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ALSA: hda_intel: add position_fix quirk for Asus K53E
[deliverable/linux.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <linux/ratelimit.h>
27 #include <linux/kthread.h>
28 #include <asm/div64.h>
29 #include "compat.h"
30 #include "ctree.h"
31 #include "extent_map.h"
32 #include "disk-io.h"
33 #include "transaction.h"
34 #include "print-tree.h"
35 #include "volumes.h"
36 #include "async-thread.h"
37 #include "check-integrity.h"
38 #include "rcu-string.h"
39
40 static int init_first_rw_device(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root,
42 struct btrfs_device *device);
43 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
44 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
45 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
46
47 static DEFINE_MUTEX(uuid_mutex);
48 static LIST_HEAD(fs_uuids);
49
50 static void lock_chunks(struct btrfs_root *root)
51 {
52 mutex_lock(&root->fs_info->chunk_mutex);
53 }
54
55 static void unlock_chunks(struct btrfs_root *root)
56 {
57 mutex_unlock(&root->fs_info->chunk_mutex);
58 }
59
60 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
61 {
62 struct btrfs_device *device;
63 WARN_ON(fs_devices->opened);
64 while (!list_empty(&fs_devices->devices)) {
65 device = list_entry(fs_devices->devices.next,
66 struct btrfs_device, dev_list);
67 list_del(&device->dev_list);
68 rcu_string_free(device->name);
69 kfree(device);
70 }
71 kfree(fs_devices);
72 }
73
74 void btrfs_cleanup_fs_uuids(void)
75 {
76 struct btrfs_fs_devices *fs_devices;
77
78 while (!list_empty(&fs_uuids)) {
79 fs_devices = list_entry(fs_uuids.next,
80 struct btrfs_fs_devices, list);
81 list_del(&fs_devices->list);
82 free_fs_devices(fs_devices);
83 }
84 }
85
86 static noinline struct btrfs_device *__find_device(struct list_head *head,
87 u64 devid, u8 *uuid)
88 {
89 struct btrfs_device *dev;
90
91 list_for_each_entry(dev, head, dev_list) {
92 if (dev->devid == devid &&
93 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
94 return dev;
95 }
96 }
97 return NULL;
98 }
99
100 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
101 {
102 struct btrfs_fs_devices *fs_devices;
103
104 list_for_each_entry(fs_devices, &fs_uuids, list) {
105 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
106 return fs_devices;
107 }
108 return NULL;
109 }
110
111 static void requeue_list(struct btrfs_pending_bios *pending_bios,
112 struct bio *head, struct bio *tail)
113 {
114
115 struct bio *old_head;
116
117 old_head = pending_bios->head;
118 pending_bios->head = head;
119 if (pending_bios->tail)
120 tail->bi_next = old_head;
121 else
122 pending_bios->tail = tail;
123 }
124
125 /*
126 * we try to collect pending bios for a device so we don't get a large
127 * number of procs sending bios down to the same device. This greatly
128 * improves the schedulers ability to collect and merge the bios.
129 *
130 * But, it also turns into a long list of bios to process and that is sure
131 * to eventually make the worker thread block. The solution here is to
132 * make some progress and then put this work struct back at the end of
133 * the list if the block device is congested. This way, multiple devices
134 * can make progress from a single worker thread.
135 */
136 static noinline void run_scheduled_bios(struct btrfs_device *device)
137 {
138 struct bio *pending;
139 struct backing_dev_info *bdi;
140 struct btrfs_fs_info *fs_info;
141 struct btrfs_pending_bios *pending_bios;
142 struct bio *tail;
143 struct bio *cur;
144 int again = 0;
145 unsigned long num_run;
146 unsigned long batch_run = 0;
147 unsigned long limit;
148 unsigned long last_waited = 0;
149 int force_reg = 0;
150 int sync_pending = 0;
151 struct blk_plug plug;
152
153 /*
154 * this function runs all the bios we've collected for
155 * a particular device. We don't want to wander off to
156 * another device without first sending all of these down.
157 * So, setup a plug here and finish it off before we return
158 */
159 blk_start_plug(&plug);
160
161 bdi = blk_get_backing_dev_info(device->bdev);
162 fs_info = device->dev_root->fs_info;
163 limit = btrfs_async_submit_limit(fs_info);
164 limit = limit * 2 / 3;
165
166 loop:
167 spin_lock(&device->io_lock);
168
169 loop_lock:
170 num_run = 0;
171
172 /* take all the bios off the list at once and process them
173 * later on (without the lock held). But, remember the
174 * tail and other pointers so the bios can be properly reinserted
175 * into the list if we hit congestion
176 */
177 if (!force_reg && device->pending_sync_bios.head) {
178 pending_bios = &device->pending_sync_bios;
179 force_reg = 1;
180 } else {
181 pending_bios = &device->pending_bios;
182 force_reg = 0;
183 }
184
185 pending = pending_bios->head;
186 tail = pending_bios->tail;
187 WARN_ON(pending && !tail);
188
189 /*
190 * if pending was null this time around, no bios need processing
191 * at all and we can stop. Otherwise it'll loop back up again
192 * and do an additional check so no bios are missed.
193 *
194 * device->running_pending is used to synchronize with the
195 * schedule_bio code.
196 */
197 if (device->pending_sync_bios.head == NULL &&
198 device->pending_bios.head == NULL) {
199 again = 0;
200 device->running_pending = 0;
201 } else {
202 again = 1;
203 device->running_pending = 1;
204 }
205
206 pending_bios->head = NULL;
207 pending_bios->tail = NULL;
208
209 spin_unlock(&device->io_lock);
210
211 while (pending) {
212
213 rmb();
214 /* we want to work on both lists, but do more bios on the
215 * sync list than the regular list
216 */
217 if ((num_run > 32 &&
218 pending_bios != &device->pending_sync_bios &&
219 device->pending_sync_bios.head) ||
220 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
221 device->pending_bios.head)) {
222 spin_lock(&device->io_lock);
223 requeue_list(pending_bios, pending, tail);
224 goto loop_lock;
225 }
226
227 cur = pending;
228 pending = pending->bi_next;
229 cur->bi_next = NULL;
230 atomic_dec(&fs_info->nr_async_bios);
231
232 if (atomic_read(&fs_info->nr_async_bios) < limit &&
233 waitqueue_active(&fs_info->async_submit_wait))
234 wake_up(&fs_info->async_submit_wait);
235
236 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
237
238 /*
239 * if we're doing the sync list, record that our
240 * plug has some sync requests on it
241 *
242 * If we're doing the regular list and there are
243 * sync requests sitting around, unplug before
244 * we add more
245 */
246 if (pending_bios == &device->pending_sync_bios) {
247 sync_pending = 1;
248 } else if (sync_pending) {
249 blk_finish_plug(&plug);
250 blk_start_plug(&plug);
251 sync_pending = 0;
252 }
253
254 btrfsic_submit_bio(cur->bi_rw, cur);
255 num_run++;
256 batch_run++;
257 if (need_resched())
258 cond_resched();
259
260 /*
261 * we made progress, there is more work to do and the bdi
262 * is now congested. Back off and let other work structs
263 * run instead
264 */
265 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
266 fs_info->fs_devices->open_devices > 1) {
267 struct io_context *ioc;
268
269 ioc = current->io_context;
270
271 /*
272 * the main goal here is that we don't want to
273 * block if we're going to be able to submit
274 * more requests without blocking.
275 *
276 * This code does two great things, it pokes into
277 * the elevator code from a filesystem _and_
278 * it makes assumptions about how batching works.
279 */
280 if (ioc && ioc->nr_batch_requests > 0 &&
281 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
282 (last_waited == 0 ||
283 ioc->last_waited == last_waited)) {
284 /*
285 * we want to go through our batch of
286 * requests and stop. So, we copy out
287 * the ioc->last_waited time and test
288 * against it before looping
289 */
290 last_waited = ioc->last_waited;
291 if (need_resched())
292 cond_resched();
293 continue;
294 }
295 spin_lock(&device->io_lock);
296 requeue_list(pending_bios, pending, tail);
297 device->running_pending = 1;
298
299 spin_unlock(&device->io_lock);
300 btrfs_requeue_work(&device->work);
301 goto done;
302 }
303 /* unplug every 64 requests just for good measure */
304 if (batch_run % 64 == 0) {
305 blk_finish_plug(&plug);
306 blk_start_plug(&plug);
307 sync_pending = 0;
308 }
309 }
310
311 cond_resched();
312 if (again)
313 goto loop;
314
315 spin_lock(&device->io_lock);
316 if (device->pending_bios.head || device->pending_sync_bios.head)
317 goto loop_lock;
318 spin_unlock(&device->io_lock);
319
320 done:
321 blk_finish_plug(&plug);
322 }
323
324 static void pending_bios_fn(struct btrfs_work *work)
325 {
326 struct btrfs_device *device;
327
328 device = container_of(work, struct btrfs_device, work);
329 run_scheduled_bios(device);
330 }
331
332 static noinline int device_list_add(const char *path,
333 struct btrfs_super_block *disk_super,
334 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
335 {
336 struct btrfs_device *device;
337 struct btrfs_fs_devices *fs_devices;
338 struct rcu_string *name;
339 u64 found_transid = btrfs_super_generation(disk_super);
340
341 fs_devices = find_fsid(disk_super->fsid);
342 if (!fs_devices) {
343 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
344 if (!fs_devices)
345 return -ENOMEM;
346 INIT_LIST_HEAD(&fs_devices->devices);
347 INIT_LIST_HEAD(&fs_devices->alloc_list);
348 list_add(&fs_devices->list, &fs_uuids);
349 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
350 fs_devices->latest_devid = devid;
351 fs_devices->latest_trans = found_transid;
352 mutex_init(&fs_devices->device_list_mutex);
353 device = NULL;
354 } else {
355 device = __find_device(&fs_devices->devices, devid,
356 disk_super->dev_item.uuid);
357 }
358 if (!device) {
359 if (fs_devices->opened)
360 return -EBUSY;
361
362 device = kzalloc(sizeof(*device), GFP_NOFS);
363 if (!device) {
364 /* we can safely leave the fs_devices entry around */
365 return -ENOMEM;
366 }
367 device->devid = devid;
368 device->dev_stats_valid = 0;
369 device->work.func = pending_bios_fn;
370 memcpy(device->uuid, disk_super->dev_item.uuid,
371 BTRFS_UUID_SIZE);
372 spin_lock_init(&device->io_lock);
373
374 name = rcu_string_strdup(path, GFP_NOFS);
375 if (!name) {
376 kfree(device);
377 return -ENOMEM;
378 }
379 rcu_assign_pointer(device->name, name);
380 INIT_LIST_HEAD(&device->dev_alloc_list);
381
382 /* init readahead state */
383 spin_lock_init(&device->reada_lock);
384 device->reada_curr_zone = NULL;
385 atomic_set(&device->reada_in_flight, 0);
386 device->reada_next = 0;
387 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
388 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
389
390 mutex_lock(&fs_devices->device_list_mutex);
391 list_add_rcu(&device->dev_list, &fs_devices->devices);
392 mutex_unlock(&fs_devices->device_list_mutex);
393
394 device->fs_devices = fs_devices;
395 fs_devices->num_devices++;
396 } else if (!device->name || strcmp(device->name->str, path)) {
397 name = rcu_string_strdup(path, GFP_NOFS);
398 if (!name)
399 return -ENOMEM;
400 rcu_string_free(device->name);
401 rcu_assign_pointer(device->name, name);
402 if (device->missing) {
403 fs_devices->missing_devices--;
404 device->missing = 0;
405 }
406 }
407
408 if (found_transid > fs_devices->latest_trans) {
409 fs_devices->latest_devid = devid;
410 fs_devices->latest_trans = found_transid;
411 }
412 *fs_devices_ret = fs_devices;
413 return 0;
414 }
415
416 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
417 {
418 struct btrfs_fs_devices *fs_devices;
419 struct btrfs_device *device;
420 struct btrfs_device *orig_dev;
421
422 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
423 if (!fs_devices)
424 return ERR_PTR(-ENOMEM);
425
426 INIT_LIST_HEAD(&fs_devices->devices);
427 INIT_LIST_HEAD(&fs_devices->alloc_list);
428 INIT_LIST_HEAD(&fs_devices->list);
429 mutex_init(&fs_devices->device_list_mutex);
430 fs_devices->latest_devid = orig->latest_devid;
431 fs_devices->latest_trans = orig->latest_trans;
432 fs_devices->total_devices = orig->total_devices;
433 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
434
435 /* We have held the volume lock, it is safe to get the devices. */
436 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
437 struct rcu_string *name;
438
439 device = kzalloc(sizeof(*device), GFP_NOFS);
440 if (!device)
441 goto error;
442
443 /*
444 * This is ok to do without rcu read locked because we hold the
445 * uuid mutex so nothing we touch in here is going to disappear.
446 */
447 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
448 if (!name) {
449 kfree(device);
450 goto error;
451 }
452 rcu_assign_pointer(device->name, name);
453
454 device->devid = orig_dev->devid;
455 device->work.func = pending_bios_fn;
456 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
457 spin_lock_init(&device->io_lock);
458 INIT_LIST_HEAD(&device->dev_list);
459 INIT_LIST_HEAD(&device->dev_alloc_list);
460
461 list_add(&device->dev_list, &fs_devices->devices);
462 device->fs_devices = fs_devices;
463 fs_devices->num_devices++;
464 }
465 return fs_devices;
466 error:
467 free_fs_devices(fs_devices);
468 return ERR_PTR(-ENOMEM);
469 }
470
471 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
472 {
473 struct btrfs_device *device, *next;
474
475 struct block_device *latest_bdev = NULL;
476 u64 latest_devid = 0;
477 u64 latest_transid = 0;
478
479 mutex_lock(&uuid_mutex);
480 again:
481 /* This is the initialized path, it is safe to release the devices. */
482 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
483 if (device->in_fs_metadata) {
484 if (!latest_transid ||
485 device->generation > latest_transid) {
486 latest_devid = device->devid;
487 latest_transid = device->generation;
488 latest_bdev = device->bdev;
489 }
490 continue;
491 }
492
493 if (device->bdev) {
494 blkdev_put(device->bdev, device->mode);
495 device->bdev = NULL;
496 fs_devices->open_devices--;
497 }
498 if (device->writeable) {
499 list_del_init(&device->dev_alloc_list);
500 device->writeable = 0;
501 fs_devices->rw_devices--;
502 }
503 list_del_init(&device->dev_list);
504 fs_devices->num_devices--;
505 rcu_string_free(device->name);
506 kfree(device);
507 }
508
509 if (fs_devices->seed) {
510 fs_devices = fs_devices->seed;
511 goto again;
512 }
513
514 fs_devices->latest_bdev = latest_bdev;
515 fs_devices->latest_devid = latest_devid;
516 fs_devices->latest_trans = latest_transid;
517
518 mutex_unlock(&uuid_mutex);
519 }
520
521 static void __free_device(struct work_struct *work)
522 {
523 struct btrfs_device *device;
524
525 device = container_of(work, struct btrfs_device, rcu_work);
526
527 if (device->bdev)
528 blkdev_put(device->bdev, device->mode);
529
530 rcu_string_free(device->name);
531 kfree(device);
532 }
533
534 static void free_device(struct rcu_head *head)
535 {
536 struct btrfs_device *device;
537
538 device = container_of(head, struct btrfs_device, rcu);
539
540 INIT_WORK(&device->rcu_work, __free_device);
541 schedule_work(&device->rcu_work);
542 }
543
544 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
545 {
546 struct btrfs_device *device;
547
548 if (--fs_devices->opened > 0)
549 return 0;
550
551 mutex_lock(&fs_devices->device_list_mutex);
552 list_for_each_entry(device, &fs_devices->devices, dev_list) {
553 struct btrfs_device *new_device;
554 struct rcu_string *name;
555
556 if (device->bdev)
557 fs_devices->open_devices--;
558
559 if (device->writeable) {
560 list_del_init(&device->dev_alloc_list);
561 fs_devices->rw_devices--;
562 }
563
564 if (device->can_discard)
565 fs_devices->num_can_discard--;
566
567 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
568 BUG_ON(!new_device); /* -ENOMEM */
569 memcpy(new_device, device, sizeof(*new_device));
570
571 /* Safe because we are under uuid_mutex */
572 name = rcu_string_strdup(device->name->str, GFP_NOFS);
573 BUG_ON(device->name && !name); /* -ENOMEM */
574 rcu_assign_pointer(new_device->name, name);
575 new_device->bdev = NULL;
576 new_device->writeable = 0;
577 new_device->in_fs_metadata = 0;
578 new_device->can_discard = 0;
579 list_replace_rcu(&device->dev_list, &new_device->dev_list);
580
581 call_rcu(&device->rcu, free_device);
582 }
583 mutex_unlock(&fs_devices->device_list_mutex);
584
585 WARN_ON(fs_devices->open_devices);
586 WARN_ON(fs_devices->rw_devices);
587 fs_devices->opened = 0;
588 fs_devices->seeding = 0;
589
590 return 0;
591 }
592
593 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
594 {
595 struct btrfs_fs_devices *seed_devices = NULL;
596 int ret;
597
598 mutex_lock(&uuid_mutex);
599 ret = __btrfs_close_devices(fs_devices);
600 if (!fs_devices->opened) {
601 seed_devices = fs_devices->seed;
602 fs_devices->seed = NULL;
603 }
604 mutex_unlock(&uuid_mutex);
605
606 while (seed_devices) {
607 fs_devices = seed_devices;
608 seed_devices = fs_devices->seed;
609 __btrfs_close_devices(fs_devices);
610 free_fs_devices(fs_devices);
611 }
612 return ret;
613 }
614
615 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
616 fmode_t flags, void *holder)
617 {
618 struct request_queue *q;
619 struct block_device *bdev;
620 struct list_head *head = &fs_devices->devices;
621 struct btrfs_device *device;
622 struct block_device *latest_bdev = NULL;
623 struct buffer_head *bh;
624 struct btrfs_super_block *disk_super;
625 u64 latest_devid = 0;
626 u64 latest_transid = 0;
627 u64 devid;
628 int seeding = 1;
629 int ret = 0;
630
631 flags |= FMODE_EXCL;
632
633 list_for_each_entry(device, head, dev_list) {
634 if (device->bdev)
635 continue;
636 if (!device->name)
637 continue;
638
639 bdev = blkdev_get_by_path(device->name->str, flags, holder);
640 if (IS_ERR(bdev)) {
641 printk(KERN_INFO "open %s failed\n", device->name->str);
642 goto error;
643 }
644 filemap_write_and_wait(bdev->bd_inode->i_mapping);
645 invalidate_bdev(bdev);
646 set_blocksize(bdev, 4096);
647
648 bh = btrfs_read_dev_super(bdev);
649 if (!bh)
650 goto error_close;
651
652 disk_super = (struct btrfs_super_block *)bh->b_data;
653 devid = btrfs_stack_device_id(&disk_super->dev_item);
654 if (devid != device->devid)
655 goto error_brelse;
656
657 if (memcmp(device->uuid, disk_super->dev_item.uuid,
658 BTRFS_UUID_SIZE))
659 goto error_brelse;
660
661 device->generation = btrfs_super_generation(disk_super);
662 if (!latest_transid || device->generation > latest_transid) {
663 latest_devid = devid;
664 latest_transid = device->generation;
665 latest_bdev = bdev;
666 }
667
668 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
