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Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <linux/ratelimit.h>
27 #include <linux/kthread.h>
28 #include <asm/div64.h>
29 #include "compat.h"
30 #include "ctree.h"
31 #include "extent_map.h"
32 #include "disk-io.h"
33 #include "transaction.h"
34 #include "print-tree.h"
35 #include "volumes.h"
36 #include "async-thread.h"
37 #include "check-integrity.h"
38 #include "rcu-string.h"
39
40 static int init_first_rw_device(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root,
42 struct btrfs_device *device);
43 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
44 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
45 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
46
47 static DEFINE_MUTEX(uuid_mutex);
48 static LIST_HEAD(fs_uuids);
49
50 static void lock_chunks(struct btrfs_root *root)
51 {
52 mutex_lock(&root->fs_info->chunk_mutex);
53 }
54
55 static void unlock_chunks(struct btrfs_root *root)
56 {
57 mutex_unlock(&root->fs_info->chunk_mutex);
58 }
59
60 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
61 {
62 struct btrfs_device *device;
63 WARN_ON(fs_devices->opened);
64 while (!list_empty(&fs_devices->devices)) {
65 device = list_entry(fs_devices->devices.next,
66 struct btrfs_device, dev_list);
67 list_del(&device->dev_list);
68 rcu_string_free(device->name);
69 kfree(device);
70 }
71 kfree(fs_devices);
72 }
73
74 void btrfs_cleanup_fs_uuids(void)
75 {
76 struct btrfs_fs_devices *fs_devices;
77
78 while (!list_empty(&fs_uuids)) {
79 fs_devices = list_entry(fs_uuids.next,
80 struct btrfs_fs_devices, list);
81 list_del(&fs_devices->list);
82 free_fs_devices(fs_devices);
83 }
84 }
85
86 static noinline struct btrfs_device *__find_device(struct list_head *head,
87 u64 devid, u8 *uuid)
88 {
89 struct btrfs_device *dev;
90
91 list_for_each_entry(dev, head, dev_list) {
92 if (dev->devid == devid &&
93 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
94 return dev;
95 }
96 }
97 return NULL;
98 }
99
100 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
101 {
102 struct btrfs_fs_devices *fs_devices;
103
104 list_for_each_entry(fs_devices, &fs_uuids, list) {
105 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
106 return fs_devices;
107 }
108 return NULL;
109 }
110
111 static void requeue_list(struct btrfs_pending_bios *pending_bios,
112 struct bio *head, struct bio *tail)
113 {
114
115 struct bio *old_head;
116
117 old_head = pending_bios->head;
118 pending_bios->head = head;
119 if (pending_bios->tail)
120 tail->bi_next = old_head;
121 else
122 pending_bios->tail = tail;
123 }
124
125 /*
126 * we try to collect pending bios for a device so we don't get a large
127 * number of procs sending bios down to the same device. This greatly
128 * improves the schedulers ability to collect and merge the bios.
129 *
130 * But, it also turns into a long list of bios to process and that is sure
131 * to eventually make the worker thread block. The solution here is to
132 * make some progress and then put this work struct back at the end of
133 * the list if the block device is congested. This way, multiple devices
134 * can make progress from a single worker thread.
135 */
136 static noinline void run_scheduled_bios(struct btrfs_device *device)
137 {
138 struct bio *pending;
139 struct backing_dev_info *bdi;
140 struct btrfs_fs_info *fs_info;
141 struct btrfs_pending_bios *pending_bios;
142 struct bio *tail;
143 struct bio *cur;
144 int again = 0;
145 unsigned long num_run;
146 unsigned long batch_run = 0;
147 unsigned long limit;
148 unsigned long last_waited = 0;
149 int force_reg = 0;
150 int sync_pending = 0;
151 struct blk_plug plug;
152
153 /*
154 * this function runs all the bios we've collected for
155 * a particular device. We don't want to wander off to
156 * another device without first sending all of these down.
157 * So, setup a plug here and finish it off before we return
158 */
159 blk_start_plug(&plug);
160
161 bdi = blk_get_backing_dev_info(device->bdev);
162 fs_info = device->dev_root->fs_info;
163 limit = btrfs_async_submit_limit(fs_info);
164 limit = limit * 2 / 3;
165
166 loop:
167 spin_lock(&device->io_lock);
168
169 loop_lock:
170 num_run = 0;
171
172 /* take all the bios off the list at once and process them
173 * later on (without the lock held). But, remember the
174 * tail and other pointers so the bios can be properly reinserted
175 * into the list if we hit congestion
176 */
177 if (!force_reg && device->pending_sync_bios.head) {
178 pending_bios = &device->pending_sync_bios;
179 force_reg = 1;
180 } else {
181 pending_bios = &device->pending_bios;
182 force_reg = 0;
183 }
184
185 pending = pending_bios->head;
186 tail = pending_bios->tail;
187 WARN_ON(pending && !tail);
188
189 /*
190 * if pending was null this time around, no bios need processing
191 * at all and we can stop. Otherwise it'll loop back up again
192 * and do an additional check so no bios are missed.
193 *
194 * device->running_pending is used to synchronize with the
195 * schedule_bio code.
196 */
197 if (device->pending_sync_bios.head == NULL &&
198 device->pending_bios.head == NULL) {
199 again = 0;
200 device->running_pending = 0;
201 } else {
202 again = 1;
203 device->running_pending = 1;
204 }
205
206 pending_bios->head = NULL;
207 pending_bios->tail = NULL;
208
209 spin_unlock(&device->io_lock);
210
211 while (pending) {
212
213 rmb();
214 /* we want to work on both lists, but do more bios on the
215 * sync list than the regular list
216 */
217 if ((num_run > 32 &&
218 pending_bios != &device->pending_sync_bios &&
219 device->pending_sync_bios.head) ||
220 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
221 device->pending_bios.head)) {
222 spin_lock(&device->io_lock);
223 requeue_list(pending_bios, pending, tail);
224 goto loop_lock;
225 }
226
227 cur = pending;
228 pending = pending->bi_next;
229 cur->bi_next = NULL;
230 atomic_dec(&fs_info->nr_async_bios);
231
232 if (atomic_read(&fs_info->nr_async_bios) < limit &&
233 waitqueue_active(&fs_info->async_submit_wait))
234 wake_up(&fs_info->async_submit_wait);
235
236 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
237
238 /*
239 * if we're doing the sync list, record that our
240 * plug has some sync requests on it
241 *
242 * If we're doing the regular list and there are
243 * sync requests sitting around, unplug before
244 * we add more
245 */
246 if (pending_bios == &device->pending_sync_bios) {
247 sync_pending = 1;
248 } else if (sync_pending) {
249 blk_finish_plug(&plug);
250 blk_start_plug(&plug);
251 sync_pending = 0;
252 }
253
254 btrfsic_submit_bio(cur->bi_rw, cur);
255 num_run++;
256 batch_run++;
257 if (need_resched())
258 cond_resched();
259
260 /*
261 * we made progress, there is more work to do and the bdi
262 * is now congested. Back off and let other work structs
263 * run instead
264 */
265 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
266 fs_info->fs_devices->open_devices > 1) {
267 struct io_context *ioc;
268
269 ioc = current->io_context;
270
271 /*
272 * the main goal here is that we don't want to
273 * block if we're going to be able to submit
274 * more requests without blocking.
275 *
276 * This code does two great things, it pokes into
277 * the elevator code from a filesystem _and_
278 * it makes assumptions about how batching works.
