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Merge branch 'kirkwood/dt' of git://git.infradead.org/users/jcooper/linux into late...
[linux-2.6.git] / fs / btrfs / volumes.c
blob88b969aeeb71a53128ae941e569ad19f7b1038c3
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 "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 /*
1479 * at this point, the device is zero sized. We want to
1480 * remove it from the devices list and zero out the old super
1481 */
1482 if (clear_super) {
1483 /* make sure this device isn't detected as part of
1484 * the FS anymore
1485 */
1486 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1487 set_buffer_dirty(bh);
1488 sync_dirty_buffer(bh);
1489 }
1490
1491 ret = 0;
1492
1493 error_brelse:
1494 brelse(bh);
1495 error_close:
1496 if (bdev)
1497 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1498 out:
1499 mutex_unlock(&uuid_mutex);
1500 return ret;
1501 error_undo:
1502 if (device->writeable) {
1503 lock_chunks(root);
1504 list_add(&device->dev_alloc_list,
1505 &root->fs_info->fs_devices->alloc_list);
1506 unlock_chunks(root);
1507 root->fs_info->fs_devices->rw_devices++;
1508 }
1509 goto error_brelse;
1510 }
1511
1512 /*
1513 * does all the dirty work required for changing file system's UUID.
1514 */
1515 static int btrfs_prepare_sprout(struct btrfs_root *root)
1516 {
1517 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1518 struct btrfs_fs_devices *old_devices;
1519 struct btrfs_fs_devices *seed_devices;
1520 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1521 struct btrfs_device *device;
1522 u64 super_flags;
1523
1524 BUG_ON(!mutex_is_locked(&uuid_mutex));
1525 if (!fs_devices->seeding)
1526 return -EINVAL;
1527
1528 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1529 if (!seed_devices)
1530 return -ENOMEM;
1531
1532 old_devices = clone_fs_devices(fs_devices);
1533 if (IS_ERR(old_devices)) {
1534 kfree(seed_devices);
1535 return PTR_ERR(old_devices);
1536 }
1537
1538 list_add(&old_devices->list, &fs_uuids);
1539
1540 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1541 seed_devices->opened = 1;
1542 INIT_LIST_HEAD(&seed_devices->devices);
1543 INIT_LIST_HEAD(&seed_devices->alloc_list);
1544 mutex_init(&seed_devices->device_list_mutex);
1545
1546 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1547 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1548 synchronize_rcu);
1549 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1550
1551 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1552 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1553 device->fs_devices = seed_devices;
1554 }
1555
1556 fs_devices->seeding = 0;
1557 fs_devices->num_devices = 0;
1558 fs_devices->open_devices = 0;
1559 fs_devices->total_devices = 0;
1560 fs_devices->seed = seed_devices;
1561
1562 generate_random_uuid(fs_devices->fsid);
1563 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1564 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1565 super_flags = btrfs_super_flags(disk_super) &
1566 ~BTRFS_SUPER_FLAG_SEEDING;
1567 btrfs_set_super_flags(disk_super, super_flags);
1568
1569 return 0;
1570 }
1571
1572 /*
1573 * strore the expected generation for seed devices in device items.
1574 */
1575 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1576 struct btrfs_root *root)
1577 {
1578 struct btrfs_path *path;
1579 struct extent_buffer *leaf;
1580 struct btrfs_dev_item *dev_item;
1581 struct btrfs_device *device;
1582 struct btrfs_key key;
1583 u8 fs_uuid[BTRFS_UUID_SIZE];
1584 u8 dev_uuid[BTRFS_UUID_SIZE];
1585 u64 devid;
1586 int ret;
1587
1588 path = btrfs_alloc_path();
1589 if (!path)
1590 return -ENOMEM;
1591
1592 root = root->fs_info->chunk_root;
1593 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1594 key.offset = 0;
1595 key.type = BTRFS_DEV_ITEM_KEY;
1596
1597 while (1) {
1598 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1599 if (ret < 0)
1600 goto error;
1601
1602 leaf = path->nodes[0];
1603 next_slot:
1604 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1605 ret = btrfs_next_leaf(root, path);
1606 if (ret > 0)
1607 break;
1608 if (ret < 0)
1609 goto error;
1610 leaf = path->nodes[0];
1611 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1612 btrfs_release_path(path);
1613 continue;
1614 }
1615
1616 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1617 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1618 key.type != BTRFS_DEV_ITEM_KEY)
1619 break;
1620
1621 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1622 struct btrfs_dev_item);
1623 devid = btrfs_device_id(leaf, dev_item);
1624 read_extent_buffer(leaf, dev_uuid,
1625 (unsigned long)btrfs_device_uuid(dev_item),
1626 BTRFS_UUID_SIZE);
1627 read_extent_buffer(leaf, fs_uuid,
1628 (unsigned long)btrfs_device_fsid(dev_item),
1629 BTRFS_UUID_SIZE);
1630 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1631 BUG_ON(!device); /* Logic error */
1632
1633 if (device->fs_devices->seeding) {
1634 btrfs_set_device_generation(leaf, dev_item,
1635 device->generation);
1636 btrfs_mark_buffer_dirty(leaf);
1637 }
1638
1639 path->slots[0]++;
1640 goto next_slot;
1641 }
1642 ret = 0;
1643 error:
1644 btrfs_free_path(path);
1645 return ret;
1646 }
1647
1648 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1649 {
1650 struct request_queue *q;
1651 struct btrfs_trans_handle *trans;
1652 struct btrfs_device *device;
1653 struct block_device *bdev;
1654 struct list_head *devices;
1655 struct super_block *sb = root->fs_info->sb;
1656 struct rcu_string *name;
1657 u64 total_bytes;
1658 int seeding_dev = 0;
1659 int ret = 0;
1660
1661 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1662 return -EROFS;
1663
1664 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1665 root->fs_info->bdev_holder);
1666 if (IS_ERR(bdev))
1667 return PTR_ERR(bdev);
1668
1669 if (root->fs_info->fs_devices->seeding) {
1670 seeding_dev = 1;
1671 down_write(&sb->s_umount);
1672 mutex_lock(&uuid_mutex);
1673 }
1674
1675 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1676
1677 devices = &root->fs_info->fs_devices->devices;
1678 /*
1679 * we have the volume lock, so we don't need the extra
1680 * device list mutex while reading the list here.
1681 */
1682 list_for_each_entry(device, devices, dev_list) {
1683 if (device->bdev == bdev) {
1684 ret = -EEXIST;
1685 goto error;
1686 }
1687 }
1688
1689 device = kzalloc(sizeof(*device), GFP_NOFS);
1690 if (!device) {
1691 /* we can safely leave the fs_devices entry around */
1692 ret = -ENOMEM;
1693 goto error;
1694 }
1695
1696 name = rcu_string_strdup(device_path, GFP_NOFS);
1697 if (!name) {
1698 kfree(device);
1699 ret = -ENOMEM;
1700 goto error;
1701 }
1702 rcu_assign_pointer(device->name, name);
1703
1704 ret = find_next_devid(root, &device->devid);
1705 if (ret) {
1706 rcu_string_free(device->name);
1707 kfree(device);
1708 goto error;
1709 }
1710
1711 trans = btrfs_start_transaction(root, 0);
1712 if (IS_ERR(trans)) {
1713 rcu_string_free(device->name);
1714 kfree(device);
1715 ret = PTR_ERR(trans);
1716 goto error;
1717 }
1718
1719 lock_chunks(root);
1720
1721 q = bdev_get_queue(bdev);
1722 if (blk_queue_discard(q))
1723 device->can_discard = 1;
1724 device->writeable = 1;
1725 device->work.func = pending_bios_fn;
1726 generate_random_uuid(device->uuid);
1727 spin_lock_init(&device->io_lock);
1728 device->generation = trans->transid;
1729 device->io_width = root->sectorsize;
1730 device->io_align = root->sectorsize;
1731 device->sector_size = root->sectorsize;
1732 device->total_bytes = i_size_read(bdev->bd_inode);
1733 device->disk_total_bytes = device->total_bytes;
1734 device->dev_root = root->fs_info->dev_root;
1735 device->bdev = bdev;
1736 device->in_fs_metadata = 1;
1737 device->mode = FMODE_EXCL;
1738 set_blocksize(device->bdev, 4096);
1739
1740 if (seeding_dev) {
1741 sb->s_flags &= ~MS_RDONLY;
1742 ret = btrfs_prepare_sprout(root);
1743 BUG_ON(ret); /* -ENOMEM */
1744 }
1745
1746 device->fs_devices = root->fs_info->fs_devices;
1747
1748 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1749 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1750 list_add(&device->dev_alloc_list,
1751 &root->fs_info->fs_devices->alloc_list);
1752 root->fs_info->fs_devices->num_devices++;
1753 root->fs_info->fs_devices->open_devices++;
1754 root->fs_info->fs_devices->rw_devices++;
1755 root->fs_info->fs_devices->total_devices++;
1756 if (device->can_discard)
1757 root->fs_info->fs_devices->num_can_discard++;
1758 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1759
1760 spin_lock(&root->fs_info->free_chunk_lock);
1761 root->fs_info->free_chunk_space += device->total_bytes;
1762 spin_unlock(&root->fs_info->free_chunk_lock);
1763
1764 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1765 root->fs_info->fs_devices->rotating = 1;
1766
1767 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1768 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1769 total_bytes + device->total_bytes);
1770
1771 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1772 btrfs_set_super_num_devices(root->fs_info->super_copy,
1773 total_bytes + 1);
1774 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1775
1776 if (seeding_dev) {
1777 ret = init_first_rw_device(trans, root, device);
1778 if (ret)
1779 goto error_trans;
1780 ret = btrfs_finish_sprout(trans, root);
1781 if (ret)
1782 goto error_trans;
1783 } else {
1784 ret = btrfs_add_device(trans, root, device);
1785 if (ret)
1786 goto error_trans;
1787 }
1788
1789 /*
1790 * we've got more storage, clear any full flags on the space
1791 * infos
1792 */
1793 btrfs_clear_space_info_full(root->fs_info);
1794
1795 unlock_chunks(root);
1796 ret = btrfs_commit_transaction(trans, root);
1797
1798 if (seeding_dev) {
1799 mutex_unlock(&uuid_mutex);
1800 up_write(&sb->s_umount);
1801
1802 if (ret) /* transaction commit */
1803 return ret;
1804
1805 ret = btrfs_relocate_sys_chunks(root);
1806 if (ret < 0)
1807 btrfs_error(root->fs_info, ret,
1808 "Failed to relocate sys chunks after "
1809 "device initialization. This can be fixed "
1810 "using the \"btrfs balance\" command.");
1811 }
1812
1813 return ret;
1814
1815 error_trans:
1816 unlock_chunks(root);
1817 btrfs_abort_transaction(trans, root, ret);
1818 btrfs_end_transaction(trans, root);
1819 rcu_string_free(device->name);
1820 kfree(device);
1821 error:
1822 blkdev_put(bdev, FMODE_EXCL);
1823 if (seeding_dev) {
1824 mutex_unlock(&uuid_mutex);
1825 up_write(&sb->s_umount);
1826 }
1827 return ret;
1828 }
1829
1830 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1831 struct btrfs_device *device)
1832 {
1833 int ret;
1834 struct btrfs_path *path;
1835 struct btrfs_root *root;
1836 struct btrfs_dev_item *dev_item;
1837 struct extent_buffer *leaf;
1838 struct btrfs_key key;
1839
1840 root = device->dev_root->fs_info->chunk_root;
1841
1842 path = btrfs_alloc_path();
1843 if (!path)
1844 return -ENOMEM;
1845
1846 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1847 key.type = BTRFS_DEV_ITEM_KEY;
1848 key.offset = device->devid;
1849
1850 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1851 if (ret < 0)
1852 goto out;
1853
1854 if (ret > 0) {
1855 ret = -ENOENT;
1856 goto out;
1857 }
1858
1859 leaf = path->nodes[0];
1860 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1861
1862 btrfs_set_device_id(leaf, dev_item, device->devid);
1863 btrfs_set_device_type(leaf, dev_item, device->type);
1864 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1865 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1866 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1867 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1868 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1869 btrfs_mark_buffer_dirty(leaf);
1870
1871 out:
1872 btrfs_free_path(path);
1873 return ret;
1874 }
1875
1876 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1877 struct btrfs_device *device, u64 new_size)
1878 {
1879 struct btrfs_super_block *super_copy =