669 device->writeable = 0;
670 } else {
671 device->writeable = !bdev_read_only(bdev);
672 seeding = 0;
673 }
674
675 q = bdev_get_queue(bdev);
676 if (blk_queue_discard(q)) {
677 device->can_discard = 1;
678 fs_devices->num_can_discard++;
679 }
680
681 device->bdev = bdev;
682 device->in_fs_metadata = 0;
683 device->mode = flags;
684
685 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
686 fs_devices->rotating = 1;
687
688 fs_devices->open_devices++;
689 if (device->writeable) {
690 fs_devices->rw_devices++;
691 list_add(&device->dev_alloc_list,
692 &fs_devices->alloc_list);
693 }
694 brelse(bh);
695 continue;
696
697 error_brelse:
698 brelse(bh);
699 error_close:
700 blkdev_put(bdev, flags);
701 error:
702 continue;
703 }
704 if (fs_devices->open_devices == 0) {
705 ret = -EINVAL;
706 goto out;
707 }
708 fs_devices->seeding = seeding;
709 fs_devices->opened = 1;
710 fs_devices->latest_bdev = latest_bdev;
711 fs_devices->latest_devid = latest_devid;
712 fs_devices->latest_trans = latest_transid;
713 fs_devices->total_rw_bytes = 0;
714 out:
715 return ret;
716 }
717
718 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
719 fmode_t flags, void *holder)
720 {
721 int ret;
722
723 mutex_lock(&uuid_mutex);
724 if (fs_devices->opened) {
725 fs_devices->opened++;
726 ret = 0;
727 } else {
728 ret = __btrfs_open_devices(fs_devices, flags, holder);
729 }
730 mutex_unlock(&uuid_mutex);
731 return ret;
732 }
733
734 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
735 struct btrfs_fs_devices **fs_devices_ret)
736 {
737 struct btrfs_super_block *disk_super;
738 struct block_device *bdev;
739 struct buffer_head *bh;
740 int ret;
741 u64 devid;
742 u64 transid;
743 u64 total_devices;
744
745 flags |= FMODE_EXCL;
746 bdev = blkdev_get_by_path(path, flags, holder);
747
748 if (IS_ERR(bdev)) {
749 ret = PTR_ERR(bdev);
750 goto error;
751 }
752
753 mutex_lock(&uuid_mutex);
754 ret = set_blocksize(bdev, 4096);
755 if (ret)
756 goto error_close;
757 bh = btrfs_read_dev_super(bdev);
758 if (!bh) {
759 ret = -EINVAL;
760 goto error_close;
761 }
762 disk_super = (struct btrfs_super_block *)bh->b_data;
763 devid = btrfs_stack_device_id(&disk_super->dev_item);
764 transid = btrfs_super_generation(disk_super);
765 total_devices = btrfs_super_num_devices(disk_super);
766 if (disk_super->label[0])
767 printk(KERN_INFO "device label %s ", disk_super->label);
768 else
769 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
770 printk(KERN_CONT "devid %llu transid %llu %s\n",
771 (unsigned long long)devid, (unsigned long long)transid, path);
772 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
773 if (!ret && fs_devices_ret)
774 (*fs_devices_ret)->total_devices = total_devices;
775 brelse(bh);
776 error_close:
777 mutex_unlock(&uuid_mutex);
778 blkdev_put(bdev, flags);
779 error:
780 return ret;
781 }
782
783 /* helper to account the used device space in the range */
784 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
785 u64 end, u64 *length)
786 {
787 struct btrfs_key key;
788 struct btrfs_root *root = device->dev_root;
789 struct btrfs_dev_extent *dev_extent;
790 struct btrfs_path *path;
791 u64 extent_end;
792 int ret;
793 int slot;
794 struct extent_buffer *l;
795
796 *length = 0;
797
798 if (start >= device->total_bytes)
799 return 0;
800
801 path = btrfs_alloc_path();
802 if (!path)
803 return -ENOMEM;
804 path->reada = 2;
805
806 key.objectid = device->devid;
807 key.offset = start;
808 key.type = BTRFS_DEV_EXTENT_KEY;
809
810 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
811 if (ret < 0)
812 goto out;
813 if (ret > 0) {
814 ret = btrfs_previous_item(root, path, key.objectid, key.type);
815 if (ret < 0)
816 goto out;
817 }
818
819 while (1) {
820 l = path->nodes[0];
821 slot = path->slots[0];
822 if (slot >= btrfs_header_nritems(l)) {
823 ret = btrfs_next_leaf(root, path);
824 if (ret == 0)
825 continue;
826 if (ret < 0)
827 goto out;
828
829 break;
830 }
831 btrfs_item_key_to_cpu(l, &key, slot);
832
833 if (key.objectid < device->devid)
834 goto next;
835
836 if (key.objectid > device->devid)
837 break;
838
839 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
840 goto next;
841
842 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
843 extent_end = key.offset + btrfs_dev_extent_length(l,
844 dev_extent);
845 if (key.offset <= start && extent_end > end) {
846 *length = end - start + 1;
847 break;
848 } else if (key.offset <= start && extent_end > start)
849 *length += extent_end - start;
850 else if (key.offset > start && extent_end <= end)
851 *length += extent_end - key.offset;
852 else if (key.offset > start && key.offset <= end) {
853 *length += end - key.offset + 1;
854 break;
855 } else if (key.offset > end)
856 break;
857
858 next:
859 path->slots[0]++;
860 }
861 ret = 0;
862 out:
863 btrfs_free_path(path);
864 return ret;
865 }
866
867 /*
868 * find_free_dev_extent - find free space in the specified device
869 * @device: the device which we search the free space in
870 * @num_bytes: the size of the free space that we need
871 * @start: store the start of the free space.
872 * @len: the size of the free space. that we find, or the size of the max
873 * free space if we don't find suitable free space
874 *
875 * this uses a pretty simple search, the expectation is that it is
876 * called very infrequently and that a given device has a small number
877 * of extents
878 *
879 * @start is used to store the start of the free space if we find. But if we
880 * don't find suitable free space, it will be used to store the start position
881 * of the max free space.
882 *
883 * @len is used to store the size of the free space that we find.
884 * But if we don't find suitable free space, it is used to store the size of
885 * the max free space.
886 */
887 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
888 u64 *start, u64 *len)
889 {
890 struct btrfs_key key;
891 struct btrfs_root *root = device->dev_root;
892 struct btrfs_dev_extent *dev_extent;
893 struct btrfs_path *path;
894 u64 hole_size;
895 u64 max_hole_start;
896 u64 max_hole_size;
897 u64 extent_end;
898 u64 search_start;
899 u64 search_end = device->total_bytes;
900 int ret;
901 int slot;
902 struct extent_buffer *l;
903
904 /* FIXME use last free of some kind */
905
906 /* we don't want to overwrite the superblock on the drive,
907 * so we make sure to start at an offset of at least 1MB
908 */
909 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
910
911 max_hole_start = search_start;
912 max_hole_size = 0;
913 hole_size = 0;
914
915 if (search_start >= search_end) {
916 ret = -ENOSPC;
917 goto error;
918 }
919
920 path = btrfs_alloc_path();
921 if (!path) {
922 ret = -ENOMEM;
923 goto error;
924 }
925 path->reada = 2;
926
927 key.objectid = device->devid;
928 key.offset = search_start;
929 key.type = BTRFS_DEV_EXTENT_KEY;
930
931 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
932 if (ret < 0)
933 goto out;
934 if (ret > 0) {
935 ret = btrfs_previous_item(root, path, key.objectid, key.type);
936 if (ret < 0)
937 goto out;
938 }
939
940 while (1) {
941 l = path->nodes[0];
942 slot = path->slots[0];
943 if (slot >= btrfs_header_nritems(l)) {
944 ret = btrfs_next_leaf(root, path);
945 if (ret == 0)
946 continue;
947 if (ret < 0)
948 goto out;
949
950 break;
951 }
952 btrfs_item_key_to_cpu(l, &key, slot);
953
954 if (key.objectid < device->devid)
955 goto next;
956
957 if (key.objectid > device->devid)
958 break;
959
960 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
961 goto next;
962
963 if (key.offset > search_start) {
964 hole_size = key.offset - search_start;
965
966 if (hole_size > max_hole_size) {
967 max_hole_start = search_start;
968 max_hole_size = hole_size;
969 }
970
971 /*
972 * If this free space is greater than which we need,
973 * it must be the max free space that we have found
974 * until now, so max_hole_start must point to the start
975 * of this free space and the length of this free space
976 * is stored in max_hole_size. Thus, we return
977 * max_hole_start and max_hole_size and go back to the
978 * caller.
979 */
980 if (hole_size >= num_bytes) {
981 ret = 0;
982 goto out;
983 }
984 }
985
986 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
987 extent_end = key.offset + btrfs_dev_extent_length(l,
988 dev_extent);
989 if (extent_end > search_start)
990 search_start = extent_end;
991 next:
992 path->slots[0]++;
993 cond_resched();
994 }
995
996 /*
997 * At this point, search_start should be the end of
998 * allocated dev extents, and when shrinking the device,
999 * search_end may be smaller than search_start.
1000 */
1001 if (search_end > search_start)
1002 hole_size = search_end - search_start;
1003
1004 if (hole_size > max_hole_size) {
1005 max_hole_start = search_start;
1006 max_hole_size = hole_size;
1007 }
1008
1009 /* See above. */
1010 if (hole_size < num_bytes)
1011 ret = -ENOSPC;
1012 else
1013 ret = 0;
1014
1015 out:
1016 btrfs_free_path(path);
1017 error:
1018 *start = max_hole_start;
1019 if (len)
1020 *len = max_hole_size;
1021 return ret;
1022 }
1023
1024 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1025 struct btrfs_device *device,
1026 u64 start)
1027 {
1028 int ret;
1029 struct btrfs_path *path;
1030 struct btrfs_root *root = device->dev_root;
1031 struct btrfs_key key;
1032 struct btrfs_key found_key;
1033 struct extent_buffer *leaf = NULL;
1034 struct btrfs_dev_extent *extent = NULL;
1035
1036 path = btrfs_alloc_path();
1037 if (!path)
1038 return -ENOMEM;
1039
1040 key.objectid = device->devid;
1041 key.offset = start;
1042 key.type = BTRFS_DEV_EXTENT_KEY;
1043 again:
1044 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1045 if (ret > 0) {
1046 ret = btrfs_previous_item(root, path, key.objectid,
1047 BTRFS_DEV_EXTENT_KEY);
1048 if (ret)
1049 goto out;
1050 leaf = path->nodes[0];
1051 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1052 extent = btrfs_item_ptr(leaf, path->slots[0],
1053 struct btrfs_dev_extent);
1054 BUG_ON(found_key.offset > start || found_key.offset +
1055 btrfs_dev_extent_length(leaf, extent) < start);
1056 key = found_key;
1057 btrfs_release_path(path);
1058 goto again;
1059 } else if (ret == 0) {
1060 leaf = path->nodes[0];
1061 extent = btrfs_item_ptr(leaf, path->slots[0],
1062 struct btrfs_dev_extent);
1063 } else {
1064 btrfs_error(root->fs_info, ret, "Slot search failed");
1065 goto out;
1066 }
1067
1068 if (device->bytes_used > 0) {
1069 u64 len = btrfs_dev_extent_length(leaf, extent);
1070 device->bytes_used -= len;
1071 spin_lock(&root->fs_info->free_chunk_lock);
1072 root->fs_info->free_chunk_space += len;
1073 spin_unlock(&root->fs_info->free_chunk_lock);
1074 }
1075 ret = btrfs_del_item(trans, root, path);
1076 if (ret) {
1077 btrfs_error(root->fs_info, ret,
1078 "Failed to remove dev extent item");
1079 }
1080 out:
1081 btrfs_free_path(path);
1082 return ret;
1083 }
1084
1085 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1086 struct btrfs_device *device,
1087 u64 chunk_tree, u64 chunk_objectid,
1088 u64 chunk_offset, u64 start, u64 num_bytes)
1089 {
1090 int ret;
1091 struct btrfs_path *path;
1092 struct btrfs_root *root = device->dev_root;
1093 struct btrfs_dev_extent *extent;
1094 struct extent_buffer *leaf;
1095 struct btrfs_key key;
1096
1097 WARN_ON(!device->in_fs_metadata);
1098 path = btrfs_alloc_path();
1099 if (!path)
1100 return -ENOMEM;
1101
1102 key.objectid = device->devid;
1103 key.offset = start;
1104 key.type = BTRFS_DEV_EXTENT_KEY;
1105 ret = btrfs_insert_empty_item(trans, root, path, &key,
1106 sizeof(*extent));
1107 if (ret)
1108 goto out;
1109
1110 leaf = path->nodes[0];
1111 extent = btrfs_item_ptr(leaf, path->slots[0],
1112 struct btrfs_dev_extent);
1113 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1114 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1115 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1116
1117 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1118 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1119 BTRFS_UUID_SIZE);
1120
1121 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1122 btrfs_mark_buffer_dirty(leaf);
1123 out:
1124 btrfs_free_path(path);
1125 return ret;
1126 }
1127
1128 static noinline int find_next_chunk(struct btrfs_root *root,
1129 u64 objectid, u64 *offset)
1130 {
1131 struct btrfs_path *path;
1132 int ret;
1133 struct btrfs_key key;
1134 struct btrfs_chunk *chunk;
1135 struct btrfs_key found_key;
1136
1137 path = btrfs_alloc_path();
1138 if (!path)
1139 return -ENOMEM;
1140
1141 key.objectid = objectid;
1142 key.offset = (u64)-1;
1143 key.type = BTRFS_CHUNK_ITEM_KEY;
1144
1145 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1146 if (ret < 0)
1147 goto error;
1148
1149 BUG_ON(ret == 0); /* Corruption */
1150
1151 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1152 if (ret) {
1153 *offset = 0;
1154 } else {
1155 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1156 path->slots[0]);
1157 if (found_key.objectid != objectid)
1158 *offset = 0;
1159 else {
1160 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1161 struct btrfs_chunk);
1162 *offset = found_key.offset +
1163 btrfs_chunk_length(path->nodes[0], chunk);
1164 }
1165 }
1166 ret = 0;
1167 error:
1168 btrfs_free_path(path);
1169 return ret;
1170 }
1171
1172 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1173 {
1174 int ret;
1175 struct btrfs_key key;
1176 struct btrfs_key found_key;
1177 struct btrfs_path *path;
1178
1179 root = root->fs_info->chunk_root;
1180
1181 path = btrfs_alloc_path();
1182 if (!path)
1183 return -ENOMEM;
1184
1185 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1186 key.type = BTRFS_DEV_ITEM_KEY;
1187 key.offset = (u64)-1;
1188
1189 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1190 if (ret < 0)
1191 goto error;
1192
1193 BUG_ON(ret == 0); /* Corruption */
1194
1195 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1196 BTRFS_DEV_ITEM_KEY);
1197 if (ret) {
1198 *objectid = 1;
1199 } else {
1200 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1201 path->slots[0]);
1202 *objectid = found_key.offset + 1;
1203 }
1204 ret = 0;
1205 error:
1206 btrfs_free_path(path);
1207 return ret;
1208 }
1209
1210 /*
1211 * the device information is stored in the chunk root
1212 * the btrfs_device struct should be fully filled in
1213 */
1214 int btrfs_add_device(struct btrfs_trans_handle *trans,
1215 struct btrfs_root *root,
1216 struct btrfs_device *device)
1217 {
1218 int ret;
1219 struct btrfs_path *path;
1220 struct btrfs_dev_item *dev_item;
1221 struct extent_buffer *leaf;
1222 struct btrfs_key key;
1223 unsigned long ptr;
1224
1225 root = root->fs_info->chunk_root;
1226
1227 path = btrfs_alloc_path();
1228 if (!path)
1229 return -ENOMEM;
1230
1231 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1232 key.type = BTRFS_DEV_ITEM_KEY;
1233 key.offset = device->devid;
1234
1235 ret = btrfs_insert_empty_item(trans, root, path, &key,
1236 sizeof(*dev_item));
1237 if (ret)
1238 goto out;
1239
1240 leaf = path->nodes[0];
1241 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1242
1243 btrfs_set_device_id(leaf, dev_item, device->devid);
1244 btrfs_set_device_generation(leaf, dev_item, 0);
1245 btrfs_set_device_type(leaf, dev_item, device->type);
1246 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1247 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1248 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1249 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1250 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1251 btrfs_set_device_group(leaf, dev_item, 0);
1252 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1253 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1254 btrfs_set_device_start_offset(leaf, dev_item, 0);
1255
1256 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1257 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1258 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1259 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1260 btrfs_mark_buffer_dirty(leaf);
1261
1262 ret = 0;
1263 out:
1264 btrfs_free_path(path);
1265 return ret;
1266 }
1267
1268 static int btrfs_rm_dev_item(struct btrfs_root *root,
1269 struct btrfs_device *device)
1270 {
1271 int ret;
1272 struct btrfs_path *path;
1273 struct btrfs_key key;
1274 struct btrfs_trans_handle *trans;
1275
1276 root = root->fs_info->chunk_root;
1277
1278 path = btrfs_alloc_path();
1279 if (!path)
1280 return -ENOMEM;
1281
1282 trans = btrfs_start_transaction(root, 0);
1283 if (IS_ERR(trans)) {
1284 btrfs_free_path(path);
1285 return PTR_ERR(trans);
1286 }
1287 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1288 key.type = BTRFS_DEV_ITEM_KEY;
1289 key.offset = device->devid;
1290 lock_chunks(root);
1291
1292 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1293 if (ret < 0)
1294 goto out;
1295
1296 if (ret > 0) {
1297 ret = -ENOENT;
1298 goto out;
1299 }
1300
1301 ret = btrfs_del_item(trans, root, path);
1302 if (ret)
1303 goto out;
1304 out:
1305 btrfs_free_path(path);
1306 unlock_chunks(root);
1307 btrfs_commit_transaction(trans, root);
1308 return ret;
1309 }
1310
1311 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1312 {
1313 struct btrfs_device *device;
1314 struct btrfs_device *next_device;
1315 struct block_device *bdev;
1316 struct buffer_head *bh = NULL;
1317 struct btrfs_super_block *disk_super;
1318 struct btrfs_fs_devices *cur_devices;
1319 u64 all_avail;
1320 u64 devid;
1321 u64 num_devices;
1322 u8 *dev_uuid;
1323 int ret = 0;
1324 bool clear_super = false;
1325
1326 mutex_lock(&uuid_mutex);
1327
1328 all_avail = root->fs_info->avail_data_alloc_bits |
1329 root->fs_info->avail_system_alloc_bits |
1330 root->fs_info->avail_metadata_alloc_bits;
1331
1332 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1333 root->fs_info->fs_devices->num_devices <= 4) {
1334 printk(KERN_ERR "btrfs: unable to go below four devices "
1335 "on raid10\n");
1336 ret = -EINVAL;
1337 goto out;
1338 }
1339
1340 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1341 root->fs_info->fs_devices->num_devices <= 2) {
1342 printk(KERN_ERR "btrfs: unable to go below two "
1343 "devices on raid1\n");
1344 ret = -EINVAL;
1345 goto out;
1346 }
1347
1348 if (strcmp(device_path, "missing") == 0) {
1349 struct list_head *devices;
1350 struct btrfs_device *tmp;
1351
1352 device = NULL;
1353 devices = &root->fs_info->fs_devices->devices;
1354 /*
1355 * It is safe to read the devices since the volume_mutex
1356 * is held.
