projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Merge tag 'md-3.7-fixes' of git://neil.brown.name/md
[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
231 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
232 waitqueue_active(&fs_info->async_submit_wait))
233 wake_up(&fs_info->async_submit_wait);
234
235 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
236
237 /*
238 * if we're doing the sync list, record that our
239 * plug has some sync requests on it
240 *
241 * If we're doing the regular list and there are
242 * sync requests sitting around, unplug before
243 * we add more
244 */
245 if (pending_bios == &device->pending_sync_bios) {
246 sync_pending = 1;
247 } else if (sync_pending) {
248 blk_finish_plug(&plug);
249 blk_start_plug(&plug);
250 sync_pending = 0;
251 }
252
253 btrfsic_submit_bio(cur->bi_rw, cur);
254 num_run++;
255 batch_run++;
256 if (need_resched())
257 cond_resched();
258
259 /*
260 * we made progress, there is more work to do and the bdi
261 * is now congested. Back off and let other work structs
262 * run instead
263 */
264 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
265 fs_info->fs_devices->open_devices > 1) {
266 struct io_context *ioc;
267
268 ioc = current->io_context;
269
270 /*
271 * the main goal here is that we don't want to
272 * block if we're going to be able to submit
273 * more requests without blocking.
274 *
275 * This code does two great things, it pokes into
276 * the elevator code from a filesystem _and_
277 * it makes assumptions about how batching works.
278 */
279 if (ioc && ioc->nr_batch_requests > 0 &&
280 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
281 (last_waited == 0 ||
282 ioc->last_waited == last_waited)) {
283 /*
284 * we want to go through our batch of
285 * requests and stop. So, we copy out
286 * the ioc->last_waited time and test
287 * against it before looping
288 */
289 last_waited = ioc->last_waited;
290 if (need_resched())
291 cond_resched();
292 continue;
293 }
294 spin_lock(&device->io_lock);
295 requeue_list(pending_bios, pending, tail);
296 device->running_pending = 1;
297
298 spin_unlock(&device->io_lock);
299 btrfs_requeue_work(&device->work);
300 goto done;
301 }
302 /* unplug every 64 requests just for good measure */
303 if (batch_run % 64 == 0) {
304 blk_finish_plug(&plug);
305 blk_start_plug(&plug);
306 sync_pending = 0;
307 }
308 }
309
310 cond_resched();
311 if (again)
312 goto loop;
313
314 spin_lock(&device->io_lock);
315 if (device->pending_bios.head || device->pending_sync_bios.head)
316 goto loop_lock;
317 spin_unlock(&device->io_lock);
318
319 done:
320 blk_finish_plug(&plug);
321 }
322
323 static void pending_bios_fn(struct btrfs_work *work)
324 {
325 struct btrfs_device *device;
326
327 device = container_of(work, struct btrfs_device, work);
328 run_scheduled_bios(device);
329 }
330
331 static noinline int device_list_add(const char *path,
332 struct btrfs_super_block *disk_super,
333 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
334 {
335 struct btrfs_device *device;
336 struct btrfs_fs_devices *fs_devices;
337 struct rcu_string *name;
338 u64 found_transid = btrfs_super_generation(disk_super);
339
340 fs_devices = find_fsid(disk_super->fsid);
341 if (!fs_devices) {
342 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
343 if (!fs_devices)
344 return -ENOMEM;
345 INIT_LIST_HEAD(&fs_devices->devices);
346 INIT_LIST_HEAD(&fs_devices->alloc_list);
347 list_add(&fs_devices->list, &fs_uuids);
348 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
349 fs_devices->latest_devid = devid;
350 fs_devices->latest_trans = found_transid;
351 mutex_init(&fs_devices->device_list_mutex);
352 device = NULL;
353 } else {
354 device = __find_device(&fs_devices->devices, devid,
355 disk_super->dev_item.uuid);
356 }
357 if (!device) {
358 if (fs_devices->opened)
359 return -EBUSY;
360
361 device = kzalloc(sizeof(*device), GFP_NOFS);
362 if (!device) {
363 /* we can safely leave the fs_devices entry around */
364 return -ENOMEM;
365 }
366 device->devid = devid;
367 device->dev_stats_valid = 0;
368 device->work.func = pending_bios_fn;
369 memcpy(device->uuid, disk_super->dev_item.uuid,
370 BTRFS_UUID_SIZE);
371 spin_lock_init(&device->io_lock);
372
373 name = rcu_string_strdup(path, GFP_NOFS);
374 if (!name) {
375 kfree(device);
376 return -ENOMEM;
377 }
378 rcu_assign_pointer(device->name, name);
379 INIT_LIST_HEAD(&device->dev_alloc_list);
380
381 /* init readahead state */
382 spin_lock_init(&device->reada_lock);
383 device->reada_curr_zone = NULL;
384 atomic_set(&device->reada_in_flight, 0);
385 device->reada_next = 0;
386 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
387 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
388
389 mutex_lock(&fs_devices->device_list_mutex);
390 list_add_rcu(&device->dev_list, &fs_devices->devices);
391 mutex_unlock(&fs_devices->device_list_mutex);
392
393 device->fs_devices = fs_devices;
394 fs_devices->num_devices++;
395 } else if (!device->name || strcmp(device->name->str, path)) {
396 name = rcu_string_strdup(path, GFP_NOFS);
397 if (!name)
398 return -ENOMEM;
399 rcu_string_free(device->name);
400 rcu_assign_pointer(device->name, name);
401 if (device->missing) {
402 fs_devices->missing_devices--;
403 device->missing = 0;
404 }
405 }
406
407 if (found_transid > fs_devices->latest_trans) {
408 fs_devices->latest_devid = devid;
409 fs_devices->latest_trans = found_transid;
410 }
411 *fs_devices_ret = fs_devices;
412 return 0;
413 }
414
415 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
416 {
417 struct btrfs_fs_devices *fs_devices;
418 struct btrfs_device *device;
419 struct btrfs_device *orig_dev;
420
421 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
422 if (!fs_devices)
423 return ERR_PTR(-ENOMEM);
424
425 INIT_LIST_HEAD(&fs_devices->devices);
426 INIT_LIST_HEAD(&fs_devices->alloc_list);
427 INIT_LIST_HEAD(&fs_devices->list);
428 mutex_init(&fs_devices->device_list_mutex);
429 fs_devices->latest_devid = orig->latest_devid;
430 fs_devices->latest_trans = orig->latest_trans;
431 fs_devices->total_devices = orig->total_devices;
432 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
433
434 /* We have held the volume lock, it is safe to get the devices. */
435 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
436 struct rcu_string *name;
437
438 device = kzalloc(sizeof(*device), GFP_NOFS);
439 if (!device)
440 goto error;
441
442 /*
443 * This is ok to do without rcu read locked because we hold the
444 * uuid mutex so nothing we touch in here is going to disappear.
445 */
446 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
447 if (!name) {
448 kfree(device);
449 goto error;
450 }
451 rcu_assign_pointer(device->name, name);
452
453 device->devid = orig_dev->devid;
454 device->work.func = pending_bios_fn;
455 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
456 spin_lock_init(&device->io_lock);
457 INIT_LIST_HEAD(&device->dev_list);
458 INIT_LIST_HEAD(&device->dev_alloc_list);
459
460 list_add(&device->dev_list, &fs_devices->devices);
461 device->fs_devices = fs_devices;
462 fs_devices->num_devices++;
463 }
464 return fs_devices;
465 error:
466 free_fs_devices(fs_devices);
467 return ERR_PTR(-ENOMEM);
468 }
469
470 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
471 {
472 struct btrfs_device *device, *next;
473
474 struct block_device *latest_bdev = NULL;
475 u64 latest_devid = 0;
476 u64 latest_transid = 0;
477
478 mutex_lock(&uuid_mutex);
479 again:
480 /* This is the initialized path, it is safe to release the devices. */
481 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
482 if (device->in_fs_metadata) {
483 if (!latest_transid ||
484 device->generation > latest_transid) {
485 latest_devid = device->devid;
486 latest_transid = device->generation;
487 latest_bdev = device->bdev;
488 }
489 continue;
490 }
491
492 if (device->bdev) {
493 blkdev_put(device->bdev, device->mode);
494 device->bdev = NULL;
495 fs_devices->open_devices--;
496 }
497 if (device->writeable) {
498 list_del_init(&device->dev_alloc_list);
499 device->writeable = 0;
500 fs_devices->rw_devices--;
501 }
502 list_del_init(&device->dev_list);
503 fs_devices->num_devices--;
504 rcu_string_free(device->name);
505 kfree(device);
506 }
507
508 if (fs_devices->seed) {
509 fs_devices = fs_devices->seed;
510 goto again;
511 }
512
513 fs_devices->latest_bdev = latest_bdev;
514 fs_devices->latest_devid = latest_devid;
515 fs_devices->latest_trans = latest_transid;
516
517 mutex_unlock(&uuid_mutex);
518 }
519
520 static void __free_device(struct work_struct *work)
521 {
522 struct btrfs_device *device;
523
524 device = container_of(work, struct btrfs_device, rcu_work);
525
526 if (device->bdev)
527 blkdev_put(device->bdev, device->mode);
528
529 rcu_string_free(device->name);
530 kfree(device);
531 }
532
533 static void free_device(struct rcu_head *head)
534 {
535 struct btrfs_device *device;
536
537 device = container_of(head, struct btrfs_device, rcu);
538
539 INIT_WORK(&device->rcu_work, __free_device);
540 schedule_work(&device->rcu_work);
541 }
542
543 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
544 {
545 struct btrfs_device *device;
546
547 if (--fs_devices->opened > 0)
548 return 0;
549
550 mutex_lock(&fs_devices->device_list_mutex);
551 list_for_each_entry(device, &fs_devices->devices, dev_list) {
552 struct btrfs_device *new_device;
553 struct rcu_string *name;
554
555 if (device->bdev)
556 fs_devices->open_devices--;
557
558 if (device->writeable) {
559 list_del_init(&device->dev_alloc_list);
560 fs_devices->rw_devices--;
561 }
562
563 if (device->can_discard)
564 fs_devices->num_can_discard--;
565
566 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
567 BUG_ON(!new_device); /* -ENOMEM */
568 memcpy(new_device, device, sizeof(*new_device));
569
570 /* Safe because we are under uuid_mutex */
571 if (device->name) {
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 }
576 new_device->bdev = NULL;
577 new_device->writeable = 0;
578 new_device->in_fs_metadata = 0;
579 new_device->can_discard = 0;
580 list_replace_rcu(&device->dev_list, &new_device->dev_list);
581
582 call_rcu(&device->rcu, free_device);
583 }
584 mutex_unlock(&fs_devices->device_list_mutex);
585
586 WARN_ON(fs_devices->open_devices);
587 WARN_ON(fs_devices->rw_devices);
588 fs_devices->opened = 0;
589 fs_devices->seeding = 0;
590
591 return 0;
592 }
593
594 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
595 {
596 struct btrfs_fs_devices *seed_devices = NULL;
597 int ret;
598
599 mutex_lock(&uuid_mutex);
600 ret = __btrfs_close_devices(fs_devices);
601 if (!fs_devices->opened) {
602 seed_devices = fs_devices->seed;
603 fs_devices->seed = NULL;
604 }
605 mutex_unlock(&uuid_mutex);
606
607 while (seed_devices) {
608 fs_devices = seed_devices;
609 seed_devices = fs_devices->seed;
610 __btrfs_close_devices(fs_devices);
611 free_fs_devices(fs_devices);
612 }
613 return ret;
614 }
615
616 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
617 fmode_t flags, void *holder)
618 {
619 struct request_queue *q;
620 struct block_device *bdev;
621 struct list_head *head = &fs_devices->devices;
622 struct btrfs_device *device;
623 struct block_device *latest_bdev = NULL;
624 struct buffer_head *bh;
625 struct btrfs_super_block *disk_super;
626 u64 latest_devid = 0;
627 u64 latest_transid = 0;
628 u64 devid;
629 int seeding = 1;
630 int ret = 0;
631
632 flags |= FMODE_EXCL;
633
634 list_for_each_entry(device, head, dev_list) {
635 if (device->bdev)
636 continue;
637 if (!device->name)
638 continue;
639
640 bdev = blkdev_get_by_path(device->name->str, flags, holder);
641 if (IS_ERR(bdev)) {
642 printk(KERN_INFO "btrfs: open %s failed\n", device->name->str);
643 goto error;
644 }
645 filemap_write_and_wait(bdev->bd_inode->i_mapping);
646 invalidate_bdev(bdev);
647 set_blocksize(bdev, 4096);
648
649 bh = btrfs_read_dev_super(bdev);
650 if (!bh)
651 goto error_close;
652
653 disk_super = (struct btrfs_super_block *)bh->b_data;
654 devid = btrfs_stack_device_id(&disk_super->dev_item);
655 if (devid != device->devid)
656 goto error_brelse;
657
658 if (memcmp(device->uuid, disk_super->dev_item.uuid,
659 BTRFS_UUID_SIZE))
660 goto error_brelse;
661
662 device->generation = btrfs_super_generation(disk_super);
663 if (!latest_transid || device->generation > latest_transid) {
664 latest_devid = devid;
665 latest_transid = device->generation;
666 latest_bdev = bdev;
667 }
668
669 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
670 device->writeable = 0;
671 } else {
672 device->writeable = !bdev_read_only(bdev);
673 seeding = 0;
674 }
675
676 q = bdev_get_queue(bdev);
677 if (blk_queue_discard(q)) {
678 device->can_discard = 1;
679 fs_devices->num_can_discard++;
680 }
681
682 device->bdev = bdev;
683 device->in_fs_metadata = 0;
684 device->mode = flags;
685
686 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
687 fs_devices->rotating = 1;
688
689 fs_devices->open_devices++;
690 if (device->writeable) {
691 fs_devices->rw_devices++;
692 list_add(&device->dev_alloc_list,
693 &fs_devices->alloc_list);
694 }
695 brelse(bh);
696 continue;
697
698 error_brelse:
699 brelse(bh);
700 error_close:
701 blkdev_put(bdev, flags);
702 error:
703 continue;
704 }
705 if (fs_devices->open_devices == 0) {
706 ret = -EINVAL;
707 goto out;
708 }
709 fs_devices->seeding = seeding;
710 fs_devices->opened = 1;
711 fs_devices->latest_bdev = latest_bdev;
712 fs_devices->latest_devid = latest_devid;
713 fs_devices->latest_trans = latest_transid;
714 fs_devices->total_rw_bytes = 0;
715 out:
716 return ret;
717 }
718
719 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
720 fmode_t flags, void *holder)
721 {
722 int ret;
723
724 mutex_lock(&uuid_mutex);
725 if (fs_devices->opened) {
726 fs_devices->opened++;
727 ret = 0;
728 } else {
729 ret = __btrfs_open_devices(fs_devices, flags, holder);
730 }
731 mutex_unlock(&uuid_mutex);
732 return ret;
733 }
734
735 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
736 struct btrfs_fs_devices **fs_devices_ret)
737 {
738 struct btrfs_super_block *disk_super;
739 struct block_device *bdev;
740 struct buffer_head *bh;
741 int ret;
742 u64 devid;
743 u64 transid;
744 u64 total_devices;
745
746 flags |= FMODE_EXCL;
747 bdev = blkdev_get_by_path(path, flags, holder);
748
749 if (IS_ERR(bdev)) {
750 ret = PTR_ERR(bdev);
751 goto error;
752 }
753
754 mutex_lock(&uuid_mutex);
755 ret = set_blocksize(bdev, 4096);
756 if (ret)
757 goto error_close;
758 bh = btrfs_read_dev_super(bdev);
759 if (!bh) {
760 ret = -EINVAL;
761 goto error_close;
762 }
763 disk_super = (struct btrfs_super_block *)bh->b_data;
764 devid = btrfs_stack_device_id(&disk_super->dev_item);
765 transid = btrfs_super_generation(disk_super);
766 total_devices = btrfs_super_num_devices(disk_super);
767 if (disk_super->label[0])
768 printk(KERN_INFO "device label %s ", disk_super->label);
769 else
770 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
771 printk(KERN_CONT "devid %llu transid %llu %s\n",
772 (unsigned long long)devid, (unsigned long long)transid, path);
773 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
774 if (!ret && fs_devices_ret)
775 (*fs_devices_ret)->total_devices = total_devices;
776 brelse(bh);
777 error_close:
778 mutex_unlock(&uuid_mutex);
779 blkdev_put(bdev, flags);
780 error:
781 return ret;
782 }
783
784 /* helper to account the used device space in the range */
785 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
786 u64 end, u64 *length)
787 {
788 struct btrfs_key key;
789 struct btrfs_root *root = device->dev_root;
790 struct btrfs_dev_extent *dev_extent;
791 struct btrfs_path *path;
792 u64 extent_end;
793 int ret;
794 int slot;
795 struct extent_buffer *l;
796
797 *length = 0;
798
799 if (start >= device->total_bytes)
800 return 0;
801
802 path = btrfs_alloc_path();
803 if (!path)
804 return -ENOMEM;
805 path->reada = 2;
806
807 key.objectid = device->devid;
808 key.offset = start;
809 key.type = BTRFS_DEV_EXTENT_KEY;
810
811 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
812 if (ret < 0)
813 goto out;
814 if (ret > 0) {
815 ret = btrfs_previous_item(root, path, key.objectid, key.type);
816 if (ret < 0)
817 goto out;
818 }
819
820 while (1) {
821 l = path->nodes[0];
822 slot = path->slots[0];
823 if (slot >= btrfs_header_nritems(l)) {
824 ret = btrfs_next_leaf(root, path);
825 if (ret == 0)
826 continue;
827 if (ret < 0)
828 goto out;
829
830 break;
831 }
832 btrfs_item_key_to_cpu(l, &key, slot);
833
834 if (key.objectid < device->devid)
835 goto next;
836
837 if (key.objectid > device->devid)
838 break;
839
840 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
841 goto next;
842
843 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
844 extent_end = key.offset + btrfs_dev_extent_length(l,
845 dev_extent);
846 if (key.offset <= start && extent_end > end) {
847 *length = end - start + 1;
848 break;
849 } else if (key.offset <= start && extent_end > start)
850 *length += extent_end - start;
851 else if (key.offset > start && extent_end <= end)
852 *length += extent_end - key.offset;
853 else if (key.offset > start && key.offset <= end) {
854 *length += end - key.offset + 1;
855 break;
856 } else if (key.offset > end)
857 break;
858
859 next:
860 path->slots[0]++;
861 }
862 ret = 0;
863 out:
864 btrfs_free_path(path);
865 return ret;
866 }
867
868 /*
869 * find_free_dev_extent - find free space in the specified device
870 * @device: the device which we search the free space in
871 * @num_bytes: the size of the free space that we need
872 * @start: store the start of the free space.