1880 device->dev_root->fs_info->super_copy;
1881 u64 old_total = btrfs_super_total_bytes(super_copy);
1882 u64 diff = new_size - device->total_bytes;
1883
1884 if (!device->writeable)
1885 return -EACCES;
1886 if (new_size <= device->total_bytes)
1887 return -EINVAL;
1888
1889 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1890 device->fs_devices->total_rw_bytes += diff;
1891
1892 device->total_bytes = new_size;
1893 device->disk_total_bytes = new_size;
1894 btrfs_clear_space_info_full(device->dev_root->fs_info);
1895
1896 return btrfs_update_device(trans, device);
1897 }
1898
1899 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1900 struct btrfs_device *device, u64 new_size)
1901 {
1902 int ret;
1903 lock_chunks(device->dev_root);
1904 ret = __btrfs_grow_device(trans, device, new_size);
1905 unlock_chunks(device->dev_root);
1906 return ret;
1907 }
1908
1909 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1910 struct btrfs_root *root,
1911 u64 chunk_tree, u64 chunk_objectid,
1912 u64 chunk_offset)
1913 {
1914 int ret;
1915 struct btrfs_path *path;
1916 struct btrfs_key key;
1917
1918 root = root->fs_info->chunk_root;
1919 path = btrfs_alloc_path();
1920 if (!path)
1921 return -ENOMEM;
1922
1923 key.objectid = chunk_objectid;
1924 key.offset = chunk_offset;
1925 key.type = BTRFS_CHUNK_ITEM_KEY;
1926
1927 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1928 if (ret < 0)
1929 goto out;
1930 else if (ret > 0) { /* Logic error or corruption */
1931 btrfs_error(root->fs_info, -ENOENT,
1932 "Failed lookup while freeing chunk.");
1933 ret = -ENOENT;
1934 goto out;
1935 }
1936
1937 ret = btrfs_del_item(trans, root, path);
1938 if (ret < 0)
1939 btrfs_error(root->fs_info, ret,
1940 "Failed to delete chunk item.");
1941 out:
1942 btrfs_free_path(path);
1943 return ret;
1944 }
1945
1946 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1947 chunk_offset)
1948 {
1949 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1950 struct btrfs_disk_key *disk_key;
1951 struct btrfs_chunk *chunk;
1952 u8 *ptr;
1953 int ret = 0;
1954 u32 num_stripes;
1955 u32 array_size;
1956 u32 len = 0;
1957 u32 cur;
1958 struct btrfs_key key;
1959
1960 array_size = btrfs_super_sys_array_size(super_copy);
1961
1962 ptr = super_copy->sys_chunk_array;
1963 cur = 0;
1964
1965 while (cur < array_size) {
1966 disk_key = (struct btrfs_disk_key *)ptr;
1967 btrfs_disk_key_to_cpu(&key, disk_key);
1968
1969 len = sizeof(*disk_key);
1970
1971 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1972 chunk = (struct btrfs_chunk *)(ptr + len);
1973 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1974 len += btrfs_chunk_item_size(num_stripes);
1975 } else {
1976 ret = -EIO;
1977 break;
1978 }
1979 if (key.objectid == chunk_objectid &&
1980 key.offset == chunk_offset) {
1981 memmove(ptr, ptr + len, array_size - (cur + len));
1982 array_size -= len;
1983 btrfs_set_super_sys_array_size(super_copy, array_size);
1984 } else {
1985 ptr += len;
1986 cur += len;
1987 }
1988 }
1989 return ret;
1990 }
1991
1992 static int btrfs_relocate_chunk(struct btrfs_root *root,
1993 u64 chunk_tree, u64 chunk_objectid,
1994 u64 chunk_offset)
1995 {
1996 struct extent_map_tree *em_tree;
1997 struct btrfs_root *extent_root;
1998 struct btrfs_trans_handle *trans;
1999 struct extent_map *em;
2000 struct map_lookup *map;
2001 int ret;
2002 int i;
2003
2004 root = root->fs_info->chunk_root;
2005 extent_root = root->fs_info->extent_root;
2006 em_tree = &root->fs_info->mapping_tree.map_tree;
2007
2008 ret = btrfs_can_relocate(extent_root, chunk_offset);
2009 if (ret)
2010 return -ENOSPC;
2011
2012 /* step one, relocate all the extents inside this chunk */
2013 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2014 if (ret)
2015 return ret;
2016
2017 trans = btrfs_start_transaction(root, 0);
2018 BUG_ON(IS_ERR(trans));
2019
2020 lock_chunks(root);
2021
2022 /*
2023 * step two, delete the device extents and the
2024 * chunk tree entries
2025 */
2026 read_lock(&em_tree->lock);
2027 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2028 read_unlock(&em_tree->lock);
2029
2030 BUG_ON(!em || em->start > chunk_offset ||
2031 em->start + em->len < chunk_offset);
2032 map = (struct map_lookup *)em->bdev;
2033
2034 for (i = 0; i < map->num_stripes; i++) {
2035 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2036 map->stripes[i].physical);
2037 BUG_ON(ret);
2038
2039 if (map->stripes[i].dev) {
2040 ret = btrfs_update_device(trans, map->stripes[i].dev);
2041 BUG_ON(ret);
2042 }
2043 }
2044 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2045 chunk_offset);
2046
2047 BUG_ON(ret);
2048
2049 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2050
2051 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2052 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2053 BUG_ON(ret);
2054 }
2055
2056 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2057 BUG_ON(ret);
2058
2059 write_lock(&em_tree->lock);
2060 remove_extent_mapping(em_tree, em);
2061 write_unlock(&em_tree->lock);
2062
2063 kfree(map);
2064 em->bdev = NULL;
2065
2066 /* once for the tree */
2067 free_extent_map(em);
2068 /* once for us */
2069 free_extent_map(em);
2070
2071 unlock_chunks(root);
2072 btrfs_end_transaction(trans, root);
2073 return 0;
2074 }
2075
2076 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2077 {
2078 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2079 struct btrfs_path *path;
2080 struct extent_buffer *leaf;
2081 struct btrfs_chunk *chunk;
2082 struct btrfs_key key;
2083 struct btrfs_key found_key;
2084 u64 chunk_tree = chunk_root->root_key.objectid;
2085 u64 chunk_type;
2086 bool retried = false;
2087 int failed = 0;
2088 int ret;
2089
2090 path = btrfs_alloc_path();
2091 if (!path)
2092 return -ENOMEM;
2093
2094 again:
2095 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2096 key.offset = (u64)-1;
2097 key.type = BTRFS_CHUNK_ITEM_KEY;
2098
2099 while (1) {
2100 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2101 if (ret < 0)
2102 goto error;
2103 BUG_ON(ret == 0); /* Corruption */
2104
2105 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2106 key.type);
2107 if (ret < 0)
2108 goto error;
2109 if (ret > 0)
2110 break;
2111
2112 leaf = path->nodes[0];
2113 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2114
2115 chunk = btrfs_item_ptr(leaf, path->slots[0],
2116 struct btrfs_chunk);
2117 chunk_type = btrfs_chunk_type(leaf, chunk);
2118 btrfs_release_path(path);
2119
2120 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2121 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2122 found_key.objectid,
2123 found_key.offset);
2124 if (ret == -ENOSPC)
2125 failed++;
2126 else if (ret)
2127 BUG();
2128 }
2129
2130 if (found_key.offset == 0)
2131 break;
2132 key.offset = found_key.offset - 1;
2133 }
2134 ret = 0;
2135 if (failed && !retried) {
2136 failed = 0;
2137 retried = true;
2138 goto again;
2139 } else if (failed && retried) {
2140 WARN_ON(1);
2141 ret = -ENOSPC;
2142 }
2143 error:
2144 btrfs_free_path(path);
2145 return ret;
2146 }
2147
2148 static int insert_balance_item(struct btrfs_root *root,
2149 struct btrfs_balance_control *bctl)
2150 {
2151 struct btrfs_trans_handle *trans;
2152 struct btrfs_balance_item *item;
2153 struct btrfs_disk_balance_args disk_bargs;
2154 struct btrfs_path *path;
2155 struct extent_buffer *leaf;
2156 struct btrfs_key key;
2157 int ret, err;
2158
2159 path = btrfs_alloc_path();
2160 if (!path)
2161 return -ENOMEM;
2162
2163 trans = btrfs_start_transaction(root, 0);
2164 if (IS_ERR(trans)) {
2165 btrfs_free_path(path);
2166 return PTR_ERR(trans);
2167 }
2168
2169 key.objectid = BTRFS_BALANCE_OBJECTID;
2170 key.type = BTRFS_BALANCE_ITEM_KEY;
2171 key.offset = 0;
2172
2173 ret = btrfs_insert_empty_item(trans, root, path, &key,
2174 sizeof(*item));
2175 if (ret)
2176 goto out;
2177
2178 leaf = path->nodes[0];
2179 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2180
2181 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2182
2183 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2184 btrfs_set_balance_data(leaf, item, &disk_bargs);
2185 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2186 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2187 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2188 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2189
2190 btrfs_set_balance_flags(leaf, item, bctl->flags);
2191
2192 btrfs_mark_buffer_dirty(leaf);
2193 out:
2194 btrfs_free_path(path);
2195 err = btrfs_commit_transaction(trans, root);
2196 if (err && !ret)
2197 ret = err;
2198 return ret;
2199 }
2200
2201 static int del_balance_item(struct btrfs_root *root)
2202 {
2203 struct btrfs_trans_handle *trans;
2204 struct btrfs_path *path;
2205 struct btrfs_key key;
2206 int ret, err;
2207
2208 path = btrfs_alloc_path();
2209 if (!path)
2210 return -ENOMEM;
2211
2212 trans = btrfs_start_transaction(root, 0);
2213 if (IS_ERR(trans)) {
2214 btrfs_free_path(path);
2215 return PTR_ERR(trans);
2216 }
2217
2218 key.objectid = BTRFS_BALANCE_OBJECTID;
2219 key.type = BTRFS_BALANCE_ITEM_KEY;
2220 key.offset = 0;
2221
2222 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2223 if (ret < 0)
2224 goto out;
2225 if (ret > 0) {
2226 ret = -ENOENT;
2227 goto out;
2228 }
2229
2230 ret = btrfs_del_item(trans, root, path);
2231 out:
2232 btrfs_free_path(path);
2233 err = btrfs_commit_transaction(trans, root);
2234 if (err && !ret)
2235 ret = err;
2236 return ret;
2237 }
2238
2239 /*
2240 * This is a heuristic used to reduce the number of chunks balanced on
2241 * resume after balance was interrupted.
2242 */
2243 static void update_balance_args(struct btrfs_balance_control *bctl)
2244 {
2245 /*
2246 * Turn on soft mode for chunk types that were being converted.
2247 */
2248 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2249 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2250 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2251 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2252 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2253 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2254
2255 /*
2256 * Turn on usage filter if is not already used. The idea is
2257 * that chunks that we have already balanced should be
2258 * reasonably full. Don't do it for chunks that are being
2259 * converted - that will keep us from relocating unconverted
2260 * (albeit full) chunks.
2261 */
2262 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2263 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2264 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2265 bctl->data.usage = 90;
2266 }
2267 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2268 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2269 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2270 bctl->sys.usage = 90;
2271 }
2272 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2273 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2274 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2275 bctl->meta.usage = 90;
2276 }
2277 }
2278
2279 /*
2280 * Should be called with both balance and volume mutexes held to
2281 * serialize other volume operations (add_dev/rm_dev/resize) with
2282 * restriper. Same goes for unset_balance_control.
2283 */
2284 static void set_balance_control(struct btrfs_balance_control *bctl)
2285 {
2286 struct btrfs_fs_info *fs_info = bctl->fs_info;
2287
2288 BUG_ON(fs_info->balance_ctl);
2289
2290 spin_lock(&fs_info->balance_lock);
2291 fs_info->balance_ctl = bctl;
2292 spin_unlock(&fs_info->balance_lock);
2293 }
2294
2295 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2296 {
2297 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2298
2299 BUG_ON(!fs_info->balance_ctl);
2300
2301 spin_lock(&fs_info->balance_lock);
2302 fs_info->balance_ctl = NULL;
2303 spin_unlock(&fs_info->balance_lock);
2304
2305 kfree(bctl);
2306 }
2307
2308 /*
2309 * Balance filters. Return 1 if chunk should be filtered out
2310 * (should not be balanced).