1357 */
1358 list_for_each_entry(tmp, devices, dev_list) {
1359 if (tmp->in_fs_metadata && !tmp->bdev) {
1360 device = tmp;
1361 break;
1362 }
1363 }
1364 bdev = NULL;
1365 bh = NULL;
1366 disk_super = NULL;
1367 if (!device) {
1368 printk(KERN_ERR "btrfs: no missing devices found to "
1369 "remove\n");
1370 goto out;
1371 }
1372 } else {
1373 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1374 root->fs_info->bdev_holder);
1375 if (IS_ERR(bdev)) {
1376 ret = PTR_ERR(bdev);
1377 goto out;
1378 }
1379
1380 set_blocksize(bdev, 4096);
1381 invalidate_bdev(bdev);
1382 bh = btrfs_read_dev_super(bdev);
1383 if (!bh) {
1384 ret = -EINVAL;
1385 goto error_close;
1386 }
1387 disk_super = (struct btrfs_super_block *)bh->b_data;
1388 devid = btrfs_stack_device_id(&disk_super->dev_item);
1389 dev_uuid = disk_super->dev_item.uuid;
1390 device = btrfs_find_device(root, devid, dev_uuid,
1391 disk_super->fsid);
1392 if (!device) {
1393 ret = -ENOENT;
1394 goto error_brelse;
1395 }
1396 }
1397
1398 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1399 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1400 "device\n");
1401 ret = -EINVAL;
1402 goto error_brelse;
1403 }
1404
1405 if (device->writeable) {
1406 lock_chunks(root);
1407 list_del_init(&device->dev_alloc_list);
1408 unlock_chunks(root);
1409 root->fs_info->fs_devices->rw_devices--;
1410 clear_super = true;
1411 }
1412
1413 ret = btrfs_shrink_device(device, 0);
1414 if (ret)
1415 goto error_undo;
1416
1417 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1418 if (ret)
1419 goto error_undo;
1420
1421 spin_lock(&root->fs_info->free_chunk_lock);
1422 root->fs_info->free_chunk_space = device->total_bytes -
1423 device->bytes_used;
1424 spin_unlock(&root->fs_info->free_chunk_lock);
1425
1426 device->in_fs_metadata = 0;
1427 btrfs_scrub_cancel_dev(root, device);
1428
1429 /*
1430 * the device list mutex makes sure that we don't change
1431 * the device list while someone else is writing out all
1432 * the device supers.
1433 */
1434
1435 cur_devices = device->fs_devices;
1436 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1437 list_del_rcu(&device->dev_list);
1438
1439 device->fs_devices->num_devices--;
1440 device->fs_devices->total_devices--;
1441
1442 if (device->missing)
1443 root->fs_info->fs_devices->missing_devices--;
1444
1445 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1446 struct btrfs_device, dev_list);
1447 if (device->bdev == root->fs_info->sb->s_bdev)
1448 root->fs_info->sb->s_bdev = next_device->bdev;
1449 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1450 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1451
1452 if (device->bdev)
1453 device->fs_devices->open_devices--;
1454
1455 call_rcu(&device->rcu, free_device);
1456 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1457
1458 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1459 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1460
1461 if (cur_devices->open_devices == 0) {
1462 struct btrfs_fs_devices *fs_devices;
1463 fs_devices = root->fs_info->fs_devices;
1464 while (fs_devices) {
1465 if (fs_devices->seed == cur_devices)
1466 break;
1467 fs_devices = fs_devices->seed;
1468 }
1469 fs_devices->seed = cur_devices->seed;
1470 cur_devices->seed = NULL;
1471 lock_chunks(root);
1472 __btrfs_close_devices(cur_devices);
1473 unlock_chunks(root);
1474 free_fs_devices(cur_devices);
1475 }
1476
1477 /*
1478 * at this point, the device is zero sized. We want to
1479 * remove it from the devices list and zero out the old super
1480 */
1481 if (clear_super) {
1482 /* make sure this device isn't detected as part of
1483 * the FS anymore
1484 */
1485 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1486 set_buffer_dirty(bh);
1487 sync_dirty_buffer(bh);
1488 }
1489
1490 ret = 0;
1491
1492 error_brelse:
1493 brelse(bh);
1494 error_close:
1495 if (bdev)
1496 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1497 out:
1498 mutex_unlock(&uuid_mutex);
1499 return ret;
1500 error_undo:
1501 if (device->writeable) {
1502 lock_chunks(root);
1503 list_add(&device->dev_alloc_list,
1504 &root->fs_info->fs_devices->alloc_list);
1505 unlock_chunks(root);
1506 root->fs_info->fs_devices->rw_devices++;
1507 }
1508 goto error_brelse;
1509 }
1510
1511 /*
1512 * does all the dirty work required for changing file system's UUID.
1513 */
1514 static int btrfs_prepare_sprout(struct btrfs_root *root)
1515 {
1516 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1517 struct btrfs_fs_devices *old_devices;
1518 struct btrfs_fs_devices *seed_devices;
1519 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1520 struct btrfs_device *device;
1521 u64 super_flags;
1522
1523 BUG_ON(!mutex_is_locked(&uuid_mutex));
1524 if (!fs_devices->seeding)
1525 return -EINVAL;
1526
1527 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1528 if (!seed_devices)
1529 return -ENOMEM;
1530
1531 old_devices = clone_fs_devices(fs_devices);
1532 if (IS_ERR(old_devices)) {
1533 kfree(seed_devices);
1534 return PTR_ERR(old_devices);
1535 }
1536
1537 list_add(&old_devices->list, &fs_uuids);
1538
1539 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1540 seed_devices->opened = 1;
1541 INIT_LIST_HEAD(&seed_devices->devices);
1542 INIT_LIST_HEAD(&seed_devices->alloc_list);
1543 mutex_init(&seed_devices->device_list_mutex);
1544
1545 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1546 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1547 synchronize_rcu);
1548 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1549
1550 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1551 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1552 device->fs_devices = seed_devices;
1553 }
1554
1555 fs_devices->seeding = 0;
1556 fs_devices->num_devices = 0;
1557 fs_devices->open_devices = 0;
1558 fs_devices->total_devices = 0;
1559 fs_devices->seed = seed_devices;
1560
1561 generate_random_uuid(fs_devices->fsid);
1562 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1563 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1564 super_flags = btrfs_super_flags(disk_super) &
1565 ~BTRFS_SUPER_FLAG_SEEDING;
1566 btrfs_set_super_flags(disk_super, super_flags);
1567
1568 return 0;
1569 }
1570
1571 /*
1572 * strore the expected generation for seed devices in device items.
1573 */
1574 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1575 struct btrfs_root *root)
1576 {
1577 struct btrfs_path *path;
1578 struct extent_buffer *leaf;
1579 struct btrfs_dev_item *dev_item;
1580 struct btrfs_device *device;
1581 struct btrfs_key key;
1582 u8 fs_uuid[BTRFS_UUID_SIZE];
1583 u8 dev_uuid[BTRFS_UUID_SIZE];
1584 u64 devid;
1585 int ret;
1586
1587 path = btrfs_alloc_path();
1588 if (!path)
1589 return -ENOMEM;
1590
1591 root = root->fs_info->chunk_root;
1592 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1593 key.offset = 0;
1594 key.type = BTRFS_DEV_ITEM_KEY;
1595
1596 while (1) {
1597 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1598 if (ret < 0)
1599 goto error;
1600
1601 leaf = path->nodes[0];
1602 next_slot:
1603 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1604 ret = btrfs_next_leaf(root, path);
1605 if (ret > 0)
1606 break;
1607 if (ret < 0)
1608 goto error;
1609 leaf = path->nodes[0];
1610 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1611 btrfs_release_path(path);
1612 continue;
1613 }
1614
1615 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1616 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1617 key.type != BTRFS_DEV_ITEM_KEY)
1618 break;
1619
1620 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1621 struct btrfs_dev_item);
1622 devid = btrfs_device_id(leaf, dev_item);
1623 read_extent_buffer(leaf, dev_uuid,
1624 (unsigned long)btrfs_device_uuid(dev_item),
1625 BTRFS_UUID_SIZE);
1626 read_extent_buffer(leaf, fs_uuid,
1627 (unsigned long)btrfs_device_fsid(dev_item),
1628 BTRFS_UUID_SIZE);
1629 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1630 BUG_ON(!device); /* Logic error */
1631
1632 if (device->fs_devices->seeding) {
1633 btrfs_set_device_generation(leaf, dev_item,
1634 device->generation);
1635 btrfs_mark_buffer_dirty(leaf);
1636 }
1637
1638 path->slots[0]++;
1639 goto next_slot;
1640 }
1641 ret = 0;
1642 error:
1643 btrfs_free_path(path);
1644 return ret;
1645 }
1646
1647 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1648 {
1649 struct request_queue *q;
1650 struct btrfs_trans_handle *trans;
1651 struct btrfs_device *device;
1652 struct block_device *bdev;
1653 struct list_head *devices;
1654 struct super_block *sb = root->fs_info->sb;
1655 struct rcu_string *name;
1656 u64 total_bytes;
1657 int seeding_dev = 0;
1658 int ret = 0;
1659
1660 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1661 return -EROFS;
1662
1663 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1664 root->fs_info->bdev_holder);
1665 if (IS_ERR(bdev))
1666 return PTR_ERR(bdev);
1667
1668 if (root->fs_info->fs_devices->seeding) {
1669 seeding_dev = 1;
1670 down_write(&sb->s_umount);
1671 mutex_lock(&uuid_mutex);
1672 }
1673
1674 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1675
1676 devices = &root->fs_info->fs_devices->devices;
1677 /*
1678 * we have the volume lock, so we don't need the extra
1679 * device list mutex while reading the list here.
1680 */
1681 list_for_each_entry(device, devices, dev_list) {
1682 if (device->bdev == bdev) {
1683 ret = -EEXIST;
1684 goto error;
1685 }
1686 }
1687
1688 device = kzalloc(sizeof(*device), GFP_NOFS);
1689 if (!device) {
1690 /* we can safely leave the fs_devices entry around */
1691 ret = -ENOMEM;
1692 goto error;
1693 }
1694
1695 name = rcu_string_strdup(device_path, GFP_NOFS);
1696 if (!name) {
1697 kfree(device);
1698 ret = -ENOMEM;
1699 goto error;
1700 }
1701 rcu_assign_pointer(device->name, name);
1702
1703 ret = find_next_devid(root, &device->devid);
1704 if (ret) {
1705 rcu_string_free(device->name);
1706 kfree(device);
1707 goto error;
1708 }
1709
1710 trans = btrfs_start_transaction(root, 0);
1711 if (IS_ERR(trans)) {
1712 rcu_string_free(device->name);
1713 kfree(device);
1714 ret = PTR_ERR(trans);
1715 goto error;
1716 }
1717
1718 lock_chunks(root);
1719
1720 q = bdev_get_queue(bdev);
1721 if (blk_queue_discard(q))
1722 device->can_discard = 1;
1723 device->writeable = 1;
1724 device->work.func = pending_bios_fn;
1725 generate_random_uuid(device->uuid);
1726 spin_lock_init(&device->io_lock);
1727 device->generation = trans->transid;
1728 device->io_width = root->sectorsize;
1729 device->io_align = root->sectorsize;
1730 device->sector_size = root->sectorsize;
1731 device->total_bytes = i_size_read(bdev->bd_inode);
1732 device->disk_total_bytes = device->total_bytes;
1733 device->dev_root = root->fs_info->dev_root;
1734 device->bdev = bdev;
1735 device->in_fs_metadata = 1;
1736 device->mode = FMODE_EXCL;
1737 set_blocksize(device->bdev, 4096);
1738
1739 if (seeding_dev) {
1740 sb->s_flags &= ~MS_RDONLY;
1741 ret = btrfs_prepare_sprout(root);
1742 BUG_ON(ret); /* -ENOMEM */
1743 }
1744
1745 device->fs_devices = root->fs_info->fs_devices;
1746
1747 /*
1748 * we don't want write_supers to jump in here with our device
1749 * half setup
1750 */
1751 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1752 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1753 list_add(&device->dev_alloc_list,
1754 &root->fs_info->fs_devices->alloc_list);
1755 root->fs_info->fs_devices->num_devices++;
1756 root->fs_info->fs_devices->open_devices++;
1757 root->fs_info->fs_devices->rw_devices++;
1758 root->fs_info->fs_devices->total_devices++;
1759 if (device->can_discard)
1760 root->fs_info->fs_devices->num_can_discard++;
1761 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1762
1763 spin_lock(&root->fs_info->free_chunk_lock);
1764 root->fs_info->free_chunk_space += device->total_bytes;
1765 spin_unlock(&root->fs_info->free_chunk_lock);
1766
1767 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1768 root->fs_info->fs_devices->rotating = 1;
1769
1770 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1771 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1772 total_bytes + device->total_bytes);
1773
1774 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1775 btrfs_set_super_num_devices(root->fs_info->super_copy,
1776 total_bytes + 1);
1777 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1778
1779 if (seeding_dev) {
1780 ret = init_first_rw_device(trans, root, device);
1781 if (ret)
1782 goto error_trans;
1783 ret = btrfs_finish_sprout(trans, root);
1784 if (ret)
1785 goto error_trans;
1786 } else {
1787 ret = btrfs_add_device(trans, root, device);
1788 if (ret)
1789 goto error_trans;
1790 }
1791
1792 /*
1793 * we've got more storage, clear any full flags on the space
1794 * infos
1795 */
1796 btrfs_clear_space_info_full(root->fs_info);
1797
1798 unlock_chunks(root);
1799 ret = btrfs_commit_transaction(trans, root);
1800
1801 if (seeding_dev) {
1802 mutex_unlock(&uuid_mutex);
1803 up_write(&sb->s_umount);
1804
1805 if (ret) /* transaction commit */
1806 return ret;
1807
1808 ret = btrfs_relocate_sys_chunks(root);
1809 if (ret < 0)
1810 btrfs_error(root->fs_info, ret,
1811 "Failed to relocate sys chunks after "
1812 "device initialization. This can be fixed "
1813 "using the \"btrfs balance\" command.");
1814 }
1815
1816 return ret;
1817
1818 error_trans:
1819 unlock_chunks(root);
1820 btrfs_abort_transaction(trans, root, ret);
1821 btrfs_end_transaction(trans, root);
1822 rcu_string_free(device->name);
1823 kfree(device);
1824 error:
1825 blkdev_put(bdev, FMODE_EXCL);
1826 if (seeding_dev) {
1827 mutex_unlock(&uuid_mutex);
1828 up_write(&sb->s_umount);
1829 }
1830 return ret;
1831 }
1832
1833 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1834 struct btrfs_device *device)
1835 {
1836 int ret;
1837 struct btrfs_path *path;
1838 struct btrfs_root *root;
1839 struct btrfs_dev_item *dev_item;
1840 struct extent_buffer *leaf;
1841 struct btrfs_key key;
1842
1843 root = device->dev_root->fs_info->chunk_root;
1844
1845 path = btrfs_alloc_path();
1846 if (!path)
1847 return -ENOMEM;
1848
1849 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1850 key.type = BTRFS_DEV_ITEM_KEY;
1851 key.offset = device->devid;
1852
1853 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1854 if (ret < 0)
1855 goto out;
1856
1857 if (ret > 0) {
1858 ret = -ENOENT;
1859 goto out;
1860 }
1861
1862 leaf = path->nodes[0];
1863 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1864
1865 btrfs_set_device_id(leaf, dev_item, device->devid);
1866 btrfs_set_device_type(leaf, dev_item, device->type);
1867 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1868 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1869 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1870 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1871 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1872 btrfs_mark_buffer_dirty(leaf);
1873
1874 out:
1875 btrfs_free_path(path);
1876 return ret;
1877 }
1878
1879 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1880 struct btrfs_device *device, u64 new_size)
1881 {
1882 struct btrfs_super_block *super_copy =
1883 device->dev_root->fs_info->super_copy;
1884 u64 old_total = btrfs_super_total_bytes(super_copy);
1885 u64 diff = new_size - device->total_bytes;
1886
1887 if (!device->writeable)
1888 return -EACCES;
1889 if (new_size <= device->total_bytes)
1890 return -EINVAL;
1891
1892 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1893 device->fs_devices->total_rw_bytes += diff;
1894
1895 device->total_bytes = new_size;
1896 device->disk_total_bytes = new_size;
1897 btrfs_clear_space_info_full(device->dev_root->fs_info);
1898
1899 return btrfs_update_device(trans, device);
1900 }
1901
1902 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1903 struct btrfs_device *device, u64 new_size)
1904 {
1905 int ret;
1906 lock_chunks(device->dev_root);
1907 ret = __btrfs_grow_device(trans, device, new_size);
1908 unlock_chunks(device->dev_root);
1909 return ret;
1910 }
1911
1912 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1913 struct btrfs_root *root,
1914 u64 chunk_tree, u64 chunk_objectid,
1915 u64 chunk_offset)
1916 {
1917 int ret;
1918 struct btrfs_path *path;
1919 struct btrfs_key key;
1920
1921 root = root->fs_info->chunk_root;
1922 path = btrfs_alloc_path();
1923 if (!path)
1924 return -ENOMEM;
1925
1926 key.objectid = chunk_objectid;
1927 key.offset = chunk_offset;
1928 key.type = BTRFS_CHUNK_ITEM_KEY;
1929
1930 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1931 if (ret < 0)
1932 goto out;
1933 else if (ret > 0) { /* Logic error or corruption */
1934 btrfs_error(root->fs_info, -ENOENT,
1935 "Failed lookup while freeing chunk.");
1936 ret = -ENOENT;
1937 goto out;
1938 }
1939
1940 ret = btrfs_del_item(trans, root, path);
1941 if (ret < 0)
1942 btrfs_error(root->fs_info, ret,
1943 "Failed to delete chunk item.");
1944 out:
1945 btrfs_free_path(path);
1946 return ret;
1947 }
1948
1949 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1950 chunk_offset)
1951 {
1952 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1953 struct btrfs_disk_key *disk_key;
1954 struct btrfs_chunk *chunk;
1955 u8 *ptr;
1956 int ret = 0;
1957 u32 num_stripes;
1958 u32 array_size;
1959 u32 len = 0;
1960 u32 cur;
1961 struct btrfs_key key;
1962
1963 array_size = btrfs_super_sys_array_size(super_copy);
1964
1965 ptr = super_copy->sys_chunk_array;
1966 cur = 0;
1967
1968 while (cur < array_size) {
1969 disk_key = (struct btrfs_disk_key *)ptr;
1970 btrfs_disk_key_to_cpu(&key, disk_key);
1971
1972 len = sizeof(*disk_key);
1973
1974 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1975 chunk = (struct btrfs_chunk *)(ptr + len);
1976 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1977 len += btrfs_chunk_item_size(num_stripes);
1978 } else {
1979 ret = -EIO;
1980 break;
1981 }
1982 if (key.objectid == chunk_objectid &&
1983 key.offset == chunk_offset) {
1984 memmove(ptr, ptr + len, array_size - (cur + len));
1985 array_size -= len;
1986 btrfs_set_super_sys_array_size(super_copy, array_size);
1987 } else {
1988 ptr += len;
1989 cur += len;
1990 }
1991 }
1992 return ret;
1993 }
1994
1995 static int btrfs_relocate_chunk(struct btrfs_root *root,
1996 u64 chunk_tree, u64 chunk_objectid,
1997 u64 chunk_offset)
1998 {
1999 struct extent_map_tree *em_tree;
2000 struct btrfs_root *extent_root;
2001 struct btrfs_trans_handle *trans;
2002 struct extent_map *em;
2003 struct map_lookup *map;
2004 int ret;
2005 int i;
2006
2007 root = root->fs_info->chunk_root;
2008 extent_root = root->fs_info->extent_root;
2009 em_tree = &root->fs_info->mapping_tree.map_tree;
2010
2011 ret = btrfs_can_relocate(extent_root, chunk_offset);
2012 if (ret)
2013 return -ENOSPC;
2014
2015 /* step one, relocate all the extents inside this chunk */
2016 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2017 if (ret)
2018 return ret;
2019
2020 trans = btrfs_start_transaction(root, 0);
2021 BUG_ON(IS_ERR(trans));
2022
2023 lock_chunks(root);
2024
2025 /*
2026 * step two, delete the device extents and the
2027 * chunk tree entries
2028 */
2029 read_lock(&em_tree->lock);
2030 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2031 read_unlock(&em_tree->lock);