279 */
280 if (ioc && ioc->nr_batch_requests > 0 &&
281 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
282 (last_waited == 0 ||
283 ioc->last_waited == last_waited)) {
284 /*
285 * we want to go through our batch of
286 * requests and stop. So, we copy out
287 * the ioc->last_waited time and test
288 * against it before looping
289 */
290 last_waited = ioc->last_waited;
291 if (need_resched())
292 cond_resched();
293 continue;
294 }
295 spin_lock(&device->io_lock);
296 requeue_list(pending_bios, pending, tail);
297 device->running_pending = 1;
298
299 spin_unlock(&device->io_lock);
300 btrfs_requeue_work(&device->work);
301 goto done;
302 }
303 /* unplug every 64 requests just for good measure */
304 if (batch_run % 64 == 0) {
305 blk_finish_plug(&plug);
306 blk_start_plug(&plug);
307 sync_pending = 0;
308 }
309 }
310
311 cond_resched();
312 if (again)
313 goto loop;
314
315 spin_lock(&device->io_lock);
316 if (device->pending_bios.head || device->pending_sync_bios.head)
317 goto loop_lock;
318 spin_unlock(&device->io_lock);
319
320 done:
321 blk_finish_plug(&plug);
322 }
323
324 static void pending_bios_fn(struct btrfs_work *work)
325 {
326 struct btrfs_device *device;
327
328 device = container_of(work, struct btrfs_device, work);
329 run_scheduled_bios(device);
330 }
331
332 static noinline int device_list_add(const char *path,
333 struct btrfs_super_block *disk_super,
334 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
335 {
336 struct btrfs_device *device;
337 struct btrfs_fs_devices *fs_devices;
338 struct rcu_string *name;
339 u64 found_transid = btrfs_super_generation(disk_super);
340
341 fs_devices = find_fsid(disk_super->fsid);
342 if (!fs_devices) {
343 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
344 if (!fs_devices)
345 return -ENOMEM;
346 INIT_LIST_HEAD(&fs_devices->devices);
347 INIT_LIST_HEAD(&fs_devices->alloc_list);
348 list_add(&fs_devices->list, &fs_uuids);
349 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
350 fs_devices->latest_devid = devid;
351 fs_devices->latest_trans = found_transid;
352 mutex_init(&fs_devices->device_list_mutex);
353 device = NULL;
354 } else {
355 device = __find_device(&fs_devices->devices, devid,
356 disk_super->dev_item.uuid);
357 }
358 if (!device) {
359 if (fs_devices->opened)
360 return -EBUSY;
361
362 device = kzalloc(sizeof(*device), GFP_NOFS);
363 if (!device) {
364 /* we can safely leave the fs_devices entry around */
365 return -ENOMEM;
366 }
367 device->devid = devid;
368 device->dev_stats_valid = 0;
369 device->work.func = pending_bios_fn;
370 memcpy(device->uuid, disk_super->dev_item.uuid,
371 BTRFS_UUID_SIZE);
372 spin_lock_init(&device->io_lock);
373
374 name = rcu_string_strdup(path, GFP_NOFS);
375 if (!name) {
376 kfree(device);
377 return -ENOMEM;
378 }
379 rcu_assign_pointer(device->name, name);
380 INIT_LIST_HEAD(&device->dev_alloc_list);
381
382 /* init readahead state */
383 spin_lock_init(&device->reada_lock);
384 device->reada_curr_zone = NULL;
385 atomic_set(&device->reada_in_flight, 0);
386 device->reada_next = 0;
387 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
388 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
389
390 mutex_lock(&fs_devices->device_list_mutex);
391 list_add_rcu(&device->dev_list, &fs_devices->devices);
392 mutex_unlock(&fs_devices->device_list_mutex);
393
394 device->fs_devices = fs_devices;
395 fs_devices->num_devices++;
396 } else if (!device->name || strcmp(device->name->str, path)) {
397 name = rcu_string_strdup(path, GFP_NOFS);
398 if (!name)
399 return -ENOMEM;
400 rcu_string_free(device->name);
401 rcu_assign_pointer(device->name, name);
402 if (device->missing) {
403 fs_devices->missing_devices--;
404 device->missing = 0;
405 }
406 }
407
408 if (found_transid > fs_devices->latest_trans) {
409 fs_devices->latest_devid = devid;
410 fs_devices->latest_trans = found_transid;
411 }
412 *fs_devices_ret = fs_devices;
413 return 0;
414 }
415
416 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
417 {
418 struct btrfs_fs_devices *fs_devices;
419 struct btrfs_device *device;
420 struct btrfs_device *orig_dev;
421
422 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
423 if (!fs_devices)
424 return ERR_PTR(-ENOMEM);
425
426 INIT_LIST_HEAD(&fs_devices->devices);
427 INIT_LIST_HEAD(&fs_devices->alloc_list);
428 INIT_LIST_HEAD(&fs_devices->list);
429 mutex_init(&fs_devices->device_list_mutex);
430 fs_devices->latest_devid = orig->latest_devid;
431 fs_devices->latest_trans = orig->latest_trans;
432 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 name = rcu_string_strdup(device->name->str, GFP_NOFS);
572 BUG_ON(device->name && !name); /* -ENOMEM */
573 rcu_assign_pointer(new_device->name, name);
574 new_device->bdev = NULL;
575 new_device->writeable = 0;
576 new_device->in_fs_metadata = 0;
577 new_device->can_discard = 0;
578 list_replace_rcu(&device->dev_list, &new_device->dev_list);
579
580 call_rcu(&device->rcu, free_device);
581 }
582 mutex_unlock(&fs_devices->device_list_mutex);
583
584 WARN_ON(fs_devices->open_devices);
585 WARN_ON(fs_devices->rw_devices);
586 fs_devices->opened = 0;
587 fs_devices->seeding = 0;
588
589 return 0;
590 }
591
592 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
593 {
594 struct btrfs_fs_devices *seed_devices = NULL;
595 int ret;
596
597 mutex_lock(&uuid_mutex);
598 ret = __btrfs_close_devices(fs_devices);
599 if (!fs_devices->opened) {
600 seed_devices = fs_devices->seed;
601 fs_devices->seed = NULL;
602 }
603 mutex_unlock(&uuid_mutex);
604
605 while (seed_devices) {
606 fs_devices = seed_devices;
607 seed_devices = fs_devices->seed;
608 __btrfs_close_devices(fs_devices);
609 free_fs_devices(fs_devices);
610 }
611 return ret;
612 }
613
614 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
615 fmode_t flags, void *holder)
616 {
617 struct request_queue *q;
618 struct block_device *bdev;
619 struct list_head *head = &fs_devices->devices;
620 struct btrfs_device *device;
621 struct block_device *latest_bdev = NULL;
622 struct buffer_head *bh;
623 struct btrfs_super_block *disk_super;
624 u64 latest_devid = 0;
625 u64 latest_transid = 0;
626 u64 devid;
627 int seeding = 1;
628 int ret = 0;
629
630 flags |= FMODE_EXCL;
631
632 list_for_each_entry(device, head, dev_list) {
633 if (device->bdev)
634 continue;
635 if (!device->name)
636 continue;
637
638 bdev = blkdev_get_by_path(device->name->str, flags, holder);
639 if (IS_ERR(bdev)) {
640 printk(KERN_INFO "open %s failed\n", device->name->str);
641 goto error;
642 }
643 filemap_write_and_wait(bdev->bd_inode->i_mapping);
644 invalidate_bdev(bdev);
645 set_blocksize(bdev, 4096);
646
647 bh = btrfs_read_dev_super(bdev);
648 if (!bh)
649 goto error_close;
650
651 disk_super = (struct btrfs_super_block *)bh->b_data;
652 devid = btrfs_stack_device_id(&disk_super->dev_item);
653 if (devid != device->devid)
654 goto error_brelse;
655
656 if (memcmp(device->uuid, disk_super->dev_item.uuid,
657 BTRFS_UUID_SIZE))
658 goto error_brelse;
659
660 device->generation = btrfs_super_generation(disk_super);
661 if (!latest_transid || device->generation > latest_transid) {
662 latest_devid = devid;
663 latest_transid = device->generation;
664 latest_bdev = bdev;
665 }
666
667 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
668 device->writeable = 0;
669 } else {
670 device->writeable = !bdev_read_only(bdev);
671 seeding = 0;
672 }
673
674 q = bdev_get_queue(bdev);
675 if (blk_queue_discard(q)) {
676 device->can_discard = 1;
677 fs_devices->num_can_discard++;
678 }
679
680 device->bdev = bdev;
681 device->in_fs_metadata = 0;
682 device->mode = flags;