2311 */
2312 static int chunk_profiles_filter(u64 chunk_type,
2313 struct btrfs_balance_args *bargs)
2314 {
2315 chunk_type = chunk_to_extended(chunk_type) &
2316 BTRFS_EXTENDED_PROFILE_MASK;
2317
2318 if (bargs->profiles & chunk_type)
2319 return 0;
2320
2321 return 1;
2322 }
2323
2324 static u64 div_factor_fine(u64 num, int factor)
2325 {
2326 if (factor <= 0)
2327 return 0;
2328 if (factor >= 100)
2329 return num;
2330
2331 num *= factor;
2332 do_div(num, 100);
2333 return num;
2334 }
2335
2336 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2337 struct btrfs_balance_args *bargs)
2338 {
2339 struct btrfs_block_group_cache *cache;
2340 u64 chunk_used, user_thresh;
2341 int ret = 1;
2342
2343 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2344 chunk_used = btrfs_block_group_used(&cache->item);
2345
2346 user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
2347 if (chunk_used < user_thresh)
2348 ret = 0;
2349
2350 btrfs_put_block_group(cache);
2351 return ret;
2352 }
2353
2354 static int chunk_devid_filter(struct extent_buffer *leaf,
2355 struct btrfs_chunk *chunk,
2356 struct btrfs_balance_args *bargs)
2357 {
2358 struct btrfs_stripe *stripe;
2359 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2360 int i;
2361
2362 for (i = 0; i < num_stripes; i++) {
2363 stripe = btrfs_stripe_nr(chunk, i);
2364 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2365 return 0;
2366 }
2367
2368 return 1;
2369 }
2370
2371 /* [pstart, pend) */
2372 static int chunk_drange_filter(struct extent_buffer *leaf,
2373 struct btrfs_chunk *chunk,
2374 u64 chunk_offset,
2375 struct btrfs_balance_args *bargs)
2376 {
2377 struct btrfs_stripe *stripe;
2378 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2379 u64 stripe_offset;
2380 u64 stripe_length;
2381 int factor;
2382 int i;
2383
2384 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2385 return 0;
2386
2387 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2388 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2389 factor = 2;
2390 else
2391 factor = 1;
2392 factor = num_stripes / factor;
2393
2394 for (i = 0; i < num_stripes; i++) {
2395 stripe = btrfs_stripe_nr(chunk, i);
2396 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2397 continue;
2398
2399 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2400 stripe_length = btrfs_chunk_length(leaf, chunk);
2401 do_div(stripe_length, factor);
2402
2403 if (stripe_offset < bargs->pend &&
2404 stripe_offset + stripe_length > bargs->pstart)
2405 return 0;
2406 }
2407
2408 return 1;
2409 }
2410
2411 /* [vstart, vend) */
2412 static int chunk_vrange_filter(struct extent_buffer *leaf,
2413 struct btrfs_chunk *chunk,
2414 u64 chunk_offset,
2415 struct btrfs_balance_args *bargs)
2416 {
2417 if (chunk_offset < bargs->vend &&
2418 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2419 /* at least part of the chunk is inside this vrange */
2420 return 0;
2421
2422 return 1;
2423 }
2424
2425 static int chunk_soft_convert_filter(u64 chunk_type,
2426 struct btrfs_balance_args *bargs)
2427 {
2428 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2429 return 0;
2430
2431 chunk_type = chunk_to_extended(chunk_type) &
2432 BTRFS_EXTENDED_PROFILE_MASK;
2433
2434 if (bargs->target == chunk_type)
2435 return 1;
2436
2437 return 0;
2438 }
2439
2440 static int should_balance_chunk(struct btrfs_root *root,
2441 struct extent_buffer *leaf,
2442 struct btrfs_chunk *chunk, u64 chunk_offset)
2443 {
2444 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2445 struct btrfs_balance_args *bargs = NULL;
2446 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2447
2448 /* type filter */
2449 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2450 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2451 return 0;
2452 }
2453
2454 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2455 bargs = &bctl->data;
2456 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2457 bargs = &bctl->sys;
2458 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2459 bargs = &bctl->meta;
2460
2461 /* profiles filter */
2462 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2463 chunk_profiles_filter(chunk_type, bargs)) {
2464 return 0;
2465 }
2466
2467 /* usage filter */
2468 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2469 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2470 return 0;
2471 }
2472
2473 /* devid filter */
2474 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2475 chunk_devid_filter(leaf, chunk, bargs)) {
2476 return 0;
2477 }
2478
2479 /* drange filter, makes sense only with devid filter */
2480 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2481 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2482 return 0;
2483 }
2484
2485 /* vrange filter */
2486 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2487 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2488 return 0;
2489 }
2490
2491 /* soft profile changing mode */
2492 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2493 chunk_soft_convert_filter(chunk_type, bargs)) {
2494 return 0;
2495 }
2496
2497 return 1;
2498 }
2499
2500 static u64 div_factor(u64 num, int factor)
2501 {
2502 if (factor == 10)
2503 return num;
2504 num *= factor;
2505 do_div(num, 10);
2506 return num;
2507 }
2508
2509 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2510 {
2511 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2512 struct btrfs_root *chunk_root = fs_info->chunk_root;
2513 struct btrfs_root *dev_root = fs_info->dev_root;
2514 struct list_head *devices;
2515 struct btrfs_device *device;
2516 u64 old_size;
2517 u64 size_to_free;
2518 struct btrfs_chunk *chunk;
2519 struct btrfs_path *path;
2520 struct btrfs_key key;
2521 struct btrfs_key found_key;
2522 struct btrfs_trans_handle *trans;
2523 struct extent_buffer *leaf;
2524 int slot;
2525 int ret;
2526 int enospc_errors = 0;
2527 bool counting = true;
2528
2529 /* step one make some room on all the devices */
2530 devices = &fs_info->fs_devices->devices;
2531 list_for_each_entry(device, devices, dev_list) {
2532 old_size = device->total_bytes;
2533 size_to_free = div_factor(old_size, 1);
2534 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2535 if (!device->writeable ||
2536 device->total_bytes - device->bytes_used > size_to_free)
2537 continue;
2538
2539 ret = btrfs_shrink_device(device, old_size - size_to_free);
2540 if (ret == -ENOSPC)
2541 break;
2542 BUG_ON(ret);
2543
2544 trans = btrfs_start_transaction(dev_root, 0);
2545 BUG_ON(IS_ERR(trans));
2546
2547 ret = btrfs_grow_device(trans, device, old_size);
2548 BUG_ON(ret);
2549
2550 btrfs_end_transaction(trans, dev_root);
2551 }
2552
2553 /* step two, relocate all the chunks */
2554 path = btrfs_alloc_path();
2555 if (!path) {
2556 ret = -ENOMEM;
2557 goto error;
2558 }
2559
2560 /* zero out stat counters */
2561 spin_lock(&fs_info->balance_lock);
2562 memset(&bctl->stat, 0, sizeof(bctl->stat));
2563 spin_unlock(&fs_info->balance_lock);
2564 again:
2565 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2566 key.offset = (u64)-1;
2567 key.type = BTRFS_CHUNK_ITEM_KEY;
2568
2569 while (1) {
2570 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2571 atomic_read(&fs_info->balance_cancel_req)) {
2572 ret = -ECANCELED;
2573 goto error;
2574 }
2575
2576 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2577 if (ret < 0)
2578 goto error;
2579
2580 /*
2581 * this shouldn't happen, it means the last relocate
2582 * failed
2583 */
2584 if (ret == 0)
2585 BUG(); /* FIXME break ? */
2586
2587 ret = btrfs_previous_item(chunk_root, path, 0,
2588 BTRFS_CHUNK_ITEM_KEY);
2589 if (ret) {
2590 ret = 0;
2591 break;
2592 }
2593
2594 leaf = path->nodes[0];
2595 slot = path->slots[0];
2596 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2597
2598 if (found_key.objectid != key.objectid)
2599 break;
2600
2601 /* chunk zero is special */
2602 if (found_key.offset == 0)
2603 break;
2604
2605 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2606
2607 if (!counting) {
2608 spin_lock(&fs_info->balance_lock);
2609 bctl->stat.considered++;
2610 spin_unlock(&fs_info->balance_lock);
2611 }
2612
2613 ret = should_balance_chunk(chunk_root, leaf, chunk,
2614 found_key.offset);
2615 btrfs_release_path(path);
2616 if (!ret)
2617 goto loop;
2618
2619 if (counting) {
2620 spin_lock(&fs_info->balance_lock);
2621 bctl->stat.expected++;
2622 spin_unlock(&fs_info->balance_lock);
2623 goto loop;
2624 }
2625
2626 ret = btrfs_relocate_chunk(chunk_root,
2627 chunk_root->root_key.objectid,
2628 found_key.objectid,
2629 found_key.offset);
2630 if (ret && ret != -ENOSPC)
2631 goto error;
2632 if (ret == -ENOSPC) {
2633 enospc_errors++;
2634 } else {
2635 spin_lock(&fs_info->balance_lock);
2636 bctl->stat.completed++;
2637 spin_unlock(&fs_info->balance_lock);
2638 }
2639 loop:
2640 key.offset = found_key.offset - 1;
2641 }
2642
2643 if (counting) {
2644 btrfs_release_path(path);
2645 counting = false;
2646 goto again;
2647 }
2648 error:
2649 btrfs_free_path(path);
2650 if (enospc_errors) {
2651 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2652 enospc_errors);
2653 if (!ret)
2654 ret = -ENOSPC;
2655 }
2656
2657 return ret;
2658 }
2659
2660 /**
2661 * alloc_profile_is_valid - see if a given profile is valid and reduced
2662 * @flags: profile to validate
2663 * @extended: if true @flags is treated as an extended profile
2664 */
2665 static int alloc_profile_is_valid(u64 flags, int extended)
2666 {
2667 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
2668 BTRFS_BLOCK_GROUP_PROFILE_MASK);
2669
2670 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
2671
2672 /* 1) check that all other bits are zeroed */
2673 if (flags & ~mask)
2674 return 0;
2675
2676 /* 2) see if profile is reduced */
2677 if (flags == 0)
2678 return !extended; /* "0" is valid for usual profiles */
2679
2680 /* true if exactly one bit set */
2681 return (flags & (flags - 1)) == 0;
2682 }
2683
2684 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2685 {
2686 /* cancel requested || normal exit path */
2687 return atomic_read(&fs_info->balance_cancel_req) ||
2688 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2689 atomic_read(&fs_info->balance_cancel_req) == 0);
2690 }
2691
2692 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2693 {
2694 int ret;
2695
2696 unset_balance_control(fs_info);
2697 ret = del_balance_item(fs_info->tree_root);
2698 BUG_ON(ret);
2699 }
2700
2701 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2702 struct btrfs_ioctl_balance_args *bargs);
2703
2704 /*
2705 * Should be called with both balance and volume mutexes held
2706 */
2707 int btrfs_balance(struct btrfs_balance_control *bctl,
2708 struct btrfs_ioctl_balance_args *bargs)
2709 {
2710 struct btrfs_fs_info *fs_info = bctl->fs_info;
2711 u64 allowed;
2712 int mixed = 0;
2713 int ret;
2714
2715 if (btrfs_fs_closing(fs_info) ||
2716 atomic_read(&fs_info->balance_pause_req) ||
2717 atomic_read(&fs_info->balance_cancel_req)) {
2718 ret = -EINVAL;
2719 goto out;
2720 }
2721
2722 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2723 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
2724 mixed = 1;
2725
2726 /*
2727 * In case of mixed groups both data and meta should be picked,
2728 * and identical options should be given for both of them.