2032
2033 BUG_ON(!em || em->start > chunk_offset ||
2034 em->start + em->len < chunk_offset);
2035 map = (struct map_lookup *)em->bdev;
2036
2037 for (i = 0; i < map->num_stripes; i++) {
2038 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2039 map->stripes[i].physical);
2040 BUG_ON(ret);
2041
2042 if (map->stripes[i].dev) {
2043 ret = btrfs_update_device(trans, map->stripes[i].dev);
2044 BUG_ON(ret);
2045 }
2046 }
2047 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2048 chunk_offset);
2049
2050 BUG_ON(ret);
2051
2052 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2053
2054 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2055 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2056 BUG_ON(ret);
2057 }
2058
2059 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2060 BUG_ON(ret);
2061
2062 write_lock(&em_tree->lock);
2063 remove_extent_mapping(em_tree, em);
2064 write_unlock(&em_tree->lock);
2065
2066 kfree(map);
2067 em->bdev = NULL;
2068
2069 /* once for the tree */
2070 free_extent_map(em);
2071 /* once for us */
2072 free_extent_map(em);
2073
2074 unlock_chunks(root);
2075 btrfs_end_transaction(trans, root);
2076 return 0;
2077 }
2078
2079 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2080 {
2081 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2082 struct btrfs_path *path;
2083 struct extent_buffer *leaf;
2084 struct btrfs_chunk *chunk;
2085 struct btrfs_key key;
2086 struct btrfs_key found_key;
2087 u64 chunk_tree = chunk_root->root_key.objectid;
2088 u64 chunk_type;
2089 bool retried = false;
2090 int failed = 0;
2091 int ret;
2092
2093 path = btrfs_alloc_path();
2094 if (!path)
2095 return -ENOMEM;
2096
2097 again:
2098 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2099 key.offset = (u64)-1;
2100 key.type = BTRFS_CHUNK_ITEM_KEY;
2101
2102 while (1) {
2103 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2104 if (ret < 0)
2105 goto error;
2106 BUG_ON(ret == 0); /* Corruption */
2107
2108 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2109 key.type);
2110 if (ret < 0)
2111 goto error;
2112 if (ret > 0)
2113 break;
2114
2115 leaf = path->nodes[0];
2116 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2117
2118 chunk = btrfs_item_ptr(leaf, path->slots[0],
2119 struct btrfs_chunk);
2120 chunk_type = btrfs_chunk_type(leaf, chunk);
2121 btrfs_release_path(path);
2122
2123 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2124 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2125 found_key.objectid,
2126 found_key.offset);
2127 if (ret == -ENOSPC)
2128 failed++;
2129 else if (ret)
2130 BUG();
2131 }
2132
2133 if (found_key.offset == 0)
2134 break;
2135 key.offset = found_key.offset - 1;
2136 }
2137 ret = 0;
2138 if (failed && !retried) {
2139 failed = 0;
2140 retried = true;
2141 goto again;
2142 } else if (failed && retried) {
2143 WARN_ON(1);
2144 ret = -ENOSPC;
2145 }
2146 error:
2147 btrfs_free_path(path);
2148 return ret;
2149 }
2150
2151 static int insert_balance_item(struct btrfs_root *root,
2152 struct btrfs_balance_control *bctl)
2153 {
2154 struct btrfs_trans_handle *trans;
2155 struct btrfs_balance_item *item;
2156 struct btrfs_disk_balance_args disk_bargs;
2157 struct btrfs_path *path;
2158 struct extent_buffer *leaf;
2159 struct btrfs_key key;
2160 int ret, err;
2161
2162 path = btrfs_alloc_path();
2163 if (!path)
2164 return -ENOMEM;
2165
2166 trans = btrfs_start_transaction(root, 0);
2167 if (IS_ERR(trans)) {
2168 btrfs_free_path(path);
2169 return PTR_ERR(trans);
2170 }
2171
2172 key.objectid = BTRFS_BALANCE_OBJECTID;
2173 key.type = BTRFS_BALANCE_ITEM_KEY;
2174 key.offset = 0;
2175
2176 ret = btrfs_insert_empty_item(trans, root, path, &key,
2177 sizeof(*item));
2178 if (ret)
2179 goto out;
2180
2181 leaf = path->nodes[0];
2182 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2183
2184 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2185
2186 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2187 btrfs_set_balance_data(leaf, item, &disk_bargs);
2188 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2189 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2190 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2191 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2192
2193 btrfs_set_balance_flags(leaf, item, bctl->flags);
2194
2195 btrfs_mark_buffer_dirty(leaf);
2196 out:
2197 btrfs_free_path(path);
2198 err = btrfs_commit_transaction(trans, root);
2199 if (err && !ret)
2200 ret = err;
2201 return ret;
2202 }
2203
2204 static int del_balance_item(struct btrfs_root *root)
2205 {
2206 struct btrfs_trans_handle *trans;
2207 struct btrfs_path *path;
2208 struct btrfs_key key;
2209 int ret, err;
2210
2211 path = btrfs_alloc_path();
2212 if (!path)
2213 return -ENOMEM;
2214
2215 trans = btrfs_start_transaction(root, 0);
2216 if (IS_ERR(trans)) {
2217 btrfs_free_path(path);
2218 return PTR_ERR(trans);
2219 }
2220
2221 key.objectid = BTRFS_BALANCE_OBJECTID;
2222 key.type = BTRFS_BALANCE_ITEM_KEY;
2223 key.offset = 0;
2224
2225 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2226 if (ret < 0)
2227 goto out;
2228 if (ret > 0) {
2229 ret = -ENOENT;
2230 goto out;
2231 }
2232
2233 ret = btrfs_del_item(trans, root, path);
2234 out:
2235 btrfs_free_path(path);
2236 err = btrfs_commit_transaction(trans, root);
2237 if (err && !ret)
2238 ret = err;
2239 return ret;
2240 }
2241
2242 /*
2243 * This is a heuristic used to reduce the number of chunks balanced on
2244 * resume after balance was interrupted.
2245 */
2246 static void update_balance_args(struct btrfs_balance_control *bctl)
2247 {
2248 /*
2249 * Turn on soft mode for chunk types that were being converted.
2250 */
2251 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2252 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2253 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2254 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2255 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2256 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2257
2258 /*
2259 * Turn on usage filter if is not already used. The idea is
2260 * that chunks that we have already balanced should be
2261 * reasonably full. Don't do it for chunks that are being
2262 * converted - that will keep us from relocating unconverted
2263 * (albeit full) chunks.
2264 */
2265 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2266 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2267 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2268 bctl->data.usage = 90;
2269 }
2270 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2271 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2272 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2273 bctl->sys.usage = 90;
2274 }
2275 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2276 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2277 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2278 bctl->meta.usage = 90;
2279 }
2280 }
2281
2282 /*
2283 * Should be called with both balance and volume mutexes held to
2284 * serialize other volume operations (add_dev/rm_dev/resize) with
2285 * restriper. Same goes for unset_balance_control.
2286 */
2287 static void set_balance_control(struct btrfs_balance_control *bctl)
2288 {
2289 struct btrfs_fs_info *fs_info = bctl->fs_info;
2290
2291 BUG_ON(fs_info->balance_ctl);
2292
2293 spin_lock(&fs_info->balance_lock);
2294 fs_info->balance_ctl = bctl;
2295 spin_unlock(&fs_info->balance_lock);
2296 }
2297
2298 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2299 {
2300 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2301
2302 BUG_ON(!fs_info->balance_ctl);
2303
2304 spin_lock(&fs_info->balance_lock);
2305 fs_info->balance_ctl = NULL;
2306 spin_unlock(&fs_info->balance_lock);
2307
2308 kfree(bctl);
2309 }
2310
2311 /*
2312 * Balance filters. Return 1 if chunk should be filtered out
2313 * (should not be balanced).
2314 */
2315 static int chunk_profiles_filter(u64 chunk_type,
2316 struct btrfs_balance_args *bargs)
2317 {
2318 chunk_type = chunk_to_extended(chunk_type) &
2319 BTRFS_EXTENDED_PROFILE_MASK;
2320
2321 if (bargs->profiles & chunk_type)
2322 return 0;
2323
2324 return 1;
2325 }
2326
2327 static u64 div_factor_fine(u64 num, int factor)
2328 {
2329 if (factor <= 0)
2330 return 0;
2331 if (factor >= 100)
2332 return num;
2333
2334 num *= factor;
2335 do_div(num, 100);
2336 return num;
2337 }
2338
2339 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2340 struct btrfs_balance_args *bargs)
2341 {
2342 struct btrfs_block_group_cache *cache;
2343 u64 chunk_used, user_thresh;
2344 int ret = 1;
2345
2346 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2347 chunk_used = btrfs_block_group_used(&cache->item);
2348
2349 user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
2350 if (chunk_used < user_thresh)
2351 ret = 0;
2352
2353 btrfs_put_block_group(cache);
2354 return ret;
2355 }
2356
2357 static int chunk_devid_filter(struct extent_buffer *leaf,
2358 struct btrfs_chunk *chunk,
2359 struct btrfs_balance_args *bargs)
2360 {
2361 struct btrfs_stripe *stripe;
2362 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2363 int i;
2364
2365 for (i = 0; i < num_stripes; i++) {
2366 stripe = btrfs_stripe_nr(chunk, i);
2367 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2368 return 0;
2369 }
2370
2371 return 1;
2372 }
2373
2374 /* [pstart, pend) */
2375 static int chunk_drange_filter(struct extent_buffer *leaf,
2376 struct btrfs_chunk *chunk,
2377 u64 chunk_offset,
2378 struct btrfs_balance_args *bargs)
2379 {
2380 struct btrfs_stripe *stripe;
2381 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2382 u64 stripe_offset;
2383 u64 stripe_length;
2384 int factor;
2385 int i;
2386
2387 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2388 return 0;
2389
2390 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2391 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2392 factor = 2;
2393 else
2394 factor = 1;
2395 factor = num_stripes / factor;
2396
2397 for (i = 0; i < num_stripes; i++) {
2398 stripe = btrfs_stripe_nr(chunk, i);
2399 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2400 continue;
2401
2402 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2403 stripe_length = btrfs_chunk_length(leaf, chunk);
2404 do_div(stripe_length, factor);
2405
2406 if (stripe_offset < bargs->pend &&
2407 stripe_offset + stripe_length > bargs->pstart)
2408 return 0;
2409 }
2410
2411 return 1;
2412 }
2413
2414 /* [vstart, vend) */
2415 static int chunk_vrange_filter(struct extent_buffer *leaf,
2416 struct btrfs_chunk *chunk,
2417 u64 chunk_offset,
2418 struct btrfs_balance_args *bargs)
2419 {
2420 if (chunk_offset < bargs->vend &&
2421 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2422 /* at least part of the chunk is inside this vrange */
2423 return 0;
2424
2425 return 1;
2426 }
2427
2428 static int chunk_soft_convert_filter(u64 chunk_type,
2429 struct btrfs_balance_args *bargs)
2430 {
2431 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2432 return 0;
2433
2434 chunk_type = chunk_to_extended(chunk_type) &
2435 BTRFS_EXTENDED_PROFILE_MASK;
2436
2437 if (bargs->target == chunk_type)
2438 return 1;
2439
2440 return 0;
2441 }
2442
2443 static int should_balance_chunk(struct btrfs_root *root,
2444 struct extent_buffer *leaf,
2445 struct btrfs_chunk *chunk, u64 chunk_offset)
2446 {
2447 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2448 struct btrfs_balance_args *bargs = NULL;
2449 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2450
2451 /* type filter */
2452 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2453 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2454 return 0;
2455 }
2456
2457 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2458 bargs = &bctl->data;
2459 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2460 bargs = &bctl->sys;
2461 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2462 bargs = &bctl->meta;
2463
2464 /* profiles filter */
2465 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2466 chunk_profiles_filter(chunk_type, bargs)) {
2467 return 0;
2468 }
2469
2470 /* usage filter */
2471 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2472 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2473 return 0;
2474 }
2475
2476 /* devid filter */
2477 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2478 chunk_devid_filter(leaf, chunk, bargs)) {
2479 return 0;
2480 }
2481
2482 /* drange filter, makes sense only with devid filter */
2483 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2484 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2485 return 0;
2486 }
2487
2488 /* vrange filter */
2489 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2490 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2491 return 0;
2492 }
2493
2494 /* soft profile changing mode */
2495 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2496 chunk_soft_convert_filter(chunk_type, bargs)) {
2497 return 0;
2498 }
2499
2500 return 1;
2501 }
2502
2503 static u64 div_factor(u64 num, int factor)
2504 {
2505 if (factor == 10)
2506 return num;
2507 num *= factor;
2508 do_div(num, 10);
2509 return num;
2510 }
2511
2512 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2513 {
2514 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2515 struct btrfs_root *chunk_root = fs_info->chunk_root;
2516 struct btrfs_root *dev_root = fs_info->dev_root;
2517 struct list_head *devices;
2518 struct btrfs_device *device;
2519 u64 old_size;
2520 u64 size_to_free;
2521 struct btrfs_chunk *chunk;
2522 struct btrfs_path *path;
2523 struct btrfs_key key;
2524 struct btrfs_key found_key;
2525 struct btrfs_trans_handle *trans;
2526 struct extent_buffer *leaf;
2527 int slot;
2528 int ret;
2529 int enospc_errors = 0;
2530 bool counting = true;
2531
2532 /* step one make some room on all the devices */
2533 devices = &fs_info->fs_devices->devices;
2534 list_for_each_entry(device, devices, dev_list) {
2535 old_size = device->total_bytes;
2536 size_to_free = div_factor(old_size, 1);
2537 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2538 if (!device->writeable ||
2539 device->total_bytes - device->bytes_used > size_to_free)
2540 continue;
2541
2542 ret = btrfs_shrink_device(device, old_size - size_to_free);
2543 if (ret == -ENOSPC)
2544 break;
2545 BUG_ON(ret);
2546
2547 trans = btrfs_start_transaction(dev_root, 0);
2548 BUG_ON(IS_ERR(trans));
2549
2550 ret = btrfs_grow_device(trans, device, old_size);
2551 BUG_ON(ret);
2552
2553 btrfs_end_transaction(trans, dev_root);
2554 }
2555
2556 /* step two, relocate all the chunks */
2557 path = btrfs_alloc_path();
2558 if (!path) {
2559 ret = -ENOMEM;
2560 goto error;
2561 }
2562
2563 /* zero out stat counters */
2564 spin_lock(&fs_info->balance_lock);
2565 memset(&bctl->stat, 0, sizeof(bctl->stat));
2566 spin_unlock(&fs_info->balance_lock);
2567 again:
2568 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2569 key.offset = (u64)-1;
2570 key.type = BTRFS_CHUNK_ITEM_KEY;
2571
2572 while (1) {
2573 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2574 atomic_read(&fs_info->balance_cancel_req)) {
2575 ret = -ECANCELED;
2576 goto error;
2577 }
2578
2579 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2580 if (ret < 0)
2581 goto error;
2582
2583 /*
2584 * this shouldn't happen, it means the last relocate
2585 * failed
2586 */
2587 if (ret == 0)
2588 BUG(); /* FIXME break ? */
2589
2590 ret = btrfs_previous_item(chunk_root, path, 0,
2591 BTRFS_CHUNK_ITEM_KEY);
2592 if (ret) {
2593 ret = 0;
2594 break;
2595 }
2596
2597 leaf = path->nodes[0];
2598 slot = path->slots[0];
2599 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2600
2601 if (found_key.objectid != key.objectid)
2602 break;
2603
2604 /* chunk zero is special */
2605 if (found_key.offset == 0)
2606 break;
2607
2608 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2609
2610 if (!counting) {
2611 spin_lock(&fs_info->balance_lock);
2612 bctl->stat.considered++;
2613 spin_unlock(&fs_info->balance_lock);
2614 }
2615
2616 ret = should_balance_chunk(chunk_root, leaf, chunk,
2617 found_key.offset);
2618 btrfs_release_path(path);
2619 if (!ret)
2620 goto loop;
2621
2622 if (counting) {
2623 spin_lock(&fs_info->balance_lock);
2624 bctl->stat.expected++;
2625 spin_unlock(&fs_info->balance_lock);
2626 goto loop;
2627 }
2628
2629 ret = btrfs_relocate_chunk(chunk_root,
2630 chunk_root->root_key.objectid,
2631 found_key.objectid,
2632 found_key.offset);
2633 if (ret && ret != -ENOSPC)
2634 goto error;
2635 if (ret == -ENOSPC) {
2636 enospc_errors++;
2637 } else {
2638 spin_lock(&fs_info->balance_lock);
2639 bctl->stat.completed++;
2640 spin_unlock(&fs_info->balance_lock);
2641 }
2642 loop:
2643 key.offset = found_key.offset - 1;
2644 }
2645
2646 if (counting) {
2647 btrfs_release_path(path);
2648 counting = false;
2649 goto again;
2650 }
2651 error:
2652 btrfs_free_path(path);
2653 if (enospc_errors) {
2654 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2655 enospc_errors);
2656 if (!ret)
2657 ret = -ENOSPC;
2658 }
2659
2660 return ret;
2661 }
2662
2663 /**
2664 * alloc_profile_is_valid - see if a given profile is valid and reduced
2665 * @flags: profile to validate
2666 * @extended: if true @flags is treated as an extended profile
2667 */
2668 static int alloc_profile_is_valid(u64 flags, int extended)
2669 {
2670 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
2671 BTRFS_BLOCK_GROUP_PROFILE_MASK);
2672
2673 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
2674
2675 /* 1) check that all other bits are zeroed */
2676 if (flags & ~mask)
2677 return 0;
2678
2679 /* 2) see if profile is reduced */
2680 if (flags == 0)
2681 return !extended; /* "0" is valid for usual profiles */
2682
2683 /* true if exactly one bit set */
2684 return (flags & (flags - 1)) == 0;
2685 }
2686
2687 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2688 {
2689 /* cancel requested || normal exit path */
2690 return atomic_read(&fs_info->balance_cancel_req) ||
2691 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2692 atomic_read(&fs_info->balance_cancel_req) == 0);
2693 }
2694
2695 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2696 {
2697 int ret;
2698
2699 unset_balance_control(fs_info);
2700 ret = del_balance_item(fs_info->tree_root);
2701 BUG_ON(ret);
2702 }
2703
2704 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2705 struct btrfs_ioctl_balance_args *bargs);
2706
2707 /*
2708 * Should be called with both balance and volume mutexes held
2709 */
2710 int btrfs_balance(struct btrfs_balance_control *bctl,
2711 struct btrfs_ioctl_balance_args *bargs)
2712 {
2713 struct btrfs_fs_info *fs_info = bctl->fs_info;
2714 u64 allowed;
2715 int mixed = 0;
2716 int ret;
2717
2718 if (btrfs_fs_closing(fs_info) ||
2719 atomic_read(&fs_info->balance_pause_req) ||
2720 atomic_read(&fs_info->balance_cancel_req)) {
2721 ret = -EINVAL;
2722 goto out;
2723 }
2724
2725 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2726 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
2727 mixed = 1;
2728
2729 /*
2730 * In case of mixed groups both data and meta should be picked,
2731 * and identical options should be given for both of them.