873 * @len: the size of the free space. that we find, or the size of the max
874 * free space if we don't find suitable free space
875 *
876 * this uses a pretty simple search, the expectation is that it is
877 * called very infrequently and that a given device has a small number
878 * of extents
879 *
880 * @start is used to store the start of the free space if we find. But if we
881 * don't find suitable free space, it will be used to store the start position
882 * of the max free space.
883 *
884 * @len is used to store the size of the free space that we find.
885 * But if we don't find suitable free space, it is used to store the size of
886 * the max free space.
887 */
888 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
889 u64 *start, u64 *len)
890 {
891 struct btrfs_key key;
892 struct btrfs_root *root = device->dev_root;
893 struct btrfs_dev_extent *dev_extent;
894 struct btrfs_path *path;
895 u64 hole_size;
896 u64 max_hole_start;
897 u64 max_hole_size;
898 u64 extent_end;
899 u64 search_start;
900 u64 search_end = device->total_bytes;
901 int ret;
902 int slot;
903 struct extent_buffer *l;
904
905 /* FIXME use last free of some kind */
906
907 /* we don't want to overwrite the superblock on the drive,
908 * so we make sure to start at an offset of at least 1MB
909 */
910 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
911
912 max_hole_start = search_start;
913 max_hole_size = 0;
914 hole_size = 0;
915
916 if (search_start >= search_end) {
917 ret = -ENOSPC;
918 goto error;
919 }
920
921 path = btrfs_alloc_path();
922 if (!path) {
923 ret = -ENOMEM;
924 goto error;
925 }
926 path->reada = 2;
927
928 key.objectid = device->devid;
929 key.offset = search_start;
930 key.type = BTRFS_DEV_EXTENT_KEY;
931
932 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
933 if (ret < 0)
934 goto out;
935 if (ret > 0) {
936 ret = btrfs_previous_item(root, path, key.objectid, key.type);
937 if (ret < 0)
938 goto out;
939 }
940
941 while (1) {
942 l = path->nodes[0];
943 slot = path->slots[0];
944 if (slot >= btrfs_header_nritems(l)) {
945 ret = btrfs_next_leaf(root, path);
946 if (ret == 0)
947 continue;
948 if (ret < 0)
949 goto out;
950
951 break;
952 }
953 btrfs_item_key_to_cpu(l, &key, slot);
954
955 if (key.objectid < device->devid)
956 goto next;
957
958 if (key.objectid > device->devid)
959 break;
960
961 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
962 goto next;
963
964 if (key.offset > search_start) {
965 hole_size = key.offset - search_start;
966
967 if (hole_size > max_hole_size) {
968 max_hole_start = search_start;
969 max_hole_size = hole_size;
970 }
971
972 /*
973 * If this free space is greater than which we need,
974 * it must be the max free space that we have found
975 * until now, so max_hole_start must point to the start
976 * of this free space and the length of this free space
977 * is stored in max_hole_size. Thus, we return
978 * max_hole_start and max_hole_size and go back to the
979 * caller.
980 */
981 if (hole_size >= num_bytes) {
982 ret = 0;
983 goto out;
984 }
985 }
986
987 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
988 extent_end = key.offset + btrfs_dev_extent_length(l,
989 dev_extent);
990 if (extent_end > search_start)
991 search_start = extent_end;
992 next:
993 path->slots[0]++;
994 cond_resched();
995 }
996
997 /*
998 * At this point, search_start should be the end of
999 * allocated dev extents, and when shrinking the device,
1000 * search_end may be smaller than search_start.
1001 */
1002 if (search_end > search_start)
1003 hole_size = search_end - search_start;
1004
1005 if (hole_size > max_hole_size) {
1006 max_hole_start = search_start;
1007 max_hole_size = hole_size;
1008 }
1009
1010 /* See above. */
1011 if (hole_size < num_bytes)
1012 ret = -ENOSPC;
1013 else
1014 ret = 0;
1015
1016 out:
1017 btrfs_free_path(path);
1018 error:
1019 *start = max_hole_start;
1020 if (len)
1021 *len = max_hole_size;
1022 return ret;
1023 }
1024
1025 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1026 struct btrfs_device *device,
1027 u64 start)
1028 {
1029 int ret;
1030 struct btrfs_path *path;
1031 struct btrfs_root *root = device->dev_root;
1032 struct btrfs_key key;
1033 struct btrfs_key found_key;
1034 struct extent_buffer *leaf = NULL;
1035 struct btrfs_dev_extent *extent = NULL;
1036
1037 path = btrfs_alloc_path();
1038 if (!path)
1039 return -ENOMEM;
1040
1041 key.objectid = device->devid;
1042 key.offset = start;
1043 key.type = BTRFS_DEV_EXTENT_KEY;
1044 again:
1045 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1046 if (ret > 0) {
1047 ret = btrfs_previous_item(root, path, key.objectid,
1048 BTRFS_DEV_EXTENT_KEY);
1049 if (ret)
1050 goto out;
1051 leaf = path->nodes[0];
1052 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1053 extent = btrfs_item_ptr(leaf, path->slots[0],
1054 struct btrfs_dev_extent);
1055 BUG_ON(found_key.offset > start || found_key.offset +
1056 btrfs_dev_extent_length(leaf, extent) < start);
1057 key = found_key;
1058 btrfs_release_path(path);
1059 goto again;
1060 } else if (ret == 0) {
1061 leaf = path->nodes[0];
1062 extent = btrfs_item_ptr(leaf, path->slots[0],
1063 struct btrfs_dev_extent);
1064 } else {
1065 btrfs_error(root->fs_info, ret, "Slot search failed");
1066 goto out;
1067 }
1068
1069 if (device->bytes_used > 0) {
1070 u64 len = btrfs_dev_extent_length(leaf, extent);
1071 device->bytes_used -= len;
1072 spin_lock(&root->fs_info->free_chunk_lock);
1073 root->fs_info->free_chunk_space += len;
1074 spin_unlock(&root->fs_info->free_chunk_lock);
1075 }
1076 ret = btrfs_del_item(trans, root, path);
1077 if (ret) {
1078 btrfs_error(root->fs_info, ret,
1079 "Failed to remove dev extent item");
1080 }
1081 out:
1082 btrfs_free_path(path);
1083 return ret;
1084 }
1085
1086 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1087 struct btrfs_device *device,
1088 u64 chunk_tree, u64 chunk_objectid,
1089 u64 chunk_offset, u64 start, u64 num_bytes)
1090 {
1091 int ret;
1092 struct btrfs_path *path;
1093 struct btrfs_root *root = device->dev_root;
1094 struct btrfs_dev_extent *extent;
1095 struct extent_buffer *leaf;
1096 struct btrfs_key key;
1097
1098 WARN_ON(!device->in_fs_metadata);
1099 path = btrfs_alloc_path();
1100 if (!path)
1101 return -ENOMEM;
1102
1103 key.objectid = device->devid;
1104 key.offset = start;
1105 key.type = BTRFS_DEV_EXTENT_KEY;
1106 ret = btrfs_insert_empty_item(trans, root, path, &key,
1107 sizeof(*extent));
1108 if (ret)
1109 goto out;
1110
1111 leaf = path->nodes[0];
1112 extent = btrfs_item_ptr(leaf, path->slots[0],
1113 struct btrfs_dev_extent);
1114 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1115 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1116 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1117
1118 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1119 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1120 BTRFS_UUID_SIZE);
1121
1122 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1123 btrfs_mark_buffer_dirty(leaf);
1124 out:
1125 btrfs_free_path(path);
1126 return ret;
1127 }
1128
1129 static noinline int find_next_chunk(struct btrfs_root *root,
1130 u64 objectid, u64 *offset)
1131 {
1132 struct btrfs_path *path;
1133 int ret;
1134 struct btrfs_key key;
1135 struct btrfs_chunk *chunk;
1136 struct btrfs_key found_key;
1137
1138 path = btrfs_alloc_path();
1139 if (!path)
1140 return -ENOMEM;
1141
1142 key.objectid = objectid;
1143 key.offset = (u64)-1;
1144 key.type = BTRFS_CHUNK_ITEM_KEY;
1145
1146 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1147 if (ret < 0)
1148 goto error;
1149
1150 BUG_ON(ret == 0); /* Corruption */
1151
1152 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1153 if (ret) {
1154 *offset = 0;
1155 } else {
1156 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1157 path->slots[0]);
1158 if (found_key.objectid != objectid)
1159 *offset = 0;
1160 else {
1161 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1162 struct btrfs_chunk);
1163 *offset = found_key.offset +
1164 btrfs_chunk_length(path->nodes[0], chunk);
1165 }
1166 }
1167 ret = 0;
1168 error:
1169 btrfs_free_path(path);
1170 return ret;
1171 }
1172
1173 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1174 {
1175 int ret;
1176 struct btrfs_key key;
1177 struct btrfs_key found_key;
1178 struct btrfs_path *path;
1179
1180 root = root->fs_info->chunk_root;
1181
1182 path = btrfs_alloc_path();
1183 if (!path)
1184 return -ENOMEM;
1185
1186 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1187 key.type = BTRFS_DEV_ITEM_KEY;
1188 key.offset = (u64)-1;
1189
1190 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1191 if (ret < 0)
1192 goto error;
1193
1194 BUG_ON(ret == 0); /* Corruption */
1195
1196 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1197 BTRFS_DEV_ITEM_KEY);
1198 if (ret) {
1199 *objectid = 1;
1200 } else {
1201 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1202 path->slots[0]);
1203 *objectid = found_key.offset + 1;
1204 }
1205 ret = 0;
1206 error:
1207 btrfs_free_path(path);
1208 return ret;
1209 }
1210
1211 /*
1212 * the device information is stored in the chunk root
1213 * the btrfs_device struct should be fully filled in
1214 */
1215 int btrfs_add_device(struct btrfs_trans_handle *trans,
1216 struct btrfs_root *root,
1217 struct btrfs_device *device)
1218 {
1219 int ret;
1220 struct btrfs_path *path;
1221 struct btrfs_dev_item *dev_item;
1222 struct extent_buffer *leaf;
1223 struct btrfs_key key;
1224 unsigned long ptr;
1225
1226 root = root->fs_info->chunk_root;
1227
1228 path = btrfs_alloc_path();
1229 if (!path)
1230 return -ENOMEM;
1231
1232 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1233 key.type = BTRFS_DEV_ITEM_KEY;
1234 key.offset = device->devid;
1235
1236 ret = btrfs_insert_empty_item(trans, root, path, &key,
1237 sizeof(*dev_item));
1238 if (ret)
1239 goto out;
1240
1241 leaf = path->nodes[0];
1242 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1243
1244 btrfs_set_device_id(leaf, dev_item, device->devid);
1245 btrfs_set_device_generation(leaf, dev_item, 0);
1246 btrfs_set_device_type(leaf, dev_item, device->type);
1247 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1248 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1249 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1250 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1251 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1252 btrfs_set_device_group(leaf, dev_item, 0);
1253 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1254 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1255 btrfs_set_device_start_offset(leaf, dev_item, 0);
1256
1257 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1258 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1259 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1260 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1261 btrfs_mark_buffer_dirty(leaf);
1262
1263 ret = 0;
1264 out:
1265 btrfs_free_path(path);
1266 return ret;
1267 }
1268
1269 static int btrfs_rm_dev_item(struct btrfs_root *root,
1270 struct btrfs_device *device)
1271 {
1272 int ret;
1273 struct btrfs_path *path;
1274 struct btrfs_key key;
1275 struct btrfs_trans_handle *trans;
1276
1277 root = root->fs_info->chunk_root;
1278
1279 path = btrfs_alloc_path();
1280 if (!path)
1281 return -ENOMEM;
1282
1283 trans = btrfs_start_transaction(root, 0);
1284 if (IS_ERR(trans)) {
1285 btrfs_free_path(path);
1286 return PTR_ERR(trans);
1287 }
1288 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1289 key.type = BTRFS_DEV_ITEM_KEY;
1290 key.offset = device->devid;
1291 lock_chunks(root);
1292
1293 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1294 if (ret < 0)
1295 goto out;
1296
1297 if (ret > 0) {
1298 ret = -ENOENT;
1299 goto out;
1300 }
1301
1302 ret = btrfs_del_item(trans, root, path);
1303 if (ret)
1304 goto out;
1305 out:
1306 btrfs_free_path(path);
1307 unlock_chunks(root);
1308 btrfs_commit_transaction(trans, root);
1309 return ret;
1310 }
1311
1312 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1313 {
1314 struct btrfs_device *device;
1315 struct btrfs_device *next_device;
1316 struct block_device *bdev;
1317 struct buffer_head *bh = NULL;
1318 struct btrfs_super_block *disk_super;
1319 struct btrfs_fs_devices *cur_devices;
1320 u64 all_avail;
1321 u64 devid;
1322 u64 num_devices;
1323 u8 *dev_uuid;
1324 int ret = 0;
1325 bool clear_super = false;
1326
1327 mutex_lock(&uuid_mutex);
1328
1329 all_avail = root->fs_info->avail_data_alloc_bits |
1330 root->fs_info->avail_system_alloc_bits |
1331 root->fs_info->avail_metadata_alloc_bits;
1332
1333 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1334 root->fs_info->fs_devices->num_devices <= 4) {
1335 printk(KERN_ERR "btrfs: unable to go below four devices "
1336 "on raid10\n");
1337 ret = -EINVAL;
1338 goto out;
1339 }
1340
1341 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1342 root->fs_info->fs_devices->num_devices <= 2) {
1343 printk(KERN_ERR "btrfs: unable to go below two "
1344 "devices on raid1\n");
1345 ret = -EINVAL;
1346 goto out;
1347 }
1348
1349 if (strcmp(device_path, "missing") == 0) {
1350 struct list_head *devices;
1351 struct btrfs_device *tmp;
1352
1353 device = NULL;
1354 devices = &root->fs_info->fs_devices->devices;
1355 /*
1356 * It is safe to read the devices since the volume_mutex
1357 * is held.
1358 */
1359 list_for_each_entry(tmp, devices, dev_list) {
1360 if (tmp->in_fs_metadata && !tmp->bdev) {
1361 device = tmp;
1362 break;
1363 }
1364 }
1365 bdev = NULL;
1366 bh = NULL;
1367 disk_super = NULL;
1368 if (!device) {
1369 printk(KERN_ERR "btrfs: no missing devices found to "
1370 "remove\n");
1371 goto out;
1372 }
1373 } else {
1374 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1375 root->fs_info->bdev_holder);
1376 if (IS_ERR(bdev)) {
1377 ret = PTR_ERR(bdev);
1378 goto out;
1379 }
1380
1381 set_blocksize(bdev, 4096);
1382 invalidate_bdev(bdev);
1383 bh = btrfs_read_dev_super(bdev);
1384 if (!bh) {
1385 ret = -EINVAL;
1386 goto error_close;
1387 }
1388 disk_super = (struct btrfs_super_block *)bh->b_data;
1389 devid = btrfs_stack_device_id(&disk_super->dev_item);
1390 dev_uuid = disk_super->dev_item.uuid;
1391 device = btrfs_find_device(root, devid, dev_uuid,
1392 disk_super->fsid);
1393 if (!device) {
1394 ret = -ENOENT;
1395 goto error_brelse;
1396 }
1397 }
1398
1399 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1400 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1401 "device\n");
1402 ret = -EINVAL;
1403 goto error_brelse;
1404 }
1405
1406 if (device->writeable) {
1407 lock_chunks(root);
1408 list_del_init(&device->dev_alloc_list);
1409 unlock_chunks(root);
1410 root->fs_info->fs_devices->rw_devices--;
1411 clear_super = true;
1412 }
1413
1414 ret = btrfs_shrink_device(device, 0);
1415 if (ret)
1416 goto error_undo;
1417
1418 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1419 if (ret)
1420 goto error_undo;
1421
1422 spin_lock(&root->fs_info->free_chunk_lock);
1423 root->fs_info->free_chunk_space = device->total_bytes -
1424 device->bytes_used;
1425 spin_unlock(&root->fs_info->free_chunk_lock);
1426
1427 device->in_fs_metadata = 0;
1428 btrfs_scrub_cancel_dev(root, device);
1429
1430 /*
1431 * the device list mutex makes sure that we don't change
1432 * the device list while someone else is writing out all
1433 * the device supers.