683
684 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
685 fs_devices->rotating = 1;
686
687 fs_devices->open_devices++;
688 if (device->writeable) {
689 fs_devices->rw_devices++;
690 list_add(&device->dev_alloc_list,
691 &fs_devices->alloc_list);
692 }
693 brelse(bh);
694 continue;
695
696 error_brelse:
697 brelse(bh);
698 error_close:
699 blkdev_put(bdev, flags);
700 error:
701 continue;
702 }
703 if (fs_devices->open_devices == 0) {
704 ret = -EINVAL;
705 goto out;
706 }
707 fs_devices->seeding = seeding;
708 fs_devices->opened = 1;
709 fs_devices->latest_bdev = latest_bdev;
710 fs_devices->latest_devid = latest_devid;
711 fs_devices->latest_trans = latest_transid;
712 fs_devices->total_rw_bytes = 0;
713 out:
714 return ret;
715 }
716
717 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
718 fmode_t flags, void *holder)
719 {
720 int ret;
721
722 mutex_lock(&uuid_mutex);
723 if (fs_devices->opened) {
724 fs_devices->opened++;
725 ret = 0;
726 } else {
727 ret = __btrfs_open_devices(fs_devices, flags, holder);
728 }
729 mutex_unlock(&uuid_mutex);
730 return ret;
731 }
732
733 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
734 struct btrfs_fs_devices **fs_devices_ret)
735 {
736 struct btrfs_super_block *disk_super;
737 struct block_device *bdev;
738 struct buffer_head *bh;
739 int ret;
740 u64 devid;
741 u64 transid;
742
743 flags |= FMODE_EXCL;
744 bdev = blkdev_get_by_path(path, flags, holder);
745
746 if (IS_ERR(bdev)) {
747 ret = PTR_ERR(bdev);
748 goto error;
749 }
750
751 mutex_lock(&uuid_mutex);
752 ret = set_blocksize(bdev, 4096);
753 if (ret)
754 goto error_close;
755 bh = btrfs_read_dev_super(bdev);
756 if (!bh) {
757 ret = -EINVAL;
758 goto error_close;
759 }
760 disk_super = (struct btrfs_super_block *)bh->b_data;
761 devid = btrfs_stack_device_id(&disk_super->dev_item);
762 transid = btrfs_super_generation(disk_super);
763 if (disk_super->label[0])
764 printk(KERN_INFO "device label %s ", disk_super->label);
765 else
766 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
767 printk(KERN_CONT "devid %llu transid %llu %s\n",
768 (unsigned long long)devid, (unsigned long long)transid, path);
769 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
770
771 brelse(bh);
772 error_close:
773 mutex_unlock(&uuid_mutex);
774 blkdev_put(bdev, flags);
775 error:
776 return ret;
777 }
778
779 /* helper to account the used device space in the range */
780 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
781 u64 end, u64 *length)
782 {
783 struct btrfs_key key;
784 struct btrfs_root *root = device->dev_root;
785 struct btrfs_dev_extent *dev_extent;
786 struct btrfs_path *path;
787 u64 extent_end;
788 int ret;
789 int slot;
790 struct extent_buffer *l;
791
792 *length = 0;
793
794 if (start >= device->total_bytes)
795 return 0;
796
797 path = btrfs_alloc_path();
798 if (!path)
799 return -ENOMEM;
800 path->reada = 2;
801
802 key.objectid = device->devid;
803 key.offset = start;
804 key.type = BTRFS_DEV_EXTENT_KEY;
805
806 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
807 if (ret < 0)
808 goto out;
809 if (ret > 0) {
810 ret = btrfs_previous_item(root, path, key.objectid, key.type);
811 if (ret < 0)
812 goto out;
813 }
814
815 while (1) {
816 l = path->nodes[0];
817 slot = path->slots[0];
818 if (slot >= btrfs_header_nritems(l)) {
819 ret = btrfs_next_leaf(root, path);
820 if (ret == 0)
821 continue;
822 if (ret < 0)
823 goto out;
824
825 break;
826 }
827 btrfs_item_key_to_cpu(l, &key, slot);
828
829 if (key.objectid < device->devid)
830 goto next;
831
832 if (key.objectid > device->devid)
833 break;
834
835 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
836 goto next;
837
838 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
839 extent_end = key.offset + btrfs_dev_extent_length(l,
840 dev_extent);
841 if (key.offset <= start && extent_end > end) {
842 *length = end - start + 1;
843 break;
844 } else if (key.offset <= start && extent_end > start)
845 *length += extent_end - start;
846 else if (key.offset > start && extent_end <= end)
847 *length += extent_end - key.offset;
848 else if (key.offset > start && key.offset <= end) {
849 *length += end - key.offset + 1;
850 break;
851 } else if (key.offset > end)
852 break;
853
854 next:
855 path->slots[0]++;
856 }
857 ret = 0;
858 out:
859 btrfs_free_path(path);
860 return ret;
861 }
862
863 /*
864 * find_free_dev_extent - find free space in the specified device
865 * @device: the device which we search the free space in
866 * @num_bytes: the size of the free space that we need
867 * @start: store the start of the free space.
868 * @len: the size of the free space. that we find, or the size of the max
869 * free space if we don't find suitable free space
870 *
871 * this uses a pretty simple search, the expectation is that it is
872 * called very infrequently and that a given device has a small number
873 * of extents
874 *
875 * @start is used to store the start of the free space if we find. But if we
876 * don't find suitable free space, it will be used to store the start position
877 * of the max free space.
878 *
879 * @len is used to store the size of the free space that we find.
880 * But if we don't find suitable free space, it is used to store the size of
881 * the max free space.
882 */
883 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
884 u64 *start, u64 *len)
885 {
886 struct btrfs_key key;
887 struct btrfs_root *root = device->dev_root;
888 struct btrfs_dev_extent *dev_extent;
889 struct btrfs_path *path;
890 u64 hole_size;
891 u64 max_hole_start;
892 u64 max_hole_size;
893 u64 extent_end;
894 u64 search_start;
895 u64 search_end = device->total_bytes;
896 int ret;
897 int slot;
898 struct extent_buffer *l;
899
900 /* FIXME use last free of some kind */
901
902 /* we don't want to overwrite the superblock on the drive,
903 * so we make sure to start at an offset of at least 1MB
904 */
905 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
906
907 max_hole_start = search_start;
908 max_hole_size = 0;
909 hole_size = 0;
910
911 if (search_start >= search_end) {
912 ret = -ENOSPC;
913 goto error;
914 }
915
916 path = btrfs_alloc_path();
917 if (!path) {
918 ret = -ENOMEM;
919 goto error;
920 }
921 path->reada = 2;
922
923 key.objectid = device->devid;
924 key.offset = search_start;
925 key.type = BTRFS_DEV_EXTENT_KEY;
926
927 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
928 if (ret < 0)
929 goto out;
930 if (ret > 0) {
931 ret = btrfs_previous_item(root, path, key.objectid, key.type);
932 if (ret < 0)
933 goto out;
934 }
935
936 while (1) {
937 l = path->nodes[0];
938 slot = path->slots[0];
939 if (slot >= btrfs_header_nritems(l)) {
940 ret = btrfs_next_leaf(root, path);
941 if (ret == 0)
942 continue;
943 if (ret < 0)
944 goto out;
945
946 break;
947 }
948 btrfs_item_key_to_cpu(l, &key, slot);
949
950 if (key.objectid < device->devid)
951 goto next;
952
953 if (key.objectid > device->devid)
954 break;
955
956 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
957 goto next;
958
959 if (key.offset > search_start) {
960 hole_size = key.offset - search_start;
961
962 if (hole_size > max_hole_size) {
963 max_hole_start = search_start;
964 max_hole_size = hole_size;
965 }
966
967 /*
968 * If this free space is greater than which we need,
969 * it must be the max free space that we have found
970 * until now, so max_hole_start must point to the start
971 * of this free space and the length of this free space
972 * is stored in max_hole_size. Thus, we return
973 * max_hole_start and max_hole_size and go back to the
974 * caller.