2732 */
2733 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
2734 if (mixed && (bctl->flags & allowed)) {
2735 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
2736 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
2737 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
2738 printk(KERN_ERR "btrfs: with mixed groups data and "
2739 "metadata balance options must be the same\n");
2740 ret = -EINVAL;
2741 goto out;
2742 }
2743 }
2744
2745 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2746 if (fs_info->fs_devices->num_devices == 1)
2747 allowed |= BTRFS_BLOCK_GROUP_DUP;
2748 else if (fs_info->fs_devices->num_devices < 4)
2749 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
2750 else
2751 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2752 BTRFS_BLOCK_GROUP_RAID10);
2753
2754 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2755 (!alloc_profile_is_valid(bctl->data.target, 1) ||
2756 (bctl->data.target & ~allowed))) {
2757 printk(KERN_ERR "btrfs: unable to start balance with target "
2758 "data profile %llu\n",
2759 (unsigned long long)bctl->data.target);
2760 ret = -EINVAL;
2761 goto out;
2762 }
2763 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2764 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
2765 (bctl->meta.target & ~allowed))) {
2766 printk(KERN_ERR "btrfs: unable to start balance with target "
2767 "metadata profile %llu\n",
2768 (unsigned long long)bctl->meta.target);
2769 ret = -EINVAL;
2770 goto out;
2771 }
2772 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2773 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
2774 (bctl->sys.target & ~allowed))) {
2775 printk(KERN_ERR "btrfs: unable to start balance with target "
2776 "system profile %llu\n",
2777 (unsigned long long)bctl->sys.target);
2778 ret = -EINVAL;
2779 goto out;
2780 }
2781
2782 /* allow dup'ed data chunks only in mixed mode */
2783 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2784 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
2785 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
2786 ret = -EINVAL;
2787 goto out;
2788 }
2789
2790 /* allow to reduce meta or sys integrity only if force set */
2791 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
2792 BTRFS_BLOCK_GROUP_RAID10;
2793 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2794 (fs_info->avail_system_alloc_bits & allowed) &&
2795 !(bctl->sys.target & allowed)) ||
2796 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2797 (fs_info->avail_metadata_alloc_bits & allowed) &&
2798 !(bctl->meta.target & allowed))) {
2799 if (bctl->flags & BTRFS_BALANCE_FORCE) {
2800 printk(KERN_INFO "btrfs: force reducing metadata "
2801 "integrity\n");
2802 } else {
2803 printk(KERN_ERR "btrfs: balance will reduce metadata "
2804 "integrity, use force if you want this\n");
2805 ret = -EINVAL;
2806 goto out;
2807 }
2808 }
2809
2810 ret = insert_balance_item(fs_info->tree_root, bctl);
2811 if (ret && ret != -EEXIST)
2812 goto out;
2813
2814 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
2815 BUG_ON(ret == -EEXIST);
2816 set_balance_control(bctl);
2817 } else {
2818 BUG_ON(ret != -EEXIST);
2819 spin_lock(&fs_info->balance_lock);
2820 update_balance_args(bctl);
2821 spin_unlock(&fs_info->balance_lock);
2822 }
2823
2824 atomic_inc(&fs_info->balance_running);
2825 mutex_unlock(&fs_info->balance_mutex);
2826
2827 ret = __btrfs_balance(fs_info);
2828
2829 mutex_lock(&fs_info->balance_mutex);
2830 atomic_dec(&fs_info->balance_running);
2831
2832 if (bargs) {
2833 memset(bargs, 0, sizeof(*bargs));
2834 update_ioctl_balance_args(fs_info, 0, bargs);
2835 }
2836
2837 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
2838 balance_need_close(fs_info)) {
2839 __cancel_balance(fs_info);
2840 }
2841
2842 wake_up(&fs_info->balance_wait_q);
2843
2844 return ret;
2845 out:
2846 if (bctl->flags & BTRFS_BALANCE_RESUME)
2847 __cancel_balance(fs_info);
2848 else
2849 kfree(bctl);
2850 return ret;
2851 }
2852
2853 static int balance_kthread(void *data)
2854 {
2855 struct btrfs_fs_info *fs_info = data;
2856 int ret = 0;
2857
2858 mutex_lock(&fs_info->volume_mutex);
2859 mutex_lock(&fs_info->balance_mutex);
2860
2861 if (fs_info->balance_ctl) {
2862 printk(KERN_INFO "btrfs: continuing balance\n");
2863 ret = btrfs_balance(fs_info->balance_ctl, NULL);
2864 }
2865
2866 mutex_unlock(&fs_info->balance_mutex);
2867 mutex_unlock(&fs_info->volume_mutex);
2868
2869 return ret;
2870 }
2871
2872 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
2873 {
2874 struct task_struct *tsk;
2875
2876 spin_lock(&fs_info->balance_lock);
2877 if (!fs_info->balance_ctl) {
2878 spin_unlock(&fs_info->balance_lock);
2879 return 0;
2880 }
2881 spin_unlock(&fs_info->balance_lock);
2882
2883 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
2884 printk(KERN_INFO "btrfs: force skipping balance\n");
2885 return 0;
2886 }
2887
2888 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
2889 if (IS_ERR(tsk))
2890 return PTR_ERR(tsk);
2891
2892 return 0;
2893 }
2894
2895 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
2896 {
2897 struct btrfs_balance_control *bctl;
2898 struct btrfs_balance_item *item;
2899 struct btrfs_disk_balance_args disk_bargs;
2900 struct btrfs_path *path;
2901 struct extent_buffer *leaf;
2902 struct btrfs_key key;
2903 int ret;
2904
2905 path = btrfs_alloc_path();
2906 if (!path)
2907 return -ENOMEM;
2908
2909 key.objectid = BTRFS_BALANCE_OBJECTID;
2910 key.type = BTRFS_BALANCE_ITEM_KEY;
2911 key.offset = 0;
2912
2913 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2914 if (ret < 0)
2915 goto out;
2916 if (ret > 0) { /* ret = -ENOENT; */
2917 ret = 0;
2918 goto out;
2919 }
2920
2921 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
2922 if (!bctl) {
2923 ret = -ENOMEM;
2924 goto out;
2925 }
2926
2927 leaf = path->nodes[0];
2928 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2929
2930 bctl->fs_info = fs_info;
2931 bctl->flags = btrfs_balance_flags(leaf, item);
2932 bctl->flags |= BTRFS_BALANCE_RESUME;
2933
2934 btrfs_balance_data(leaf, item, &disk_bargs);
2935 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
2936 btrfs_balance_meta(leaf, item, &disk_bargs);
2937 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
2938 btrfs_balance_sys(leaf, item, &disk_bargs);
2939 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
2940
2941 mutex_lock(&fs_info->volume_mutex);
2942 mutex_lock(&fs_info->balance_mutex);
2943
2944 set_balance_control(bctl);
2945
2946 mutex_unlock(&fs_info->balance_mutex);
2947 mutex_unlock(&fs_info->volume_mutex);
2948 out:
2949 btrfs_free_path(path);
2950 return ret;
2951 }
2952
2953 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
2954 {
2955 int ret = 0;
2956
2957 mutex_lock(&fs_info->balance_mutex);
2958 if (!fs_info->balance_ctl) {
2959 mutex_unlock(&fs_info->balance_mutex);
2960 return -ENOTCONN;
2961 }
2962
2963 if (atomic_read(&fs_info->balance_running)) {
2964 atomic_inc(&fs_info->balance_pause_req);
2965 mutex_unlock(&fs_info->balance_mutex);
2966
2967 wait_event(fs_info->balance_wait_q,
2968 atomic_read(&fs_info->balance_running) == 0);
2969
2970 mutex_lock(&fs_info->balance_mutex);
2971 /* we are good with balance_ctl ripped off from under us */
2972 BUG_ON(atomic_read(&fs_info->balance_running));
2973 atomic_dec(&fs_info->balance_pause_req);
2974 } else {
2975 ret = -ENOTCONN;
2976 }
2977
2978 mutex_unlock(&fs_info->balance_mutex);
2979 return ret;
2980 }
2981
2982 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
2983 {
2984 mutex_lock(&fs_info->balance_mutex);
2985 if (!fs_info->balance_ctl) {
2986 mutex_unlock(&fs_info->balance_mutex);
2987 return -ENOTCONN;
2988 }
2989
2990 atomic_inc(&fs_info->balance_cancel_req);
2991 /*
2992 * if we are running just wait and return, balance item is
2993 * deleted in btrfs_balance in this case
2994 */
2995 if (atomic_read(&fs_info->balance_running)) {
2996 mutex_unlock(&fs_info->balance_mutex);
2997 wait_event(fs_info->balance_wait_q,
2998 atomic_read(&fs_info->balance_running) == 0);
2999 mutex_lock(&fs_info->balance_mutex);
3000 } else {
3001 /* __cancel_balance needs volume_mutex */
3002 mutex_unlock(&fs_info->balance_mutex);
3003 mutex_lock(&fs_info->volume_mutex);
3004 mutex_lock(&fs_info->balance_mutex);
3005
3006 if (fs_info->balance_ctl)
3007 __cancel_balance(fs_info);
3008
3009 mutex_unlock(&fs_info->volume_mutex);
3010 }
3011
3012 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3013 atomic_dec(&fs_info->balance_cancel_req);
3014 mutex_unlock(&fs_info->balance_mutex);
3015 return 0;
3016 }
3017
3018 /*
3019 * shrinking a device means finding all of the device extents past
3020 * the new size, and then following the back refs to the chunks.
3021 * The chunk relocation code actually frees the device extent
3022 */
3023 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3024 {
3025 struct btrfs_trans_handle *trans;
3026 struct btrfs_root *root = device->dev_root;
3027 struct btrfs_dev_extent *dev_extent = NULL;
3028 struct btrfs_path *path;
3029 u64 length;
3030 u64 chunk_tree;
3031 u64 chunk_objectid;
3032 u64 chunk_offset;
3033 int ret;
3034 int slot;
3035 int failed = 0;
3036 bool retried = false;
3037 struct extent_buffer *l;
3038 struct btrfs_key key;
3039 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3040 u64 old_total = btrfs_super_total_bytes(super_copy);
3041 u64 old_size = device->total_bytes;
3042 u64 diff = device->total_bytes - new_size;
3043
3044 if (new_size >= device->total_bytes)
3045 return -EINVAL;
3046
3047 path = btrfs_alloc_path();
3048 if (!path)
3049 return -ENOMEM;
3050
3051 path->reada = 2;
3052
3053 lock_chunks(root);
3054
3055 device->total_bytes = new_size;
3056 if (device->writeable) {
3057 device->fs_devices->total_rw_bytes -= diff;
3058 spin_lock(&root->fs_info->free_chunk_lock);
3059 root->fs_info->free_chunk_space -= diff;
3060 spin_unlock(&root->fs_info->free_chunk_lock);
3061 }
3062 unlock_chunks(root);
3063
3064 again:
3065 key.objectid = device->devid;
3066 key.offset = (u64)-1;
3067 key.type = BTRFS_DEV_EXTENT_KEY;
3068
3069 do {
3070 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3071 if (ret < 0)
3072 goto done;
3073
3074 ret = btrfs_previous_item(root, path, 0, key.type);
3075 if (ret < 0)
3076 goto done;
3077 if (ret) {
3078 ret = 0;
3079 btrfs_release_path(path);
3080 break;
3081 }
3082
3083 l = path->nodes[0];
3084 slot = path->slots[0];
3085 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3086
3087 if (key.objectid != device->devid) {
3088 btrfs_release_path(path);
3089 break;
3090 }
3091
3092 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3093 length = btrfs_dev_extent_length(l, dev_extent);
3094
3095 if (key.offset + length <= new_size) {
3096 btrfs_release_path(path);
3097 break;
3098 }
3099
3100 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3101 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3102 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3103 btrfs_release_path(path);
3104
3105 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3106 chunk_offset);
3107 if (ret && ret != -ENOSPC)
3108 goto done;
3109 if (ret == -ENOSPC)
3110 failed++;
3111 } while (key.offset-- > 0);
3112
3113 if (failed && !retried) {
3114 failed = 0;
3115 retried = true;
3116 goto again;
3117 } else if (failed && retried) {
3118 ret = -ENOSPC;
3119 lock_chunks(root);
3120
3121 device->total_bytes = old_size;
3122 if (device->writeable)
3123 device->fs_devices->total_rw_bytes += diff;
3124 spin_lock(&root->fs_info->free_chunk_lock);
3125 root->fs_info->free_chunk_space += diff;
3126 spin_unlock(&root->fs_info->free_chunk_lock);
3127 unlock_chunks(root);
3128 goto done;
3129 }
3130
3131 /* Shrinking succeeded, else we would be at "done". */
3132 trans = btrfs_start_transaction(root, 0);
3133 if (IS_ERR(trans)) {
3134 ret = PTR_ERR(trans);
3135 goto done;
3136 }
3137
3138 lock_chunks(root);
3139
3140 device->disk_total_bytes = new_size;
3141 /* Now btrfs_update_device() will change the on-disk size. */
3142 ret = btrfs_update_device(trans, device);
3143 if (ret) {
3144 unlock_chunks(root);
3145 btrfs_end_transaction(trans, root);
3146 goto done;
3147 }
3148 WARN_ON(diff > old_total);
3149 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3150 unlock_chunks(root);
3151 btrfs_end_transaction(trans, root);
3152 done:
3153 btrfs_free_path(path);
3154 return ret;
3155 }
3156
3157 static int btrfs_add_system_chunk(struct btrfs_root *root,
3158 struct btrfs_key *key,
3159 struct btrfs_chunk *chunk, int item_size)
3160 {
3161 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3162 struct btrfs_disk_key disk_key;
3163 u32 array_size;
3164 u8 *ptr;
3165
3166 array_size = btrfs_super_sys_array_size(super_copy);
3167 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3168 return -EFBIG;
3169
3170 ptr = super_copy->sys_chunk_array + array_size;
3171 btrfs_cpu_key_to_disk(&disk_key, key);
3172 memcpy(ptr, &disk_key, sizeof(disk_key));
3173 ptr += sizeof(disk_key);
3174 memcpy(ptr, chunk, item_size);
3175 item_size += sizeof(disk_key);
3176 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3177 return 0;
3178 }
3179
3180 /*
3181 * sort the devices in descending order by max_avail, total_avail
3182 */
3183 static int btrfs_cmp_device_info(const void *a, const void *b)
3184 {
3185 const struct btrfs_device_info *di_a = a;
3186 const struct btrfs_device_info *di_b = b;
3187
3188 if (di_a->max_avail > di_b->max_avail)
3189 return -1;
3190 if (di_a->max_avail < di_b->max_avail)
3191 return 1;
3192 if (di_a->total_avail > di_b->total_avail)
3193 return -1;
3194 if (di_a->total_avail < di_b->total_avail)
3195 return 1;
3196 return 0;
3197 }
3198
3199 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3200 struct btrfs_root *extent_root,
3201 struct map_lookup **map_ret,
3202 u64 *num_bytes_out, u64 *stripe_size_out,
3203 u64 start, u64 type)
3204 {
3205 struct btrfs_fs_info *info = extent_root->fs_info;
3206 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3207 struct list_head *cur;
3208 struct map_lookup *map = NULL;
3209 struct extent_map_tree *em_tree;
3210 struct extent_map *em;
3211 struct btrfs_device_info *devices_info = NULL;
3212 u64 total_avail;
3213 int num_stripes; /* total number of stripes to allocate */
3214 int sub_stripes; /* sub_stripes info for map */
3215 int dev_stripes; /* stripes per dev */
3216 int devs_max; /* max devs to use */
3217 int devs_min; /* min devs needed */
3218 int devs_increment; /* ndevs has to be a multiple of this */
3219 int ncopies; /* how many copies to data has */
3220 int ret;
3221 u64 max_stripe_size;
3222 u64 max_chunk_size;
3223 u64 stripe_size;
3224 u64 num_bytes;
3225 int ndevs;
3226 int i;
3227 int j;
3228
3229 BUG_ON(!alloc_profile_is_valid(type, 0));
3230
3231 if (list_empty(&fs_devices->alloc_list))
3232 return -ENOSPC;
3233
3234 sub_stripes = 1;
3235 dev_stripes = 1;
3236 devs_increment = 1;
3237 ncopies = 1;
3238 devs_max = 0; /* 0 == as many as possible */
3239 devs_min = 1;
3240
3241 /*
3242 * define the properties of each RAID type.