1434 */
1435
1436 cur_devices = device->fs_devices;
1437 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1438 list_del_rcu(&device->dev_list);
1439
1440 device->fs_devices->num_devices--;
1441 device->fs_devices->total_devices--;
1442
1443 if (device->missing)
1444 root->fs_info->fs_devices->missing_devices--;
1445
1446 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1447 struct btrfs_device, dev_list);
1448 if (device->bdev == root->fs_info->sb->s_bdev)
1449 root->fs_info->sb->s_bdev = next_device->bdev;
1450 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1451 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1452
1453 if (device->bdev)
1454 device->fs_devices->open_devices--;
1455
1456 call_rcu(&device->rcu, free_device);
1457 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1458
1459 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1460 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1461
1462 if (cur_devices->open_devices == 0) {
1463 struct btrfs_fs_devices *fs_devices;
1464 fs_devices = root->fs_info->fs_devices;
1465 while (fs_devices) {
1466 if (fs_devices->seed == cur_devices)
1467 break;
1468 fs_devices = fs_devices->seed;
1469 }
1470 fs_devices->seed = cur_devices->seed;
1471 cur_devices->seed = NULL;
1472 lock_chunks(root);
1473 __btrfs_close_devices(cur_devices);
1474 unlock_chunks(root);
1475 free_fs_devices(cur_devices);
1476 }
1477
1478 root->fs_info->num_tolerated_disk_barrier_failures =
1479 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1480
1481 /*
1482 * at this point, the device is zero sized. We want to
1483 * remove it from the devices list and zero out the old super
1484 */
1485 if (clear_super) {
1486 /* make sure this device isn't detected as part of
1487 * the FS anymore
1488 */
1489 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1490 set_buffer_dirty(bh);
1491 sync_dirty_buffer(bh);
1492 }
1493
1494 ret = 0;
1495
1496 error_brelse:
1497 brelse(bh);
1498 error_close:
1499 if (bdev)
1500 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1501 out:
1502 mutex_unlock(&uuid_mutex);
1503 return ret;
1504 error_undo:
1505 if (device->writeable) {
1506 lock_chunks(root);
1507 list_add(&device->dev_alloc_list,
1508 &root->fs_info->fs_devices->alloc_list);
1509 unlock_chunks(root);
1510 root->fs_info->fs_devices->rw_devices++;
1511 }
1512 goto error_brelse;
1513 }
1514
1515 /*
1516 * does all the dirty work required for changing file system's UUID.
1517 */
1518 static int btrfs_prepare_sprout(struct btrfs_root *root)
1519 {
1520 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1521 struct btrfs_fs_devices *old_devices;
1522 struct btrfs_fs_devices *seed_devices;
1523 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1524 struct btrfs_device *device;
1525 u64 super_flags;
1526
1527 BUG_ON(!mutex_is_locked(&uuid_mutex));
1528 if (!fs_devices->seeding)
1529 return -EINVAL;
1530
1531 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1532 if (!seed_devices)
1533 return -ENOMEM;
1534
1535 old_devices = clone_fs_devices(fs_devices);
1536 if (IS_ERR(old_devices)) {
1537 kfree(seed_devices);
1538 return PTR_ERR(old_devices);
1539 }
1540
1541 list_add(&old_devices->list, &fs_uuids);
1542
1543 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1544 seed_devices->opened = 1;
1545 INIT_LIST_HEAD(&seed_devices->devices);
1546 INIT_LIST_HEAD(&seed_devices->alloc_list);
1547 mutex_init(&seed_devices->device_list_mutex);
1548
1549 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1550 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1551 synchronize_rcu);
1552 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1553
1554 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1555 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1556 device->fs_devices = seed_devices;
1557 }
1558
1559 fs_devices->seeding = 0;
1560 fs_devices->num_devices = 0;
1561 fs_devices->open_devices = 0;
1562 fs_devices->total_devices = 0;
1563 fs_devices->seed = seed_devices;
1564
1565 generate_random_uuid(fs_devices->fsid);
1566 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1567 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1568 super_flags = btrfs_super_flags(disk_super) &
1569 ~BTRFS_SUPER_FLAG_SEEDING;
1570 btrfs_set_super_flags(disk_super, super_flags);
1571
1572 return 0;
1573 }
1574
1575 /*
1576 * strore the expected generation for seed devices in device items.
1577 */
1578 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1579 struct btrfs_root *root)
1580 {
1581 struct btrfs_path *path;
1582 struct extent_buffer *leaf;
1583 struct btrfs_dev_item *dev_item;
1584 struct btrfs_device *device;
1585 struct btrfs_key key;
1586 u8 fs_uuid[BTRFS_UUID_SIZE];
1587 u8 dev_uuid[BTRFS_UUID_SIZE];
1588 u64 devid;
1589 int ret;
1590
1591 path = btrfs_alloc_path();
1592 if (!path)
1593 return -ENOMEM;
1594
1595 root = root->fs_info->chunk_root;
1596 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1597 key.offset = 0;
1598 key.type = BTRFS_DEV_ITEM_KEY;
1599
1600 while (1) {
1601 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1602 if (ret < 0)
1603 goto error;
1604
1605 leaf = path->nodes[0];
1606 next_slot:
1607 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1608 ret = btrfs_next_leaf(root, path);
1609 if (ret > 0)
1610 break;
1611 if (ret < 0)
1612 goto error;
1613 leaf = path->nodes[0];
1614 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1615 btrfs_release_path(path);
1616 continue;
1617 }
1618
1619 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1620 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1621 key.type != BTRFS_DEV_ITEM_KEY)
1622 break;
1623
1624 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1625 struct btrfs_dev_item);
1626 devid = btrfs_device_id(leaf, dev_item);
1627 read_extent_buffer(leaf, dev_uuid,
1628 (unsigned long)btrfs_device_uuid(dev_item),
1629 BTRFS_UUID_SIZE);
1630 read_extent_buffer(leaf, fs_uuid,
1631 (unsigned long)btrfs_device_fsid(dev_item),
1632 BTRFS_UUID_SIZE);
1633 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1634 BUG_ON(!device); /* Logic error */
1635
1636 if (device->fs_devices->seeding) {
1637 btrfs_set_device_generation(leaf, dev_item,
1638 device->generation);
1639 btrfs_mark_buffer_dirty(leaf);
1640 }
1641
1642 path->slots[0]++;
1643 goto next_slot;
1644 }
1645 ret = 0;
1646 error:
1647 btrfs_free_path(path);
1648 return ret;
1649 }
1650
1651 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1652 {
1653 struct request_queue *q;
1654 struct btrfs_trans_handle *trans;
1655 struct btrfs_device *device;
1656 struct block_device *bdev;
1657 struct list_head *devices;
1658 struct super_block *sb = root->fs_info->sb;
1659 struct rcu_string *name;
1660 u64 total_bytes;
1661 int seeding_dev = 0;
1662 int ret = 0;
1663
1664 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1665 return -EROFS;
1666
1667 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1668 root->fs_info->bdev_holder);
1669 if (IS_ERR(bdev))
1670 return PTR_ERR(bdev);
1671
1672 if (root->fs_info->fs_devices->seeding) {
1673 seeding_dev = 1;
1674 down_write(&sb->s_umount);
1675 mutex_lock(&uuid_mutex);
1676 }
1677
1678 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1679
1680 devices = &root->fs_info->fs_devices->devices;
1681 /*
1682 * we have the volume lock, so we don't need the extra
1683 * device list mutex while reading the list here.
1684 */
1685 list_for_each_entry(device, devices, dev_list) {
1686 if (device->bdev == bdev) {
1687 ret = -EEXIST;
1688 goto error;
1689 }
1690 }
1691
1692 device = kzalloc(sizeof(*device), GFP_NOFS);
1693 if (!device) {
1694 /* we can safely leave the fs_devices entry around */
1695 ret = -ENOMEM;
1696 goto error;
1697 }
1698
1699 name = rcu_string_strdup(device_path, GFP_NOFS);
1700 if (!name) {
1701 kfree(device);
1702 ret = -ENOMEM;
1703 goto error;
1704 }
1705 rcu_assign_pointer(device->name, name);
1706
1707 ret = find_next_devid(root, &device->devid);
1708 if (ret) {
1709 rcu_string_free(device->name);
1710 kfree(device);
1711 goto error;
1712 }
1713
1714 trans = btrfs_start_transaction(root, 0);
1715 if (IS_ERR(trans)) {
1716 rcu_string_free(device->name);
1717 kfree(device);
1718 ret = PTR_ERR(trans);
1719 goto error;
1720 }
1721
1722 lock_chunks(root);
1723
1724 q = bdev_get_queue(bdev);
1725 if (blk_queue_discard(q))
1726 device->can_discard = 1;
1727 device->writeable = 1;
1728 device->work.func = pending_bios_fn;
1729 generate_random_uuid(device->uuid);
1730 spin_lock_init(&device->io_lock);
1731 device->generation = trans->transid;
1732 device->io_width = root->sectorsize;
1733 device->io_align = root->sectorsize;
1734 device->sector_size = root->sectorsize;
1735 device->total_bytes = i_size_read(bdev->bd_inode);
1736 device->disk_total_bytes = device->total_bytes;
1737 device->dev_root = root->fs_info->dev_root;
1738 device->bdev = bdev;
1739 device->in_fs_metadata = 1;
1740 device->mode = FMODE_EXCL;
1741 set_blocksize(device->bdev, 4096);
1742
1743 if (seeding_dev) {
1744 sb->s_flags &= ~MS_RDONLY;
1745 ret = btrfs_prepare_sprout(root);
1746 BUG_ON(ret); /* -ENOMEM */
1747 }
1748
1749 device->fs_devices = root->fs_info->fs_devices;
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 btrfs_abort_transaction(trans, root, ret);
1783 goto error_trans;
1784 }
1785 ret = btrfs_finish_sprout(trans, root);
1786 if (ret) {
1787 btrfs_abort_transaction(trans, root, ret);
1788 goto error_trans;
1789 }
1790 } else {
1791 ret = btrfs_add_device(trans, root, device);
1792 if (ret) {
1793 btrfs_abort_transaction(trans, root, ret);
1794 goto error_trans;
1795 }
1796 }
1797
1798 /*
1799 * we've got more storage, clear any full flags on the space
1800 * infos
1801 */
1802 btrfs_clear_space_info_full(root->fs_info);
1803
1804 unlock_chunks(root);
1805 root->fs_info->num_tolerated_disk_barrier_failures =
1806 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1807 ret = btrfs_commit_transaction(trans, root);
1808
1809 if (seeding_dev) {
1810 mutex_unlock(&uuid_mutex);
1811 up_write(&sb->s_umount);
1812
1813 if (ret) /* transaction commit */
1814 return ret;
1815
1816 ret = btrfs_relocate_sys_chunks(root);
1817 if (ret < 0)
1818 btrfs_error(root->fs_info, ret,
1819 "Failed to relocate sys chunks after "
1820 "device initialization. This can be fixed "
1821 "using the \"btrfs balance\" command.");
1822 trans = btrfs_attach_transaction(root);
1823 if (IS_ERR(trans)) {
1824 if (PTR_ERR(trans) == -ENOENT)
1825 return 0;
1826 return PTR_ERR(trans);
1827 }
1828 ret = btrfs_commit_transaction(trans, root);
1829 }
1830
1831 return ret;
1832
1833 error_trans:
1834 unlock_chunks(root);
1835 btrfs_end_transaction(trans, root);
1836 rcu_string_free(device->name);
1837 kfree(device);
1838 error:
1839 blkdev_put(bdev, FMODE_EXCL);
1840 if (seeding_dev) {
1841 mutex_unlock(&uuid_mutex);
1842 up_write(&sb->s_umount);
1843 }
1844 return ret;
1845 }
1846
1847 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1848 struct btrfs_device *device)
1849 {
1850 int ret;
1851 struct btrfs_path *path;
1852 struct btrfs_root *root;
1853 struct btrfs_dev_item *dev_item;
1854 struct extent_buffer *leaf;
1855 struct btrfs_key key;
1856
1857 root = device->dev_root->fs_info->chunk_root;
1858
1859 path = btrfs_alloc_path();
1860 if (!path)
1861 return -ENOMEM;
1862
1863 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1864 key.type = BTRFS_DEV_ITEM_KEY;
1865 key.offset = device->devid;
1866
1867 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1868 if (ret < 0)
1869 goto out;
1870
1871 if (ret > 0) {
1872 ret = -ENOENT;
1873 goto out;
1874 }
1875
1876 leaf = path->nodes[0];
1877 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1878
1879 btrfs_set_device_id(leaf, dev_item, device->devid);
1880 btrfs_set_device_type(leaf, dev_item, device->type);
1881 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1882 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1883 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1884 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1885 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1886 btrfs_mark_buffer_dirty(leaf);
1887
1888 out:
1889 btrfs_free_path(path);
1890 return ret;
1891 }
1892
1893 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1894 struct btrfs_device *device, u64 new_size)
1895 {
1896 struct btrfs_super_block *super_copy =
1897 device->dev_root->fs_info->super_copy;
1898 u64 old_total = btrfs_super_total_bytes(super_copy);
1899 u64 diff = new_size - device->total_bytes;
1900
1901 if (!device->writeable)
1902 return -EACCES;
1903 if (new_size <= device->total_bytes)
1904 return -EINVAL;
1905
1906 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1907 device->fs_devices->total_rw_bytes += diff;
1908
1909 device->total_bytes = new_size;
1910 device->disk_total_bytes = new_size;
1911 btrfs_clear_space_info_full(device->dev_root->fs_info);
1912
1913 return btrfs_update_device(trans, device);
1914 }
1915
1916 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1917 struct btrfs_device *device, u64 new_size)
1918 {
1919 int ret;
1920 lock_chunks(device->dev_root);
1921 ret = __btrfs_grow_device(trans, device, new_size);
1922 unlock_chunks(device->dev_root);
1923 return ret;
1924 }
1925
1926 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1927 struct btrfs_root *root,
1928 u64 chunk_tree, u64 chunk_objectid,
1929 u64 chunk_offset)
1930 {
1931 int ret;
1932 struct btrfs_path *path;
1933 struct btrfs_key key;
1934
1935 root = root->fs_info->chunk_root;
1936 path = btrfs_alloc_path();
1937 if (!path)
1938 return -ENOMEM;
1939
1940 key.objectid = chunk_objectid;
1941 key.offset = chunk_offset;
1942 key.type = BTRFS_CHUNK_ITEM_KEY;
1943
1944 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1945 if (ret < 0)
1946 goto out;
1947 else if (ret > 0) { /* Logic error or corruption */
1948 btrfs_error(root->fs_info, -ENOENT,
1949 "Failed lookup while freeing chunk.");
1950 ret = -ENOENT;
1951 goto out;
1952 }
1953
1954 ret = btrfs_del_item(trans, root, path);
1955 if (ret < 0)
1956 btrfs_error(root->fs_info, ret,
1957 "Failed to delete chunk item.");
1958 out:
1959 btrfs_free_path(path);
1960 return ret;
1961 }
1962
1963 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1964 chunk_offset)
1965 {
1966 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1967 struct btrfs_disk_key *disk_key;
1968 struct btrfs_chunk *chunk;
1969 u8 *ptr;
1970 int ret = 0;
1971 u32 num_stripes;
1972 u32 array_size;
1973 u32 len = 0;
1974 u32 cur;
1975 struct btrfs_key key;
1976
1977 array_size = btrfs_super_sys_array_size(super_copy);
1978
1979 ptr = super_copy->sys_chunk_array;
1980 cur = 0;
1981
1982 while (cur < array_size) {
1983 disk_key = (struct btrfs_disk_key *)ptr;
1984 btrfs_disk_key_to_cpu(&key, disk_key);
1985
1986 len = sizeof(*disk_key);
1987
1988 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1989 chunk = (struct btrfs_chunk *)(ptr + len);
1990 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1991 len += btrfs_chunk_item_size(num_stripes);
1992 } else {
1993 ret = -EIO;
1994 break;
1995 }
1996 if (key.objectid == chunk_objectid &&
1997 key.offset == chunk_offset) {
1998 memmove(ptr, ptr + len, array_size - (cur + len));
1999 array_size -= len;
2000 btrfs_set_super_sys_array_size(super_copy, array_size);
2001 } else {
2002 ptr += len;
2003 cur += len;
2004 }
2005 }
2006 return ret;
2007 }
2008
2009 static int btrfs_relocate_chunk(struct btrfs_root *root,
2010 u64 chunk_tree, u64 chunk_objectid,
2011 u64 chunk_offset)
2012 {
2013 struct extent_map_tree *em_tree;
2014 struct btrfs_root *extent_root;
2015 struct btrfs_trans_handle *trans;
2016 struct extent_map *em;
2017 struct map_lookup *map;
2018 int ret;
2019 int i;
2020
2021 root = root->fs_info->chunk_root;
2022 extent_root = root->fs_info->extent_root;
2023 em_tree = &root->fs_info->mapping_tree.map_tree;
2024
2025 ret = btrfs_can_relocate(extent_root, chunk_offset);
2026 if (ret)
2027 return -ENOSPC;
2028
2029 /* step one, relocate all the extents inside this chunk */
2030 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2031 if (ret)
2032 return ret;
2033
2034 trans = btrfs_start_transaction(root, 0);
2035 BUG_ON(IS_ERR(trans));
2036
2037 lock_chunks(root);
2038
2039 /*
2040 * step two, delete the device extents and the
2041 * chunk tree entries
2042 */
2043 read_lock(&em_tree->lock);
2044 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2045 read_unlock(&em_tree->lock);
2046
2047 BUG_ON(!em || em->start > chunk_offset ||
2048 em->start + em->len < chunk_offset);
2049 map = (struct map_lookup *)em->bdev;
2050
2051 for (i = 0; i < map->num_stripes; i++) {
2052 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2053 map->stripes[i].physical);
2054 BUG_ON(ret);
2055
2056 if (map->stripes[i].dev) {
2057 ret = btrfs_update_device(trans, map->stripes[i].dev);
2058 BUG_ON(ret);
2059 }
2060 }
2061 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2062 chunk_offset);
2063
2064 BUG_ON(ret);
2065
2066 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2067
2068 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2069 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2070 BUG_ON(ret);
2071 }
2072
2073 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2074 BUG_ON(ret);
2075
2076 write_lock(&em_tree->lock);
2077 remove_extent_mapping(em_tree, em);
2078 write_unlock(&em_tree->lock);
2079
2080 kfree(map);
2081 em->bdev = NULL;
2082
2083 /* once for the tree */
2084 free_extent_map(em);
2085 /* once for us */
2086 free_extent_map(em);
2087
2088 unlock_chunks(root);
2089 btrfs_end_transaction(trans, root);
2090 return 0;
2091 }
2092
2093 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2094 {
2095 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2096 struct btrfs_path *path;
2097 struct extent_buffer *leaf;