975 */
976 if (hole_size >= num_bytes) {
977 ret = 0;
978 goto out;
979 }
980 }
981
982 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
983 extent_end = key.offset + btrfs_dev_extent_length(l,
984 dev_extent);
985 if (extent_end > search_start)
986 search_start = extent_end;
987 next:
988 path->slots[0]++;
989 cond_resched();
990 }
991
992 /*
993 * At this point, search_start should be the end of
994 * allocated dev extents, and when shrinking the device,
995 * search_end may be smaller than search_start.
996 */
997 if (search_end > search_start)
998 hole_size = search_end - search_start;
999
1000 if (hole_size > max_hole_size) {
1001 max_hole_start = search_start;
1002 max_hole_size = hole_size;
1003 }
1004
1005 /* See above. */
1006 if (hole_size < num_bytes)
1007 ret = -ENOSPC;
1008 else
1009 ret = 0;
1010
1011 out:
1012 btrfs_free_path(path);
1013 error:
1014 *start = max_hole_start;
1015 if (len)
1016 *len = max_hole_size;
1017 return ret;
1018 }
1019
1020 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1021 struct btrfs_device *device,
1022 u64 start)
1023 {
1024 int ret;
1025 struct btrfs_path *path;
1026 struct btrfs_root *root = device->dev_root;
1027 struct btrfs_key key;
1028 struct btrfs_key found_key;
1029 struct extent_buffer *leaf = NULL;
1030 struct btrfs_dev_extent *extent = NULL;
1031
1032 path = btrfs_alloc_path();
1033 if (!path)
1034 return -ENOMEM;
1035
1036 key.objectid = device->devid;
1037 key.offset = start;
1038 key.type = BTRFS_DEV_EXTENT_KEY;
1039 again:
1040 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1041 if (ret > 0) {
1042 ret = btrfs_previous_item(root, path, key.objectid,
1043 BTRFS_DEV_EXTENT_KEY);
1044 if (ret)
1045 goto out;
1046 leaf = path->nodes[0];
1047 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1048 extent = btrfs_item_ptr(leaf, path->slots[0],
1049 struct btrfs_dev_extent);
1050 BUG_ON(found_key.offset > start || found_key.offset +
1051 btrfs_dev_extent_length(leaf, extent) < start);
1052 key = found_key;
1053 btrfs_release_path(path);
1054 goto again;
1055 } else if (ret == 0) {
1056 leaf = path->nodes[0];
1057 extent = btrfs_item_ptr(leaf, path->slots[0],
1058 struct btrfs_dev_extent);
1059 } else {
1060 btrfs_error(root->fs_info, ret, "Slot search failed");
1061 goto out;
1062 }
1063
1064 if (device->bytes_used > 0) {
1065 u64 len = btrfs_dev_extent_length(leaf, extent);
1066 device->bytes_used -= len;
1067 spin_lock(&root->fs_info->free_chunk_lock);
1068 root->fs_info->free_chunk_space += len;
1069 spin_unlock(&root->fs_info->free_chunk_lock);
1070 }
1071 ret = btrfs_del_item(trans, root, path);
1072 if (ret) {
1073 btrfs_error(root->fs_info, ret,
1074 "Failed to remove dev extent item");
1075 }
1076 out:
1077 btrfs_free_path(path);
1078 return ret;
1079 }
1080
1081 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1082 struct btrfs_device *device,
1083 u64 chunk_tree, u64 chunk_objectid,
1084 u64 chunk_offset, u64 start, u64 num_bytes)
1085 {
1086 int ret;
1087 struct btrfs_path *path;
1088 struct btrfs_root *root = device->dev_root;
1089 struct btrfs_dev_extent *extent;
1090 struct extent_buffer *leaf;
1091 struct btrfs_key key;
1092
1093 WARN_ON(!device->in_fs_metadata);
1094 path = btrfs_alloc_path();
1095 if (!path)
1096 return -ENOMEM;
1097
1098 key.objectid = device->devid;
1099 key.offset = start;
1100 key.type = BTRFS_DEV_EXTENT_KEY;
1101 ret = btrfs_insert_empty_item(trans, root, path, &key,
1102 sizeof(*extent));
1103 if (ret)
1104 goto out;
1105
1106 leaf = path->nodes[0];
1107 extent = btrfs_item_ptr(leaf, path->slots[0],
1108 struct btrfs_dev_extent);
1109 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1110 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1111 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1112
1113 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1114 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1115 BTRFS_UUID_SIZE);
1116
1117 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1118 btrfs_mark_buffer_dirty(leaf);
1119 out:
1120 btrfs_free_path(path);
1121 return ret;
1122 }
1123
1124 static noinline int find_next_chunk(struct btrfs_root *root,
1125 u64 objectid, u64 *offset)
1126 {
1127 struct btrfs_path *path;
1128 int ret;
1129 struct btrfs_key key;
1130 struct btrfs_chunk *chunk;
1131 struct btrfs_key found_key;
1132
1133 path = btrfs_alloc_path();
1134 if (!path)
1135 return -ENOMEM;
1136
1137 key.objectid = objectid;
1138 key.offset = (u64)-1;
1139 key.type = BTRFS_CHUNK_ITEM_KEY;
1140
1141 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1142 if (ret < 0)
1143 goto error;
1144
1145 BUG_ON(ret == 0); /* Corruption */
1146
1147 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1148 if (ret) {
1149 *offset = 0;
1150 } else {
1151 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1152 path->slots[0]);
1153 if (found_key.objectid != objectid)
1154 *offset = 0;
1155 else {
1156 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1157 struct btrfs_chunk);
1158 *offset = found_key.offset +
1159 btrfs_chunk_length(path->nodes[0], chunk);
1160 }
1161 }
1162 ret = 0;
1163 error:
1164 btrfs_free_path(path);
1165 return ret;
1166 }
1167
1168 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1169 {
1170 int ret;
1171 struct btrfs_key key;
1172 struct btrfs_key found_key;
1173 struct btrfs_path *path;
1174
1175 root = root->fs_info->chunk_root;
1176
1177 path = btrfs_alloc_path();
1178 if (!path)
1179 return -ENOMEM;
1180
1181 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1182 key.type = BTRFS_DEV_ITEM_KEY;
1183 key.offset = (u64)-1;
1184
1185 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1186 if (ret < 0)
1187 goto error;
1188
1189 BUG_ON(ret == 0); /* Corruption */
1190
1191 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1192 BTRFS_DEV_ITEM_KEY);
1193 if (ret) {
1194 *objectid = 1;
1195 } else {
1196 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1197 path->slots[0]);
1198 *objectid = found_key.offset + 1;
1199 }
1200 ret = 0;
1201 error:
1202 btrfs_free_path(path);
1203 return ret;
1204 }
1205
1206 /*
1207 * the device information is stored in the chunk root
1208 * the btrfs_device struct should be fully filled in
1209 */
1210 int btrfs_add_device(struct btrfs_trans_handle *trans,
1211 struct btrfs_root *root,
1212 struct btrfs_device *device)
1213 {
1214 int ret;
1215 struct btrfs_path *path;
1216 struct btrfs_dev_item *dev_item;
1217 struct extent_buffer *leaf;
1218 struct btrfs_key key;
1219 unsigned long ptr;
1220
1221 root = root->fs_info->chunk_root;
1222
1223 path = btrfs_alloc_path();
1224 if (!path)
1225 return -ENOMEM;
1226
1227 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1228 key.type = BTRFS_DEV_ITEM_KEY;
1229 key.offset = device->devid;
1230
1231 ret = btrfs_insert_empty_item(trans, root, path, &key,
1232 sizeof(*dev_item));
1233 if (ret)
1234 goto out;
1235
1236 leaf = path->nodes[0];
1237 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1238
1239 btrfs_set_device_id(leaf, dev_item, device->devid);
1240 btrfs_set_device_generation(leaf, dev_item, 0);
1241 btrfs_set_device_type(leaf, dev_item, device->type);
1242 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1243 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1244 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1245 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1246 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1247 btrfs_set_device_group(leaf, dev_item, 0);