2729 */
2730 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
2731 if (mixed && (bctl->flags & allowed)) {
2732 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
2733 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
2734 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
2735 printk(KERN_ERR "btrfs: with mixed groups data and "
2736 "metadata balance options must be the same\n");
2737 ret = -EINVAL;
2738 goto out;
2739 }
2740 }
2741
2742 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2743 if (fs_info->fs_devices->num_devices == 1)
2744 allowed |= BTRFS_BLOCK_GROUP_DUP;
2745 else if (fs_info->fs_devices->num_devices < 4)
2746 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
2747 else
2748 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2749 BTRFS_BLOCK_GROUP_RAID10);
2750
2751 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2752 (!alloc_profile_is_valid(bctl->data.target, 1) ||
2753 (bctl->data.target & ~allowed))) {
2754 printk(KERN_ERR "btrfs: unable to start balance with target "
2755 "data profile %llu\n",
2756 (unsigned long long)bctl->data.target);
2757 ret = -EINVAL;
2758 goto out;
2759 }
2760 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2761 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
2762 (bctl->meta.target & ~allowed))) {
2763 printk(KERN_ERR "btrfs: unable to start balance with target "
2764 "metadata profile %llu\n",
2765 (unsigned long long)bctl->meta.target);
2766 ret = -EINVAL;
2767 goto out;
2768 }
2769 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2770 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
2771 (bctl->sys.target & ~allowed))) {
2772 printk(KERN_ERR "btrfs: unable to start balance with target "
2773 "system profile %llu\n",
2774 (unsigned long long)bctl->sys.target);
2775 ret = -EINVAL;
2776 goto out;
2777 }
2778
2779 /* allow dup'ed data chunks only in mixed mode */
2780 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2781 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
2782 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
2783 ret = -EINVAL;
2784 goto out;
2785 }
2786
2787 /* allow to reduce meta or sys integrity only if force set */
2788 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
2789 BTRFS_BLOCK_GROUP_RAID10;
2790 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2791 (fs_info->avail_system_alloc_bits & allowed) &&
2792 !(bctl->sys.target & allowed)) ||
2793 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2794 (fs_info->avail_metadata_alloc_bits & allowed) &&
2795 !(bctl->meta.target & allowed))) {
2796 if (bctl->flags & BTRFS_BALANCE_FORCE) {
2797 printk(KERN_INFO "btrfs: force reducing metadata "
2798 "integrity\n");
2799 } else {
2800 printk(KERN_ERR "btrfs: balance will reduce metadata "
2801 "integrity, use force if you want this\n");
2802 ret = -EINVAL;
2803 goto out;
2804 }
2805 }
2806
2807 ret = insert_balance_item(fs_info->tree_root, bctl);
2808 if (ret && ret != -EEXIST)
2809 goto out;
2810
2811 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
2812 BUG_ON(ret == -EEXIST);
2813 set_balance_control(bctl);
2814 } else {
2815 BUG_ON(ret != -EEXIST);
2816 spin_lock(&fs_info->balance_lock);
2817 update_balance_args(bctl);
2818 spin_unlock(&fs_info->balance_lock);
2819 }
2820
2821 atomic_inc(&fs_info->balance_running);
2822 mutex_unlock(&fs_info->balance_mutex);
2823
2824 ret = __btrfs_balance(fs_info);
2825
2826 mutex_lock(&fs_info->balance_mutex);
2827 atomic_dec(&fs_info->balance_running);
2828
2829 if (bargs) {
2830 memset(bargs, 0, sizeof(*bargs));
2831 update_ioctl_balance_args(fs_info, 0, bargs);
2832 }
2833
2834 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
2835 balance_need_close(fs_info)) {
2836 __cancel_balance(fs_info);
2837 }
2838
2839 wake_up(&fs_info->balance_wait_q);
2840
2841 return ret;
2842 out:
2843 if (bctl->flags & BTRFS_BALANCE_RESUME)
2844 __cancel_balance(fs_info);
2845 else
2846 kfree(bctl);
2847 return ret;
2848 }
2849
2850 static int balance_kthread(void *data)
2851 {
2852 struct btrfs_fs_info *fs_info = data;
2853 int ret = 0;
2854
2855 mutex_lock(&fs_info->volume_mutex);
2856 mutex_lock(&fs_info->balance_mutex);
2857
2858 if (fs_info->balance_ctl) {
2859 printk(KERN_INFO "btrfs: continuing balance\n");
2860 ret = btrfs_balance(fs_info->balance_ctl, NULL);
2861 }
2862
2863 mutex_unlock(&fs_info->balance_mutex);
2864 mutex_unlock(&fs_info->volume_mutex);
2865
2866 return ret;
2867 }
2868
2869 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
2870 {
2871 struct task_struct *tsk;
2872
2873 spin_lock(&fs_info->balance_lock);
2874 if (!fs_info->balance_ctl) {
2875 spin_unlock(&fs_info->balance_lock);
2876 return 0;
2877 }
2878 spin_unlock(&fs_info->balance_lock);
2879
2880 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
2881 printk(KERN_INFO "btrfs: force skipping balance\n");
2882 return 0;
2883 }
2884
2885 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
2886 if (IS_ERR(tsk))
2887 return PTR_ERR(tsk);
2888
2889 return 0;
2890 }
2891
2892 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
2893 {
2894 struct btrfs_balance_control *bctl;
2895 struct btrfs_balance_item *item;
2896 struct btrfs_disk_balance_args disk_bargs;
2897 struct btrfs_path *path;
2898 struct extent_buffer *leaf;
2899 struct btrfs_key key;
2900 int ret;
2901
2902 path = btrfs_alloc_path();
2903 if (!path)
2904 return -ENOMEM;
2905
2906 key.objectid = BTRFS_BALANCE_OBJECTID;
2907 key.type = BTRFS_BALANCE_ITEM_KEY;
2908 key.offset = 0;
2909
2910 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2911 if (ret < 0)
2912 goto out;
2913 if (ret > 0) { /* ret = -ENOENT; */
2914 ret = 0;
2915 goto out;
2916 }
2917
2918 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
2919 if (!bctl) {
2920 ret = -ENOMEM;
2921 goto out;
2922 }
2923
2924 leaf = path->nodes[0];
2925 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2926
2927 bctl->fs_info = fs_info;
2928 bctl->flags = btrfs_balance_flags(leaf, item);
2929 bctl->flags |= BTRFS_BALANCE_RESUME;
2930
2931 btrfs_balance_data(leaf, item, &disk_bargs);
2932 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
2933 btrfs_balance_meta(leaf, item, &disk_bargs);
2934 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
2935 btrfs_balance_sys(leaf, item, &disk_bargs);
2936 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
2937
2938 mutex_lock(&fs_info->volume_mutex);
2939 mutex_lock(&fs_info->balance_mutex);
2940
2941 set_balance_control(bctl);
2942
2943 mutex_unlock(&fs_info->balance_mutex);
2944 mutex_unlock(&fs_info->volume_mutex);
2945 out:
2946 btrfs_free_path(path);
2947 return ret;
2948 }
2949
2950 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
2951 {
2952 int ret = 0;
2953
2954 mutex_lock(&fs_info->balance_mutex);
2955 if (!fs_info->balance_ctl) {
2956 mutex_unlock(&fs_info->balance_mutex);
2957 return -ENOTCONN;
2958 }
2959
2960 if (atomic_read(&fs_info->balance_running)) {
2961 atomic_inc(&fs_info->balance_pause_req);
2962 mutex_unlock(&fs_info->balance_mutex);
2963
2964 wait_event(fs_info->balance_wait_q,
2965 atomic_read(&fs_info->balance_running) == 0);
2966
2967 mutex_lock(&fs_info->balance_mutex);
2968 /* we are good with balance_ctl ripped off from under us */
2969 BUG_ON(atomic_read(&fs_info->balance_running));
2970 atomic_dec(&fs_info->balance_pause_req);
2971 } else {
2972 ret = -ENOTCONN;
2973 }
2974
2975 mutex_unlock(&fs_info->balance_mutex);
2976 return ret;
2977 }
2978
2979 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
2980 {
2981 mutex_lock(&fs_info->balance_mutex);
2982 if (!fs_info->balance_ctl) {
2983 mutex_unlock(&fs_info->balance_mutex);
2984 return -ENOTCONN;
2985 }
2986
2987 atomic_inc(&fs_info->balance_cancel_req);
2988 /*
2989 * if we are running just wait and return, balance item is
2990 * deleted in btrfs_balance in this case
2991 */
2992 if (atomic_read(&fs_info->balance_running)) {
2993 mutex_unlock(&fs_info->balance_mutex);
2994 wait_event(fs_info->balance_wait_q,
2995 atomic_read(&fs_info->balance_running) == 0);
2996 mutex_lock(&fs_info->balance_mutex);
2997 } else {
2998 /* __cancel_balance needs volume_mutex */
2999 mutex_unlock(&fs_info->balance_mutex);
3000 mutex_lock(&fs_info->volume_mutex);
3001 mutex_lock(&fs_info->balance_mutex);
3002
3003 if (fs_info->balance_ctl)
3004 __cancel_balance(fs_info);
3005
3006 mutex_unlock(&fs_info->volume_mutex);
3007 }
3008
3009 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3010 atomic_dec(&fs_info->balance_cancel_req);
3011 mutex_unlock(&fs_info->balance_mutex);
3012 return 0;
3013 }
3014
3015 /*
3016 * shrinking a device means finding all of the device extents past
3017 * the new size, and then following the back refs to the chunks.
3018 * The chunk relocation code actually frees the device extent
3019 */
3020 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3021 {
3022 struct btrfs_trans_handle *trans;
3023 struct btrfs_root *root = device->dev_root;
3024 struct btrfs_dev_extent *dev_extent = NULL;
3025 struct btrfs_path *path;
3026 u64 length;
3027 u64 chunk_tree;
3028 u64 chunk_objectid;
3029 u64 chunk_offset;
3030 int ret;
3031 int slot;
3032 int failed = 0;
3033 bool retried = false;
3034 struct extent_buffer *l;
3035 struct btrfs_key key;
3036 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3037 u64 old_total = btrfs_super_total_bytes(super_copy);
3038 u64 old_size = device->total_bytes;
3039 u64 diff = device->total_bytes - new_size;
3040
3041 if (new_size >= device->total_bytes)
3042 return -EINVAL;
3043
3044 path = btrfs_alloc_path();
3045 if (!path)
3046 return -ENOMEM;
3047
3048 path->reada = 2;
3049
3050 lock_chunks(root);
3051
3052 device->total_bytes = new_size;
3053 if (device->writeable) {
3054 device->fs_devices->total_rw_bytes -= diff;
3055 spin_lock(&root->fs_info->free_chunk_lock);
3056 root->fs_info->free_chunk_space -= diff;
3057 spin_unlock(&root->fs_info->free_chunk_lock);
3058 }
3059 unlock_chunks(root);
3060
3061 again:
3062 key.objectid = device->devid;
3063 key.offset = (u64)-1;
3064 key.type = BTRFS_DEV_EXTENT_KEY;
3065
3066 do {
3067 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3068 if (ret < 0)
3069 goto done;
3070
3071 ret = btrfs_previous_item(root, path, 0, key.type);
3072 if (ret < 0)
3073 goto done;
3074 if (ret) {
3075 ret = 0;
3076 btrfs_release_path(path);
3077 break;
3078 }
3079
3080 l = path->nodes[0];
3081 slot = path->slots[0];
3082 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3083
3084 if (key.objectid != device->devid) {
3085 btrfs_release_path(path);
3086 break;
3087 }
3088
3089 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3090 length = btrfs_dev_extent_length(l, dev_extent);
3091
3092 if (key.offset + length <= new_size) {
3093 btrfs_release_path(path);
3094 break;
3095 }
3096
3097 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3098 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3099 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3100 btrfs_release_path(path);
3101
3102 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3103 chunk_offset);
3104 if (ret && ret != -ENOSPC)
3105 goto done;
3106 if (ret == -ENOSPC)
3107 failed++;
3108 } while (key.offset-- > 0);
3109
3110 if (failed && !retried) {
3111 failed = 0;
3112 retried = true;
3113 goto again;
3114 } else if (failed && retried) {
3115 ret = -ENOSPC;
3116 lock_chunks(root);
3117
3118 device->total_bytes = old_size;
3119 if (device->writeable)
3120 device->fs_devices->total_rw_bytes += diff;
3121 spin_lock(&root->fs_info->free_chunk_lock);
3122 root->fs_info->free_chunk_space += diff;
3123 spin_unlock(&root->fs_info->free_chunk_lock);
3124 unlock_chunks(root);
3125 goto done;
3126 }
3127
3128 /* Shrinking succeeded, else we would be at "done". */
3129 trans = btrfs_start_transaction(root, 0);
3130 if (IS_ERR(trans)) {
3131 ret = PTR_ERR(trans);
3132 goto done;
3133 }
3134
3135 lock_chunks(root);
3136
3137 device->disk_total_bytes = new_size;
3138 /* Now btrfs_update_device() will change the on-disk size. */
3139 ret = btrfs_update_device(trans, device);
3140 if (ret) {
3141 unlock_chunks(root);
3142 btrfs_end_transaction(trans, root);
3143 goto done;
3144 }
3145 WARN_ON(diff > old_total);
3146 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3147 unlock_chunks(root);
3148 btrfs_end_transaction(trans, root);
3149 done:
3150 btrfs_free_path(path);
3151 return ret;
3152 }
3153
3154 static int btrfs_add_system_chunk(struct btrfs_root *root,
3155 struct btrfs_key *key,
3156 struct btrfs_chunk *chunk, int item_size)
3157 {
3158 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3159 struct btrfs_disk_key disk_key;
3160 u32 array_size;
3161 u8 *ptr;
3162
3163 array_size = btrfs_super_sys_array_size(super_copy);
3164 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3165 return -EFBIG;
3166
3167 ptr = super_copy->sys_chunk_array + array_size;
3168 btrfs_cpu_key_to_disk(&disk_key, key);
3169 memcpy(ptr, &disk_key, sizeof(disk_key));
3170 ptr += sizeof(disk_key);
3171 memcpy(ptr, chunk, item_size);
3172 item_size += sizeof(disk_key);
3173 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3174 return 0;
3175 }
3176
3177 /*
3178 * sort the devices in descending order by max_avail, total_avail
3179 */
3180 static int btrfs_cmp_device_info(const void *a, const void *b)
3181 {
3182 const struct btrfs_device_info *di_a = a;
3183 const struct btrfs_device_info *di_b = b;
3184
3185 if (di_a->max_avail > di_b->max_avail)
3186 return -1;
3187 if (di_a->max_avail < di_b->max_avail)
3188 return 1;
3189 if (di_a->total_avail > di_b->total_avail)
3190 return -1;
3191 if (di_a->total_avail < di_b->total_avail)
3192 return 1;
3193 return 0;
3194 }
3195
3196 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3197 struct btrfs_root *extent_root,
3198 struct map_lookup **map_ret,
3199 u64 *num_bytes_out, u64 *stripe_size_out,
3200 u64 start, u64 type)
3201 {
3202 struct btrfs_fs_info *info = extent_root->fs_info;
3203 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3204 struct list_head *cur;
3205 struct map_lookup *map = NULL;
3206 struct extent_map_tree *em_tree;
3207 struct extent_map *em;
3208 struct btrfs_device_info *devices_info = NULL;
3209 u64 total_avail;
3210 int num_stripes; /* total number of stripes to allocate */
3211 int sub_stripes; /* sub_stripes info for map */
3212 int dev_stripes; /* stripes per dev */
3213 int devs_max; /* max devs to use */
3214 int devs_min; /* min devs needed */
3215 int devs_increment; /* ndevs has to be a multiple of this */
3216 int ncopies; /* how many copies to data has */
3217 int ret;
3218 u64 max_stripe_size;
3219 u64 max_chunk_size;
3220 u64 stripe_size;
3221 u64 num_bytes;
3222 int ndevs;
3223 int i;
3224 int j;
3225
3226 BUG_ON(!alloc_profile_is_valid(type, 0));
3227
3228 if (list_empty(&fs_devices->alloc_list))
3229 return -ENOSPC;
3230
3231 sub_stripes = 1;
3232 dev_stripes = 1;
3233 devs_increment = 1;
3234 ncopies = 1;
3235 devs_max = 0; /* 0 == as many as possible */
3236 devs_min = 1;
3237
3238 /*
3239 * define the properties of each RAID type.