2098 struct btrfs_chunk *chunk;
2099 struct btrfs_key key;
2100 struct btrfs_key found_key;
2101 u64 chunk_tree = chunk_root->root_key.objectid;
2102 u64 chunk_type;
2103 bool retried = false;
2104 int failed = 0;
2105 int ret;
2106
2107 path = btrfs_alloc_path();
2108 if (!path)
2109 return -ENOMEM;
2110
2111 again:
2112 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2113 key.offset = (u64)-1;
2114 key.type = BTRFS_CHUNK_ITEM_KEY;
2115
2116 while (1) {
2117 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2118 if (ret < 0)
2119 goto error;
2120 BUG_ON(ret == 0); /* Corruption */
2121
2122 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2123 key.type);
2124 if (ret < 0)
2125 goto error;
2126 if (ret > 0)
2127 break;
2128
2129 leaf = path->nodes[0];
2130 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2131
2132 chunk = btrfs_item_ptr(leaf, path->slots[0],
2133 struct btrfs_chunk);
2134 chunk_type = btrfs_chunk_type(leaf, chunk);
2135 btrfs_release_path(path);
2136
2137 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2138 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2139 found_key.objectid,
2140 found_key.offset);
2141 if (ret == -ENOSPC)
2142 failed++;
2143 else if (ret)
2144 BUG();
2145 }
2146
2147 if (found_key.offset == 0)
2148 break;
2149 key.offset = found_key.offset - 1;
2150 }
2151 ret = 0;
2152 if (failed && !retried) {
2153 failed = 0;
2154 retried = true;
2155 goto again;
2156 } else if (failed && retried) {
2157 WARN_ON(1);
2158 ret = -ENOSPC;
2159 }
2160 error:
2161 btrfs_free_path(path);
2162 return ret;
2163 }
2164
2165 static int insert_balance_item(struct btrfs_root *root,
2166 struct btrfs_balance_control *bctl)
2167 {
2168 struct btrfs_trans_handle *trans;
2169 struct btrfs_balance_item *item;
2170 struct btrfs_disk_balance_args disk_bargs;
2171 struct btrfs_path *path;
2172 struct extent_buffer *leaf;
2173 struct btrfs_key key;
2174 int ret, err;
2175
2176 path = btrfs_alloc_path();
2177 if (!path)
2178 return -ENOMEM;
2179
2180 trans = btrfs_start_transaction(root, 0);
2181 if (IS_ERR(trans)) {
2182 btrfs_free_path(path);
2183 return PTR_ERR(trans);
2184 }
2185
2186 key.objectid = BTRFS_BALANCE_OBJECTID;
2187 key.type = BTRFS_BALANCE_ITEM_KEY;
2188 key.offset = 0;
2189
2190 ret = btrfs_insert_empty_item(trans, root, path, &key,
2191 sizeof(*item));
2192 if (ret)
2193 goto out;
2194
2195 leaf = path->nodes[0];
2196 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2197
2198 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2199
2200 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2201 btrfs_set_balance_data(leaf, item, &disk_bargs);
2202 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2203 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2204 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2205 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2206
2207 btrfs_set_balance_flags(leaf, item, bctl->flags);
2208
2209 btrfs_mark_buffer_dirty(leaf);
2210 out:
2211 btrfs_free_path(path);
2212 err = btrfs_commit_transaction(trans, root);
2213 if (err && !ret)
2214 ret = err;
2215 return ret;
2216 }
2217
2218 static int del_balance_item(struct btrfs_root *root)
2219 {
2220 struct btrfs_trans_handle *trans;
2221 struct btrfs_path *path;
2222 struct btrfs_key key;
2223 int ret, err;
2224
2225 path = btrfs_alloc_path();
2226 if (!path)
2227 return -ENOMEM;
2228
2229 trans = btrfs_start_transaction(root, 0);
2230 if (IS_ERR(trans)) {
2231 btrfs_free_path(path);
2232 return PTR_ERR(trans);
2233 }
2234
2235 key.objectid = BTRFS_BALANCE_OBJECTID;
2236 key.type = BTRFS_BALANCE_ITEM_KEY;
2237 key.offset = 0;
2238
2239 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2240 if (ret < 0)
2241 goto out;
2242 if (ret > 0) {
2243 ret = -ENOENT;
2244 goto out;
2245 }
2246
2247 ret = btrfs_del_item(trans, root, path);
2248 out:
2249 btrfs_free_path(path);
2250 err = btrfs_commit_transaction(trans, root);
2251 if (err && !ret)
2252 ret = err;
2253 return ret;
2254 }
2255
2256 /*
2257 * This is a heuristic used to reduce the number of chunks balanced on
2258 * resume after balance was interrupted.
2259 */
2260 static void update_balance_args(struct btrfs_balance_control *bctl)
2261 {
2262 /*
2263 * Turn on soft mode for chunk types that were being converted.
2264 */
2265 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2266 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2267 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2268 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2269 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2270 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2271
2272 /*
2273 * Turn on usage filter if is not already used. The idea is
2274 * that chunks that we have already balanced should be
2275 * reasonably full. Don't do it for chunks that are being
2276 * converted - that will keep us from relocating unconverted
2277 * (albeit full) chunks.
2278 */
2279 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2280 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2281 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2282 bctl->data.usage = 90;
2283 }
2284 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2285 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2286 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2287 bctl->sys.usage = 90;
2288 }
2289 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2290 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2291 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2292 bctl->meta.usage = 90;
2293 }
2294 }
2295
2296 /*
2297 * Should be called with both balance and volume mutexes held to
2298 * serialize other volume operations (add_dev/rm_dev/resize) with
2299 * restriper. Same goes for unset_balance_control.
2300 */
2301 static void set_balance_control(struct btrfs_balance_control *bctl)
2302 {
2303 struct btrfs_fs_info *fs_info = bctl->fs_info;
2304
2305 BUG_ON(fs_info->balance_ctl);
2306
2307 spin_lock(&fs_info->balance_lock);
2308 fs_info->balance_ctl = bctl;
2309 spin_unlock(&fs_info->balance_lock);
2310 }
2311
2312 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2313 {
2314 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2315
2316 BUG_ON(!fs_info->balance_ctl);
2317
2318 spin_lock(&fs_info->balance_lock);
2319 fs_info->balance_ctl = NULL;
2320 spin_unlock(&fs_info->balance_lock);
2321
2322 kfree(bctl);
2323 }
2324
2325 /*
2326 * Balance filters. Return 1 if chunk should be filtered out
2327 * (should not be balanced).
2328 */
2329 static int chunk_profiles_filter(u64 chunk_type,
2330 struct btrfs_balance_args *bargs)
2331 {
2332 chunk_type = chunk_to_extended(chunk_type) &
2333 BTRFS_EXTENDED_PROFILE_MASK;
2334
2335 if (bargs->profiles & chunk_type)
2336 return 0;
2337
2338 return 1;
2339 }
2340
2341 static u64 div_factor_fine(u64 num, int factor)
2342 {
2343 if (factor <= 0)
2344 return 0;
2345 if (factor >= 100)
2346 return num;
2347
2348 num *= factor;
2349 do_div(num, 100);
2350 return num;
2351 }
2352
2353 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2354 struct btrfs_balance_args *bargs)
2355 {
2356 struct btrfs_block_group_cache *cache;
2357 u64 chunk_used, user_thresh;
2358 int ret = 1;
2359
2360 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2361 chunk_used = btrfs_block_group_used(&cache->item);
2362
2363 user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
2364 if (chunk_used < user_thresh)
2365 ret = 0;
2366
2367 btrfs_put_block_group(cache);
2368 return ret;
2369 }
2370
2371 static int chunk_devid_filter(struct extent_buffer *leaf,
2372 struct btrfs_chunk *chunk,
2373 struct btrfs_balance_args *bargs)
2374 {
2375 struct btrfs_stripe *stripe;
2376 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2377 int i;
2378
2379 for (i = 0; i < num_stripes; i++) {
2380 stripe = btrfs_stripe_nr(chunk, i);
2381 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2382 return 0;
2383 }
2384
2385 return 1;
2386 }
2387
2388 /* [pstart, pend) */
2389 static int chunk_drange_filter(struct extent_buffer *leaf,
2390 struct btrfs_chunk *chunk,
2391 u64 chunk_offset,
2392 struct btrfs_balance_args *bargs)
2393 {
2394 struct btrfs_stripe *stripe;
2395 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2396 u64 stripe_offset;
2397 u64 stripe_length;
2398 int factor;
2399 int i;
2400
2401 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2402 return 0;
2403
2404 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2405 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2406 factor = 2;
2407 else
2408 factor = 1;
2409 factor = num_stripes / factor;
2410
2411 for (i = 0; i < num_stripes; i++) {
2412 stripe = btrfs_stripe_nr(chunk, i);
2413 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2414 continue;
2415
2416 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2417 stripe_length = btrfs_chunk_length(leaf, chunk);
2418 do_div(stripe_length, factor);
2419
2420 if (stripe_offset < bargs->pend &&
2421 stripe_offset + stripe_length > bargs->pstart)
2422 return 0;
2423 }
2424
2425 return 1;
2426 }
2427
2428 /* [vstart, vend) */
2429 static int chunk_vrange_filter(struct extent_buffer *leaf,
2430 struct btrfs_chunk *chunk,
2431 u64 chunk_offset,
2432 struct btrfs_balance_args *bargs)
2433 {
2434 if (chunk_offset < bargs->vend &&
2435 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2436 /* at least part of the chunk is inside this vrange */
2437 return 0;
2438
2439 return 1;
2440 }
2441
2442 static int chunk_soft_convert_filter(u64 chunk_type,
2443 struct btrfs_balance_args *bargs)
2444 {
2445 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2446 return 0;
2447
2448 chunk_type = chunk_to_extended(chunk_type) &
2449 BTRFS_EXTENDED_PROFILE_MASK;
2450
2451 if (bargs->target == chunk_type)
2452 return 1;
2453
2454 return 0;
2455 }
2456
2457 static int should_balance_chunk(struct btrfs_root *root,
2458 struct extent_buffer *leaf,
2459 struct btrfs_chunk *chunk, u64 chunk_offset)
2460 {
2461 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2462 struct btrfs_balance_args *bargs = NULL;
2463 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2464
2465 /* type filter */
2466 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2467 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2468 return 0;
2469 }
2470
2471 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2472 bargs = &bctl->data;
2473 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2474 bargs = &bctl->sys;
2475 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2476 bargs = &bctl->meta;
2477
2478 /* profiles filter */
2479 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2480 chunk_profiles_filter(chunk_type, bargs)) {
2481 return 0;
2482 }
2483
2484 /* usage filter */
2485 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2486 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2487 return 0;
2488 }
2489
2490 /* devid filter */
2491 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2492 chunk_devid_filter(leaf, chunk, bargs)) {
2493 return 0;
2494 }
2495
2496 /* drange filter, makes sense only with devid filter */
2497 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2498 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2499 return 0;
2500 }
2501
2502 /* vrange filter */
2503 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2504 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2505 return 0;
2506 }
2507
2508 /* soft profile changing mode */
2509 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2510 chunk_soft_convert_filter(chunk_type, bargs)) {
2511 return 0;
2512 }
2513
2514 return 1;
2515 }
2516
2517 static u64 div_factor(u64 num, int factor)
2518 {
2519 if (factor == 10)
2520 return num;
2521 num *= factor;
2522 do_div(num, 10);
2523 return num;
2524 }
2525
2526 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2527 {
2528 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2529 struct btrfs_root *chunk_root = fs_info->chunk_root;
2530 struct btrfs_root *dev_root = fs_info->dev_root;
2531 struct list_head *devices;
2532 struct btrfs_device *device;
2533 u64 old_size;
2534 u64 size_to_free;
2535 struct btrfs_chunk *chunk;
2536 struct btrfs_path *path;
2537 struct btrfs_key key;
2538 struct btrfs_key found_key;
2539 struct btrfs_trans_handle *trans;
2540 struct extent_buffer *leaf;
2541 int slot;
2542 int ret;
2543 int enospc_errors = 0;
2544 bool counting = true;
2545
2546 /* step one make some room on all the devices */
2547 devices = &fs_info->fs_devices->devices;
2548 list_for_each_entry(device, devices, dev_list) {
2549 old_size = device->total_bytes;
2550 size_to_free = div_factor(old_size, 1);
2551 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2552 if (!device->writeable ||
2553 device->total_bytes - device->bytes_used > size_to_free)
2554 continue;
2555
2556 ret = btrfs_shrink_device(device, old_size - size_to_free);
2557 if (ret == -ENOSPC)
2558 break;
2559 BUG_ON(ret);
2560
2561 trans = btrfs_start_transaction(dev_root, 0);
2562 BUG_ON(IS_ERR(trans));
2563
2564 ret = btrfs_grow_device(trans, device, old_size);
2565 BUG_ON(ret);
2566
2567 btrfs_end_transaction(trans, dev_root);
2568 }
2569
2570 /* step two, relocate all the chunks */
2571 path = btrfs_alloc_path();
2572 if (!path) {
2573 ret = -ENOMEM;
2574 goto error;
2575 }
2576
2577 /* zero out stat counters */
2578 spin_lock(&fs_info->balance_lock);
2579 memset(&bctl->stat, 0, sizeof(bctl->stat));
2580 spin_unlock(&fs_info->balance_lock);
2581 again:
2582 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2583 key.offset = (u64)-1;
2584 key.type = BTRFS_CHUNK_ITEM_KEY;
2585
2586 while (1) {
2587 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2588 atomic_read(&fs_info->balance_cancel_req)) {
2589 ret = -ECANCELED;
2590 goto error;
2591 }
2592
2593 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2594 if (ret < 0)
2595 goto error;
2596
2597 /*
2598 * this shouldn't happen, it means the last relocate
2599 * failed
2600 */
2601 if (ret == 0)
2602 BUG(); /* FIXME break ? */
2603
2604 ret = btrfs_previous_item(chunk_root, path, 0,
2605 BTRFS_CHUNK_ITEM_KEY);
2606 if (ret) {
2607 ret = 0;
2608 break;
2609 }
2610
2611 leaf = path->nodes[0];
2612 slot = path->slots[0];
2613 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2614
2615 if (found_key.objectid != key.objectid)
2616 break;
2617
2618 /* chunk zero is special */
2619 if (found_key.offset == 0)
2620 break;
2621
2622 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2623
2624 if (!counting) {
2625 spin_lock(&fs_info->balance_lock);
2626 bctl->stat.considered++;
2627 spin_unlock(&fs_info->balance_lock);
2628 }
2629
2630 ret = should_balance_chunk(chunk_root, leaf, chunk,
2631 found_key.offset);
2632 btrfs_release_path(path);
2633 if (!ret)
2634 goto loop;
2635
2636 if (counting) {
2637 spin_lock(&fs_info->balance_lock);
2638 bctl->stat.expected++;
2639 spin_unlock(&fs_info->balance_lock);
2640 goto loop;
2641 }
2642
2643 ret = btrfs_relocate_chunk(chunk_root,
2644 chunk_root->root_key.objectid,
2645 found_key.objectid,
2646 found_key.offset);
2647 if (ret && ret != -ENOSPC)
2648 goto error;
2649 if (ret == -ENOSPC) {
2650 enospc_errors++;
2651 } else {
2652 spin_lock(&fs_info->balance_lock);
2653 bctl->stat.completed++;
2654 spin_unlock(&fs_info->balance_lock);
2655 }
2656 loop:
2657 key.offset = found_key.offset - 1;
2658 }
2659
2660 if (counting) {
2661 btrfs_release_path(path);
2662 counting = false;
2663 goto again;
2664 }
2665 error:
2666 btrfs_free_path(path);
2667 if (enospc_errors) {
2668 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2669 enospc_errors);
2670 if (!ret)
2671 ret = -ENOSPC;
2672 }
2673
2674 return ret;
2675 }
2676
2677 /**
2678 * alloc_profile_is_valid - see if a given profile is valid and reduced
2679 * @flags: profile to validate
2680 * @extended: if true @flags is treated as an extended profile
2681 */
2682 static int alloc_profile_is_valid(u64 flags, int extended)
2683 {
2684 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
2685 BTRFS_BLOCK_GROUP_PROFILE_MASK);
2686
2687 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
2688
2689 /* 1) check that all other bits are zeroed */
2690 if (flags & ~mask)
2691 return 0;
2692
2693 /* 2) see if profile is reduced */
2694 if (flags == 0)
2695 return !extended; /* "0" is valid for usual profiles */
2696
2697 /* true if exactly one bit set */
2698 return (flags & (flags - 1)) == 0;
2699 }
2700
2701 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2702 {
2703 /* cancel requested || normal exit path */
2704 return atomic_read(&fs_info->balance_cancel_req) ||
2705 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2706 atomic_read(&fs_info->balance_cancel_req) == 0);
2707 }
2708
2709 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2710 {
2711 int ret;
2712
2713 unset_balance_control(fs_info);
2714 ret = del_balance_item(fs_info->tree_root);
2715 BUG_ON(ret);
2716 }
2717
2718 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2719 struct btrfs_ioctl_balance_args *bargs);
2720
2721 /*
2722 * Should be called with both balance and volume mutexes held
2723 */
2724 int btrfs_balance(struct btrfs_balance_control *bctl,
2725 struct btrfs_ioctl_balance_args *bargs)
2726 {
2727 struct btrfs_fs_info *fs_info = bctl->fs_info;
2728 u64 allowed;
2729 int mixed = 0;
2730 int ret;
2731
2732 if (btrfs_fs_closing(fs_info) ||
2733 atomic_read(&fs_info->balance_pause_req) ||
2734 atomic_read(&fs_info->balance_cancel_req)) {
2735 ret = -EINVAL;
2736 goto out;
2737 }
2738
2739 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2740 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
2741 mixed = 1;
2742
2743 /*
2744 * In case of mixed groups both data and meta should be picked,
2745 * and identical options should be given for both of them.