1248 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1249 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1250 btrfs_set_device_start_offset(leaf, dev_item, 0);
1251
1252 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1253 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1254 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1255 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1256 btrfs_mark_buffer_dirty(leaf);
1257
1258 ret = 0;
1259 out:
1260 btrfs_free_path(path);
1261 return ret;
1262 }
1263
1264 static int btrfs_rm_dev_item(struct btrfs_root *root,
1265 struct btrfs_device *device)
1266 {
1267 int ret;
1268 struct btrfs_path *path;
1269 struct btrfs_key key;
1270 struct btrfs_trans_handle *trans;
1271
1272 root = root->fs_info->chunk_root;
1273
1274 path = btrfs_alloc_path();
1275 if (!path)
1276 return -ENOMEM;
1277
1278 trans = btrfs_start_transaction(root, 0);
1279 if (IS_ERR(trans)) {
1280 btrfs_free_path(path);
1281 return PTR_ERR(trans);
1282 }
1283 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1284 key.type = BTRFS_DEV_ITEM_KEY;
1285 key.offset = device->devid;
1286 lock_chunks(root);
1287
1288 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1289 if (ret < 0)
1290 goto out;
1291
1292 if (ret > 0) {
1293 ret = -ENOENT;
1294 goto out;
1295 }
1296
1297 ret = btrfs_del_item(trans, root, path);
1298 if (ret)
1299 goto out;
1300 out:
1301 btrfs_free_path(path);
1302 unlock_chunks(root);
1303 btrfs_commit_transaction(trans, root);
1304 return ret;
1305 }
1306
1307 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1308 {
1309 struct btrfs_device *device;
1310 struct btrfs_device *next_device;
1311 struct block_device *bdev;
1312 struct buffer_head *bh = NULL;
1313 struct btrfs_super_block *disk_super;
1314 struct btrfs_fs_devices *cur_devices;
1315 u64 all_avail;
1316 u64 devid;
1317 u64 num_devices;
1318 u8 *dev_uuid;
1319 int ret = 0;
1320 bool clear_super = false;
1321
1322 mutex_lock(&uuid_mutex);
1323
1324 all_avail = root->fs_info->avail_data_alloc_bits |
1325 root->fs_info->avail_system_alloc_bits |
1326 root->fs_info->avail_metadata_alloc_bits;
1327
1328 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1329 root->fs_info->fs_devices->num_devices <= 4) {
1330 printk(KERN_ERR "btrfs: unable to go below four devices "
1331 "on raid10\n");
1332 ret = -EINVAL;
1333 goto out;
1334 }
1335
1336 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1337 root->fs_info->fs_devices->num_devices <= 2) {
1338 printk(KERN_ERR "btrfs: unable to go below two "
1339 "devices on raid1\n");
1340 ret = -EINVAL;
1341 goto out;
1342 }
1343
1344 if (strcmp(device_path, "missing") == 0) {
1345 struct list_head *devices;
1346 struct btrfs_device *tmp;
1347
1348 device = NULL;
1349 devices = &root->fs_info->fs_devices->devices;
1350 /*
1351 * It is safe to read the devices since the volume_mutex
1352 * is held.
1353 */
1354 list_for_each_entry(tmp, devices, dev_list) {
1355 if (tmp->in_fs_metadata && !tmp->bdev) {
1356 device = tmp;
1357 break;
1358 }
1359 }
1360 bdev = NULL;
1361 bh = NULL;
1362 disk_super = NULL;
1363 if (!device) {
1364 printk(KERN_ERR "btrfs: no missing devices found to "
1365 "remove\n");
1366 goto out;
1367 }
1368 } else {
1369 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1370 root->fs_info->bdev_holder);
1371 if (IS_ERR(bdev)) {
1372 ret = PTR_ERR(bdev);
1373 goto out;
1374 }
1375
1376 set_blocksize(bdev, 4096);
1377 invalidate_bdev(bdev);
1378 bh = btrfs_read_dev_super(bdev);
1379 if (!bh) {
1380 ret = -EINVAL;
1381 goto error_close;
1382 }
1383 disk_super = (struct btrfs_super_block *)bh->b_data;
1384 devid = btrfs_stack_device_id(&disk_super->dev_item);
1385 dev_uuid = disk_super->dev_item.uuid;
1386 device = btrfs_find_device(root, devid, dev_uuid,
1387 disk_super->fsid);
1388 if (!device) {
1389 ret = -ENOENT;
1390 goto error_brelse;
1391 }
1392 }
1393
1394 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1395 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1396 "device\n");
1397 ret = -EINVAL;
1398 goto error_brelse;
1399 }
1400
1401 if (device->writeable) {
1402 lock_chunks(root);
1403 list_del_init(&device->dev_alloc_list);
1404 unlock_chunks(root);
1405 root->fs_info->fs_devices->rw_devices--;
1406 clear_super = true;
1407 }
1408
1409 ret = btrfs_shrink_device(device, 0);
1410 if (ret)
1411 goto error_undo;
1412
1413 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1414 if (ret)
1415 goto error_undo;
1416
1417 spin_lock(&root->fs_info->free_chunk_lock);
1418 root->fs_info->free_chunk_space = device->total_bytes -
1419 device->bytes_used;
1420 spin_unlock(&root->fs_info->free_chunk_lock);
1421
1422 device->in_fs_metadata = 0;
1423 btrfs_scrub_cancel_dev(root, device);
1424
1425 /*
1426 * the device list mutex makes sure that we don't change
1427 * the device list while someone else is writing out all
1428 * the device supers.
1429 */
1430
1431 cur_devices = device->fs_devices;
1432 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1433 list_del_rcu(&device->dev_list);
1434
1435 device->fs_devices->num_devices--;
1436
1437 if (device->missing)
1438 root->fs_info->fs_devices->missing_devices--;
1439
1440 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1441 struct btrfs_device, dev_list);
1442 if (device->bdev == root->fs_info->sb->s_bdev)
1443 root->fs_info->sb->s_bdev = next_device->bdev;
1444 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1445 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1446
1447 if (device->bdev)
1448 device->fs_devices->open_devices--;
1449
1450 call_rcu(&device->rcu, free_device);
1451 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1452
1453 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1454 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1455
1456 if (cur_devices->open_devices == 0) {
1457 struct btrfs_fs_devices *fs_devices;
1458 fs_devices = root->fs_info->fs_devices;
1459 while (fs_devices) {
1460 if (fs_devices->seed == cur_devices)
1461 break;
1462 fs_devices = fs_devices->seed;
1463 }
1464 fs_devices->seed = cur_devices->seed;
1465 cur_devices->seed = NULL;
1466 lock_chunks(root);
1467 __btrfs_close_devices(cur_devices);
1468 unlock_chunks(root);
1469 free_fs_devices(cur_devices);
1470 }
1471
1472 /*
1473 * at this point, the device is zero sized. We want to
1474 * remove it from the devices list and zero out the old super
1475 */
1476 if (clear_super) {
1477 /* make sure this device isn't detected as part of
1478 * the FS anymore
1479 */
1480 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1481 set_buffer_dirty(bh);
1482 sync_dirty_buffer(bh);
1483 }
1484
1485 ret = 0;
1486
1487 error_brelse:
1488 brelse(bh);
1489 error_close:
1490 if (bdev)
1491 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1492 out:
1493 mutex_unlock(&uuid_mutex);
1494 return ret;
1495 error_undo:
1496 if (device->writeable) {
1497 lock_chunks(root);
1498 list_add(&device->dev_alloc_list,
1499 &root->fs_info->fs_devices->alloc_list);
1500 unlock_chunks(root);
1501 root->fs_info->fs_devices->rw_devices++;
1502 }
1503 goto error_brelse;
1504 }
1505
1506 /*
1507 * does all the dirty work required for changing file system's UUID.