3243 * FIXME: move this to a global table and use it in all RAID
3244 * calculation code
3245 */
3246 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
3247 dev_stripes = 2;
3248 ncopies = 2;
3249 devs_max = 1;
3250 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
3251 devs_min = 2;
3252 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
3253 devs_increment = 2;
3254 ncopies = 2;
3255 devs_max = 2;
3256 devs_min = 2;
3257 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
3258 sub_stripes = 2;
3259 devs_increment = 2;
3260 ncopies = 2;
3261 devs_min = 4;
3262 } else {
3263 devs_max = 1;
3264 }
3265
3266 if (type & BTRFS_BLOCK_GROUP_DATA) {
3267 max_stripe_size = 1024 * 1024 * 1024;
3268 max_chunk_size = 10 * max_stripe_size;
3269 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3270 /* for larger filesystems, use larger metadata chunks */
3271 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3272 max_stripe_size = 1024 * 1024 * 1024;
3273 else
3274 max_stripe_size = 256 * 1024 * 1024;
3275 max_chunk_size = max_stripe_size;
3276 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3277 max_stripe_size = 32 * 1024 * 1024;
3278 max_chunk_size = 2 * max_stripe_size;
3279 } else {
3280 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3281 type);
3282 BUG_ON(1);
3283 }
3284
3285 /* we don't want a chunk larger than 10% of writeable space */
3286 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3287 max_chunk_size);
3288
3289 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3290 GFP_NOFS);
3291 if (!devices_info)
3292 return -ENOMEM;
3293
3294 cur = fs_devices->alloc_list.next;
3295
3296 /*
3297 * in the first pass through the devices list, we gather information
3298 * about the available holes on each device.
3299 */
3300 ndevs = 0;
3301 while (cur != &fs_devices->alloc_list) {
3302 struct btrfs_device *device;
3303 u64 max_avail;
3304 u64 dev_offset;
3305
3306 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3307
3308 cur = cur->next;
3309
3310 if (!device->writeable) {
3311 printk(KERN_ERR
3312 "btrfs: read-only device in alloc_list\n");
3313 WARN_ON(1);
3314 continue;
3315 }
3316
3317 if (!device->in_fs_metadata)
3318 continue;
3319
3320 if (device->total_bytes > device->bytes_used)
3321 total_avail = device->total_bytes - device->bytes_used;
3322 else
3323 total_avail = 0;
3324
3325 /* If there is no space on this device, skip it. */
3326 if (total_avail == 0)
3327 continue;
3328
3329 ret = find_free_dev_extent(device,
3330 max_stripe_size * dev_stripes,
3331 &dev_offset, &max_avail);
3332 if (ret && ret != -ENOSPC)
3333 goto error;
3334
3335 if (ret == 0)
3336 max_avail = max_stripe_size * dev_stripes;
3337
3338 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3339 continue;
3340
3341 devices_info[ndevs].dev_offset = dev_offset;
3342 devices_info[ndevs].max_avail = max_avail;
3343 devices_info[ndevs].total_avail = total_avail;
3344 devices_info[ndevs].dev = device;
3345 ++ndevs;
3346 }
3347
3348 /*
3349 * now sort the devices by hole size / available space
3350 */
3351 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3352 btrfs_cmp_device_info, NULL);
3353
3354 /* round down to number of usable stripes */
3355 ndevs -= ndevs % devs_increment;
3356
3357 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3358 ret = -ENOSPC;
3359 goto error;
3360 }
3361
3362 if (devs_max && ndevs > devs_max)
3363 ndevs = devs_max;
3364 /*
3365 * the primary goal is to maximize the number of stripes, so use as many
3366 * devices as possible, even if the stripes are not maximum sized.
3367 */
3368 stripe_size = devices_info[ndevs-1].max_avail;
3369 num_stripes = ndevs * dev_stripes;
3370
3371 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3372 stripe_size = max_chunk_size * ncopies;
3373 do_div(stripe_size, ndevs);
3374 }
3375
3376 do_div(stripe_size, dev_stripes);
3377
3378 /* align to BTRFS_STRIPE_LEN */
3379 do_div(stripe_size, BTRFS_STRIPE_LEN);
3380 stripe_size *= BTRFS_STRIPE_LEN;
3381
3382 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3383 if (!map) {
3384 ret = -ENOMEM;
3385 goto error;
3386 }
3387 map->num_stripes = num_stripes;
3388
3389 for (i = 0; i < ndevs; ++i) {
3390 for (j = 0; j < dev_stripes; ++j) {
3391 int s = i * dev_stripes + j;
3392 map->stripes[s].dev = devices_info[i].dev;
3393 map->stripes[s].physical = devices_info[i].dev_offset +
3394 j * stripe_size;
3395 }
3396 }
3397 map->sector_size = extent_root->sectorsize;
3398 map->stripe_len = BTRFS_STRIPE_LEN;
3399 map->io_align = BTRFS_STRIPE_LEN;
3400 map->io_width = BTRFS_STRIPE_LEN;
3401 map->type = type;
3402 map->sub_stripes = sub_stripes;
3403
3404 *map_ret = map;
3405 num_bytes = stripe_size * (num_stripes / ncopies);
3406
3407 *stripe_size_out = stripe_size;
3408 *num_bytes_out = num_bytes;
3409
3410 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3411
3412 em = alloc_extent_map();
3413 if (!em) {
3414 ret = -ENOMEM;
3415 goto error;
3416 }
3417 em->bdev = (struct block_device *)map;
3418 em->start = start;
3419 em->len = num_bytes;
3420 em->block_start = 0;
3421 em->block_len = em->len;
3422
3423 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3424 write_lock(&em_tree->lock);
3425 ret = add_extent_mapping(em_tree, em);
3426 write_unlock(&em_tree->lock);
3427 free_extent_map(em);
3428 if (ret)
3429 goto error;
3430
3431 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3432 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3433 start, num_bytes);
3434 if (ret)
3435 goto error;
3436
3437 for (i = 0; i < map->num_stripes; ++i) {
3438 struct btrfs_device *device;
3439 u64 dev_offset;
3440
3441 device = map->stripes[i].dev;
3442 dev_offset = map->stripes[i].physical;
3443
3444 ret = btrfs_alloc_dev_extent(trans, device,
3445 info->chunk_root->root_key.objectid,
3446 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3447 start, dev_offset, stripe_size);
3448 if (ret) {
3449 btrfs_abort_transaction(trans, extent_root, ret);
3450 goto error;
3451 }
3452 }
3453
3454 kfree(devices_info);
3455 return 0;
3456
3457 error:
3458 kfree(map);
3459 kfree(devices_info);
3460 return ret;
3461 }
3462
3463 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3464 struct btrfs_root *extent_root,
3465 struct map_lookup *map, u64 chunk_offset,
3466 u64 chunk_size, u64 stripe_size)
3467 {
3468 u64 dev_offset;
3469 struct btrfs_key key;
3470 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3471 struct btrfs_device *device;
3472 struct btrfs_chunk *chunk;
3473 struct btrfs_stripe *stripe;
3474 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3475 int index = 0;
3476 int ret;
3477
3478 chunk = kzalloc(item_size, GFP_NOFS);
3479 if (!chunk)
3480 return -ENOMEM;
3481
3482 index = 0;
3483 while (index < map->num_stripes) {
3484 device = map->stripes[index].dev;
3485 device->bytes_used += stripe_size;
3486 ret = btrfs_update_device(trans, device);
3487 if (ret)
3488 goto out_free;
3489 index++;
3490 }
3491
3492 spin_lock(&extent_root->fs_info->free_chunk_lock);
3493 extent_root->fs_info->free_chunk_space -= (stripe_size *
3494 map->num_stripes);
3495 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3496
3497 index = 0;
3498 stripe = &chunk->stripe;
3499 while (index < map->num_stripes) {
3500 device = map->stripes[index].dev;
3501 dev_offset = map->stripes[index].physical;
3502
3503 btrfs_set_stack_stripe_devid(stripe, device->devid);
3504 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3505 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3506 stripe++;
3507 index++;
3508 }
3509
3510 btrfs_set_stack_chunk_length(chunk, chunk_size);
3511 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3512 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3513 btrfs_set_stack_chunk_type(chunk, map->type);
3514 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3515 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3516 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3517 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3518 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3519
3520 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3521 key.type = BTRFS_CHUNK_ITEM_KEY;
3522 key.offset = chunk_offset;
3523
3524 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3525
3526 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3527 /*
3528 * TODO: Cleanup of inserted chunk root in case of
3529 * failure.
3530 */
3531 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3532 item_size);
3533 }
3534
3535 out_free:
3536 kfree(chunk);
3537 return ret;
3538 }
3539
3540 /*
3541 * Chunk allocation falls into two parts. The first part does works
3542 * that make the new allocated chunk useable, but not do any operation
3543 * that modifies the chunk tree. The second part does the works that
3544 * require modifying the chunk tree. This division is important for the
3545 * bootstrap process of adding storage to a seed btrfs.
3546 */
3547 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3548 struct btrfs_root *extent_root, u64 type)
3549 {
3550 u64 chunk_offset;
3551 u64 chunk_size;
3552 u64 stripe_size;
3553 struct map_lookup *map;
3554 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3555 int ret;
3556
3557 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3558 &chunk_offset);
3559 if (ret)
3560 return ret;
3561
3562 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3563 &stripe_size, chunk_offset, type);
3564 if (ret)
3565 return ret;
3566
3567 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3568 chunk_size, stripe_size);
3569 if (ret)
3570 return ret;
3571 return 0;
3572 }
3573
3574 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3575 struct btrfs_root *root,
3576 struct btrfs_device *device)
3577 {
3578 u64 chunk_offset;
3579 u64 sys_chunk_offset;
3580 u64 chunk_size;
3581 u64 sys_chunk_size;
3582 u64 stripe_size;
3583 u64 sys_stripe_size;
3584 u64 alloc_profile;
3585 struct map_lookup *map;
3586 struct map_lookup *sys_map;
3587 struct btrfs_fs_info *fs_info = root->fs_info;
3588 struct btrfs_root *extent_root = fs_info->extent_root;
3589 int ret;
3590
3591 ret = find_next_chunk(fs_info->chunk_root,
3592 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3593 if (ret)
3594 return ret;
3595
3596 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3597 fs_info->avail_metadata_alloc_bits;
3598 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3599
3600 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3601 &stripe_size, chunk_offset, alloc_profile);
3602 if (ret)
3603 return ret;
3604
3605 sys_chunk_offset = chunk_offset + chunk_size;
3606
3607 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3608 fs_info->avail_system_alloc_bits;
3609 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3610
3611 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3612 &sys_chunk_size, &sys_stripe_size,
3613 sys_chunk_offset, alloc_profile);
3614 if (ret)
3615 goto abort;
3616
3617 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3618 if (ret)
3619 goto abort;
3620
3621 /*
3622 * Modifying chunk tree needs allocating new blocks from both
3623 * system block group and metadata block group. So we only can
3624 * do operations require modifying the chunk tree after both
3625 * block groups were created.