3240 * FIXME: move this to a global table and use it in all RAID
3241 * calculation code
3242 */
3243 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
3244 dev_stripes = 2;
3245 ncopies = 2;
3246 devs_max = 1;
3247 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
3248 devs_min = 2;
3249 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
3250 devs_increment = 2;
3251 ncopies = 2;
3252 devs_max = 2;
3253 devs_min = 2;
3254 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
3255 sub_stripes = 2;
3256 devs_increment = 2;
3257 ncopies = 2;
3258 devs_min = 4;
3259 } else {
3260 devs_max = 1;
3261 }
3262
3263 if (type & BTRFS_BLOCK_GROUP_DATA) {
3264 max_stripe_size = 1024 * 1024 * 1024;
3265 max_chunk_size = 10 * max_stripe_size;
3266 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3267 /* for larger filesystems, use larger metadata chunks */
3268 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3269 max_stripe_size = 1024 * 1024 * 1024;
3270 else
3271 max_stripe_size = 256 * 1024 * 1024;
3272 max_chunk_size = max_stripe_size;
3273 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3274 max_stripe_size = 32 * 1024 * 1024;
3275 max_chunk_size = 2 * max_stripe_size;
3276 } else {
3277 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3278 type);
3279 BUG_ON(1);
3280 }
3281
3282 /* we don't want a chunk larger than 10% of writeable space */
3283 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3284 max_chunk_size);
3285
3286 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3287 GFP_NOFS);
3288 if (!devices_info)
3289 return -ENOMEM;
3290
3291 cur = fs_devices->alloc_list.next;
3292
3293 /*
3294 * in the first pass through the devices list, we gather information
3295 * about the available holes on each device.
3296 */
3297 ndevs = 0;
3298 while (cur != &fs_devices->alloc_list) {
3299 struct btrfs_device *device;
3300 u64 max_avail;
3301 u64 dev_offset;
3302
3303 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3304
3305 cur = cur->next;
3306
3307 if (!device->writeable) {
3308 printk(KERN_ERR
3309 "btrfs: read-only device in alloc_list\n");
3310 WARN_ON(1);
3311 continue;
3312 }
3313
3314 if (!device->in_fs_metadata)
3315 continue;
3316
3317 if (device->total_bytes > device->bytes_used)
3318 total_avail = device->total_bytes - device->bytes_used;
3319 else
3320 total_avail = 0;
3321
3322 /* If there is no space on this device, skip it. */
3323 if (total_avail == 0)
3324 continue;
3325
3326 ret = find_free_dev_extent(device,
3327 max_stripe_size * dev_stripes,
3328 &dev_offset, &max_avail);
3329 if (ret && ret != -ENOSPC)
3330 goto error;
3331
3332 if (ret == 0)
3333 max_avail = max_stripe_size * dev_stripes;
3334
3335 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3336 continue;
3337
3338 devices_info[ndevs].dev_offset = dev_offset;
3339 devices_info[ndevs].max_avail = max_avail;
3340 devices_info[ndevs].total_avail = total_avail;
3341 devices_info[ndevs].dev = device;
3342 ++ndevs;
3343 }
3344
3345 /*
3346 * now sort the devices by hole size / available space
3347 */
3348 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3349 btrfs_cmp_device_info, NULL);
3350
3351 /* round down to number of usable stripes */
3352 ndevs -= ndevs % devs_increment;
3353
3354 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3355 ret = -ENOSPC;
3356 goto error;
3357 }
3358
3359 if (devs_max && ndevs > devs_max)
3360 ndevs = devs_max;
3361 /*
3362 * the primary goal is to maximize the number of stripes, so use as many
3363 * devices as possible, even if the stripes are not maximum sized.
3364 */
3365 stripe_size = devices_info[ndevs-1].max_avail;
3366 num_stripes = ndevs * dev_stripes;
3367
3368 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3369 stripe_size = max_chunk_size * ncopies;
3370 do_div(stripe_size, ndevs);
3371 }
3372
3373 do_div(stripe_size, dev_stripes);
3374
3375 /* align to BTRFS_STRIPE_LEN */
3376 do_div(stripe_size, BTRFS_STRIPE_LEN);
3377 stripe_size *= BTRFS_STRIPE_LEN;
3378
3379 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3380 if (!map) {
3381 ret = -ENOMEM;
3382 goto error;
3383 }
3384 map->num_stripes = num_stripes;
3385
3386 for (i = 0; i < ndevs; ++i) {
3387 for (j = 0; j < dev_stripes; ++j) {
3388 int s = i * dev_stripes + j;
3389 map->stripes[s].dev = devices_info[i].dev;
3390 map->stripes[s].physical = devices_info[i].dev_offset +
3391 j * stripe_size;
3392 }
3393 }
3394 map->sector_size = extent_root->sectorsize;
3395 map->stripe_len = BTRFS_STRIPE_LEN;
3396 map->io_align = BTRFS_STRIPE_LEN;
3397 map->io_width = BTRFS_STRIPE_LEN;
3398 map->type = type;
3399 map->sub_stripes = sub_stripes;
3400
3401 *map_ret = map;
3402 num_bytes = stripe_size * (num_stripes / ncopies);
3403
3404 *stripe_size_out = stripe_size;
3405 *num_bytes_out = num_bytes;
3406
3407 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3408
3409 em = alloc_extent_map();
3410 if (!em) {
3411 ret = -ENOMEM;
3412 goto error;
3413 }
3414 em->bdev = (struct block_device *)map;
3415 em->start = start;
3416 em->len = num_bytes;
3417 em->block_start = 0;
3418 em->block_len = em->len;
3419
3420 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3421 write_lock(&em_tree->lock);
3422 ret = add_extent_mapping(em_tree, em);
3423 write_unlock(&em_tree->lock);
3424 free_extent_map(em);
3425 if (ret)
3426 goto error;
3427
3428 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3429 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3430 start, num_bytes);
3431 if (ret)
3432 goto error;
3433
3434 for (i = 0; i < map->num_stripes; ++i) {
3435 struct btrfs_device *device;
3436 u64 dev_offset;
3437
3438 device = map->stripes[i].dev;
3439 dev_offset = map->stripes[i].physical;
3440
3441 ret = btrfs_alloc_dev_extent(trans, device,
3442 info->chunk_root->root_key.objectid,
3443 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3444 start, dev_offset, stripe_size);
3445 if (ret) {
3446 btrfs_abort_transaction(trans, extent_root, ret);
3447 goto error;
3448 }
3449 }
3450
3451 kfree(devices_info);
3452 return 0;
3453
3454 error:
3455 kfree(map);
3456 kfree(devices_info);
3457 return ret;
3458 }
3459
3460 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3461 struct btrfs_root *extent_root,
3462 struct map_lookup *map, u64 chunk_offset,
3463 u64 chunk_size, u64 stripe_size)
3464 {
3465 u64 dev_offset;
3466 struct btrfs_key key;
3467 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3468 struct btrfs_device *device;
3469 struct btrfs_chunk *chunk;
3470 struct btrfs_stripe *stripe;
3471 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3472 int index = 0;
3473 int ret;
3474
3475 chunk = kzalloc(item_size, GFP_NOFS);
3476 if (!chunk)
3477 return -ENOMEM;
3478
3479 index = 0;
3480 while (index < map->num_stripes) {
3481 device = map->stripes[index].dev;
3482 device->bytes_used += stripe_size;
3483 ret = btrfs_update_device(trans, device);
3484 if (ret)
3485 goto out_free;
3486 index++;
3487 }
3488
3489 spin_lock(&extent_root->fs_info->free_chunk_lock);
3490 extent_root->fs_info->free_chunk_space -= (stripe_size *
3491 map->num_stripes);
3492 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3493
3494 index = 0;
3495 stripe = &chunk->stripe;
3496 while (index < map->num_stripes) {
3497 device = map->stripes[index].dev;
3498 dev_offset = map->stripes[index].physical;
3499
3500 btrfs_set_stack_stripe_devid(stripe, device->devid);
3501 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3502 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3503 stripe++;
3504 index++;
3505 }
3506
3507 btrfs_set_stack_chunk_length(chunk, chunk_size);
3508 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3509 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3510 btrfs_set_stack_chunk_type(chunk, map->type);
3511 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3512 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3513 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3514 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3515 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3516
3517 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3518 key.type = BTRFS_CHUNK_ITEM_KEY;
3519 key.offset = chunk_offset;
3520
3521 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3522
3523 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3524 /*
3525 * TODO: Cleanup of inserted chunk root in case of
3526 * failure.
3527 */
3528 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3529 item_size);
3530 }
3531
3532 out_free:
3533 kfree(chunk);
3534 return ret;
3535 }
3536
3537 /*
3538 * Chunk allocation falls into two parts. The first part does works
3539 * that make the new allocated chunk useable, but not do any operation
3540 * that modifies the chunk tree. The second part does the works that
3541 * require modifying the chunk tree. This division is important for the
3542 * bootstrap process of adding storage to a seed btrfs.
3543 */
3544 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3545 struct btrfs_root *extent_root, u64 type)
3546 {
3547 u64 chunk_offset;
3548 u64 chunk_size;
3549 u64 stripe_size;
3550 struct map_lookup *map;
3551 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3552 int ret;
3553
3554 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3555 &chunk_offset);
3556 if (ret)
3557 return ret;
3558
3559 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3560 &stripe_size, chunk_offset, type);
3561 if (ret)
3562 return ret;
3563
3564 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3565 chunk_size, stripe_size);
3566 if (ret)
3567 return ret;
3568 return 0;
3569 }
3570
3571 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3572 struct btrfs_root *root,
3573 struct btrfs_device *device)
3574 {
3575 u64 chunk_offset;
3576 u64 sys_chunk_offset;
3577 u64 chunk_size;
3578 u64 sys_chunk_size;
3579 u64 stripe_size;
3580 u64 sys_stripe_size;
3581 u64 alloc_profile;
3582 struct map_lookup *map;
3583 struct map_lookup *sys_map;
3584 struct btrfs_fs_info *fs_info = root->fs_info;
3585 struct btrfs_root *extent_root = fs_info->extent_root;
3586 int ret;
3587
3588 ret = find_next_chunk(fs_info->chunk_root,
3589 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3590 if (ret)
3591 return ret;
3592
3593 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3594 fs_info->avail_metadata_alloc_bits;
3595 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3596
3597 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3598 &stripe_size, chunk_offset, alloc_profile);
3599 if (ret)
3600 return ret;
3601
3602 sys_chunk_offset = chunk_offset + chunk_size;
3603
3604 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3605 fs_info->avail_system_alloc_bits;
3606 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3607
3608 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3609 &sys_chunk_size, &sys_stripe_size,
3610 sys_chunk_offset, alloc_profile);
3611 if (ret)
3612 goto abort;
3613
3614 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3615 if (ret)
3616 goto abort;
3617
3618 /*
3619 * Modifying chunk tree needs allocating new blocks from both
3620 * system block group and metadata block group. So we only can
3621 * do operations require modifying the chunk tree after both
3622 * block groups were created.