1508 */
1509 static int btrfs_prepare_sprout(struct btrfs_root *root)
1510 {
1511 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1512 struct btrfs_fs_devices *old_devices;
1513 struct btrfs_fs_devices *seed_devices;
1514 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1515 struct btrfs_device *device;
1516 u64 super_flags;
1517
1518 BUG_ON(!mutex_is_locked(&uuid_mutex));
1519 if (!fs_devices->seeding)
1520 return -EINVAL;
1521
1522 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1523 if (!seed_devices)
1524 return -ENOMEM;
1525
1526 old_devices = clone_fs_devices(fs_devices);
1527 if (IS_ERR(old_devices)) {
1528 kfree(seed_devices);
1529 return PTR_ERR(old_devices);
1530 }
1531
1532 list_add(&old_devices->list, &fs_uuids);
1533
1534 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1535 seed_devices->opened = 1;
1536 INIT_LIST_HEAD(&seed_devices->devices);
1537 INIT_LIST_HEAD(&seed_devices->alloc_list);
1538 mutex_init(&seed_devices->device_list_mutex);
1539
1540 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1541 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1542 synchronize_rcu);
1543 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1544
1545 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1546 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1547 device->fs_devices = seed_devices;
1548 }
1549
1550 fs_devices->seeding = 0;
1551 fs_devices->num_devices = 0;
1552 fs_devices->open_devices = 0;
1553 fs_devices->seed = seed_devices;
1554
1555 generate_random_uuid(fs_devices->fsid);
1556 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1557 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1558 super_flags = btrfs_super_flags(disk_super) &
1559 ~BTRFS_SUPER_FLAG_SEEDING;
1560 btrfs_set_super_flags(disk_super, super_flags);
1561
1562 return 0;
1563 }
1564
1565 /*
1566 * strore the expected generation for seed devices in device items.
1567 */
1568 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1569 struct btrfs_root *root)
1570 {
1571 struct btrfs_path *path;
1572 struct extent_buffer *leaf;
1573 struct btrfs_dev_item *dev_item;
1574 struct btrfs_device *device;
1575 struct btrfs_key key;
1576 u8 fs_uuid[BTRFS_UUID_SIZE];
1577 u8 dev_uuid[BTRFS_UUID_SIZE];
1578 u64 devid;
1579 int ret;
1580
1581 path = btrfs_alloc_path();
1582 if (!path)
1583 return -ENOMEM;
1584
1585 root = root->fs_info->chunk_root;
1586 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1587 key.offset = 0;
1588 key.type = BTRFS_DEV_ITEM_KEY;
1589
1590 while (1) {
1591 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1592 if (ret < 0)
1593 goto error;
1594
1595 leaf = path->nodes[0];
1596 next_slot:
1597 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1598 ret = btrfs_next_leaf(root, path);
1599 if (ret > 0)
1600 break;
1601 if (ret < 0)
1602 goto error;
1603 leaf = path->nodes[0];
1604 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1605 btrfs_release_path(path);
1606 continue;
1607 }
1608
1609 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1610 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1611 key.type != BTRFS_DEV_ITEM_KEY)
1612 break;
1613
1614 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1615 struct btrfs_dev_item);
1616 devid = btrfs_device_id(leaf, dev_item);
1617 read_extent_buffer(leaf, dev_uuid,
1618 (unsigned long)btrfs_device_uuid(dev_item),
1619 BTRFS_UUID_SIZE);
1620 read_extent_buffer(leaf, fs_uuid,
1621 (unsigned long)btrfs_device_fsid(dev_item),
1622 BTRFS_UUID_SIZE);
1623 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1624 BUG_ON(!device); /* Logic error */
1625
1626 if (device->fs_devices->seeding) {
1627 btrfs_set_device_generation(leaf, dev_item,
1628 device->generation);
1629 btrfs_mark_buffer_dirty(leaf);
1630 }
1631
1632 path->slots[0]++;
1633 goto next_slot;
1634 }
1635 ret = 0;
1636 error:
1637 btrfs_free_path(path);
1638 return ret;
1639 }
1640
1641 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1642 {
1643 struct request_queue *q;
1644 struct btrfs_trans_handle *trans;
1645 struct btrfs_device *device;
1646 struct block_device *bdev;
1647 struct list_head *devices;
1648 struct super_block *sb = root->fs_info->sb;
1649 struct rcu_string *name;
1650 u64 total_bytes;
1651 int seeding_dev = 0;
1652 int ret = 0;
1653
1654 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1655 return -EROFS;
1656
1657 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1658 root->fs_info->bdev_holder);
1659 if (IS_ERR(bdev))
1660 return PTR_ERR(bdev);
1661
1662 if (root->fs_info->fs_devices->seeding) {
1663 seeding_dev = 1;
1664 down_write(&sb->s_umount);
1665 mutex_lock(&uuid_mutex);
1666 }
1667
1668 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1669
1670 devices = &root->fs_info->fs_devices->devices;
1671 /*
1672 * we have the volume lock, so we don't need the extra
1673 * device list mutex while reading the list here.
1674 */
1675 list_for_each_entry(device, devices, dev_list) {
1676 if (device->bdev == bdev) {
1677 ret = -EEXIST;
1678 goto error;
1679 }
1680 }
1681
1682 device = kzalloc(sizeof(*device), GFP_NOFS);
1683 if (!device) {
1684 /* we can safely leave the fs_devices entry around */
1685 ret = -ENOMEM;
1686 goto error;
1687 }
1688
1689 name = rcu_string_strdup(device_path, GFP_NOFS);
1690 if (!name) {
1691 kfree(device);
1692 ret = -ENOMEM;
1693 goto error;
1694 }
1695 rcu_assign_pointer(device->name, name);
1696
1697 ret = find_next_devid(root, &device->devid);
1698 if (ret) {
1699 rcu_string_free(device->name);
1700 kfree(device);
1701 goto error;
1702 }
1703
1704 trans = btrfs_start_transaction(root, 0);
1705 if (IS_ERR(trans)) {
1706 rcu_string_free(device->name);
1707 kfree(device);
1708 ret = PTR_ERR(trans);
1709 goto error;
1710 }
1711
1712 lock_chunks(root);
1713
1714 q = bdev_get_queue(bdev);
1715 if (blk_queue_discard(q))
1716 device->can_discard = 1;
1717 device->writeable = 1;
1718 device->work.func = pending_bios_fn;
1719 generate_random_uuid(device->uuid);
1720 spin_lock_init(&device->io_lock);
1721 device->generation = trans->transid;
1722 device->io_width = root->sectorsize;
1723 device->io_align = root->sectorsize;
1724 device->sector_size = root->sectorsize;
1725 device->total_bytes = i_size_read(bdev->bd_inode);
1726 device->disk_total_bytes = device->total_bytes;
1727 device->dev_root = root->fs_info->dev_root;
1728 device->bdev = bdev;
1729 device->in_fs_metadata = 1;
1730 device->mode = FMODE_EXCL;
1731 set_blocksize(device->bdev, 4096);
1732
1733 if (seeding_dev) {
1734 sb->s_flags &= ~MS_RDONLY;
1735 ret = btrfs_prepare_sprout(root);
1736 BUG_ON(ret); /* -ENOMEM */
1737 }
1738
1739 device->fs_devices = root->fs_info->fs_devices;
1740
1741 /*
1742 * we don't want write_supers to jump in here with our device
1743 * half setup
1744 */
1745 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1746 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1747 list_add(&device->dev_alloc_list,
1748 &root->fs_info->fs_devices->alloc_list);
1749 root->fs_info->fs_devices->num_devices++;
1750 root->fs_info->fs_devices->open_devices++;
1751 root->fs_info->fs_devices->rw_devices++;
1752 if (device->can_discard)
1753 root->fs_info->fs_devices->num_can_discard++;
1754 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1755
1756 spin_lock(&root->fs_info->free_chunk_lock);
1757 root->fs_info->free_chunk_space += device->total_bytes;
1758 spin_unlock(&root->fs_info->free_chunk_lock);
1759
1760 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1761 root->fs_info->fs_devices->rotating = 1;
1762