2746 */
2747 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
2748 if (mixed && (bctl->flags & allowed)) {
2749 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
2750 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
2751 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
2752 printk(KERN_ERR "btrfs: with mixed groups data and "
2753 "metadata balance options must be the same\n");
2754 ret = -EINVAL;
2755 goto out;
2756 }
2757 }
2758
2759 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2760 if (fs_info->fs_devices->num_devices == 1)
2761 allowed |= BTRFS_BLOCK_GROUP_DUP;
2762 else if (fs_info->fs_devices->num_devices < 4)
2763 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
2764 else
2765 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2766 BTRFS_BLOCK_GROUP_RAID10);
2767
2768 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2769 (!alloc_profile_is_valid(bctl->data.target, 1) ||
2770 (bctl->data.target & ~allowed))) {
2771 printk(KERN_ERR "btrfs: unable to start balance with target "
2772 "data profile %llu\n",
2773 (unsigned long long)bctl->data.target);
2774 ret = -EINVAL;
2775 goto out;
2776 }
2777 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2778 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
2779 (bctl->meta.target & ~allowed))) {
2780 printk(KERN_ERR "btrfs: unable to start balance with target "
2781 "metadata profile %llu\n",
2782 (unsigned long long)bctl->meta.target);
2783 ret = -EINVAL;
2784 goto out;
2785 }
2786 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2787 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
2788 (bctl->sys.target & ~allowed))) {
2789 printk(KERN_ERR "btrfs: unable to start balance with target "
2790 "system profile %llu\n",
2791 (unsigned long long)bctl->sys.target);
2792 ret = -EINVAL;
2793 goto out;
2794 }
2795
2796 /* allow dup'ed data chunks only in mixed mode */
2797 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2798 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
2799 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
2800 ret = -EINVAL;
2801 goto out;
2802 }
2803
2804 /* allow to reduce meta or sys integrity only if force set */
2805 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
2806 BTRFS_BLOCK_GROUP_RAID10;
2807 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2808 (fs_info->avail_system_alloc_bits & allowed) &&
2809 !(bctl->sys.target & allowed)) ||
2810 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2811 (fs_info->avail_metadata_alloc_bits & allowed) &&
2812 !(bctl->meta.target & allowed))) {
2813 if (bctl->flags & BTRFS_BALANCE_FORCE) {
2814 printk(KERN_INFO "btrfs: force reducing metadata "
2815 "integrity\n");
2816 } else {
2817 printk(KERN_ERR "btrfs: balance will reduce metadata "
2818 "integrity, use force if you want this\n");
2819 ret = -EINVAL;
2820 goto out;
2821 }
2822 }
2823
2824 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
2825 int num_tolerated_disk_barrier_failures;
2826 u64 target = bctl->sys.target;
2827
2828 num_tolerated_disk_barrier_failures =
2829 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2830 if (num_tolerated_disk_barrier_failures > 0 &&
2831 (target &
2832 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
2833 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
2834 num_tolerated_disk_barrier_failures = 0;
2835 else if (num_tolerated_disk_barrier_failures > 1 &&
2836 (target &
2837 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
2838 num_tolerated_disk_barrier_failures = 1;
2839
2840 fs_info->num_tolerated_disk_barrier_failures =
2841 num_tolerated_disk_barrier_failures;
2842 }
2843
2844 ret = insert_balance_item(fs_info->tree_root, bctl);
2845 if (ret && ret != -EEXIST)
2846 goto out;
2847
2848 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
2849 BUG_ON(ret == -EEXIST);
2850 set_balance_control(bctl);
2851 } else {
2852 BUG_ON(ret != -EEXIST);
2853 spin_lock(&fs_info->balance_lock);
2854 update_balance_args(bctl);
2855 spin_unlock(&fs_info->balance_lock);
2856 }
2857
2858 atomic_inc(&fs_info->balance_running);
2859 mutex_unlock(&fs_info->balance_mutex);
2860
2861 ret = __btrfs_balance(fs_info);
2862
2863 mutex_lock(&fs_info->balance_mutex);
2864 atomic_dec(&fs_info->balance_running);
2865
2866 if (bargs) {
2867 memset(bargs, 0, sizeof(*bargs));
2868 update_ioctl_balance_args(fs_info, 0, bargs);
2869 }
2870
2871 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
2872 balance_need_close(fs_info)) {
2873 __cancel_balance(fs_info);
2874 }
2875
2876 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
2877 fs_info->num_tolerated_disk_barrier_failures =
2878 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2879 }
2880
2881 wake_up(&fs_info->balance_wait_q);
2882
2883 return ret;
2884 out:
2885 if (bctl->flags & BTRFS_BALANCE_RESUME)
2886 __cancel_balance(fs_info);
2887 else
2888 kfree(bctl);
2889 return ret;
2890 }
2891
2892 static int balance_kthread(void *data)
2893 {
2894 struct btrfs_fs_info *fs_info = data;
2895 int ret = 0;
2896
2897 mutex_lock(&fs_info->volume_mutex);
2898 mutex_lock(&fs_info->balance_mutex);
2899
2900 if (fs_info->balance_ctl) {
2901 printk(KERN_INFO "btrfs: continuing balance\n");
2902 ret = btrfs_balance(fs_info->balance_ctl, NULL);
2903 }
2904
2905 mutex_unlock(&fs_info->balance_mutex);
2906 mutex_unlock(&fs_info->volume_mutex);
2907
2908 return ret;
2909 }
2910
2911 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
2912 {
2913 struct task_struct *tsk;
2914
2915 spin_lock(&fs_info->balance_lock);
2916 if (!fs_info->balance_ctl) {
2917 spin_unlock(&fs_info->balance_lock);
2918 return 0;
2919 }
2920 spin_unlock(&fs_info->balance_lock);
2921
2922 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
2923 printk(KERN_INFO "btrfs: force skipping balance\n");
2924 return 0;
2925 }
2926
2927 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
2928 if (IS_ERR(tsk))
2929 return PTR_ERR(tsk);
2930
2931 return 0;
2932 }
2933
2934 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
2935 {
2936 struct btrfs_balance_control *bctl;
2937 struct btrfs_balance_item *item;
2938 struct btrfs_disk_balance_args disk_bargs;
2939 struct btrfs_path *path;
2940 struct extent_buffer *leaf;
2941 struct btrfs_key key;
2942 int ret;
2943
2944 path = btrfs_alloc_path();
2945 if (!path)
2946 return -ENOMEM;
2947
2948 key.objectid = BTRFS_BALANCE_OBJECTID;
2949 key.type = BTRFS_BALANCE_ITEM_KEY;
2950 key.offset = 0;
2951
2952 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2953 if (ret < 0)
2954 goto out;
2955 if (ret > 0) { /* ret = -ENOENT; */
2956 ret = 0;
2957 goto out;
2958 }
2959
2960 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
2961 if (!bctl) {
2962 ret = -ENOMEM;
2963 goto out;
2964 }
2965
2966 leaf = path->nodes[0];
2967 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2968
2969 bctl->fs_info = fs_info;
2970 bctl->flags = btrfs_balance_flags(leaf, item);
2971 bctl->flags |= BTRFS_BALANCE_RESUME;
2972
2973 btrfs_balance_data(leaf, item, &disk_bargs);
2974 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
2975 btrfs_balance_meta(leaf, item, &disk_bargs);
2976 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
2977 btrfs_balance_sys(leaf, item, &disk_bargs);
2978 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
2979
2980 mutex_lock(&fs_info->volume_mutex);
2981 mutex_lock(&fs_info->balance_mutex);
2982
2983 set_balance_control(bctl);
2984
2985 mutex_unlock(&fs_info->balance_mutex);
2986 mutex_unlock(&fs_info->volume_mutex);
2987 out:
2988 btrfs_free_path(path);
2989 return ret;
2990 }
2991
2992 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
2993 {
2994 int ret = 0;
2995
2996 mutex_lock(&fs_info->balance_mutex);
2997 if (!fs_info->balance_ctl) {
2998 mutex_unlock(&fs_info->balance_mutex);
2999 return -ENOTCONN;
3000 }
3001
3002 if (atomic_read(&fs_info->balance_running)) {
3003 atomic_inc(&fs_info->balance_pause_req);
3004 mutex_unlock(&fs_info->balance_mutex);
3005
3006 wait_event(fs_info->balance_wait_q,
3007 atomic_read(&fs_info->balance_running) == 0);
3008
3009 mutex_lock(&fs_info->balance_mutex);
3010 /* we are good with balance_ctl ripped off from under us */
3011 BUG_ON(atomic_read(&fs_info->balance_running));
3012 atomic_dec(&fs_info->balance_pause_req);
3013 } else {
3014 ret = -ENOTCONN;
3015 }
3016
3017 mutex_unlock(&fs_info->balance_mutex);
3018 return ret;
3019 }
3020
3021 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3022 {
3023 mutex_lock(&fs_info->balance_mutex);
3024 if (!fs_info->balance_ctl) {
3025 mutex_unlock(&fs_info->balance_mutex);
3026 return -ENOTCONN;
3027 }
3028
3029 atomic_inc(&fs_info->balance_cancel_req);
3030 /*
3031 * if we are running just wait and return, balance item is
3032 * deleted in btrfs_balance in this case
3033 */
3034 if (atomic_read(&fs_info->balance_running)) {
3035 mutex_unlock(&fs_info->balance_mutex);
3036 wait_event(fs_info->balance_wait_q,
3037 atomic_read(&fs_info->balance_running) == 0);
3038 mutex_lock(&fs_info->balance_mutex);
3039 } else {
3040 /* __cancel_balance needs volume_mutex */
3041 mutex_unlock(&fs_info->balance_mutex);
3042 mutex_lock(&fs_info->volume_mutex);
3043 mutex_lock(&fs_info->balance_mutex);
3044
3045 if (fs_info->balance_ctl)
3046 __cancel_balance(fs_info);
3047
3048 mutex_unlock(&fs_info->volume_mutex);
3049 }
3050
3051 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3052 atomic_dec(&fs_info->balance_cancel_req);
3053 mutex_unlock(&fs_info->balance_mutex);
3054 return 0;
3055 }
3056
3057 /*
3058 * shrinking a device means finding all of the device extents past
3059 * the new size, and then following the back refs to the chunks.
3060 * The chunk relocation code actually frees the device extent
3061 */
3062 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3063 {
3064 struct btrfs_trans_handle *trans;
3065 struct btrfs_root *root = device->dev_root;
3066 struct btrfs_dev_extent *dev_extent = NULL;
3067 struct btrfs_path *path;
3068 u64 length;
3069 u64 chunk_tree;
3070 u64 chunk_objectid;
3071 u64 chunk_offset;
3072 int ret;
3073 int slot;
3074 int failed = 0;
3075 bool retried = false;
3076 struct extent_buffer *l;
3077 struct btrfs_key key;
3078 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3079 u64 old_total = btrfs_super_total_bytes(super_copy);
3080 u64 old_size = device->total_bytes;
3081 u64 diff = device->total_bytes - new_size;
3082
3083 if (new_size >= device->total_bytes)
3084 return -EINVAL;
3085
3086 path = btrfs_alloc_path();
3087 if (!path)
3088 return -ENOMEM;
3089
3090 path->reada = 2;
3091
3092 lock_chunks(root);
3093
3094 device->total_bytes = new_size;
3095 if (device->writeable) {
3096 device->fs_devices->total_rw_bytes -= diff;
3097 spin_lock(&root->fs_info->free_chunk_lock);
3098 root->fs_info->free_chunk_space -= diff;
3099 spin_unlock(&root->fs_info->free_chunk_lock);
3100 }
3101 unlock_chunks(root);
3102
3103 again:
3104 key.objectid = device->devid;
3105 key.offset = (u64)-1;
3106 key.type = BTRFS_DEV_EXTENT_KEY;
3107
3108 do {
3109 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3110 if (ret < 0)
3111 goto done;
3112
3113 ret = btrfs_previous_item(root, path, 0, key.type);
3114 if (ret < 0)
3115 goto done;
3116 if (ret) {
3117 ret = 0;
3118 btrfs_release_path(path);
3119 break;
3120 }
3121
3122 l = path->nodes[0];
3123 slot = path->slots[0];
3124 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3125
3126 if (key.objectid != device->devid) {
3127 btrfs_release_path(path);
3128 break;
3129 }
3130
3131 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3132 length = btrfs_dev_extent_length(l, dev_extent);
3133
3134 if (key.offset + length <= new_size) {
3135 btrfs_release_path(path);
3136 break;
3137 }
3138
3139 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3140 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3141 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3142 btrfs_release_path(path);
3143
3144 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3145 chunk_offset);
3146 if (ret && ret != -ENOSPC)
3147 goto done;
3148 if (ret == -ENOSPC)
3149 failed++;
3150 } while (key.offset-- > 0);
3151
3152 if (failed && !retried) {
3153 failed = 0;
3154 retried = true;
3155 goto again;
3156 } else if (failed && retried) {
3157 ret = -ENOSPC;
3158 lock_chunks(root);
3159
3160 device->total_bytes = old_size;
3161 if (device->writeable)
3162 device->fs_devices->total_rw_bytes += diff;
3163 spin_lock(&root->fs_info->free_chunk_lock);
3164 root->fs_info->free_chunk_space += diff;
3165 spin_unlock(&root->fs_info->free_chunk_lock);
3166 unlock_chunks(root);
3167 goto done;
3168 }
3169
3170 /* Shrinking succeeded, else we would be at "done". */
3171 trans = btrfs_start_transaction(root, 0);
3172 if (IS_ERR(trans)) {
3173 ret = PTR_ERR(trans);
3174 goto done;
3175 }
3176
3177 lock_chunks(root);
3178
3179 device->disk_total_bytes = new_size;
3180 /* Now btrfs_update_device() will change the on-disk size. */
3181 ret = btrfs_update_device(trans, device);
3182 if (ret) {
3183 unlock_chunks(root);
3184 btrfs_end_transaction(trans, root);
3185 goto done;
3186 }
3187 WARN_ON(diff > old_total);
3188 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3189 unlock_chunks(root);
3190 btrfs_end_transaction(trans, root);
3191 done:
3192 btrfs_free_path(path);
3193 return ret;
3194 }
3195
3196 static int btrfs_add_system_chunk(struct btrfs_root *root,
3197 struct btrfs_key *key,
3198 struct btrfs_chunk *chunk, int item_size)
3199 {
3200 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3201 struct btrfs_disk_key disk_key;
3202 u32 array_size;
3203 u8 *ptr;
3204
3205 array_size = btrfs_super_sys_array_size(super_copy);
3206 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3207 return -EFBIG;
3208
3209 ptr = super_copy->sys_chunk_array + array_size;
3210 btrfs_cpu_key_to_disk(&disk_key, key);
3211 memcpy(ptr, &disk_key, sizeof(disk_key));
3212 ptr += sizeof(disk_key);
3213 memcpy(ptr, chunk, item_size);
3214 item_size += sizeof(disk_key);
3215 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3216 return 0;
3217 }
3218
3219 /*
3220 * sort the devices in descending order by max_avail, total_avail
3221 */
3222 static int btrfs_cmp_device_info(const void *a, const void *b)
3223 {
3224 const struct btrfs_device_info *di_a = a;
3225 const struct btrfs_device_info *di_b = b;
3226
3227 if (di_a->max_avail > di_b->max_avail)
3228 return -1;
3229 if (di_a->max_avail < di_b->max_avail)
3230 return 1;
3231 if (di_a->total_avail > di_b->total_avail)
3232 return -1;
3233 if (di_a->total_avail < di_b->total_avail)
3234 return 1;
3235 return 0;
3236 }
3237
3238 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3239 struct btrfs_root *extent_root,
3240 struct map_lookup **map_ret,
3241 u64 *num_bytes_out, u64 *stripe_size_out,
3242 u64 start, u64 type)
3243 {
3244 struct btrfs_fs_info *info = extent_root->fs_info;
3245 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3246 struct list_head *cur;
3247 struct map_lookup *map = NULL;
3248 struct extent_map_tree *em_tree;
3249 struct extent_map *em;
3250 struct btrfs_device_info *devices_info = NULL;
3251 u64 total_avail;
3252 int num_stripes; /* total number of stripes to allocate */
3253 int sub_stripes; /* sub_stripes info for map */
3254 int dev_stripes; /* stripes per dev */
3255 int devs_max; /* max devs to use */
3256 int devs_min; /* min devs needed */
3257 int devs_increment; /* ndevs has to be a multiple of this */
3258 int ncopies; /* how many copies to data has */
3259 int ret;
3260 u64 max_stripe_size;
3261 u64 max_chunk_size;
3262 u64 stripe_size;
3263 u64 num_bytes;
3264 int ndevs;
3265 int i;
3266 int j;
3267
3268 BUG_ON(!alloc_profile_is_valid(type, 0));
3269
3270 if (list_empty(&fs_devices->alloc_list))
3271 return -ENOSPC;
3272
3273 sub_stripes = 1;
3274 dev_stripes = 1;
3275 devs_increment = 1;
3276 ncopies = 1;
3277 devs_max = 0; /* 0 == as many as possible */
3278 devs_min = 1;
3279
3280 /*
3281 * define the properties of each RAID type.