3623 */
3624 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3625 chunk_size, stripe_size);
3626 if (ret)
3627 goto abort;
3628
3629 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3630 sys_chunk_offset, sys_chunk_size,
3631 sys_stripe_size);
3632 if (ret)
3633 goto abort;
3634
3635 return 0;
3636
3637 abort:
3638 btrfs_abort_transaction(trans, root, ret);
3639 return ret;
3640 }
3641
3642 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3643 {
3644 struct extent_map *em;
3645 struct map_lookup *map;
3646 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3647 int readonly = 0;
3648 int i;
3649
3650 read_lock(&map_tree->map_tree.lock);
3651 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3652 read_unlock(&map_tree->map_tree.lock);
3653 if (!em)
3654 return 1;
3655
3656 if (btrfs_test_opt(root, DEGRADED)) {
3657 free_extent_map(em);
3658 return 0;
3659 }
3660
3661 map = (struct map_lookup *)em->bdev;
3662 for (i = 0; i < map->num_stripes; i++) {
3663 if (!map->stripes[i].dev->writeable) {
3664 readonly = 1;
3665 break;
3666 }
3667 }
3668 free_extent_map(em);
3669 return readonly;
3670 }
3671
3672 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3673 {
3674 extent_map_tree_init(&tree->map_tree);
3675 }
3676
3677 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3678 {
3679 struct extent_map *em;
3680
3681 while (1) {
3682 write_lock(&tree->map_tree.lock);
3683 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3684 if (em)
3685 remove_extent_mapping(&tree->map_tree, em);
3686 write_unlock(&tree->map_tree.lock);
3687 if (!em)
3688 break;
3689 kfree(em->bdev);
3690 /* once for us */
3691 free_extent_map(em);
3692 /* once for the tree */
3693 free_extent_map(em);
3694 }
3695 }
3696
3697 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
3698 {
3699 struct extent_map *em;
3700 struct map_lookup *map;
3701 struct extent_map_tree *em_tree = &map_tree->map_tree;
3702 int ret;
3703
3704 read_lock(&em_tree->lock);
3705 em = lookup_extent_mapping(em_tree, logical, len);
3706 read_unlock(&em_tree->lock);
3707 BUG_ON(!em);
3708
3709 BUG_ON(em->start > logical || em->start + em->len < logical);
3710 map = (struct map_lookup *)em->bdev;
3711 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
3712 ret = map->num_stripes;
3713 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3714 ret = map->sub_stripes;
3715 else
3716 ret = 1;
3717 free_extent_map(em);
3718 return ret;
3719 }
3720
3721 static int find_live_mirror(struct map_lookup *map, int first, int num,
3722 int optimal)
3723 {
3724 int i;
3725 if (map->stripes[optimal].dev->bdev)
3726 return optimal;
3727 for (i = first; i < first + num; i++) {
3728 if (map->stripes[i].dev->bdev)
3729 return i;
3730 }
3731 /* we couldn't find one that doesn't fail. Just return something
3732 * and the io error handling code will clean up eventually
3733 */
3734 return optimal;
3735 }
3736
3737 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3738 u64 logical, u64 *length,
3739 struct btrfs_bio **bbio_ret,
3740 int mirror_num)
3741 {
3742 struct extent_map *em;
3743 struct map_lookup *map;
3744 struct extent_map_tree *em_tree = &map_tree->map_tree;
3745 u64 offset;
3746 u64 stripe_offset;
3747 u64 stripe_end_offset;
3748 u64 stripe_nr;
3749 u64 stripe_nr_orig;
3750 u64 stripe_nr_end;
3751 int stripe_index;
3752 int i;
3753 int ret = 0;
3754 int num_stripes;
3755 int max_errors = 0;
3756 struct btrfs_bio *bbio = NULL;
3757
3758 read_lock(&em_tree->lock);
3759 em = lookup_extent_mapping(em_tree, logical, *length);
3760 read_unlock(&em_tree->lock);
3761
3762 if (!em) {
3763 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
3764 (unsigned long long)logical,
3765 (unsigned long long)*length);
3766 BUG();
3767 }
3768
3769 BUG_ON(em->start > logical || em->start + em->len < logical);
3770 map = (struct map_lookup *)em->bdev;
3771 offset = logical - em->start;
3772
3773 if (mirror_num > map->num_stripes)
3774 mirror_num = 0;
3775
3776 stripe_nr = offset;
3777 /*
3778 * stripe_nr counts the total number of stripes we have to stride
3779 * to get to this block
3780 */
3781 do_div(stripe_nr, map->stripe_len);
3782
3783 stripe_offset = stripe_nr * map->stripe_len;
3784 BUG_ON(offset < stripe_offset);
3785
3786 /* stripe_offset is the offset of this block in its stripe*/
3787 stripe_offset = offset - stripe_offset;
3788
3789 if (rw & REQ_DISCARD)
3790 *length = min_t(u64, em->len - offset, *length);
3791 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3792 /* we limit the length of each bio to what fits in a stripe */
3793 *length = min_t(u64, em->len - offset,
3794 map->stripe_len - stripe_offset);
3795 } else {
3796 *length = em->len - offset;
3797 }
3798
3799 if (!bbio_ret)
3800 goto out;
3801
3802 num_stripes = 1;
3803 stripe_index = 0;
3804 stripe_nr_orig = stripe_nr;
3805 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3806 (~(map->stripe_len - 1));
3807 do_div(stripe_nr_end, map->stripe_len);
3808 stripe_end_offset = stripe_nr_end * map->stripe_len -
3809 (offset + *length);
3810 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3811 if (rw & REQ_DISCARD)
3812 num_stripes = min_t(u64, map->num_stripes,
3813 stripe_nr_end - stripe_nr_orig);
3814 stripe_index = do_div(stripe_nr, map->num_stripes);
3815 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3816 if (rw & (REQ_WRITE | REQ_DISCARD))
3817 num_stripes = map->num_stripes;
3818 else if (mirror_num)
3819 stripe_index = mirror_num - 1;
3820 else {
3821 stripe_index = find_live_mirror(map, 0,
3822 map->num_stripes,
3823 current->pid % map->num_stripes);
3824 mirror_num = stripe_index + 1;
3825 }
3826
3827 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3828 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3829 num_stripes = map->num_stripes;
3830 } else if (mirror_num) {
3831 stripe_index = mirror_num - 1;
3832 } else {
3833 mirror_num = 1;
3834 }
3835
3836 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3837 int factor = map->num_stripes / map->sub_stripes;
3838
3839 stripe_index = do_div(stripe_nr, factor);
3840 stripe_index *= map->sub_stripes;
3841
3842 if (rw & REQ_WRITE)
3843 num_stripes = map->sub_stripes;
3844 else if (rw & REQ_DISCARD)
3845 num_stripes = min_t(u64, map->sub_stripes *
3846 (stripe_nr_end - stripe_nr_orig),
3847 map->num_stripes);
3848 else if (mirror_num)
3849 stripe_index += mirror_num - 1;
3850 else {
3851 int old_stripe_index = stripe_index;
3852 stripe_index = find_live_mirror(map, stripe_index,
3853 map->sub_stripes, stripe_index +
3854 current->pid % map->sub_stripes);
3855 mirror_num = stripe_index - old_stripe_index + 1;
3856 }
3857 } else {
3858 /*
3859 * after this do_div call, stripe_nr is the number of stripes
3860 * on this device we have to walk to find the data, and
3861 * stripe_index is the number of our device in the stripe array
3862 */
3863 stripe_index = do_div(stripe_nr, map->num_stripes);
3864 mirror_num = stripe_index + 1;
3865 }
3866 BUG_ON(stripe_index >= map->num_stripes);
3867
3868 bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
3869 if (!bbio) {
3870 ret = -ENOMEM;
3871 goto out;
3872 }
3873 atomic_set(&bbio->error, 0);
3874
3875 if (rw & REQ_DISCARD) {
3876 int factor = 0;
3877 int sub_stripes = 0;
3878 u64 stripes_per_dev = 0;
3879 u32 remaining_stripes = 0;
3880 u32 last_stripe = 0;
3881
3882 if (map->type &
3883 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
3884 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3885 sub_stripes = 1;
3886 else
3887 sub_stripes = map->sub_stripes;
3888
3889 factor = map->num_stripes / sub_stripes;
3890 stripes_per_dev = div_u64_rem(stripe_nr_end -
3891 stripe_nr_orig,
3892 factor,
3893 &remaining_stripes);
3894 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
3895 last_stripe *= sub_stripes;
3896 }
3897
3898 for (i = 0; i < num_stripes; i++) {
3899 bbio->stripes[i].physical =
3900 map->stripes[stripe_index].physical +
3901 stripe_offset + stripe_nr * map->stripe_len;
3902 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3903
3904 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3905 BTRFS_BLOCK_GROUP_RAID10)) {
3906 bbio->stripes[i].length = stripes_per_dev *
3907 map->stripe_len;
3908
3909 if (i / sub_stripes < remaining_stripes)
3910 bbio->stripes[i].length +=
3911 map->stripe_len;
3912
3913 /*
3914 * Special for the first stripe and
3915 * the last stripe:
3916 *
3917 * |-------|...|-------|
3918 * |----------|
3919 * off end_off
3920 */
3921 if (i < sub_stripes)
3922 bbio->stripes[i].length -=
3923 stripe_offset;
3924
3925 if (stripe_index >= last_stripe &&
3926 stripe_index <= (last_stripe +
3927 sub_stripes - 1))
3928 bbio->stripes[i].length -=
3929 stripe_end_offset;
3930
3931 if (i == sub_stripes - 1)
3932 stripe_offset = 0;
3933 } else
3934 bbio->stripes[i].length = *length;
3935
3936 stripe_index++;
3937 if (stripe_index == map->num_stripes) {
3938 /* This could only happen for RAID0/10 */
3939 stripe_index = 0;
3940 stripe_nr++;
3941 }
3942 }
3943 } else {
3944 for (i = 0; i < num_stripes; i++) {
3945 bbio->stripes[i].physical =
3946 map->stripes[stripe_index].physical +
3947 stripe_offset +
3948 stripe_nr * map->stripe_len;
3949 bbio->stripes[i].dev =
3950 map->stripes[stripe_index].dev;
3951 stripe_index++;
3952 }
3953 }
3954
3955 if (rw & REQ_WRITE) {
3956 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
3957 BTRFS_BLOCK_GROUP_RAID10 |
3958 BTRFS_BLOCK_GROUP_DUP)) {
3959 max_errors = 1;
3960 }
3961 }
3962
3963 *bbio_ret = bbio;
3964 bbio->num_stripes = num_stripes;
3965 bbio->max_errors = max_errors;
3966 bbio->mirror_num = mirror_num;
3967 out:
3968 free_extent_map(em);
3969 return ret;
3970 }
3971
3972 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3973 u64 logical, u64 *length,
3974 struct btrfs_bio **bbio_ret, int mirror_num)
3975 {
3976 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
3977 mirror_num);
3978 }
3979
3980 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3981 u64 chunk_start, u64 physical, u64 devid,
3982 u64 **logical, int *naddrs, int *stripe_len)
3983 {
3984 struct extent_map_tree *em_tree = &map_tree->map_tree;
3985 struct extent_map *em;
3986 struct map_lookup *map;
3987 u64 *buf;
3988 u64 bytenr;
3989 u64 length;
3990 u64 stripe_nr;
3991 int i, j, nr = 0;
3992
3993 read_lock(&em_tree->lock);
3994 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3995 read_unlock(&em_tree->lock);
3996
3997 BUG_ON(!em || em->start != chunk_start);
3998 map = (struct map_lookup *)em->bdev;
3999
4000 length = em->len;
4001 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4002 do_div(length, map->num_stripes / map->sub_stripes);
4003 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4004 do_div(length, map->num_stripes);
4005
4006 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4007 BUG_ON(!buf); /* -ENOMEM */
4008
4009 for (i = 0; i < map->num_stripes; i++) {
4010 if (devid && map->stripes[i].dev->devid != devid)
4011 continue;
4012 if (map->stripes[i].physical > physical ||
4013 map->stripes[i].physical + length <= physical)
4014 continue;
4015
4016 stripe_nr = physical - map->stripes[i].physical;
4017 do_div(stripe_nr, map->stripe_len);
4018
4019 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4020 stripe_nr = stripe_nr * map->num_stripes + i;
4021 do_div(stripe_nr, map->sub_stripes);
4022 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4023 stripe_nr = stripe_nr * map->num_stripes + i;
4024 }
4025 bytenr = chunk_start + stripe_nr * map->stripe_len;
4026 WARN_ON(nr >= map->num_stripes);
4027 for (j = 0; j < nr; j++) {
4028 if (buf[j] == bytenr)
4029 break;
4030 }
4031 if (j == nr) {
4032 WARN_ON(nr >= map->num_stripes);
4033 buf[nr++] = bytenr;
4034 }
4035 }
4036
4037 *logical = buf;
4038 *naddrs = nr;
4039 *stripe_len = map->stripe_len;
4040
4041 free_extent_map(em);
4042 return 0;
4043 }
4044
4045 static void *merge_stripe_index_into_bio_private(void *bi_private,
4046 unsigned int stripe_index)
4047 {
4048 /*
4049 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4050 * at most 1.
4051 * The alternative solution (instead of stealing bits from the
4052 * pointer) would be to allocate an intermediate structure
4053 * that contains the old private pointer plus the stripe_index.