1763 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1764 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1765 total_bytes + device->total_bytes);
1766
1767 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1768 btrfs_set_super_num_devices(root->fs_info->super_copy,
1769 total_bytes + 1);
1770 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1771
1772 if (seeding_dev) {
1773 ret = init_first_rw_device(trans, root, device);
1774 if (ret)
1775 goto error_trans;
1776 ret = btrfs_finish_sprout(trans, root);
1777 if (ret)
1778 goto error_trans;
1779 } else {
1780 ret = btrfs_add_device(trans, root, device);
1781 if (ret)
1782 goto error_trans;
1783 }
1784
1785 /*
1786 * we've got more storage, clear any full flags on the space
1787 * infos
1788 */
1789 btrfs_clear_space_info_full(root->fs_info);
1790
1791 unlock_chunks(root);
1792 ret = btrfs_commit_transaction(trans, root);
1793
1794 if (seeding_dev) {
1795 mutex_unlock(&uuid_mutex);
1796 up_write(&sb->s_umount);
1797
1798 if (ret) /* transaction commit */
1799 return ret;
1800
1801 ret = btrfs_relocate_sys_chunks(root);
1802 if (ret < 0)
1803 btrfs_error(root->fs_info, ret,
1804 "Failed to relocate sys chunks after "
1805 "device initialization. This can be fixed "
1806 "using the \"btrfs balance\" command.");
1807 }
1808
1809 return ret;
1810
1811 error_trans:
1812 unlock_chunks(root);
1813 btrfs_abort_transaction(trans, root, ret);
1814 btrfs_end_transaction(trans, root);
1815 rcu_string_free(device->name);
1816 kfree(device);
1817 error:
1818 blkdev_put(bdev, FMODE_EXCL);
1819 if (seeding_dev) {
1820 mutex_unlock(&uuid_mutex);
1821 up_write(&sb->s_umount);
1822 }
1823 return ret;
1824 }
1825
1826 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1827 struct btrfs_device *device)
1828 {
1829 int ret;
1830 struct btrfs_path *path;
1831 struct btrfs_root *root;
1832 struct btrfs_dev_item *dev_item;
1833 struct extent_buffer *leaf;
1834 struct btrfs_key key;
1835
1836 root = device->dev_root->fs_info->chunk_root;
1837
1838 path = btrfs_alloc_path();
1839 if (!path)
1840 return -ENOMEM;
1841
1842 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1843 key.type = BTRFS_DEV_ITEM_KEY;
1844 key.offset = device->devid;
1845
1846 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1847 if (ret < 0)
1848 goto out;
1849
1850 if (ret > 0) {
1851 ret = -ENOENT;
1852 goto out;
1853 }
1854
1855 leaf = path->nodes[0];
1856 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1857
1858 btrfs_set_device_id(leaf, dev_item, device->devid);
1859 btrfs_set_device_type(leaf, dev_item, device->type);
1860 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1861 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1862 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1863 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1864 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1865 btrfs_mark_buffer_dirty(leaf);
1866
1867 out:
1868 btrfs_free_path(path);
1869 return ret;
1870 }
1871
1872 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1873 struct btrfs_device *device, u64 new_size)
1874 {
1875 struct btrfs_super_block *super_copy =
1876 device->dev_root->fs_info->super_copy;
1877 u64 old_total = btrfs_super_total_bytes(super_copy);
1878 u64 diff = new_size - device->total_bytes;
1879
1880 if (!device->writeable)
1881 return -EACCES;
1882 if (new_size <= device->total_bytes)
1883 return -EINVAL;
1884
1885 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1886 device->fs_devices->total_rw_bytes += diff;
1887
1888 device->total_bytes = new_size;
1889 device->disk_total_bytes = new_size;
1890 btrfs_clear_space_info_full(device->dev_root->fs_info);
1891
1892 return btrfs_update_device(trans, device);
1893 }
1894
1895 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1896 struct btrfs_device *device, u64 new_size)
1897 {
1898 int ret;
1899 lock_chunks(device->dev_root);
1900 ret = __btrfs_grow_device(trans, device, new_size);
1901 unlock_chunks(device->dev_root);
1902 return ret;
1903 }
1904
1905 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1906 struct btrfs_root *root,
1907 u64 chunk_tree, u64 chunk_objectid,
1908 u64 chunk_offset)
1909 {
1910 int ret;
1911 struct btrfs_path *path;
1912 struct btrfs_key key;
1913
1914 root = root->fs_info->chunk_root;
1915 path = btrfs_alloc_path();
1916 if (!path)
1917 return -ENOMEM;
1918
1919 key.objectid = chunk_objectid;
1920 key.offset = chunk_offset;
1921 key.type = BTRFS_CHUNK_ITEM_KEY;
1922
1923 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1924 if (ret < 0)
1925 goto out;
1926 else if (ret > 0) { /* Logic error or corruption */
1927 btrfs_error(root->fs_info, -ENOENT,
1928 "Failed lookup while freeing chunk.");
1929 ret = -ENOENT;
1930 goto out;
1931 }
1932
1933 ret = btrfs_del_item(trans, root, path);
1934 if (ret < 0)
1935 btrfs_error(root->fs_info, ret,
1936 "Failed to delete chunk item.");
1937 out:
1938 btrfs_free_path(path);
1939 return ret;
1940 }
1941
1942 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1943 chunk_offset)
1944 {
1945 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1946 struct btrfs_disk_key *disk_key;
1947 struct btrfs_chunk *chunk;
1948 u8 *ptr;
1949 int ret = 0;
1950 u32 num_stripes;
1951 u32 array_size;
1952 u32 len = 0;
1953 u32 cur;
1954 struct btrfs_key key;
1955
1956 array_size = btrfs_super_sys_array_size(super_copy);
1957
1958 ptr = super_copy->sys_chunk_array;
1959 cur = 0;
1960
1961 while (cur < array_size) {
1962 disk_key = (struct btrfs_disk_key *)ptr;
1963 btrfs_disk_key_to_cpu(&key, disk_key);
1964
1965 len = sizeof(*disk_key);
1966
1967 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1968 chunk = (struct btrfs_chunk *)(ptr + len);
1969 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1970 len += btrfs_chunk_item_size(num_stripes);
1971 } else {
1972 ret = -EIO;
1973 break;
1974 }
1975 if (key.objectid == chunk_objectid &&
1976 key.offset == chunk_offset) {
1977 memmove(ptr, ptr + len, array_size - (cur + len));
1978 array_size -= len;
1979 btrfs_set_super_sys_array_size(super_copy, array_size);
1980 } else {
1981 ptr += len;
1982 cur += len;
1983 }
1984 }
1985 return ret;
1986 }
1987
1988 static int btrfs_relocate_chunk(struct btrfs_root *root,
1989 u64 chunk_tree, u64 chunk_objectid,
1990 u64 chunk_offset)
1991 {
1992 struct extent_map_tree *em_tree;
1993 struct btrfs_root *extent_root;
1994 struct btrfs_trans_handle *trans;
1995 struct extent_map *em;
1996 struct map_lookup *map;
1997 int ret;
1998 int i;
1999
2000 root = root->fs_info->chunk_root;
2001 extent_root = root->fs_info->extent_root;
2002 em_tree = &root->fs_info->mapping_tree.map_tree;
2003
2004 ret = btrfs_can_relocate(extent_root, chunk_offset);
2005 if (ret)
2006 return -ENOSPC;
2007
2008 /* step one, relocate all the extents inside this chunk */
2009 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2010 if (ret)
2011 return ret;
2012
2013 trans = btrfs_start_transaction(root, 0);
2014 BUG_ON(IS_ERR(trans));
2015
2016 lock_chunks(root);
2017
2018 /*
2019 * step two, delete the device extents and the
2020 * chunk tree entries
2021 */
2022 read_lock(&em_tree->lock);
2023 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2024 read_unlock(&em_tree->lock);
2025
2026 BUG_ON(!em || em->start > chunk_offset ||
2027 em->start + em->len < chunk_offset);
2028 map = (struct map_lookup *)em->bdev;
2029
2030 for (i = 0; i < map->num_stripes; i++) {
2031 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2032 map->stripes[i].physical);
2033 BUG_ON(ret);
2034
2035 if (map->stripes[i].dev) {
2036 ret = btrfs_update_device(trans, map->stripes[i].dev);
2037 BUG_ON(ret);
2038 }
2039 }
