311 }
3312
3313 int btrfs_read_chunk_tree(struct btrfs_root *root)
3314 {
3315 struct btrfs_path *path;
3316 struct extent_buffer *leaf;
3317 struct btrfs_key key;
3318 struct btrfs_key found_key;
3319 int ret;
3320 int slot;
3321
3322 root = root->fs_info->chunk_root;
3323
3324 path = btrfs_alloc_path();
3325 if (!path)
3326 return -ENOMEM;
3327
3328 /* first we search for all of the device items, and then we
3329 * read in all of the chunk items. This way we can create chunk
3330 * mappings that reference all of the devices that are afound
3331 */
3332 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3333 key.offset = 0;
3334 key.type = 0;
3335 again:
3336 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3337 while (1) {
3338 leaf = path->nodes[0];
3339 slot = path->slots[0];
3340 if (slot >= btrfs_header_nritems(leaf)) {
3341 ret = btrfs_next_leaf(root, path);
3342 if (ret == 0)
3343 continue;
3344 if (ret < 0)
3345 goto error;
3346 break;
3347 }
3348 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3349 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3350 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3351 break;
3352 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3353 struct btrfs_dev_item *dev_item;
3354 dev_item = btrfs_item_ptr(leaf, slot,
3355 struct btrfs_dev_item);
3356 ret = read_one_dev(root, leaf, dev_item);
3357 if (ret)
3358 goto error;
3359 }
3360 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3361 struct btrfs_chunk *chunk;
3362 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3363 ret = read_one_chunk(root, &found_key, leaf, chunk);
3364 if (ret)
3365 goto error;
3366 }
3367 path->slots[0]++;
3368 }
3369 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3370 key.objectid = 0;
3371 btrfs_release_path(root, path);
3372 goto again;
3373 }
3374 ret = 0;
3375 error:
3376 btrfs_free_path(path);
3377 return ret;
3378 }
Support for the Chinese Samsung S3C2440 based development boards