3282 * FIXME: move this to a global table and use it in all RAID
3283 * calculation code
3284 */
3285 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
3286 dev_stripes = 2;
3287 ncopies = 2;
3288 devs_max = 1;
3289 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
3290 devs_min = 2;
3291 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
3292 devs_increment = 2;
3293 ncopies = 2;
3294 devs_max = 2;
3295 devs_min = 2;
3296 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
3297 sub_stripes = 2;
3298 devs_increment = 2;
3299 ncopies = 2;
3300 devs_min = 4;
3301 } else {
3302 devs_max = 1;
3303 }
3304
3305 if (type & BTRFS_BLOCK_GROUP_DATA) {
3306 max_stripe_size = 1024 * 1024 * 1024;
3307 max_chunk_size = 10 * max_stripe_size;
3308 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3309 /* for larger filesystems, use larger metadata chunks */
3310 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3311 max_stripe_size = 1024 * 1024 * 1024;
3312 else
3313 max_stripe_size = 256 * 1024 * 1024;
3314 max_chunk_size = max_stripe_size;
3315 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3316 max_stripe_size = 32 * 1024 * 1024;
3317 max_chunk_size = 2 * max_stripe_size;
3318 } else {
3319 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3320 type);
3321 BUG_ON(1);
3322 }
3323
3324 /* we don't want a chunk larger than 10% of writeable space */
3325 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3326 max_chunk_size);
3327
3328 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3329 GFP_NOFS);
3330 if (!devices_info)
3331 return -ENOMEM;
3332
3333 cur = fs_devices->alloc_list.next;
3334
3335 /*
3336 * in the first pass through the devices list, we gather information
3337 * about the available holes on each device.
3338 */
3339 ndevs = 0;
3340 while (cur != &fs_devices->alloc_list) {
3341 struct btrfs_device *device;
3342 u64 max_avail;
3343 u64 dev_offset;
3344
3345 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3346
3347 cur = cur->next;
3348
3349 if (!device->writeable) {
3350 printk(KERN_ERR
3351 "btrfs: read-only device in alloc_list\n");
3352 WARN_ON(1);
3353 continue;
3354 }
3355
3356 if (!device->in_fs_metadata)
3357 continue;
3358
3359 if (device->total_bytes > device->bytes_used)
3360 total_avail = device->total_bytes - device->bytes_used;
3361 else
3362 total_avail = 0;
3363
3364 /* If there is no space on this device, skip it. */
3365 if (total_avail == 0)
3366 continue;
3367
3368 ret = find_free_dev_extent(device,
3369 max_stripe_size * dev_stripes,
3370 &dev_offset, &max_avail);
3371 if (ret && ret != -ENOSPC)
3372 goto error;
3373
3374 if (ret == 0)
3375 max_avail = max_stripe_size * dev_stripes;
3376
3377 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3378 continue;
3379
3380 devices_info[ndevs].dev_offset = dev_offset;
3381 devices_info[ndevs].max_avail = max_avail;
3382 devices_info[ndevs].total_avail = total_avail;
3383 devices_info[ndevs].dev = device;
3384 ++ndevs;
3385 }
3386
3387 /*
3388 * now sort the devices by hole size / available space
3389 */
3390 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3391 btrfs_cmp_device_info, NULL);
3392
3393 /* round down to number of usable stripes */
3394 ndevs -= ndevs % devs_increment;
3395
3396 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3397 ret = -ENOSPC;
3398 goto error;
3399 }
3400
3401 if (devs_max && ndevs > devs_max)
3402 ndevs = devs_max;
3403 /*
3404 * the primary goal is to maximize the number of stripes, so use as many
3405 * devices as possible, even if the stripes are not maximum sized.
3406 */
3407 stripe_size = devices_info[ndevs-1].max_avail;
3408 num_stripes = ndevs * dev_stripes;
3409
3410 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3411 stripe_size = max_chunk_size * ncopies;
3412 do_div(stripe_size, ndevs);
3413 }
3414
3415 do_div(stripe_size, dev_stripes);
3416
3417 /* align to BTRFS_STRIPE_LEN */
3418 do_div(stripe_size, BTRFS_STRIPE_LEN);
3419 stripe_size *= BTRFS_STRIPE_LEN;
3420
3421 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3422 if (!map) {
3423 ret = -ENOMEM;
3424 goto error;
3425 }
3426 map->num_stripes = num_stripes;
3427
3428 for (i = 0; i < ndevs; ++i) {
3429 for (j = 0; j < dev_stripes; ++j) {
3430 int s = i * dev_stripes + j;
3431 map->stripes[s].dev = devices_info[i].dev;
3432 map->stripes[s].physical = devices_info[i].dev_offset +
3433 j * stripe_size;
3434 }
3435 }
3436 map->sector_size = extent_root->sectorsize;
3437 map->stripe_len = BTRFS_STRIPE_LEN;
3438 map->io_align = BTRFS_STRIPE_LEN;
3439 map->io_width = BTRFS_STRIPE_LEN;
3440 map->type = type;
3441 map->sub_stripes = sub_stripes;
3442
3443 *map_ret = map;
3444 num_bytes = stripe_size * (num_stripes / ncopies);
3445
3446 *stripe_size_out = stripe_size;
3447 *num_bytes_out = num_bytes;
3448
3449 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3450
3451 em = alloc_extent_map();
3452 if (!em) {
3453 ret = -ENOMEM;
3454 goto error;
3455 }
3456 em->bdev = (struct block_device *)map;
3457 em->start = start;
3458 em->len = num_bytes;
3459 em->block_start = 0;
3460 em->block_len = em->len;
3461
3462 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3463 write_lock(&em_tree->lock);
3464 ret = add_extent_mapping(em_tree, em);
3465 write_unlock(&em_tree->lock);
3466 free_extent_map(em);
3467 if (ret)
3468 goto error;
3469
3470 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3471 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3472 start, num_bytes);
3473 if (ret)
3474 goto error;
3475
3476 for (i = 0; i < map->num_stripes; ++i) {
3477 struct btrfs_device *device;
3478 u64 dev_offset;
3479
3480 device = map->stripes[i].dev;
3481 dev_offset = map->stripes[i].physical;
3482
3483 ret = btrfs_alloc_dev_extent(trans, device,
3484 info->chunk_root->root_key.objectid,
3485 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3486 start, dev_offset, stripe_size);
3487 if (ret) {
3488 btrfs_abort_transaction(trans, extent_root, ret);
3489 goto error;
3490 }
3491 }
3492
3493 kfree(devices_info);
3494 return 0;
3495
3496 error:
3497 kfree(map);
3498 kfree(devices_info);
3499 return ret;
3500 }
3501
3502 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3503 struct btrfs_root *extent_root,
3504 struct map_lookup *map, u64 chunk_offset,
3505 u64 chunk_size, u64 stripe_size)
3506 {
3507 u64 dev_offset;
3508 struct btrfs_key key;
3509 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3510 struct btrfs_device *device;
3511 struct btrfs_chunk *chunk;
3512 struct btrfs_stripe *stripe;
3513 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3514 int index = 0;
3515 int ret;
3516
3517 chunk = kzalloc(item_size, GFP_NOFS);
3518 if (!chunk)
3519 return -ENOMEM;
3520
3521 index = 0;
3522 while (index < map->num_stripes) {
3523 device = map->stripes[index].dev;
3524 device->bytes_used += stripe_size;
3525 ret = btrfs_update_device(trans, device);
3526 if (ret)
3527 goto out_free;
3528 index++;
3529 }
3530
3531 spin_lock(&extent_root->fs_info->free_chunk_lock);
3532 extent_root->fs_info->free_chunk_space -= (stripe_size *
3533 map->num_stripes);
3534 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3535
3536 index = 0;
3537 stripe = &chunk->stripe;
3538 while (index < map->num_stripes) {
3539 device = map->stripes[index].dev;
3540 dev_offset = map->stripes[index].physical;
3541
3542 btrfs_set_stack_stripe_devid(stripe, device->devid);
3543 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3544 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3545 stripe++;
3546 index++;
3547 }
3548
3549 btrfs_set_stack_chunk_length(chunk, chunk_size);
3550 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3551 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3552 btrfs_set_stack_chunk_type(chunk, map->type);
3553 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3554 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3555 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3556 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3557 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3558
3559 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3560 key.type = BTRFS_CHUNK_ITEM_KEY;
3561 key.offset = chunk_offset;
3562
3563 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3564
3565 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3566 /*
3567 * TODO: Cleanup of inserted chunk root in case of
3568 * failure.
3569 */
3570 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3571 item_size);
3572 }
3573
3574 out_free:
3575 kfree(chunk);
3576 return ret;
3577 }
3578
3579 /*
3580 * Chunk allocation falls into two parts. The first part does works
3581 * that make the new allocated chunk useable, but not do any operation
3582 * that modifies the chunk tree. The second part does the works that
3583 * require modifying the chunk tree. This division is important for the
3584 * bootstrap process of adding storage to a seed btrfs.
3585 */
3586 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3587 struct btrfs_root *extent_root, u64 type)
3588 {
3589 u64 chunk_offset;
3590 u64 chunk_size;
3591 u64 stripe_size;
3592 struct map_lookup *map;
3593 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3594 int ret;
3595
3596 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3597 &chunk_offset);
3598 if (ret)
3599 return ret;
3600
3601 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3602 &stripe_size, chunk_offset, type);
3603 if (ret)
3604 return ret;
3605
3606 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3607 chunk_size, stripe_size);
3608 if (ret)
3609 return ret;
3610 return 0;
3611 }
3612
3613 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3614 struct btrfs_root *root,
3615 struct btrfs_device *device)
3616 {
3617 u64 chunk_offset;
3618 u64 sys_chunk_offset;
3619 u64 chunk_size;
3620 u64 sys_chunk_size;
3621 u64 stripe_size;
3622 u64 sys_stripe_size;
3623 u64 alloc_profile;
3624 struct map_lookup *map;
3625 struct map_lookup *sys_map;
3626 struct btrfs_fs_info *fs_info = root->fs_info;
3627 struct btrfs_root *extent_root = fs_info->extent_root;
3628 int ret;
3629
3630 ret = find_next_chunk(fs_info->chunk_root,
3631 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3632 if (ret)
3633 return ret;
3634
3635 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3636 fs_info->avail_metadata_alloc_bits;
3637 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3638
3639 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3640 &stripe_size, chunk_offset, alloc_profile);
3641 if (ret)
3642 return ret;
3643
3644 sys_chunk_offset = chunk_offset + chunk_size;
3645
3646 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3647 fs_info->avail_system_alloc_bits;
3648 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3649
3650 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3651 &sys_chunk_size, &sys_stripe_size,
3652 sys_chunk_offset, alloc_profile);
3653 if (ret) {
3654 btrfs_abort_transaction(trans, root, ret);
3655 goto out;
3656 }
3657
3658 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3659 if (ret) {
3660 btrfs_abort_transaction(trans, root, ret);
3661 goto out;
3662 }
3663
3664 /*
3665 * Modifying chunk tree needs allocating new blocks from both
3666 * system block group and metadata block group. So we only can
3667 * do operations require modifying the chunk tree after both
3668 * block groups were created.