4054 */
4055 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4056 BUG_ON(stripe_index > 3);
4057 return (void *)(((uintptr_t)bi_private) | stripe_index);
4058 }
4059
4060 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4061 {
4062 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4063 }
4064
4065 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4066 {
4067 return (unsigned int)((uintptr_t)bi_private) & 3;
4068 }
4069
4070 static void btrfs_end_bio(struct bio *bio, int err)
4071 {
4072 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4073 int is_orig_bio = 0;
4074
4075 if (err) {
4076 atomic_inc(&bbio->error);
4077 if (err == -EIO || err == -EREMOTEIO) {
4078 unsigned int stripe_index =
4079 extract_stripe_index_from_bio_private(
4080 bio->bi_private);
4081 struct btrfs_device *dev;
4082
4083 BUG_ON(stripe_index >= bbio->num_stripes);
4084 dev = bbio->stripes[stripe_index].dev;
4085 if (dev->bdev) {
4086 if (bio->bi_rw & WRITE)
4087 btrfs_dev_stat_inc(dev,
4088 BTRFS_DEV_STAT_WRITE_ERRS);
4089 else
4090 btrfs_dev_stat_inc(dev,
4091 BTRFS_DEV_STAT_READ_ERRS);
4092 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4093 btrfs_dev_stat_inc(dev,
4094 BTRFS_DEV_STAT_FLUSH_ERRS);
4095 btrfs_dev_stat_print_on_error(dev);
4096 }
4097 }
4098 }
4099
4100 if (bio == bbio->orig_bio)
4101 is_orig_bio = 1;
4102
4103 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4104 if (!is_orig_bio) {
4105 bio_put(bio);
4106 bio = bbio->orig_bio;
4107 }
4108 bio->bi_private = bbio->private;
4109 bio->bi_end_io = bbio->end_io;
4110 bio->bi_bdev = (struct block_device *)
4111 (unsigned long)bbio->mirror_num;
4112 /* only send an error to the higher layers if it is
4113 * beyond the tolerance of the multi-bio
4114 */
4115 if (atomic_read(&bbio->error) > bbio->max_errors) {
4116 err = -EIO;
4117 } else {
4118 /*
4119 * this bio is actually up to date, we didn't
4120 * go over the max number of errors
4121 */
4122 set_bit(BIO_UPTODATE, &bio->bi_flags);
4123 err = 0;
4124 }
4125 kfree(bbio);
4126
4127 bio_endio(bio, err);
4128 } else if (!is_orig_bio) {
4129 bio_put(bio);
4130 }
4131 }
4132
4133 struct async_sched {
4134 struct bio *bio;
4135 int rw;
4136 struct btrfs_fs_info *info;
4137 struct btrfs_work work;
4138 };
4139
4140 /*
4141 * see run_scheduled_bios for a description of why bios are collected for
4142 * async submit.
4143 *
4144 * This will add one bio to the pending list for a device and make sure
4145 * the work struct is scheduled.
4146 */
4147 static noinline void schedule_bio(struct btrfs_root *root,
4148 struct btrfs_device *device,
4149 int rw, struct bio *bio)
4150 {
4151 int should_queue = 1;
4152 struct btrfs_pending_bios *pending_bios;
4153
4154 /* don't bother with additional async steps for reads, right now */
4155 if (!(rw & REQ_WRITE)) {
4156 bio_get(bio);
4157 btrfsic_submit_bio(rw, bio);
4158 bio_put(bio);
4159 return;
4160 }
4161
4162 /*
4163 * nr_async_bios allows us to reliably return congestion to the
4164 * higher layers. Otherwise, the async bio makes it appear we have
4165 * made progress against dirty pages when we've really just put it
4166 * on a queue for later
4167 */
4168 atomic_inc(&root->fs_info->nr_async_bios);
4169 WARN_ON(bio->bi_next);
4170 bio->bi_next = NULL;
4171 bio->bi_rw |= rw;
4172
4173 spin_lock(&device->io_lock);
4174 if (bio->bi_rw & REQ_SYNC)
4175 pending_bios = &device->pending_sync_bios;
4176 else
4177 pending_bios = &device->pending_bios;
4178
4179 if (pending_bios->tail)
4180 pending_bios->tail->bi_next = bio;
4181
4182 pending_bios->tail = bio;
4183 if (!pending_bios->head)
4184 pending_bios->head = bio;
4185 if (device->running_pending)
4186 should_queue = 0;
4187
4188 spin_unlock(&device->io_lock);
4189
4190 if (should_queue)
4191 btrfs_queue_worker(&root->fs_info->submit_workers,
4192 &device->work);
4193 }
4194
4195 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4196 int mirror_num, int async_submit)
4197 {
4198 struct btrfs_mapping_tree *map_tree;
4199 struct btrfs_device *dev;
4200 struct bio *first_bio = bio;
4201 u64 logical = (u64)bio->bi_sector << 9;
4202 u64 length = 0;
4203 u64 map_length;
4204 int ret;
4205 int dev_nr = 0;
4206 int total_devs = 1;
4207 struct btrfs_bio *bbio = NULL;
4208
4209 length = bio->bi_size;
4210 map_tree = &root->fs_info->mapping_tree;
4211 map_length = length;
4212
4213 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
4214 mirror_num);
4215 if (ret) /* -ENOMEM */
4216 return ret;
4217
4218 total_devs = bbio->num_stripes;
4219 if (map_length < length) {
4220 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
4221 "len %llu\n", (unsigned long long)logical,
4222 (unsigned long long)length,
4223 (unsigned long long)map_length);
4224 BUG();
4225 }
4226
4227 bbio->orig_bio = first_bio;
4228 bbio->private = first_bio->bi_private;
4229 bbio->end_io = first_bio->bi_end_io;
4230 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4231
4232 while (dev_nr < total_devs) {
4233 if (dev_nr < total_devs - 1) {
4234 bio = bio_clone(first_bio, GFP_NOFS);
4235 BUG_ON(!bio); /* -ENOMEM */
4236 } else {
4237 bio = first_bio;
4238 }
4239 bio->bi_private = bbio;
4240 bio->bi_private = merge_stripe_index_into_bio_private(
4241 bio->bi_private, (unsigned int)dev_nr);
4242 bio->bi_end_io = btrfs_end_bio;
4243 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
4244 dev = bbio->stripes[dev_nr].dev;
4245 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
4246 #ifdef DEBUG
4247 struct rcu_string *name;
4248
4249 rcu_read_lock();
4250 name = rcu_dereference(dev->name);
4251 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
4252 "(%s id %llu), size=%u\n", rw,
4253 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4254 name->str, dev->devid, bio->bi_size);
4255 rcu_read_unlock();
4256 #endif
4257 bio->bi_bdev = dev->bdev;
4258 if (async_submit)
4259 schedule_bio(root, dev, rw, bio);
4260 else
4261 btrfsic_submit_bio(rw, bio);
4262 } else {
4263 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
4264 bio->bi_sector = logical >> 9;
4265 bio_endio(bio, -EIO);
4266 }
4267 dev_nr++;
4268 }
4269 return 0;
4270 }
4271
4272 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
4273 u8 *uuid, u8 *fsid)
4274 {
4275 struct btrfs_device *device;
4276 struct btrfs_fs_devices *cur_devices;
4277
4278 cur_devices = root->fs_info->fs_devices;
4279 while (cur_devices) {
4280 if (!fsid ||
4281 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4282 device = __find_device(&cur_devices->devices,
4283 devid, uuid);
4284 if (device)
4285 return device;
4286 }
4287 cur_devices = cur_devices->seed;
4288 }
4289 return NULL;
4290 }
4291
4292 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4293 u64 devid, u8 *dev_uuid)
4294 {
4295 struct btrfs_device *device;
4296 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4297
4298 device = kzalloc(sizeof(*device), GFP_NOFS);
4299 if (!device)
4300 return NULL;
4301 list_add(&device->dev_list,
4302 &fs_devices->devices);
4303 device->dev_root = root->fs_info->dev_root;
4304 device->devid = devid;
4305 device->work.func = pending_bios_fn;
4306 device->fs_devices = fs_devices;
4307 device->missing = 1;
4308 fs_devices->num_devices++;
4309 fs_devices->missing_devices++;
4310 spin_lock_init(&device->io_lock);
4311 INIT_LIST_HEAD(&device->dev_alloc_list);
4312 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4313 return device;
4314 }
4315
4316 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4317 struct extent_buffer *leaf,
4318 struct btrfs_chunk *chunk)
4319 {
4320 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4321 struct map_lookup *map;
4322 struct extent_map *em;
4323 u64 logical;
4324 u64 length;
4325 u64 devid;
4326 u8 uuid[BTRFS_UUID_SIZE];
4327 int num_stripes;
4328 int ret;
4329 int i;
4330
4331 logical = key->offset;
4332 length = btrfs_chunk_length(leaf, chunk);
4333
4334 read_lock(&map_tree->map_tree.lock);
4335 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4336 read_unlock(&map_tree->map_tree.lock);
4337
4338 /* already mapped? */
4339 if (em && em->start <= logical && em->start + em->len > logical) {
4340 free_extent_map(em);
4341 return 0;
4342 } else if (em) {
4343 free_extent_map(em);
4344 }
4345
4346 em = alloc_extent_map();
4347 if (!em)
4348 return -ENOMEM;
4349 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4350 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4351 if (!map) {
4352 free_extent_map(em);
4353 return -ENOMEM;
4354 }
4355
4356 em->bdev = (struct block_device *)map;
4357 em->start = logical;
4358 em->len = length;
4359 em->block_start = 0;
4360 em->block_len = em->len;
4361
4362 map->num_stripes = num_stripes;
4363 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4364 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4365 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4366 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4367 map->type = btrfs_chunk_type(leaf, chunk);
4368 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4369 for (i = 0; i < num_stripes; i++) {
4370 map->stripes[i].physical =
4371 btrfs_stripe_offset_nr(leaf, chunk, i);
4372 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4373 read_extent_buffer(leaf, uuid, (unsigned long)
4374 btrfs_stripe_dev_uuid_nr(chunk, i),
4375 BTRFS_UUID_SIZE);
4376 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
4377 NULL);
4378 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
4379 kfree(map);
4380 free_extent_map(em);
4381 return -EIO;
4382 }
4383 if (!map->stripes[i].dev) {
4384 map->stripes[i].dev =
4385 add_missing_dev(root, devid, uuid);
4386 if (!map->stripes[i].dev) {
4387 kfree(map);
4388 free_extent_map(em);
4389 return -EIO;
4390 }
4391 }
4392 map->stripes[i].dev->in_fs_metadata = 1;
4393 }
4394
4395 write_lock(&map_tree->map_tree.lock);
4396 ret = add_extent_mapping(&map_tree->map_tree, em);
4397 write_unlock(&map_tree->map_tree.lock);
4398 BUG_ON(ret); /* Tree corruption */
4399 free_extent_map(em);
4400
4401 return 0;
4402 }
4403
4404 static void fill_device_from_item(struct extent_buffer *leaf,
4405 struct btrfs_dev_item *dev_item,
4406 struct btrfs_device *device)
4407 {
4408 unsigned long ptr;
4409
4410 device->devid = btrfs_device_id(leaf, dev_item);
4411 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
4412 device->total_bytes = device->disk_total_bytes;
4413 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
4414 device->type = btrfs_device_type(leaf, dev_item);
4415 device->io_align = btrfs_device_io_align(leaf, dev_item);
4416 device->io_width = btrfs_device_io_width(leaf, dev_item);
4417 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
4418
4419 ptr = (unsigned long)btrfs_device_uuid(dev_item);
4420 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
4421 }
4422
4423 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
4424 {
4425 struct btrfs_fs_devices *fs_devices;
4426 int ret;
4427
4428 BUG_ON(!mutex_is_locked(&uuid_mutex));
4429
4430 fs_devices = root->fs_info->fs_devices->seed;
4431 while (fs_devices) {
4432 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4433 ret = 0;
4434 goto out;
4435 }
4436 fs_devices = fs_devices->seed;
4437 }
4438
4439 fs_devices = find_fsid(fsid);
4440 if (!fs_devices) {
4441 ret = -ENOENT;
4442 goto out;
4443 }
4444
4445 fs_devices = clone_fs_devices(fs_devices);
4446 if (IS_ERR(fs_devices)) {
4447 ret = PTR_ERR(fs_devices);
4448 goto out;
4449 }
4450
4451 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
4452 root->fs_info->bdev_holder);
4453 if (ret) {
4454 free_fs_devices(fs_devices);
4455 goto out;
4456 }
4457
4458 if (!fs_devices->seeding) {
4459 __btrfs_close_devices(fs_devices);
4460 free_fs_devices(fs_devices);
4461 ret = -EINVAL;
4462 goto out;
4463 }
4464
4465 fs_devices->seed = root->fs_info->fs_devices->seed;
4466 root->fs_info->fs_devices->seed = fs_devices;
4467 out:
4468 return ret;
4469 }
4470
4471 static int read_one_dev(struct btrfs_root *root,
4472 struct extent_buffer *leaf,
4473 struct btrfs_dev_item *dev_item)
4474 {
4475 struct btrfs_device *device;
4476 u64 devid;
4477 int ret;
4478 u8 fs_uuid[BTRFS_UUID_SIZE];
4479 u8 dev_uuid[BTRFS_UUID_SIZE];
4480
4481 devid = btrfs_device_id(leaf, dev_item);
4482 read_extent_buffer(leaf, dev_uuid,
4483 (unsigned long)btrfs_device_uuid(dev_item),
4484 BTRFS_UUID_SIZE);
4485 read_extent_buffer(leaf, fs_uuid,
4486 (unsigned long)btrfs_device_fsid(dev_item),
4487 BTRFS_UUID_SIZE);
4488
4489 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
4490 ret = open_seed_devices(root, fs_uuid);
4491 if (ret && !btrfs_test_opt(root, DEGRADED))
4492 return ret;
4493 }
4494
4495 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
4496 if (!device || !device->bdev) {
4497 if (!btrfs_test_opt(root, DEGRADED))
4498 return -EIO;
4499
4500 if (!device) {
4501 printk(KERN_WARNING "warning devid %llu missing\n",
4502 (unsigned long long)devid);
4503 device = add_missing_dev(root, devid, dev_uuid);
4504 if (!device)
4505 return -ENOMEM;
4506 } else if (!device->missing) {
4507 /*
4508 * this happens when a device that was properly setup
4509 * in the device info lists suddenly goes bad.