3626 */
3627 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3628 chunk_size, stripe_size);
3629 if (ret)
3630 goto abort;
3631
3632 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3633 sys_chunk_offset, sys_chunk_size,
3634 sys_stripe_size);
3635 if (ret)
3636 goto abort;
3637
3638 return 0;
3639
3640 abort:
3641 btrfs_abort_transaction(trans, root, ret);
3642 return ret;
3643 }
3644
3645 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3646 {
3647 struct extent_map *em;
3648 struct map_lookup *map;
3649 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3650 int readonly = 0;
3651 int i;
3652
3653 read_lock(&map_tree->map_tree.lock);
3654 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3655 read_unlock(&map_tree->map_tree.lock);
3656 if (!em)
3657 return 1;
3658
3659 if (btrfs_test_opt(root, DEGRADED)) {
3660 free_extent_map(em);
3661 return 0;
3662 }
3663
3664 map = (struct map_lookup *)em->bdev;
3665 for (i = 0; i < map->num_stripes; i++) {
3666 if (!map->stripes[i].dev->writeable) {
3667 readonly = 1;
3668 break;
3669 }
3670 }
3671 free_extent_map(em);
3672 return readonly;
3673 }
3674
3675 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3676 {
3677 extent_map_tree_init(&tree->map_tree);
3678 }
3679
3680 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3681 {
3682 struct extent_map *em;
3683
3684 while (1) {
3685 write_lock(&tree->map_tree.lock);
3686 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3687 if (em)
3688 remove_extent_mapping(&tree->map_tree, em);
3689 write_unlock(&tree->map_tree.lock);
3690 if (!em)
3691 break;
3692 kfree(em->bdev);
3693 /* once for us */
3694 free_extent_map(em);
3695 /* once for the tree */
3696 free_extent_map(em);
3697 }
3698 }
3699
3700 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
3701 {
3702 struct extent_map *em;
3703 struct map_lookup *map;
3704 struct extent_map_tree *em_tree = &map_tree->map_tree;
3705 int ret;
3706
3707 read_lock(&em_tree->lock);
3708 em = lookup_extent_mapping(em_tree, logical, len);
3709 read_unlock(&em_tree->lock);
3710 BUG_ON(!em);
3711
3712 BUG_ON(em->start > logical || em->start + em->len < logical);
3713 map = (struct map_lookup *)em->bdev;
3714 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
3715 ret = map->num_stripes;
3716 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3717 ret = map->sub_stripes;
3718 else
3719 ret = 1;
3720 free_extent_map(em);
3721 return ret;
3722 }
3723
3724 static int find_live_mirror(struct map_lookup *map, int first, int num,
3725 int optimal)
3726 {
3727 int i;
3728 if (map->stripes[optimal].dev->bdev)
3729 return optimal;
3730 for (i = first; i < first + num; i++) {
3731 if (map->stripes[i].dev->bdev)
3732 return i;
3733 }
3734 /* we couldn't find one that doesn't fail. Just return something
3735 * and the io error handling code will clean up eventually
3736 */
3737 return optimal;
3738 }
3739
3740 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3741 u64 logical, u64 *length,
3742 struct btrfs_bio **bbio_ret,
3743 int mirror_num)
3744 {
3745 struct extent_map *em;
3746 struct map_lookup *map;
3747 struct extent_map_tree *em_tree = &map_tree->map_tree;
3748 u64 offset;
3749 u64 stripe_offset;
3750 u64 stripe_end_offset;
3751 u64 stripe_nr;
3752 u64 stripe_nr_orig;
3753 u64 stripe_nr_end;
3754 int stripe_index;
3755 int i;
3756 int ret = 0;
3757 int num_stripes;
3758 int max_errors = 0;
3759 struct btrfs_bio *bbio = NULL;
3760
3761 read_lock(&em_tree->lock);
3762 em = lookup_extent_mapping(em_tree, logical, *length);
3763 read_unlock(&em_tree->lock);
3764
3765 if (!em) {
3766 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
3767 (unsigned long long)logical,
3768 (unsigned long long)*length);
3769 BUG();
3770 }
3771
3772 BUG_ON(em->start > logical || em->start + em->len < logical);
3773 map = (struct map_lookup *)em->bdev;
3774 offset = logical - em->start;
3775
3776 if (mirror_num > map->num_stripes)
3777 mirror_num = 0;
3778
3779 stripe_nr = offset;
3780 /*
3781 * stripe_nr counts the total number of stripes we have to stride
3782 * to get to this block
3783 */
3784 do_div(stripe_nr, map->stripe_len);
3785
3786 stripe_offset = stripe_nr * map->stripe_len;
3787 BUG_ON(offset < stripe_offset);
3788
3789 /* stripe_offset is the offset of this block in its stripe*/
3790 stripe_offset = offset - stripe_offset;
3791
3792 if (rw & REQ_DISCARD)
3793 *length = min_t(u64, em->len - offset, *length);
3794 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3795 /* we limit the length of each bio to what fits in a stripe */
3796 *length = min_t(u64, em->len - offset,
3797 map->stripe_len - stripe_offset);
3798 } else {
3799 *length = em->len - offset;
3800 }
3801
3802 if (!bbio_ret)
3803 goto out;
3804
3805 num_stripes = 1;
3806 stripe_index = 0;
3807 stripe_nr_orig = stripe_nr;
3808 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3809 (~(map->stripe_len - 1));
3810 do_div(stripe_nr_end, map->stripe_len);
3811 stripe_end_offset = stripe_nr_end * map->stripe_len -
3812 (offset + *length);
3813 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3814 if (rw & REQ_DISCARD)
3815 num_stripes = min_t(u64, map->num_stripes,
3816 stripe_nr_end - stripe_nr_orig);
3817 stripe_index = do_div(stripe_nr, map->num_stripes);
3818 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3819 if (rw & (REQ_WRITE | REQ_DISCARD))
3820 num_stripes = map->num_stripes;
3821 else if (mirror_num)
3822 stripe_index = mirror_num - 1;
3823 else {
3824 stripe_index = find_live_mirror(map, 0,
3825 map->num_stripes,
3826 current->pid % map->num_stripes);
3827 mirror_num = stripe_index + 1;
3828 }
3829
3830 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3831 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3832 num_stripes = map->num_stripes;
3833 } else if (mirror_num) {
3834 stripe_index = mirror_num - 1;
3835 } else {
3836 mirror_num = 1;
3837 }
3838
3839 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3840 int factor = map->num_stripes / map->sub_stripes;
3841
3842 stripe_index = do_div(stripe_nr, factor);
3843 stripe_index *= map->sub_stripes;
3844
3845 if (rw & REQ_WRITE)
3846 num_stripes = map->sub_stripes;
3847 else if (rw & REQ_DISCARD)
3848 num_stripes = min_t(u64, map->sub_stripes *
3849 (stripe_nr_end - stripe_nr_orig),
3850 map->num_stripes);
3851 else if (mirror_num)
3852 stripe_index += mirror_num - 1;
3853 else {
3854 int old_stripe_index = stripe_index;
3855 stripe_index = find_live_mirror(map, stripe_index,
3856 map->sub_stripes, stripe_index +
3857 current->pid % map->sub_stripes);
3858 mirror_num = stripe_index - old_stripe_index + 1;
3859 }
3860 } else {
3861 /*
3862 * after this do_div call, stripe_nr is the number of stripes
3863 * on this device we have to walk to find the data, and
3864 * stripe_index is the number of our device in the stripe array
3865 */
3866 stripe_index = do_div(stripe_nr, map->num_stripes);
3867 mirror_num = stripe_index + 1;
3868 }
3869 BUG_ON(stripe_index >= map->num_stripes);
3870
3871 bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
3872 if (!bbio) {
3873 ret = -ENOMEM;
3874 goto out;
3875 }
3876 atomic_set(&bbio->error, 0);
3877
3878 if (rw & REQ_DISCARD) {
3879 int factor = 0;
3880 int sub_stripes = 0;
3881 u64 stripes_per_dev = 0;
3882 u32 remaining_stripes = 0;
3883 u32 last_stripe = 0;
3884
3885 if (map->type &
3886 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
3887 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3888 sub_stripes = 1;
3889 else
3890 sub_stripes = map->sub_stripes;
3891
3892 factor = map->num_stripes / sub_stripes;
3893 stripes_per_dev = div_u64_rem(stripe_nr_end -
3894 stripe_nr_orig,
3895 factor,
3896 &remaining_stripes);
3897 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
3898 last_stripe *= sub_stripes;
3899 }
3900
3901 for (i = 0; i < num_stripes; i++) {
3902 bbio->stripes[i].physical =
3903 map->stripes[stripe_index].physical +
3904 stripe_offset + stripe_nr * map->stripe_len;
3905 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3906
3907 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3908 BTRFS_BLOCK_GROUP_RAID10)) {
3909 bbio->stripes[i].length = stripes_per_dev *
3910 map->stripe_len;
3911
3912 if (i / sub_stripes < remaining_stripes)
3913 bbio->stripes[i].length +=
3914 map->stripe_len;
3915
3916 /*
3917 * Special for the first stripe and
3918 * the last stripe:
3919 *
3920 * |-------|...|-------|
3921 * |----------|
3922 * off end_off
3923 */
3924 if (i < sub_stripes)
3925 bbio->stripes[i].length -=
3926 stripe_offset;
3927
3928 if (stripe_index >= last_stripe &&
3929 stripe_index <= (last_stripe +
3930 sub_stripes - 1))
3931 bbio->stripes[i].length -=
3932 stripe_end_offset;
3933
3934 if (i == sub_stripes - 1)
3935 stripe_offset = 0;
3936 } else
3937 bbio->stripes[i].length = *length;
3938
3939 stripe_index++;
3940 if (stripe_index == map->num_stripes) {
3941 /* This could only happen for RAID0/10 */
3942 stripe_index = 0;
3943 stripe_nr++;
3944 }
3945 }
3946 } else {
3947 for (i = 0; i < num_stripes; i++) {
3948 bbio->stripes[i].physical =
3949 map->stripes[stripe_index].physical +
3950 stripe_offset +
3951 stripe_nr * map->stripe_len;
3952 bbio->stripes[i].dev =
3953 map->stripes[stripe_index].dev;
3954 stripe_index++;
3955 }
3956 }
3957
3958 if (rw & REQ_WRITE) {
3959 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
3960 BTRFS_BLOCK_GROUP_RAID10 |
3961 BTRFS_BLOCK_GROUP_DUP)) {
3962 max_errors = 1;
3963 }
3964 }
3965
3966 *bbio_ret = bbio;
3967 bbio->num_stripes = num_stripes;
3968 bbio->max_errors = max_errors;
3969 bbio->mirror_num = mirror_num;
3970 out:
3971 free_extent_map(em);
3972 return ret;
3973 }
3974
3975 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3976 u64 logical, u64 *length,
3977 struct btrfs_bio **bbio_ret, int mirror_num)
3978 {
3979 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
3980 mirror_num);
3981 }
3982
3983 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3984 u64 chunk_start, u64 physical, u64 devid,
3985 u64 **logical, int *naddrs, int *stripe_len)
3986 {
3987 struct extent_map_tree *em_tree = &map_tree->map_tree;
3988 struct extent_map *em;
3989 struct map_lookup *map;
3990 u64 *buf;
3991 u64 bytenr;
3992 u64 length;
3993 u64 stripe_nr;
3994 int i, j, nr = 0;
3995
3996 read_lock(&em_tree->lock);
3997 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3998 read_unlock(&em_tree->lock);
3999
4000 BUG_ON(!em || em->start != chunk_start);
4001 map = (struct map_lookup *)em->bdev;
4002
4003 length = em->len;
4004 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4005 do_div(length, map->num_stripes / map->sub_stripes);
4006 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4007 do_div(length, map->num_stripes);
4008
4009 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4010 BUG_ON(!buf); /* -ENOMEM */
4011
4012 for (i = 0; i < map->num_stripes; i++) {
4013 if (devid && map->stripes[i].dev->devid != devid)
4014 continue;
4015 if (map->stripes[i].physical > physical ||
4016 map->stripes[i].physical + length <= physical)
4017 continue;
4018
4019 stripe_nr = physical - map->stripes[i].physical;
4020 do_div(stripe_nr, map->stripe_len);
4021
4022 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4023 stripe_nr = stripe_nr * map->num_stripes + i;
4024 do_div(stripe_nr, map->sub_stripes);
4025 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4026 stripe_nr = stripe_nr * map->num_stripes + i;
4027 }
4028 bytenr = chunk_start + stripe_nr * map->stripe_len;
4029 WARN_ON(nr >= map->num_stripes);
4030 for (j = 0; j < nr; j++) {
4031 if (buf[j] == bytenr)
4032 break;
4033 }
4034 if (j == nr) {
4035 WARN_ON(nr >= map->num_stripes);
4036 buf[nr++] = bytenr;
4037 }
4038 }
4039
4040 *logical = buf;
4041 *naddrs = nr;
4042 *stripe_len = map->stripe_len;
4043
4044 free_extent_map(em);
4045 return 0;
4046 }
4047
4048 static void *merge_stripe_index_into_bio_private(void *bi_private,
4049 unsigned int stripe_index)
4050 {
4051 /*
4052 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4053 * at most 1.
4054 * The alternative solution (instead of stealing bits from the
4055 * pointer) would be to allocate an intermediate structure
4056 * that contains the old private pointer plus the stripe_index.
4057 */
4058 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4059 BUG_ON(stripe_index > 3);
4060 return (void *)(((uintptr_t)bi_private) | stripe_index);
4061 }
4062
4063 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4064 {
4065 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4066 }
4067
4068 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4069 {
4070 return (unsigned int)((uintptr_t)bi_private) & 3;
4071 }
4072
4073 static void btrfs_end_bio(struct bio *bio, int err)
4074 {
4075 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4076 int is_orig_bio = 0;
4077
4078 if (err) {
4079 atomic_inc(&bbio->error);
4080 if (err == -EIO || err == -EREMOTEIO) {
4081 unsigned int stripe_index =
4082 extract_stripe_index_from_bio_private(
4083 bio->bi_private);
4084 struct btrfs_device *dev;
4085
4086 BUG_ON(stripe_index >= bbio->num_stripes);
4087 dev = bbio->stripes[stripe_index].dev;
4088 if (dev->bdev) {
4089 if (bio->bi_rw & WRITE)
4090 btrfs_dev_stat_inc(dev,
4091 BTRFS_DEV_STAT_WRITE_ERRS);
4092 else
4093 btrfs_dev_stat_inc(dev,
4094 BTRFS_DEV_STAT_READ_ERRS);
4095 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4096 btrfs_dev_stat_inc(dev,
4097 BTRFS_DEV_STAT_FLUSH_ERRS);
4098 btrfs_dev_stat_print_on_error(dev);
4099 }
4100 }
4101 }
4102
4103 if (bio == bbio->orig_bio)
4104 is_orig_bio = 1;
4105
4106 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4107 if (!is_orig_bio) {
4108 bio_put(bio);
4109 bio = bbio->orig_bio;
4110 }
4111 bio->bi_private = bbio->private;
4112 bio->bi_end_io = bbio->end_io;
4113 bio->bi_bdev = (struct block_device *)
4114 (unsigned long)bbio->mirror_num;
4115 /* only send an error to the higher layers if it is
4116 * beyond the tolerance of the multi-bio
4117 */
4118 if (atomic_read(&bbio->error) > bbio->max_errors) {
4119 err = -EIO;
4120 } else {
4121 /*
4122 * this bio is actually up to date, we didn't
4123 * go over the max number of errors
4124 */
4125 set_bit(BIO_UPTODATE, &bio->bi_flags);
4126 err = 0;
4127 }
4128 kfree(bbio);
4129
4130 bio_endio(bio, err);
4131 } else if (!is_orig_bio) {
4132 bio_put(bio);
4133 }
4134 }
4135
4136 struct async_sched {
4137 struct bio *bio;
4138 int rw;
4139 struct btrfs_fs_info *info;
4140 struct btrfs_work work;
4141 };
4142
4143 /*
4144 * see run_scheduled_bios for a description of why bios are collected for
4145 * async submit.
4146 *
4147 * This will add one bio to the pending list for a device and make sure
4148 * the work struct is scheduled.
4149 */
4150 static noinline void schedule_bio(struct btrfs_root *root,
4151 struct btrfs_device *device,
4152 int rw, struct bio *bio)
4153 {
4154 int should_queue = 1;
4155 struct btrfs_pending_bios *pending_bios;
4156
4157 /* don't bother with additional async steps for reads, right now */
4158 if (!(rw & REQ_WRITE)) {
4159 bio_get(bio);
4160 btrfsic_submit_bio(rw, bio);
4161 bio_put(bio);
4162 return;
4163 }
4164
4165 /*
4166 * nr_async_bios allows us to reliably return congestion to the
4167 * higher layers. Otherwise, the async bio makes it appear we have
4168 * made progress against dirty pages when we've really just put it
4169 * on a queue for later
4170 */
4171 atomic_inc(&root->fs_info->nr_async_bios);
4172 WARN_ON(bio->bi_next);
4173 bio->bi_next = NULL;
4174 bio->bi_rw |= rw;
4175
4176 spin_lock(&device->io_lock);
4177 if (bio->bi_rw & REQ_SYNC)
4178 pending_bios = &device->pending_sync_bios;
4179 else
4180 pending_bios = &device->pending_bios;
4181
4182 if (pending_bios->tail)
4183 pending_bios->tail->bi_next = bio;
4184
4185 pending_bios->tail = bio;
4186 if (!pending_bios->head)
4187 pending_bios->head = bio;
4188 if (device->running_pending)
4189 should_queue = 0;
4190
4191 spin_unlock(&device->io_lock);
4192
4193 if (should_queue)
4194 btrfs_queue_worker(&root->fs_info->submit_workers,
4195 &device->work);
4196 }
4197
4198 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4199 int mirror_num, int async_submit)
4200 {
4201 struct btrfs_mapping_tree *map_tree;
4202 struct btrfs_device *dev;
4203 struct bio *first_bio = bio;
4204 u64 logical = (u64)bio->bi_sector << 9;
4205 u64 length = 0;
4206 u64 map_length;
4207 int ret;
4208 int dev_nr = 0;
4209 int total_devs = 1;
4210 struct btrfs_bio *bbio = NULL;
4211
4212 length = bio->bi_size;
4213 map_tree = &root->fs_info->mapping_tree;
4214 map_length = length;
4215
4216 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
4217 mirror_num);
4218 if (ret) /* -ENOMEM */
4219 return ret;
4220
4221 total_devs = bbio->num_stripes;
4222 if (map_length < length) {
4223 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
4224 "len %llu\n", (unsigned long long)logical,
4225 (unsigned long long)length,
4226 (unsigned long long)map_length);
4227 BUG();
4228 }
4229
4230 bbio->orig_bio = first_bio;
4231 bbio->private = first_bio->bi_private;
4232 bbio->end_io = first_bio->bi_end_io;
4233 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4234
4235 while (dev_nr < total_devs) {
4236 if (dev_nr < total_devs - 1) {
4237 bio = bio_clone(first_bio, GFP_NOFS);
4238 BUG_ON(!bio); /* -ENOMEM */
4239 } else {
4240 bio = first_bio;
4241 }
4242 bio->bi_private = bbio;
4243 bio->bi_private = merge_stripe_index_into_bio_private(
4244 bio->bi_private, (unsigned int)dev_nr);
4245 bio->bi_end_io = btrfs_end_bio;
4246 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
4247 dev = bbio->stripes[dev_nr].dev;
4248 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
4249 #ifdef DEBUG
4250 struct rcu_string *name;
4251
4252 rcu_read_lock();
4253 name = rcu_dereference(dev->name);
4254 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
4255 "(%s id %llu), size=%u\n", rw,
4256 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4257 name->str, dev->devid, bio->bi_size);
4258 rcu_read_unlock();
4259 #endif
4260 bio->bi_bdev = dev->bdev;
4261 if (async_submit)
4262 schedule_bio(root, dev, rw, bio);
4263 else
4264 btrfsic_submit_bio(rw, bio);
4265 } else {
4266 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
4267 bio->bi_sector = logical >> 9;
4268 bio_endio(bio, -EIO);
4269 }
4270 dev_nr++;
4271 }
4272 return 0;
4273 }
4274
4275 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
4276 u8 *uuid, u8 *fsid)
4277 {
4278 struct btrfs_device *device;
4279 struct btrfs_fs_devices *cur_devices;
4280
4281 cur_devices = root->fs_info->fs_devices;
4282 while (cur_devices) {
4283 if (!fsid ||
4284 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4285 device = __find_device(&cur_devices->devices,
4286 devid, uuid);
4287 if (device)
4288 return device;
4289 }
4290 cur_devices = cur_devices->seed;
4291 }
4292 return NULL;
4293 }
4294
4295 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4296 u64 devid, u8 *dev_uuid)
4297 {
4298 struct btrfs_device *device;
4299 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4300
4301 device = kzalloc(sizeof(*device), GFP_NOFS);
4302 if (!device)
4303 return NULL;
4304 list_add(&device->dev_list,
4305 &fs_devices->devices);
4306 device->dev_root = root->fs_info->dev_root;
4307 device->devid = devid;
4308 device->work.func = pending_bios_fn;
4309 device->fs_devices = fs_devices;
4310 device->missing = 1;
4311 fs_devices->num_devices++;
4312 fs_devices->missing_devices++;
4313 spin_lock_init(&device->io_lock);
4314 INIT_LIST_HEAD(&device->dev_alloc_list);
4315 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4316 return device;
4317 }
4318
4319 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4320 struct extent_buffer *leaf,
4321 struct btrfs_chunk *chunk)
4322 {
4323 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4324 struct map_lookup *map;
4325 struct extent_map *em;
4326 u64 logical;
4327 u64 length;
4328 u64 devid;
4329 u8 uuid[BTRFS_UUID_SIZE];
4330 int num_stripes;
4331 int ret;
4332 int i;
4333
4334 logical = key->offset;
4335 length = btrfs_chunk_length(leaf, chunk);
4336
4337 read_lock(&map_tree->map_tree.lock);
4338 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4339 read_unlock(&map_tree->map_tree.lock);
4340
4341 /* already mapped? */
4342 if (em && em->start <= logical && em->start + em->len > logical) {
4343 free_extent_map(em);
4344 return 0;
4345 } else if (em) {
4346 free_extent_map(em);
4347 }
4348
4349 em = alloc_extent_map();
4350 if (!em)
4351 return -ENOMEM;
4352 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4353 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4354 if (!map) {
4355 free_extent_map(em);
4356 return -ENOMEM;
4357 }
4358
4359 em->bdev = (struct block_device *)map;
4360 em->start = logical;
4361 em->len = length;
4362 em->block_start = 0;
4363 em->block_len = em->len;
4364
4365 map->num_stripes = num_stripes;
4366 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4367 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4368 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4369 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4370 map->type = btrfs_chunk_type(leaf, chunk);
4371 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4372 for (i = 0; i < num_stripes; i++) {
4373 map->stripes[i].physical =
4374 btrfs_stripe_offset_nr(leaf, chunk, i);
4375 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4376 read_extent_buffer(leaf, uuid, (unsigned long)
4377 btrfs_stripe_dev_uuid_nr(chunk, i),
4378 BTRFS_UUID_SIZE);
4379 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
4380 NULL);
4381 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
4382 kfree(map);
4383 free_extent_map(em);
4384 return -EIO;
4385 }
4386 if (!map->stripes[i].dev) {
4387 map->stripes[i].dev =
4388 add_missing_dev(root, devid, uuid);
4389 if (!map->stripes[i].dev) {
4390 kfree(map);
4391 free_extent_map(em);
4392 return -EIO;
4393 }
4394 }
4395 map->stripes[i].dev->in_fs_metadata = 1;
4396 }
4397
4398 write_lock(&map_tree->map_tree.lock);
4399 ret = add_extent_mapping(&map_tree->map_tree, em);
4400 write_unlock(&map_tree->map_tree.lock);
4401 BUG_ON(ret); /* Tree corruption */
4402 free_extent_map(em);
4403
4404 return 0;
4405 }
4406
4407 static void fill_device_from_item(struct extent_buffer *leaf,
4408 struct btrfs_dev_item *dev_item,
4409 struct btrfs_device *device)
4410 {
4411 unsigned long ptr;
4412
4413 device->devid = btrfs_device_id(leaf, dev_item);
4414 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
4415 device->total_bytes = device->disk_total_bytes;
4416 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
4417 device->type = btrfs_device_type(leaf, dev_item);
4418 device->io_align = btrfs_device_io_align(leaf, dev_item);
4419 device->io_width = btrfs_device_io_width(leaf, dev_item);
4420 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
4421
4422 ptr = (unsigned long)btrfs_device_uuid(dev_item);
4423 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
4424 }
4425
4426 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
4427 {
4428 struct btrfs_fs_devices *fs_devices;
4429 int ret;
4430
4431 BUG_ON(!mutex_is_locked(&uuid_mutex));
4432
4433 fs_devices = root->fs_info->fs_devices->seed;
4434 while (fs_devices) {
4435 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4436 ret = 0;
4437 goto out;
4438 }
4439 fs_devices = fs_devices->seed;
4440 }
4441
4442 fs_devices = find_fsid(fsid);
4443 if (!fs_devices) {
4444 ret = -ENOENT;
4445 goto out;
4446 }
4447
4448 fs_devices = clone_fs_devices(fs_devices);
4449 if (IS_ERR(fs_devices)) {
4450 ret = PTR_ERR(fs_devices);
4451 goto out;
4452 }
4453
4454 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
4455 root->fs_info->bdev_holder);
4456 if (ret) {
4457 free_fs_devices(fs_devices);
4458 goto out;
4459 }
4460
4461 if (!fs_devices->seeding) {
4462 __btrfs_close_devices(fs_devices);
4463 free_fs_devices(fs_devices);
4464 ret = -EINVAL;
4465 goto out;
4466 }
4467
4468 fs_devices->seed = root->fs_info->fs_devices->seed;
4469 root->fs_info->fs_devices->seed = fs_devices;
4470 out:
4471 return ret;
4472 }
4473
4474 static int read_one_dev(struct btrfs_root *root,
4475 struct extent_buffer *leaf,
4476 struct btrfs_dev_item *dev_item)
4477 {
4478 struct btrfs_device *device;
4479 u64 devid;
4480 int ret;
4481 u8 fs_uuid[BTRFS_UUID_SIZE];
4482 u8 dev_uuid[BTRFS_UUID_SIZE];
4483
4484 devid = btrfs_device_id(leaf, dev_item);
4485 read_extent_buffer(leaf, dev_uuid,
4486 (unsigned long)btrfs_device_uuid(dev_item),
4487 BTRFS_UUID_SIZE);
4488 read_extent_buffer(leaf, fs_uuid,
4489 (unsigned long)btrfs_device_fsid(dev_item),
4490 BTRFS_UUID_SIZE);
4491
4492 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
4493 ret = open_seed_devices(root, fs_uuid);
4494 if (ret && !btrfs_test_opt(root, DEGRADED))
4495 return ret;
4496 }
4497
4498 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
4499 if (!device || !device->bdev) {
4500 if (!btrfs_test_opt(root, DEGRADED))
4501 return -EIO;
4502
4503 if (!device) {
4504 printk(KERN_WARNING "warning devid %llu missing\n",
4505 (unsigned long long)devid);
4506 device = add_missing_dev(root, devid, dev_uuid);
4507 if (!device)
4508 return -ENOMEM;
4509 } else if (!device->missing) {
4510 /*
4511 * this happens when a device that was properly setup
4512 * in the device info lists suddenly goes bad.