3669 */
3670 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3671 chunk_size, stripe_size);
3672 if (ret) {
3673 btrfs_abort_transaction(trans, root, ret);
3674 goto out;
3675 }
3676
3677 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3678 sys_chunk_offset, sys_chunk_size,
3679 sys_stripe_size);
3680 if (ret)
3681 btrfs_abort_transaction(trans, root, ret);
3682
3683 out:
3684
3685 return ret;
3686 }
3687
3688 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3689 {
3690 struct extent_map *em;
3691 struct map_lookup *map;
3692 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3693 int readonly = 0;
3694 int i;
3695
3696 read_lock(&map_tree->map_tree.lock);
3697 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3698 read_unlock(&map_tree->map_tree.lock);
3699 if (!em)
3700 return 1;
3701
3702 if (btrfs_test_opt(root, DEGRADED)) {
3703 free_extent_map(em);
3704 return 0;
3705 }
3706
3707 map = (struct map_lookup *)em->bdev;
3708 for (i = 0; i < map->num_stripes; i++) {
3709 if (!map->stripes[i].dev->writeable) {
3710 readonly = 1;
3711 break;
3712 }
3713 }
3714 free_extent_map(em);
3715 return readonly;
3716 }
3717
3718 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3719 {
3720 extent_map_tree_init(&tree->map_tree);
3721 }
3722
3723 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3724 {
3725 struct extent_map *em;
3726
3727 while (1) {
3728 write_lock(&tree->map_tree.lock);
3729 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3730 if (em)
3731 remove_extent_mapping(&tree->map_tree, em);
3732 write_unlock(&tree->map_tree.lock);
3733 if (!em)
3734 break;
3735 kfree(em->bdev);
3736 /* once for us */
3737 free_extent_map(em);
3738 /* once for the tree */
3739 free_extent_map(em);
3740 }
3741 }
3742
3743 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
3744 {
3745 struct extent_map *em;
3746 struct map_lookup *map;
3747 struct extent_map_tree *em_tree = &map_tree->map_tree;
3748 int ret;
3749
3750 read_lock(&em_tree->lock);
3751 em = lookup_extent_mapping(em_tree, logical, len);
3752 read_unlock(&em_tree->lock);
3753 BUG_ON(!em);
3754
3755 BUG_ON(em->start > logical || em->start + em->len < logical);
3756 map = (struct map_lookup *)em->bdev;
3757 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
3758 ret = map->num_stripes;
3759 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3760 ret = map->sub_stripes;
3761 else
3762 ret = 1;
3763 free_extent_map(em);
3764 return ret;
3765 }
3766
3767 static int find_live_mirror(struct map_lookup *map, int first, int num,
3768 int optimal)
3769 {
3770 int i;
3771 if (map->stripes[optimal].dev->bdev)
3772 return optimal;
3773 for (i = first; i < first + num; i++) {
3774 if (map->stripes[i].dev->bdev)
3775 return i;
3776 }
3777 /* we couldn't find one that doesn't fail. Just return something
3778 * and the io error handling code will clean up eventually
3779 */
3780 return optimal;
3781 }
3782
3783 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3784 u64 logical, u64 *length,
3785 struct btrfs_bio **bbio_ret,
3786 int mirror_num)
3787 {
3788 struct extent_map *em;
3789 struct map_lookup *map;
3790 struct extent_map_tree *em_tree = &map_tree->map_tree;
3791 u64 offset;
3792 u64 stripe_offset;
3793 u64 stripe_end_offset;
3794 u64 stripe_nr;
3795 u64 stripe_nr_orig;
3796 u64 stripe_nr_end;
3797 int stripe_index;
3798 int i;
3799 int ret = 0;
3800 int num_stripes;
3801 int max_errors = 0;
3802 struct btrfs_bio *bbio = NULL;
3803
3804 read_lock(&em_tree->lock);
3805 em = lookup_extent_mapping(em_tree, logical, *length);
3806 read_unlock(&em_tree->lock);
3807
3808 if (!em) {
3809 printk(KERN_CRIT "btrfs: unable to find logical %llu len %llu\n",
3810 (unsigned long long)logical,
3811 (unsigned long long)*length);
3812 BUG();
3813 }
3814
3815 BUG_ON(em->start > logical || em->start + em->len < logical);
3816 map = (struct map_lookup *)em->bdev;
3817 offset = logical - em->start;
3818
3819 if (mirror_num > map->num_stripes)
3820 mirror_num = 0;
3821
3822 stripe_nr = offset;
3823 /*
3824 * stripe_nr counts the total number of stripes we have to stride
3825 * to get to this block
3826 */
3827 do_div(stripe_nr, map->stripe_len);
3828
3829 stripe_offset = stripe_nr * map->stripe_len;
3830 BUG_ON(offset < stripe_offset);
3831
3832 /* stripe_offset is the offset of this block in its stripe*/
3833 stripe_offset = offset - stripe_offset;
3834
3835 if (rw & REQ_DISCARD)
3836 *length = min_t(u64, em->len - offset, *length);
3837 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3838 /* we limit the length of each bio to what fits in a stripe */
3839 *length = min_t(u64, em->len - offset,
3840 map->stripe_len - stripe_offset);
3841 } else {
3842 *length = em->len - offset;
3843 }
3844
3845 if (!bbio_ret)
3846 goto out;
3847
3848 num_stripes = 1;
3849 stripe_index = 0;
3850 stripe_nr_orig = stripe_nr;
3851 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3852 (~(map->stripe_len - 1));
3853 do_div(stripe_nr_end, map->stripe_len);
3854 stripe_end_offset = stripe_nr_end * map->stripe_len -
3855 (offset + *length);
3856 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3857 if (rw & REQ_DISCARD)
3858 num_stripes = min_t(u64, map->num_stripes,
3859 stripe_nr_end - stripe_nr_orig);
3860 stripe_index = do_div(stripe_nr, map->num_stripes);
3861 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3862 if (rw & (REQ_WRITE | REQ_DISCARD))
3863 num_stripes = map->num_stripes;
3864 else if (mirror_num)
3865 stripe_index = mirror_num - 1;
3866 else {
3867 stripe_index = find_live_mirror(map, 0,
3868 map->num_stripes,
3869 current->pid % map->num_stripes);
3870 mirror_num = stripe_index + 1;
3871 }
3872
3873 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3874 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3875 num_stripes = map->num_stripes;
3876 } else if (mirror_num) {
3877 stripe_index = mirror_num - 1;
3878 } else {
3879 mirror_num = 1;
3880 }
3881
3882 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3883 int factor = map->num_stripes / map->sub_stripes;
3884
3885 stripe_index = do_div(stripe_nr, factor);
3886 stripe_index *= map->sub_stripes;
3887
3888 if (rw & REQ_WRITE)
3889 num_stripes = map->sub_stripes;
3890 else if (rw & REQ_DISCARD)
3891 num_stripes = min_t(u64, map->sub_stripes *
3892 (stripe_nr_end - stripe_nr_orig),
3893 map->num_stripes);
3894 else if (mirror_num)
3895 stripe_index += mirror_num - 1;
3896 else {
3897 int old_stripe_index = stripe_index;
3898 stripe_index = find_live_mirror(map, stripe_index,
3899 map->sub_stripes, stripe_index +
3900 current->pid % map->sub_stripes);
3901 mirror_num = stripe_index - old_stripe_index + 1;
3902 }
3903 } else {
3904 /*
3905 * after this do_div call, stripe_nr is the number of stripes
3906 * on this device we have to walk to find the data, and
3907 * stripe_index is the number of our device in the stripe array
3908 */
3909 stripe_index = do_div(stripe_nr, map->num_stripes);
3910 mirror_num = stripe_index + 1;
3911 }
3912 BUG_ON(stripe_index >= map->num_stripes);
3913
3914 bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
3915 if (!bbio) {
3916 ret = -ENOMEM;
3917 goto out;
3918 }
3919 atomic_set(&bbio->error, 0);
3920
3921 if (rw & REQ_DISCARD) {
3922 int factor = 0;
3923 int sub_stripes = 0;
3924 u64 stripes_per_dev = 0;
3925 u32 remaining_stripes = 0;
3926 u32 last_stripe = 0;
3927
3928 if (map->type &
3929 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
3930 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3931 sub_stripes = 1;
3932 else
3933 sub_stripes = map->sub_stripes;
3934
3935 factor = map->num_stripes / sub_stripes;
3936 stripes_per_dev = div_u64_rem(stripe_nr_end -
3937 stripe_nr_orig,
3938 factor,
3939 &remaining_stripes);
3940 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
3941 last_stripe *= sub_stripes;
3942 }
3943
3944 for (i = 0; i < num_stripes; i++) {
3945 bbio->stripes[i].physical =
3946 map->stripes[stripe_index].physical +
3947 stripe_offset + stripe_nr * map->stripe_len;
3948 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3949
3950 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3951 BTRFS_BLOCK_GROUP_RAID10)) {
3952 bbio->stripes[i].length = stripes_per_dev *
3953 map->stripe_len;
3954
3955 if (i / sub_stripes < remaining_stripes)
3956 bbio->stripes[i].length +=
3957 map->stripe_len;
3958
3959 /*
3960 * Special for the first stripe and
3961 * the last stripe:
3962 *
3963 * |-------|...|-------|
3964 * |----------|
3965 * off end_off
3966 */
3967 if (i < sub_stripes)
3968 bbio->stripes[i].length -=
3969 stripe_offset;
3970
3971 if (stripe_index >= last_stripe &&
3972 stripe_index <= (last_stripe +
3973 sub_stripes - 1))
3974 bbio->stripes[i].length -=
3975 stripe_end_offset;
3976
3977 if (i == sub_stripes - 1)
3978 stripe_offset = 0;
3979 } else
3980 bbio->stripes[i].length = *length;
3981
3982 stripe_index++;
3983 if (stripe_index == map->num_stripes) {
3984 /* This could only happen for RAID0/10 */
3985 stripe_index = 0;
3986 stripe_nr++;
3987 }
3988 }
3989 } else {
3990 for (i = 0; i < num_stripes; i++) {
3991 bbio->stripes[i].physical =
3992 map->stripes[stripe_index].physical +
3993 stripe_offset +
3994 stripe_nr * map->stripe_len;
3995 bbio->stripes[i].dev =
3996 map->stripes[stripe_index].dev;
3997 stripe_index++;
3998 }
3999 }
4000
4001 if (rw & REQ_WRITE) {
4002 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4003 BTRFS_BLOCK_GROUP_RAID10 |
4004 BTRFS_BLOCK_GROUP_DUP)) {
4005 max_errors = 1;
4006 }
4007 }
4008
4009 *bbio_ret = bbio;
4010 bbio->num_stripes = num_stripes;
4011 bbio->max_errors = max_errors;
4012 bbio->mirror_num = mirror_num;
4013 out:
4014 free_extent_map(em);
4015 return ret;
4016 }
4017
4018 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
4019 u64 logical, u64 *length,
4020 struct btrfs_bio **bbio_ret, int mirror_num)
4021 {
4022 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
4023 mirror_num);
4024 }
4025
4026 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4027 u64 chunk_start, u64 physical, u64 devid,
4028 u64 **logical, int *naddrs, int *stripe_len)
4029 {
4030 struct extent_map_tree *em_tree = &map_tree->map_tree;
4031 struct extent_map *em;
4032 struct map_lookup *map;
4033 u64 *buf;
4034 u64 bytenr;
4035 u64 length;
4036 u64 stripe_nr;
4037 int i, j, nr = 0;
4038
4039 read_lock(&em_tree->lock);
4040 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4041 read_unlock(&em_tree->lock);
4042
4043 BUG_ON(!em || em->start != chunk_start);
4044 map = (struct map_lookup *)em->bdev;
4045
4046 length = em->len;
4047 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4048 do_div(length, map->num_stripes / map->sub_stripes);
4049 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4050 do_div(length, map->num_stripes);
4051
4052 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4053 BUG_ON(!buf); /* -ENOMEM */
4054
4055 for (i = 0; i < map->num_stripes; i++) {
4056 if (devid && map->stripes[i].dev->devid != devid)
4057 continue;
4058 if (map->stripes[i].physical > physical ||
4059 map->stripes[i].physical + length <= physical)
4060 continue;
4061
4062 stripe_nr = physical - map->stripes[i].physical;
4063 do_div(stripe_nr, map->stripe_len);
4064
4065 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4066 stripe_nr = stripe_nr * map->num_stripes + i;
4067 do_div(stripe_nr, map->sub_stripes);
4068 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4069 stripe_nr = stripe_nr * map->num_stripes + i;
4070 }
4071 bytenr = chunk_start + stripe_nr * map->stripe_len;
4072 WARN_ON(nr >= map->num_stripes);
4073 for (j = 0; j < nr; j++) {
4074 if (buf[j] == bytenr)
4075 break;
4076 }
4077 if (j == nr) {
4078 WARN_ON(nr >= map->num_stripes);
4079 buf[nr++] = bytenr;
4080 }
4081 }
4082
4083 *logical = buf;
4084 *naddrs = nr;
4085 *stripe_len = map->stripe_len;
4086
4087 free_extent_map(em);
4088 return 0;
4089 }
4090
4091 static void *merge_stripe_index_into_bio_private(void *bi_private,
4092 unsigned int stripe_index)
4093 {
4094 /*
4095 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4096 * at most 1.
4097 * The alternative solution (instead of stealing bits from the
4098 * pointer) would be to allocate an intermediate structure
4099 * that contains the old private pointer plus the stripe_index.
4100 */
4101 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4102 BUG_ON(stripe_index > 3);
4103 return (void *)(((uintptr_t)bi_private) | stripe_index);
4104 }
4105
4106 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4107 {
4108 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4109 }
4110
4111 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4112 {
4113 return (unsigned int)((uintptr_t)bi_private) & 3;
4114 }
4115
4116 static void btrfs_end_bio(struct bio *bio, int err)
4117 {
4118 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4119 int is_orig_bio = 0;
4120
4121 if (err) {
4122 atomic_inc(&bbio->error);
4123 if (err == -EIO || err == -EREMOTEIO) {
4124 unsigned int stripe_index =
4125 extract_stripe_index_from_bio_private(
4126 bio->bi_private);
4127 struct btrfs_device *dev;
4128
4129 BUG_ON(stripe_index >= bbio->num_stripes);
4130 dev = bbio->stripes[stripe_index].dev;
4131 if (dev->bdev) {
4132 if (bio->bi_rw & WRITE)
4133 btrfs_dev_stat_inc(dev,
4134 BTRFS_DEV_STAT_WRITE_ERRS);
4135 else
4136 btrfs_dev_stat_inc(dev,
4137 BTRFS_DEV_STAT_READ_ERRS);
4138 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4139 btrfs_dev_stat_inc(dev,
4140 BTRFS_DEV_STAT_FLUSH_ERRS);
4141 btrfs_dev_stat_print_on_error(dev);
4142 }
4143 }
4144 }
4145
4146 if (bio == bbio->orig_bio)
4147 is_orig_bio = 1;
4148
4149 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4150 if (!is_orig_bio) {
4151 bio_put(bio);
4152 bio = bbio->orig_bio;
4153 }
4154 bio->bi_private = bbio->private;
4155 bio->bi_end_io = bbio->end_io;
4156 bio->bi_bdev = (struct block_device *)
4157 (unsigned long)bbio->mirror_num;
4158 /* only send an error to the higher layers if it is
4159 * beyond the tolerance of the multi-bio
4160 */
4161 if (atomic_read(&bbio->error) > bbio->max_errors) {
4162 err = -EIO;
4163 } else {
4164 /*
4165 * this bio is actually up to date, we didn't
4166 * go over the max number of errors
4167 */
4168 set_bit(BIO_UPTODATE, &bio->bi_flags);
4169 err = 0;
4170 }
4171 kfree(bbio);
4172
4173 bio_endio(bio, err);
4174 } else if (!is_orig_bio) {
4175 bio_put(bio);
4176 }
4177 }
4178
4179 struct async_sched {
4180 struct bio *bio;
4181 int rw;
4182 struct btrfs_fs_info *info;
4183 struct btrfs_work work;
4184 };
4185
4186 /*
4187 * see run_scheduled_bios for a description of why bios are collected for
4188 * async submit.
4189 *
4190 * This will add one bio to the pending list for a device and make sure
4191 * the work struct is scheduled.
4192 */
4193 static noinline void schedule_bio(struct btrfs_root *root,
4194 struct btrfs_device *device,
4195 int rw, struct bio *bio)
4196 {
4197 int should_queue = 1;
4198 struct btrfs_pending_bios *pending_bios;
4199
4200 /* don't bother with additional async steps for reads, right now */
4201 if (!(rw & REQ_WRITE)) {
4202 bio_get(bio);
4203 btrfsic_submit_bio(rw, bio);
4204 bio_put(bio);
4205 return;
4206 }
4207
4208 /*
4209 * nr_async_bios allows us to reliably return congestion to the
4210 * higher layers. Otherwise, the async bio makes it appear we have
4211 * made progress against dirty pages when we've really just put it
4212 * on a queue for later
4213 */
4214 atomic_inc(&root->fs_info->nr_async_bios);
4215 WARN_ON(bio->bi_next);
4216 bio->bi_next = NULL;
4217 bio->bi_rw |= rw;
4218
4219 spin_lock(&device->io_lock);
4220 if (bio->bi_rw & REQ_SYNC)
4221 pending_bios = &device->pending_sync_bios;
4222 else
4223 pending_bios = &device->pending_bios;
4224
4225 if (pending_bios->tail)
4226 pending_bios->tail->bi_next = bio;
4227
4228 pending_bios->tail = bio;
4229 if (!pending_bios->head)
4230 pending_bios->head = bio;
4231 if (device->running_pending)
4232 should_queue = 0;
4233
4234 spin_unlock(&device->io_lock);
4235
4236 if (should_queue)
4237 btrfs_queue_worker(&root->fs_info->submit_workers,
4238 &device->work);
4239 }
4240
4241 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4242 int mirror_num, int async_submit)
4243 {
4244 struct btrfs_mapping_tree *map_tree;
4245 struct btrfs_device *dev;
4246 struct bio *first_bio = bio;
4247 u64 logical = (u64)bio->bi_sector << 9;
4248 u64 length = 0;
4249 u64 map_length;
4250 int ret;
4251 int dev_nr = 0;
4252 int total_devs = 1;
4253 struct btrfs_bio *bbio = NULL;
4254
4255 length = bio->bi_size;
4256 map_tree = &root->fs_info->mapping_tree;
4257 map_length = length;
4258
4259 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
4260 mirror_num);
4261 if (ret) /* -ENOMEM */
4262 return ret;
4263
4264 total_devs = bbio->num_stripes;
4265 if (map_length < length) {
4266 printk(KERN_CRIT "btrfs: mapping failed logical %llu bio len %llu "
4267 "len %llu\n", (unsigned long long)logical,
4268 (unsigned long long)length,
4269 (unsigned long long)map_length);
4270 BUG();
4271 }
4272
4273 bbio->orig_bio = first_bio;
4274 bbio->private = first_bio->bi_private;
4275 bbio->end_io = first_bio->bi_end_io;
4276 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4277
4278 while (dev_nr < total_devs) {
4279 if (dev_nr < total_devs - 1) {
4280 bio = bio_clone(first_bio, GFP_NOFS);
4281 BUG_ON(!bio); /* -ENOMEM */
4282 } else {
4283 bio = first_bio;
4284 }
4285 bio->bi_private = bbio;
4286 bio->bi_private = merge_stripe_index_into_bio_private(
4287 bio->bi_private, (unsigned int)dev_nr);
4288 bio->bi_end_io = btrfs_end_bio;
4289 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
4290 dev = bbio->stripes[dev_nr].dev;
4291 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
4292 #ifdef DEBUG
4293 struct rcu_string *name;
4294
4295 rcu_read_lock();
4296 name = rcu_dereference(dev->name);
4297 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
4298 "(%s id %llu), size=%u\n", rw,
4299 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4300 name->str, dev->devid, bio->bi_size);
4301 rcu_read_unlock();
4302 #endif
4303 bio->bi_bdev = dev->bdev;
4304 if (async_submit)
4305 schedule_bio(root, dev, rw, bio);
4306 else
4307 btrfsic_submit_bio(rw, bio);
4308 } else {
4309 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
4310 bio->bi_sector = logical >> 9;
4311 bio_endio(bio, -EIO);
4312 }
4313 dev_nr++;
4314 }
4315 return 0;
4316 }
4317
4318 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
4319 u8 *uuid, u8 *fsid)
4320 {
4321 struct btrfs_device *device;
4322 struct btrfs_fs_devices *cur_devices;
4323
4324 cur_devices = root->fs_info->fs_devices;
4325 while (cur_devices) {