4510 * device->bdev is NULL, and so we have to set
4511 * device->missing to one here
4512 */
4513 root->fs_info->fs_devices->missing_devices++;
4514 device->missing = 1;
4515 }
4516 }
4517
4518 if (device->fs_devices != root->fs_info->fs_devices) {
4519 BUG_ON(device->writeable);
4520 if (device->generation !=
4521 btrfs_device_generation(leaf, dev_item))
4522 return -EINVAL;
4523 }
4524
4525 fill_device_from_item(leaf, dev_item, device);
4526 device->dev_root = root->fs_info->dev_root;
4527 device->in_fs_metadata = 1;
4528 if (device->writeable) {
4529 device->fs_devices->total_rw_bytes += device->total_bytes;
4530 spin_lock(&root->fs_info->free_chunk_lock);
4531 root->fs_info->free_chunk_space += device->total_bytes -
4532 device->bytes_used;
4533 spin_unlock(&root->fs_info->free_chunk_lock);
4534 }
4535 ret = 0;
4536 return ret;
4537 }
4538
4539 int btrfs_read_sys_array(struct btrfs_root *root)
4540 {
4541 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4542 struct extent_buffer *sb;
4543 struct btrfs_disk_key *disk_key;
4544 struct btrfs_chunk *chunk;
4545 u8 *ptr;
4546 unsigned long sb_ptr;
4547 int ret = 0;
4548 u32 num_stripes;
4549 u32 array_size;
4550 u32 len = 0;
4551 u32 cur;
4552 struct btrfs_key key;
4553
4554 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
4555 BTRFS_SUPER_INFO_SIZE);
4556 if (!sb)
4557 return -ENOMEM;
4558 btrfs_set_buffer_uptodate(sb);
4559 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
4560 /*
4561 * The sb extent buffer is artifical and just used to read the system array.
4562 * btrfs_set_buffer_uptodate() call does not properly mark all it's
4563 * pages up-to-date when the page is larger: extent does not cover the
4564 * whole page and consequently check_page_uptodate does not find all
4565 * the page's extents up-to-date (the hole beyond sb),
4566 * write_extent_buffer then triggers a WARN_ON.
4567 *
4568 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
4569 * but sb spans only this function. Add an explicit SetPageUptodate call
4570 * to silence the warning eg. on PowerPC 64.
4571 */
4572 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
4573 SetPageUptodate(sb->pages[0]);
4574
4575 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
4576 array_size = btrfs_super_sys_array_size(super_copy);
4577
4578 ptr = super_copy->sys_chunk_array;
4579 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
4580 cur = 0;
4581
4582 while (cur < array_size) {
4583 disk_key = (struct btrfs_disk_key *)ptr;
4584 btrfs_disk_key_to_cpu(&key, disk_key);
4585
4586 len = sizeof(*disk_key); ptr += len;
4587 sb_ptr += len;
4588 cur += len;
4589
4590 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
4591 chunk = (struct btrfs_chunk *)sb_ptr;
4592 ret = read_one_chunk(root, &key, sb, chunk);
4593 if (ret)
4594 break;
4595 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
4596 len = btrfs_chunk_item_size(num_stripes);
4597 } else {
4598 ret = -EIO;
4599 break;
4600 }
4601 ptr += len;
4602 sb_ptr += len;
4603 cur += len;
4604 }
4605 free_extent_buffer(sb);
4606 return ret;
4607 }
4608
4609 int btrfs_read_chunk_tree(struct btrfs_root *root)
4610 {
4611 struct btrfs_path *path;
4612 struct extent_buffer *leaf;
4613 struct btrfs_key key;
4614 struct btrfs_key found_key;
4615 int ret;
4616 int slot;
4617
4618 root = root->fs_info->chunk_root;
4619
4620 path = btrfs_alloc_path();
4621 if (!path)
4622 return -ENOMEM;
4623
4624 mutex_lock(&uuid_mutex);
4625 lock_chunks(root);
4626
4627 /* first we search for all of the device items, and then we
4628 * read in all of the chunk items. This way we can create chunk
4629 * mappings that reference all of the devices that are afound
4630 */
4631 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
4632 key.offset = 0;
4633 key.type = 0;
4634 again:
4635 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4636 if (ret < 0)
4637 goto error;
4638 while (1) {
4639 leaf = path->nodes[0];
4640 slot = path->slots[0];
4641 if (slot >= btrfs_header_nritems(leaf)) {
4642 ret = btrfs_next_leaf(root, path);
4643 if (ret == 0)
4644 continue;
4645 if (ret < 0)
4646 goto error;
4647 break;
4648 }
4649 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4650 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4651 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
4652 break;
4653 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
4654 struct btrfs_dev_item *dev_item;
4655 dev_item = btrfs_item_ptr(leaf, slot,
4656 struct btrfs_dev_item);
4657 ret = read_one_dev(root, leaf, dev_item);
4658 if (ret)
4659 goto error;
4660 }
4661 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
4662 struct btrfs_chunk *chunk;
4663 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
4664 ret = read_one_chunk(root, &found_key, leaf, chunk);
4665 if (ret)
4666 goto error;
4667 }
4668 path->slots[0]++;
4669 }
4670 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4671 key.objectid = 0;
4672 btrfs_release_path(path);
4673 goto again;
4674 }
4675 ret = 0;
4676 error:
4677 unlock_chunks(root);
4678 mutex_unlock(&uuid_mutex);
4679
4680 btrfs_free_path(path);
4681 return ret;
4682 }
4683
4684 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
4685 {
4686 int i;
4687
4688 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4689 btrfs_dev_stat_reset(dev, i);
4690 }
4691
4692 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
4693 {
4694 struct btrfs_key key;
4695 struct btrfs_key found_key;
4696 struct btrfs_root *dev_root = fs_info->dev_root;
4697 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4698 struct extent_buffer *eb;
4699 int slot;
4700 int ret = 0;
4701 struct btrfs_device *device;
4702 struct btrfs_path *path = NULL;
4703 int i;
4704
4705 path = btrfs_alloc_path();
4706 if (!path) {
4707 ret = -ENOMEM;
4708 goto out;
4709 }
4710
4711 mutex_lock(&fs_devices->device_list_mutex);
4712 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4713 int item_size;
4714 struct btrfs_dev_stats_item *ptr;
4715
4716 key.objectid = 0;
4717 key.type = BTRFS_DEV_STATS_KEY;
4718 key.offset = device->devid;
4719 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
4720 if (ret) {
4721 __btrfs_reset_dev_stats(device);
4722 device->dev_stats_valid = 1;
4723 btrfs_release_path(path);
4724 continue;
4725 }
4726 slot = path->slots[0];
4727 eb = path->nodes[0];
4728 btrfs_item_key_to_cpu(eb, &found_key, slot);
4729 item_size = btrfs_item_size_nr(eb, slot);
4730
4731 ptr = btrfs_item_ptr(eb, slot,
4732 struct btrfs_dev_stats_item);
4733
4734 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4735 if (item_size >= (1 + i) * sizeof(__le64))
4736 btrfs_dev_stat_set(device, i,
4737 btrfs_dev_stats_value(eb, ptr, i));
4738 else
4739 btrfs_dev_stat_reset(device, i);
4740 }
4741
4742 device->dev_stats_valid = 1;
4743 btrfs_dev_stat_print_on_load(device);
4744 btrfs_release_path(path);
4745 }
4746 mutex_unlock(&fs_devices->device_list_mutex);
4747
4748 out:
4749 btrfs_free_path(path);
4750 return ret < 0 ? ret : 0;
4751 }
4752
4753 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
4754 struct btrfs_root *dev_root,
4755 struct btrfs_device *device)
4756 {
4757 struct btrfs_path *path;
4758 struct btrfs_key key;
4759 struct extent_buffer *eb;
4760 struct btrfs_dev_stats_item *ptr;
4761 int ret;
4762 int i;
4763
4764 key.objectid = 0;
4765 key.type = BTRFS_DEV_STATS_KEY;
4766 key.offset = device->devid;
4767
4768 path = btrfs_alloc_path();
4769 BUG_ON(!path);
4770 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
4771 if (ret < 0) {
4772 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
4773 ret, rcu_str_deref(device->name));
4774 goto out;
4775 }
4776
4777 if (ret == 0 &&
4778 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
4779 /* need to delete old one and insert a new one */
4780 ret = btrfs_del_item(trans, dev_root, path);
4781 if (ret != 0) {
4782 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
4783 rcu_str_deref(device->name), ret);
4784 goto out;
4785 }
4786 ret = 1;
4787 }
4788
4789 if (ret == 1) {
4790 /* need to insert a new item */
4791 btrfs_release_path(path);
4792 ret = btrfs_insert_empty_item(trans, dev_root, path,
4793 &key, sizeof(*ptr));
4794 if (ret < 0) {
4795 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
4796 rcu_str_deref(device->name), ret);
4797 goto out;
4798 }
4799 }
4800
4801 eb = path->nodes[0];
4802 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
4803 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4804 btrfs_set_dev_stats_value(eb, ptr, i,
4805 btrfs_dev_stat_read(device, i));
4806 btrfs_mark_buffer_dirty(eb);
4807
4808 out:
4809 btrfs_free_path(path);
4810 return ret;
4811 }
4812
4813 /*
4814 * called from commit_transaction. Writes all changed device stats to disk.
4815 */
4816 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
4817 struct btrfs_fs_info *fs_info)
4818 {
4819 struct btrfs_root *dev_root = fs_info->dev_root;
4820 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4821 struct btrfs_device *device;
4822 int ret = 0;
4823
4824 mutex_lock(&fs_devices->device_list_mutex);
4825 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4826 if (!device->dev_stats_valid || !device->dev_stats_dirty)
4827 continue;
4828
4829 ret = update_dev_stat_item(trans, dev_root, device);
4830 if (!ret)
4831 device->dev_stats_dirty = 0;
4832 }
4833 mutex_unlock(&fs_devices->device_list_mutex);
4834
4835 return ret;
4836 }
4837
4838 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
4839 {
4840 btrfs_dev_stat_inc(dev, index);
4841 btrfs_dev_stat_print_on_error(dev);
4842 }
4843
4844 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
4845 {
4846 if (!dev->dev_stats_valid)
4847 return;
4848 printk_ratelimited_in_rcu(KERN_ERR
4849 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4850 rcu_str_deref(dev->name),
4851 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4852 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4853 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4854 btrfs_dev_stat_read(dev,
4855 BTRFS_DEV_STAT_CORRUPTION_ERRS),
4856 btrfs_dev_stat_read(dev,
4857 BTRFS_DEV_STAT_GENERATION_ERRS));
4858 }
4859
4860 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
4861 {
4862 int i;
4863
4864 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4865 if (btrfs_dev_stat_read(dev, i) != 0)
4866 break;
4867 if (i == BTRFS_DEV_STAT_VALUES_MAX)
4868 return; /* all values == 0, suppress message */
4869
4870 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4871 rcu_str_deref(dev->name),
4872 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4873 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4874 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4875 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
4876 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
4877 }
4878
4879 int btrfs_get_dev_stats(struct btrfs_root *root,
4880 struct btrfs_ioctl_get_dev_stats *stats)
4881 {
4882 struct btrfs_device *dev;
4883 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4884 int i;
4885
4886 mutex_lock(&fs_devices->device_list_mutex);
4887 dev = btrfs_find_device(root, stats->devid, NULL, NULL);
4888 mutex_unlock(&fs_devices->device_list_mutex);
4889
4890 if (!dev) {
4891 printk(KERN_WARNING
4892 "btrfs: get dev_stats failed, device not found\n");
4893 return -ENODEV;
4894 } else if (!dev->dev_stats_valid) {
4895 printk(KERN_WARNING
4896 "btrfs: get dev_stats failed, not yet valid\n");
4897 return -ENODEV;
4898 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
4899 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4900 if (stats->nr_items > i)
4901 stats->values[i] =
4902 btrfs_dev_stat_read_and_reset(dev, i);
4903 else
4904 btrfs_dev_stat_reset(dev, i);
4905 }
4906 } else {
4907 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4908 if (stats->nr_items > i)
4909 stats->values[i] = btrfs_dev_stat_read(dev, i);
4910 }
4911 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
4912 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
4913 return 0;
4914 }
Linus' kernel tree