4513 * device->bdev is NULL, and so we have to set
4514 * device->missing to one here
4515 */
4516 root->fs_info->fs_devices->missing_devices++;
4517 device->missing = 1;
4518 }
4519 }
4520
4521 if (device->fs_devices != root->fs_info->fs_devices) {
4522 BUG_ON(device->writeable);
4523 if (device->generation !=
4524 btrfs_device_generation(leaf, dev_item))
4525 return -EINVAL;
4526 }
4527
4528 fill_device_from_item(leaf, dev_item, device);
4529 device->dev_root = root->fs_info->dev_root;
4530 device->in_fs_metadata = 1;
4531 if (device->writeable) {
4532 device->fs_devices->total_rw_bytes += device->total_bytes;
4533 spin_lock(&root->fs_info->free_chunk_lock);
4534 root->fs_info->free_chunk_space += device->total_bytes -
4535 device->bytes_used;
4536 spin_unlock(&root->fs_info->free_chunk_lock);
4537 }
4538 ret = 0;
4539 return ret;
4540 }
4541
4542 int btrfs_read_sys_array(struct btrfs_root *root)
4543 {
4544 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4545 struct extent_buffer *sb;
4546 struct btrfs_disk_key *disk_key;
4547 struct btrfs_chunk *chunk;
4548 u8 *ptr;
4549 unsigned long sb_ptr;
4550 int ret = 0;
4551 u32 num_stripes;
4552 u32 array_size;
4553 u32 len = 0;
4554 u32 cur;
4555 struct btrfs_key key;
4556
4557 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
4558 BTRFS_SUPER_INFO_SIZE);
4559 if (!sb)
4560 return -ENOMEM;
4561 btrfs_set_buffer_uptodate(sb);
4562 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
4563 /*
4564 * The sb extent buffer is artifical and just used to read the system array.
4565 * btrfs_set_buffer_uptodate() call does not properly mark all it's
4566 * pages up-to-date when the page is larger: extent does not cover the
4567 * whole page and consequently check_page_uptodate does not find all
4568 * the page's extents up-to-date (the hole beyond sb),
4569 * write_extent_buffer then triggers a WARN_ON.
4570 *
4571 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
4572 * but sb spans only this function. Add an explicit SetPageUptodate call
4573 * to silence the warning eg. on PowerPC 64.
4574 */
4575 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
4576 SetPageUptodate(sb->pages[0]);
4577
4578 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
4579 array_size = btrfs_super_sys_array_size(super_copy);
4580
4581 ptr = super_copy->sys_chunk_array;
4582 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
4583 cur = 0;
4584
4585 while (cur < array_size) {
4586 disk_key = (struct btrfs_disk_key *)ptr;
4587 btrfs_disk_key_to_cpu(&key, disk_key);
4588
4589 len = sizeof(*disk_key); ptr += len;
4590 sb_ptr += len;
4591 cur += len;
4592
4593 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
4594 chunk = (struct btrfs_chunk *)sb_ptr;
4595 ret = read_one_chunk(root, &key, sb, chunk);
4596 if (ret)
4597 break;
4598 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
4599 len = btrfs_chunk_item_size(num_stripes);
4600 } else {
4601 ret = -EIO;
4602 break;
4603 }
4604 ptr += len;
4605 sb_ptr += len;
4606 cur += len;
4607 }
4608 free_extent_buffer(sb);
4609 return ret;
4610 }
4611
4612 struct btrfs_device *btrfs_find_device_for_logical(struct btrfs_root *root,
4613 u64 logical, int mirror_num)
4614 {
4615 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4616 int ret;
4617 u64 map_length = 0;
4618 struct btrfs_bio *bbio = NULL;
4619 struct btrfs_device *device;
4620
4621 BUG_ON(mirror_num == 0);
4622 ret = btrfs_map_block(map_tree, WRITE, logical, &map_length, &bbio,
4623 mirror_num);
4624 if (ret) {
4625 BUG_ON(bbio != NULL);
4626 return NULL;
4627 }
4628 BUG_ON(mirror_num != bbio->mirror_num);
4629 device = bbio->stripes[mirror_num - 1].dev;
4630 kfree(bbio);
4631 return device;
4632 }
4633
4634 int btrfs_read_chunk_tree(struct btrfs_root *root)
4635 {
4636 struct btrfs_path *path;
4637 struct extent_buffer *leaf;
4638 struct btrfs_key key;
4639 struct btrfs_key found_key;
4640 int ret;
4641 int slot;
4642
4643 root = root->fs_info->chunk_root;
4644
4645 path = btrfs_alloc_path();
4646 if (!path)
4647 return -ENOMEM;
4648
4649 mutex_lock(&uuid_mutex);
4650 lock_chunks(root);
4651
4652 /* first we search for all of the device items, and then we
4653 * read in all of the chunk items. This way we can create chunk
4654 * mappings that reference all of the devices that are afound
4655 */
4656 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
4657 key.offset = 0;
4658 key.type = 0;
4659 again:
4660 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4661 if (ret < 0)
4662 goto error;
4663 while (1) {
4664 leaf = path->nodes[0];
4665 slot = path->slots[0];
4666 if (slot >= btrfs_header_nritems(leaf)) {
4667 ret = btrfs_next_leaf(root, path);
4668 if (ret == 0)
4669 continue;
4670 if (ret < 0)
4671 goto error;
4672 break;
4673 }
4674 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4675 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4676 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
4677 break;
4678 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
4679 struct btrfs_dev_item *dev_item;
4680 dev_item = btrfs_item_ptr(leaf, slot,
4681 struct btrfs_dev_item);
4682 ret = read_one_dev(root, leaf, dev_item);
4683 if (ret)
4684 goto error;
4685 }
4686 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
4687 struct btrfs_chunk *chunk;
4688 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
4689 ret = read_one_chunk(root, &found_key, leaf, chunk);
4690 if (ret)
4691 goto error;
4692 }
4693 path->slots[0]++;
4694 }
4695 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4696 key.objectid = 0;
4697 btrfs_release_path(path);
4698 goto again;
4699 }
4700 ret = 0;
4701 error:
4702 unlock_chunks(root);
4703 mutex_unlock(&uuid_mutex);
4704
4705 btrfs_free_path(path);
4706 return ret;
4707 }
4708
4709 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
4710 {
4711 int i;
4712
4713 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4714 btrfs_dev_stat_reset(dev, i);
4715 }
4716
4717 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
4718 {
4719 struct btrfs_key key;
4720 struct btrfs_key found_key;
4721 struct btrfs_root *dev_root = fs_info->dev_root;
4722 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4723 struct extent_buffer *eb;
4724 int slot;
4725 int ret = 0;
4726 struct btrfs_device *device;
4727 struct btrfs_path *path = NULL;
4728 int i;
4729
4730 path = btrfs_alloc_path();
4731 if (!path) {
4732 ret = -ENOMEM;
4733 goto out;
4734 }
4735
4736 mutex_lock(&fs_devices->device_list_mutex);
4737 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4738 int item_size;
4739 struct btrfs_dev_stats_item *ptr;
4740
4741 key.objectid = 0;
4742 key.type = BTRFS_DEV_STATS_KEY;
4743 key.offset = device->devid;
4744 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
4745 if (ret) {
4746 __btrfs_reset_dev_stats(device);
4747 device->dev_stats_valid = 1;
4748 btrfs_release_path(path);
4749 continue;
4750 }
4751 slot = path->slots[0];
4752 eb = path->nodes[0];
4753 btrfs_item_key_to_cpu(eb, &found_key, slot);
4754 item_size = btrfs_item_size_nr(eb, slot);
4755
4756 ptr = btrfs_item_ptr(eb, slot,
4757 struct btrfs_dev_stats_item);
4758
4759 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4760 if (item_size >= (1 + i) * sizeof(__le64))
4761 btrfs_dev_stat_set(device, i,
4762 btrfs_dev_stats_value(eb, ptr, i));
4763 else
4764 btrfs_dev_stat_reset(device, i);
4765 }
4766
4767 device->dev_stats_valid = 1;
4768 btrfs_dev_stat_print_on_load(device);
4769 btrfs_release_path(path);
4770 }
4771 mutex_unlock(&fs_devices->device_list_mutex);
4772
4773 out:
4774 btrfs_free_path(path);
4775 return ret < 0 ? ret : 0;
4776 }
4777
4778 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
4779 struct btrfs_root *dev_root,
4780 struct btrfs_device *device)
4781 {
4782 struct btrfs_path *path;
4783 struct btrfs_key key;
4784 struct extent_buffer *eb;
4785 struct btrfs_dev_stats_item *ptr;
4786 int ret;
4787 int i;
4788
4789 key.objectid = 0;
4790 key.type = BTRFS_DEV_STATS_KEY;
4791 key.offset = device->devid;
4792
4793 path = btrfs_alloc_path();
4794 BUG_ON(!path);
4795 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
4796 if (ret < 0) {
4797 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
4798 ret, rcu_str_deref(device->name));
4799 goto out;
4800 }
4801
4802 if (ret == 0 &&
4803 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
4804 /* need to delete old one and insert a new one */
4805 ret = btrfs_del_item(trans, dev_root, path);
4806 if (ret != 0) {
4807 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
4808 rcu_str_deref(device->name), ret);
4809 goto out;
4810 }
4811 ret = 1;
4812 }
4813
4814 if (ret == 1) {
4815 /* need to insert a new item */
4816 btrfs_release_path(path);
4817 ret = btrfs_insert_empty_item(trans, dev_root, path,
4818 &key, sizeof(*ptr));
4819 if (ret < 0) {
4820 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
4821 rcu_str_deref(device->name), ret);
4822 goto out;
4823 }
4824 }
4825
4826 eb = path->nodes[0];
4827 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
4828 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4829 btrfs_set_dev_stats_value(eb, ptr, i,
4830 btrfs_dev_stat_read(device, i));
4831 btrfs_mark_buffer_dirty(eb);
4832
4833 out:
4834 btrfs_free_path(path);
4835 return ret;
4836 }
4837
4838 /*
4839 * called from commit_transaction. Writes all changed device stats to disk.
4840 */
4841 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
4842 struct btrfs_fs_info *fs_info)
4843 {
4844 struct btrfs_root *dev_root = fs_info->dev_root;
4845 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4846 struct btrfs_device *device;
4847 int ret = 0;
4848
4849 mutex_lock(&fs_devices->device_list_mutex);
4850 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4851 if (!device->dev_stats_valid || !device->dev_stats_dirty)
4852 continue;
4853
4854 ret = update_dev_stat_item(trans, dev_root, device);
4855 if (!ret)
4856 device->dev_stats_dirty = 0;
4857 }
4858 mutex_unlock(&fs_devices->device_list_mutex);
4859
4860 return ret;
4861 }
4862
4863 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
4864 {
4865 btrfs_dev_stat_inc(dev, index);
4866 btrfs_dev_stat_print_on_error(dev);
4867 }
4868
4869 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
4870 {
4871 if (!dev->dev_stats_valid)
4872 return;
4873 printk_ratelimited_in_rcu(KERN_ERR
4874 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4875 rcu_str_deref(dev->name),
4876 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4877 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4878 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4879 btrfs_dev_stat_read(dev,
4880 BTRFS_DEV_STAT_CORRUPTION_ERRS),
4881 btrfs_dev_stat_read(dev,
4882 BTRFS_DEV_STAT_GENERATION_ERRS));
4883 }
4884
4885 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
4886 {
4887 int i;
4888
4889 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4890 if (btrfs_dev_stat_read(dev, i) != 0)
4891 break;
4892 if (i == BTRFS_DEV_STAT_VALUES_MAX)
4893 return; /* all values == 0, suppress message */
4894
4895 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4896 rcu_str_deref(dev->name),
4897 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4898 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4899 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4900 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
4901 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
4902 }
4903
4904 int btrfs_get_dev_stats(struct btrfs_root *root,
4905 struct btrfs_ioctl_get_dev_stats *stats)
4906 {
4907 struct btrfs_device *dev;
4908 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4909 int i;
4910
4911 mutex_lock(&fs_devices->device_list_mutex);
4912 dev = btrfs_find_device(root, stats->devid, NULL, NULL);
4913 mutex_unlock(&fs_devices->device_list_mutex);
4914
4915 if (!dev) {
4916 printk(KERN_WARNING
4917 "btrfs: get dev_stats failed, device not found\n");
4918 return -ENODEV;
4919 } else if (!dev->dev_stats_valid) {
4920 printk(KERN_WARNING
4921 "btrfs: get dev_stats failed, not yet valid\n");
4922 return -ENODEV;
4923 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
4924 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4925 if (stats->nr_items > i)
4926 stats->values[i] =
4927 btrfs_dev_stat_read_and_reset(dev, i);
4928 else
4929 btrfs_dev_stat_reset(dev, i);
4930 }
4931 } else {
4932 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4933 if (stats->nr_items > i)
4934 stats->values[i] = btrfs_dev_stat_read(dev, i);
4935 }
4936 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
4937 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
4938 return 0;
4939 }
Linux kernel - Deliverables
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