4326 if (!fsid ||
4327 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4328 device = __find_device(&cur_devices->devices,
4329 devid, uuid);
4330 if (device)
4331 return device;
4332 }
4333 cur_devices = cur_devices->seed;
4334 }
4335 return NULL;
4336 }
4337
4338 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4339 u64 devid, u8 *dev_uuid)
4340 {
4341 struct btrfs_device *device;
4342 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4343
4344 device = kzalloc(sizeof(*device), GFP_NOFS);
4345 if (!device)
4346 return NULL;
4347 list_add(&device->dev_list,
4348 &fs_devices->devices);
4349 device->dev_root = root->fs_info->dev_root;
4350 device->devid = devid;
4351 device->work.func = pending_bios_fn;
4352 device->fs_devices = fs_devices;
4353 device->missing = 1;
4354 fs_devices->num_devices++;
4355 fs_devices->missing_devices++;
4356 spin_lock_init(&device->io_lock);
4357 INIT_LIST_HEAD(&device->dev_alloc_list);
4358 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4359 return device;
4360 }
4361
4362 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4363 struct extent_buffer *leaf,
4364 struct btrfs_chunk *chunk)
4365 {
4366 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4367 struct map_lookup *map;
4368 struct extent_map *em;
4369 u64 logical;
4370 u64 length;
4371 u64 devid;
4372 u8 uuid[BTRFS_UUID_SIZE];
4373 int num_stripes;
4374 int ret;
4375 int i;
4376
4377 logical = key->offset;
4378 length = btrfs_chunk_length(leaf, chunk);
4379
4380 read_lock(&map_tree->map_tree.lock);
4381 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4382 read_unlock(&map_tree->map_tree.lock);
4383
4384 /* already mapped? */
4385 if (em && em->start <= logical && em->start + em->len > logical) {
4386 free_extent_map(em);
4387 return 0;
4388 } else if (em) {
4389 free_extent_map(em);
4390 }
4391
4392 em = alloc_extent_map();
4393 if (!em)
4394 return -ENOMEM;
4395 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4396 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4397 if (!map) {
4398 free_extent_map(em);
4399 return -ENOMEM;
4400 }
4401
4402 em->bdev = (struct block_device *)map;
4403 em->start = logical;
4404 em->len = length;
4405 em->block_start = 0;
4406 em->block_len = em->len;
4407
4408 map->num_stripes = num_stripes;
4409 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4410 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4411 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4412 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4413 map->type = btrfs_chunk_type(leaf, chunk);
4414 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4415 for (i = 0; i < num_stripes; i++) {
4416 map->stripes[i].physical =
4417 btrfs_stripe_offset_nr(leaf, chunk, i);
4418 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4419 read_extent_buffer(leaf, uuid, (unsigned long)
4420 btrfs_stripe_dev_uuid_nr(chunk, i),
4421 BTRFS_UUID_SIZE);
4422 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
4423 NULL);
4424 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
4425 kfree(map);
4426 free_extent_map(em);
4427 return -EIO;
4428 }
4429 if (!map->stripes[i].dev) {
4430 map->stripes[i].dev =
4431 add_missing_dev(root, devid, uuid);
4432 if (!map->stripes[i].dev) {
4433 kfree(map);
4434 free_extent_map(em);
4435 return -EIO;
4436 }
4437 }
4438 map->stripes[i].dev->in_fs_metadata = 1;
4439 }
4440
4441 write_lock(&map_tree->map_tree.lock);
4442 ret = add_extent_mapping(&map_tree->map_tree, em);
4443 write_unlock(&map_tree->map_tree.lock);
4444 BUG_ON(ret); /* Tree corruption */
4445 free_extent_map(em);
4446
4447 return 0;
4448 }
4449
4450 static void fill_device_from_item(struct extent_buffer *leaf,
4451 struct btrfs_dev_item *dev_item,
4452 struct btrfs_device *device)
4453 {
4454 unsigned long ptr;
4455
4456 device->devid = btrfs_device_id(leaf, dev_item);
4457 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
4458 device->total_bytes = device->disk_total_bytes;
4459 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
4460 device->type = btrfs_device_type(leaf, dev_item);
4461 device->io_align = btrfs_device_io_align(leaf, dev_item);
4462 device->io_width = btrfs_device_io_width(leaf, dev_item);
4463 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
4464
4465 ptr = (unsigned long)btrfs_device_uuid(dev_item);
4466 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
4467 }
4468
4469 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
4470 {
4471 struct btrfs_fs_devices *fs_devices;
4472 int ret;
4473
4474 BUG_ON(!mutex_is_locked(&uuid_mutex));
4475
4476 fs_devices = root->fs_info->fs_devices->seed;
4477 while (fs_devices) {
4478 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4479 ret = 0;
4480 goto out;
4481 }
4482 fs_devices = fs_devices->seed;
4483 }
4484
4485 fs_devices = find_fsid(fsid);
4486 if (!fs_devices) {
4487 ret = -ENOENT;
4488 goto out;
4489 }
4490
4491 fs_devices = clone_fs_devices(fs_devices);
4492 if (IS_ERR(fs_devices)) {
4493 ret = PTR_ERR(fs_devices);
4494 goto out;
4495 }
4496
4497 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
4498 root->fs_info->bdev_holder);
4499 if (ret) {
4500 free_fs_devices(fs_devices);
4501 goto out;
4502 }
4503
4504 if (!fs_devices->seeding) {
4505 __btrfs_close_devices(fs_devices);
4506 free_fs_devices(fs_devices);
4507 ret = -EINVAL;
4508 goto out;
4509 }
4510
4511 fs_devices->seed = root->fs_info->fs_devices->seed;
4512 root->fs_info->fs_devices->seed = fs_devices;
4513 out:
4514 return ret;
4515 }
4516
4517 static int read_one_dev(struct btrfs_root *root,
4518 struct extent_buffer *leaf,
4519 struct btrfs_dev_item *dev_item)
4520 {
4521 struct btrfs_device *device;
4522 u64 devid;
4523 int ret;
4524 u8 fs_uuid[BTRFS_UUID_SIZE];
4525 u8 dev_uuid[BTRFS_UUID_SIZE];
4526
4527 devid = btrfs_device_id(leaf, dev_item);
4528 read_extent_buffer(leaf, dev_uuid,
4529 (unsigned long)btrfs_device_uuid(dev_item),
4530 BTRFS_UUID_SIZE);
4531 read_extent_buffer(leaf, fs_uuid,
4532 (unsigned long)btrfs_device_fsid(dev_item),
4533 BTRFS_UUID_SIZE);
4534
4535 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
4536 ret = open_seed_devices(root, fs_uuid);
4537 if (ret && !btrfs_test_opt(root, DEGRADED))
4538 return ret;
4539 }
4540
4541 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
4542 if (!device || !device->bdev) {
4543 if (!btrfs_test_opt(root, DEGRADED))
4544 return -EIO;
4545
4546 if (!device) {
4547 printk(KERN_WARNING "warning devid %llu missing\n",
4548 (unsigned long long)devid);
4549 device = add_missing_dev(root, devid, dev_uuid);
4550 if (!device)
4551 return -ENOMEM;
4552 } else if (!device->missing) {
4553 /*
4554 * this happens when a device that was properly setup
4555 * in the device info lists suddenly goes bad.
4556 * device->bdev is NULL, and so we have to set
4557 * device->missing to one here
4558 */
4559 root->fs_info->fs_devices->missing_devices++;
4560 device->missing = 1;
4561 }
4562 }
4563
4564 if (device->fs_devices != root->fs_info->fs_devices) {
4565 BUG_ON(device->writeable);
4566 if (device->generation !=
4567 btrfs_device_generation(leaf, dev_item))
4568 return -EINVAL;
4569 }
4570
4571 fill_device_from_item(leaf, dev_item, device);
4572 device->dev_root = root->fs_info->dev_root;
4573 device->in_fs_metadata = 1;
4574 if (device->writeable) {
4575 device->fs_devices->total_rw_bytes += device->total_bytes;
4576 spin_lock(&root->fs_info->free_chunk_lock);
4577 root->fs_info->free_chunk_space += device->total_bytes -
4578 device->bytes_used;
4579 spin_unlock(&root->fs_info->free_chunk_lock);
4580 }
4581 ret = 0;
4582 return ret;
4583 }
4584
4585 int btrfs_read_sys_array(struct btrfs_root *root)
4586 {
4587 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4588 struct extent_buffer *sb;
4589 struct btrfs_disk_key *disk_key;
4590 struct btrfs_chunk *chunk;
4591 u8 *ptr;
4592 unsigned long sb_ptr;
4593 int ret = 0;
4594 u32 num_stripes;
4595 u32 array_size;
4596 u32 len = 0;
4597 u32 cur;
4598 struct btrfs_key key;
4599
4600 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
4601 BTRFS_SUPER_INFO_SIZE);
4602 if (!sb)
4603 return -ENOMEM;
4604 btrfs_set_buffer_uptodate(sb);
4605 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
4606 /*
4607 * The sb extent buffer is artifical and just used to read the system array.
4608 * btrfs_set_buffer_uptodate() call does not properly mark all it's
4609 * pages up-to-date when the page is larger: extent does not cover the
4610 * whole page and consequently check_page_uptodate does not find all
4611 * the page's extents up-to-date (the hole beyond sb),
4612 * write_extent_buffer then triggers a WARN_ON.
4613 *
4614 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
4615 * but sb spans only this function. Add an explicit SetPageUptodate call
4616 * to silence the warning eg. on PowerPC 64.
4617 */
4618 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
4619 SetPageUptodate(sb->pages[0]);
4620
4621 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
4622 array_size = btrfs_super_sys_array_size(super_copy);
4623
4624 ptr = super_copy->sys_chunk_array;
4625 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
4626 cur = 0;
4627
4628 while (cur < array_size) {
4629 disk_key = (struct btrfs_disk_key *)ptr;
4630 btrfs_disk_key_to_cpu(&key, disk_key);
4631
4632 len = sizeof(*disk_key); ptr += len;
4633 sb_ptr += len;
4634 cur += len;
4635
4636 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
4637 chunk = (struct btrfs_chunk *)sb_ptr;
4638 ret = read_one_chunk(root, &key, sb, chunk);
4639 if (ret)
4640 break;
4641 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
4642 len = btrfs_chunk_item_size(num_stripes);
4643 } else {
4644 ret = -EIO;
4645 break;
4646 }
4647 ptr += len;
4648 sb_ptr += len;
4649 cur += len;
4650 }
4651 free_extent_buffer(sb);
4652 return ret;
4653 }
4654
4655 int btrfs_read_chunk_tree(struct btrfs_root *root)
4656 {
4657 struct btrfs_path *path;
4658 struct extent_buffer *leaf;
4659 struct btrfs_key key;
4660 struct btrfs_key found_key;
4661 int ret;
4662 int slot;
4663
4664 root = root->fs_info->chunk_root;
4665
4666 path = btrfs_alloc_path();
4667 if (!path)
4668 return -ENOMEM;
4669
4670 mutex_lock(&uuid_mutex);
4671 lock_chunks(root);
4672
4673 /* first we search for all of the device items, and then we
4674 * read in all of the chunk items. This way we can create chunk
4675 * mappings that reference all of the devices that are afound
4676 */
4677 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
4678 key.offset = 0;
4679 key.type = 0;
4680 again:
4681 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4682 if (ret < 0)
4683 goto error;
4684 while (1) {
4685 leaf = path->nodes[0];
4686 slot = path->slots[0];
4687 if (slot >= btrfs_header_nritems(leaf)) {
4688 ret = btrfs_next_leaf(root, path);
4689 if (ret == 0)
4690 continue;
4691 if (ret < 0)
4692 goto error;
4693 break;
4694 }
4695 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4696 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4697 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
4698 break;
4699 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
4700 struct btrfs_dev_item *dev_item;
4701 dev_item = btrfs_item_ptr(leaf, slot,
4702 struct btrfs_dev_item);
4703 ret = read_one_dev(root, leaf, dev_item);
4704 if (ret)
4705 goto error;
4706 }
4707 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
4708 struct btrfs_chunk *chunk;
4709 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
4710 ret = read_one_chunk(root, &found_key, leaf, chunk);
4711 if (ret)
4712 goto error;
4713 }
4714 path->slots[0]++;
4715 }
4716 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4717 key.objectid = 0;
4718 btrfs_release_path(path);
4719 goto again;
4720 }
4721 ret = 0;
4722 error:
4723 unlock_chunks(root);
4724 mutex_unlock(&uuid_mutex);
4725
4726 btrfs_free_path(path);
4727 return ret;
4728 }
4729
4730 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
4731 {
4732 int i;
4733
4734 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4735 btrfs_dev_stat_reset(dev, i);
4736 }
4737
4738 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
4739 {
4740 struct btrfs_key key;
4741 struct btrfs_key found_key;
4742 struct btrfs_root *dev_root = fs_info->dev_root;
4743 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4744 struct extent_buffer *eb;
4745 int slot;
4746 int ret = 0;
4747 struct btrfs_device *device;
4748 struct btrfs_path *path = NULL;
4749 int i;
4750
4751 path = btrfs_alloc_path();
4752 if (!path) {
4753 ret = -ENOMEM;
4754 goto out;
4755 }
4756
4757 mutex_lock(&fs_devices->device_list_mutex);
4758 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4759 int item_size;
4760 struct btrfs_dev_stats_item *ptr;
4761
4762 key.objectid = 0;
4763 key.type = BTRFS_DEV_STATS_KEY;
4764 key.offset = device->devid;
4765 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
4766 if (ret) {
4767 __btrfs_reset_dev_stats(device);
4768 device->dev_stats_valid = 1;
4769 btrfs_release_path(path);
4770 continue;
4771 }
4772 slot = path->slots[0];
4773 eb = path->nodes[0];
4774 btrfs_item_key_to_cpu(eb, &found_key, slot);
4775 item_size = btrfs_item_size_nr(eb, slot);
4776
4777 ptr = btrfs_item_ptr(eb, slot,
4778 struct btrfs_dev_stats_item);
4779
4780 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4781 if (item_size >= (1 + i) * sizeof(__le64))
4782 btrfs_dev_stat_set(device, i,
4783 btrfs_dev_stats_value(eb, ptr, i));
4784 else
4785 btrfs_dev_stat_reset(device, i);
4786 }
4787
4788 device->dev_stats_valid = 1;
4789 btrfs_dev_stat_print_on_load(device);
4790 btrfs_release_path(path);
4791 }
4792 mutex_unlock(&fs_devices->device_list_mutex);
4793
4794 out:
4795 btrfs_free_path(path);
4796 return ret < 0 ? ret : 0;
4797 }
4798
4799 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
4800 struct btrfs_root *dev_root,
4801 struct btrfs_device *device)
4802 {
4803 struct btrfs_path *path;
4804 struct btrfs_key key;
4805 struct extent_buffer *eb;
4806 struct btrfs_dev_stats_item *ptr;
4807 int ret;
4808 int i;
4809
4810 key.objectid = 0;
4811 key.type = BTRFS_DEV_STATS_KEY;
4812 key.offset = device->devid;
4813
4814 path = btrfs_alloc_path();
4815 BUG_ON(!path);
4816 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
4817 if (ret < 0) {
4818 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
4819 ret, rcu_str_deref(device->name));
4820 goto out;
4821 }
4822
4823 if (ret == 0 &&
4824 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
4825 /* need to delete old one and insert a new one */
4826 ret = btrfs_del_item(trans, dev_root, path);
4827 if (ret != 0) {
4828 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
4829 rcu_str_deref(device->name), ret);
4830 goto out;
4831 }
4832 ret = 1;
4833 }
4834
4835 if (ret == 1) {
4836 /* need to insert a new item */
4837 btrfs_release_path(path);
4838 ret = btrfs_insert_empty_item(trans, dev_root, path,
4839 &key, sizeof(*ptr));
4840 if (ret < 0) {
4841 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
4842 rcu_str_deref(device->name), ret);
4843 goto out;
4844 }
4845 }
4846
4847 eb = path->nodes[0];
4848 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
4849 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4850 btrfs_set_dev_stats_value(eb, ptr, i,
4851 btrfs_dev_stat_read(device, i));
4852 btrfs_mark_buffer_dirty(eb);
4853
4854 out:
4855 btrfs_free_path(path);
4856 return ret;
4857 }
4858
4859 /*
4860 * called from commit_transaction. Writes all changed device stats to disk.
4861 */
4862 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
4863 struct btrfs_fs_info *fs_info)
4864 {
4865 struct btrfs_root *dev_root = fs_info->dev_root;
4866 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4867 struct btrfs_device *device;
4868 int ret = 0;
4869
4870 mutex_lock(&fs_devices->device_list_mutex);
4871 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4872 if (!device->dev_stats_valid || !device->dev_stats_dirty)
4873 continue;
4874
4875 ret = update_dev_stat_item(trans, dev_root, device);
4876 if (!ret)
4877 device->dev_stats_dirty = 0;
4878 }
4879 mutex_unlock(&fs_devices->device_list_mutex);
4880
4881 return ret;
4882 }
4883
4884 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
4885 {
4886 btrfs_dev_stat_inc(dev, index);
4887 btrfs_dev_stat_print_on_error(dev);
4888 }
4889
4890 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
4891 {
4892 if (!dev->dev_stats_valid)
4893 return;
4894 printk_ratelimited_in_rcu(KERN_ERR
4895 "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,
4901 BTRFS_DEV_STAT_CORRUPTION_ERRS),
4902 btrfs_dev_stat_read(dev,
4903 BTRFS_DEV_STAT_GENERATION_ERRS));
4904 }
4905
4906 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
4907 {
4908 int i;
4909
4910 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4911 if (btrfs_dev_stat_read(dev, i) != 0)
4912 break;
4913 if (i == BTRFS_DEV_STAT_VALUES_MAX)
4914 return; /* all values == 0, suppress message */
4915
4916 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4917 rcu_str_deref(dev->name),
4918 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4919 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4920 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4921 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
4922 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
4923 }
4924
4925 int btrfs_get_dev_stats(struct btrfs_root *root,
4926 struct btrfs_ioctl_get_dev_stats *stats)
4927 {
4928 struct btrfs_device *dev;
4929 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4930 int i;
4931
4932 mutex_lock(&fs_devices->device_list_mutex);
4933 dev = btrfs_find_device(root, stats->devid, NULL, NULL);
4934 mutex_unlock(&fs_devices->device_list_mutex);
4935
4936 if (!dev) {
4937 printk(KERN_WARNING
4938 "btrfs: get dev_stats failed, device not found\n");
4939 return -ENODEV;
4940 } else if (!dev->dev_stats_valid) {
4941 printk(KERN_WARNING
4942 "btrfs: get dev_stats failed, not yet valid\n");
4943 return -ENODEV;
4944 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
4945 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4946 if (stats->nr_items > i)
4947 stats->values[i] =
4948 btrfs_dev_stat_read_and_reset(dev, i);
4949 else
4950 btrfs_dev_stat_reset(dev, i);
4951 }
4952 } else {
4953 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4954 if (stats->nr_items > i)
4955 stats->values[i] = btrfs_dev_stat_read(dev, i);
4956 }
4957 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
4958 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
4959 return 0;
4960 }
Linux kernel - Deliverables
This page took 0.207119 seconds and 6 git commands to generate.