2040 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2041 chunk_offset);
2042
2043 BUG_ON(ret);
2044
2045 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2046
2047 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2048 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2049 BUG_ON(ret);
2050 }
2051
2052 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2053 BUG_ON(ret);
2054
2055 write_lock(&em_tree->lock);
2056 remove_extent_mapping(em_tree, em);
2057 write_unlock(&em_tree->lock);
2058
2059 kfree(map);
2060 em->bdev = NULL;
2061
2062 /* once for the tree */
2063 free_extent_map(em);
2064 /* once for us */
2065 free_extent_map(em);
2066
2067 unlock_chunks(root);
2068 btrfs_end_transaction(trans, root);
2069 return 0;
2070 }
2071
2072 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2073 {
2074 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2075 struct btrfs_path *path;
2076 struct extent_buffer *leaf;
2077 struct btrfs_chunk *chunk;
2078 struct btrfs_key key;
2079 struct btrfs_key found_key;
2080 u64 chunk_tree = chunk_root->root_key.objectid;
2081 u64 chunk_type;
2082 bool retried = false;
2083 int failed = 0;
2084 int ret;
2085
2086 path = btrfs_alloc_path();
2087 if (!path)
2088 return -ENOMEM;
2089
2090 again:
2091 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2092 key.offset = (u64)-1;
2093 key.type = BTRFS_CHUNK_ITEM_KEY;
2094
2095 while (1) {
2096 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2097 if (ret < 0)
2098 goto error;
2099 BUG_ON(ret == 0); /* Corruption */
2100
2101 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2102 key.type);
2103 if (ret < 0)
2104 goto error;
2105 if (ret > 0)
2106 break;
2107
2108 leaf = path->nodes[0];
2109 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2110
2111 chunk = btrfs_item_ptr(leaf, path->slots[0],
2112 struct btrfs_chunk);
2113 chunk_type = btrfs_chunk_type(leaf, chunk);
2114 btrfs_release_path(path);
2115
2116 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2117 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2118 found_key.objectid,
2119 found_key.offset);
2120 if (ret == -ENOSPC)
2121 failed++;
2122 else if (ret)
2123 BUG();
2124 }
2125
2126 if (found_key.offset == 0)
2127 break;
2128 key.offset = found_key.offset - 1;
2129 }
2130 ret = 0;
2131 if (failed && !retried) {
2132 failed = 0;
2133 retried = true;
2134 goto again;
2135 } else if (failed && retried) {
2136 WARN_ON(1);
2137 ret = -ENOSPC;
2138 }
2139 error:
2140 btrfs_free_path(path);
2141 return ret;
2142 }
2143
2144 static int insert_balance_item(struct btrfs_root *root,
2145 struct btrfs_balance_control *bctl)
2146 {
2147 struct btrfs_trans_handle *trans;
2148 struct btrfs_balance_item *item;
2149 struct btrfs_disk_balance_args disk_bargs;
2150 struct btrfs_path *path;
2151 struct extent_buffer *leaf;
2152 struct btrfs_key key;
2153 int ret, err;
2154
2155 path = btrfs_alloc_path();
2156 if (!path)
2157 return -ENOMEM;
2158
2159 trans = btrfs_start_transaction(root, 0);
2160 if (IS_ERR(trans)) {
2161 btrfs_free_path(path);
2162 return PTR_ERR(trans);
2163 }
2164
2165 key.objectid = BTRFS_BALANCE_OBJECTID;
2166 key.type = BTRFS_BALANCE_ITEM_KEY;
2167 key.offset = 0;
2168
2169 ret = btrfs_insert_empty_item(trans, root, path, &key,
2170 sizeof(*item));
2171 if (ret)
2172 goto out;
2173
2174 leaf = path->nodes[0];
2175 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2176
2177 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2178
2179 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2180 btrfs_set_balance_data(leaf, item, &disk_bargs);
2181 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2182 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2183 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2184 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2185
2186 btrfs_set_balance_flags(leaf, item, bctl->flags);
2187
2188 btrfs_mark_buffer_dirty(leaf);
2189 out:
2190 btrfs_free_path(path);
2191 err = btrfs_commit_transaction(trans, root);
2192 if (err && !ret)
2193 ret = err;
2194 return ret;
2195 }
2196
2197 static int del_balance_item(struct btrfs_root *root)
2198 {
2199 struct btrfs_trans_handle *trans;
2200 struct btrfs_path *path;
2201 struct btrfs_key key;
2202 int ret, err;
2203
2204 path = btrfs_alloc_path();
2205 if (!path)
2206 return -ENOMEM;
2207
2208 trans = btrfs_start_transaction(root, 0);
2209 if (IS_ERR(trans)) {
2210 btrfs_free_path(path);
2211 return PTR_ERR(trans);
2212 }
2213
2214 key.objectid = BTRFS_BALANCE_OBJECTID;
2215 key.type = BTRFS_BALANCE_ITEM_KEY;
2216 key.offset = 0;
2217
2218 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2219 if (ret < 0)
2220 goto out;
2221 if (ret > 0) {
2222 ret = -ENOENT;
2223 goto out;
2224 }
2225
2226 ret = btrfs_del_item(trans, root, path);
2227 out:
2228 btrfs_free_path(path);
2229 err = btrfs_commit_transaction(trans, root);
2230 if (err && !ret)
2231 ret = err;
2232 return ret;
2233 }
2234
2235 /*
2236 * This is a heuristic used to reduce the number of chunks balanced on
2237 * resume after balance was interrupted.
2238 */
2239 static void update_balance_args(struct btrfs_balance_control *bctl)
2240 {
2241 /*
2242 * Turn on soft mode for chunk types that were being converted.
2243 */
2244 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2245 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2246 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2247 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2248 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2249 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2250
2251 /*
2252 * Turn on usage filter if is not already used. The idea is
2253 * that chunks that we have already balanced should be
2254 * reasonably full. Don't do it for chunks that are being
2255 * converted - that will keep us from relocating unconverted
2256 * (albeit full) chunks.
2257 */
2258 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2259 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2260 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2261 bctl->data.usage = 90;
2262 }
2263 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2264 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2265 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2266 bctl->sys.usage = 90;
2267 }
2268 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2269 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2270 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2271 bctl->meta.usage = 90;
2272 }
2273 }
2274
2275 /*
2276 * Should be called with both balance and volume mutexes held to
2277 * serialize other volume operations (add_dev/rm_dev/resize) with
2278 * restriper. Same goes for unset_balance_control.
2279 */
2280 static void set_balance_control(struct btrfs_balance_control *bctl)
2281 {
2282 struct btrfs_fs_info *fs_info = bctl->fs_info;
2283
2284 BUG_ON(fs_info->balance_ctl);
2285
2286 spin_lock(&fs_info->balance_lock);
2287 fs_info->balance_ctl = bctl;
2288 spin_unlock(&fs_info->balance_lock);
2289 }
2290
2291 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2292 {
2293 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2294
2295 BUG_ON(!fs_info->balance_ctl);
2296
2297 spin_lock(&fs_info->balance_lock);
2298 fs_info->balance_ctl = NULL;
2299 spin_unlock(&fs_info->balance_lock);
2300
2301 kfree(bctl);
2302 }
2303
2304 /*
2305 * Balance filters. Return 1 if chunk should be filtered out
2306 * (should not be balanced).
2307 */
2308 static int chunk_profiles_filter(u64 chunk_type,
2309 struct btrfs_balance_args *bargs)
2310 {
2311 chunk_type = chunk_to_extended(chunk_type) &
2312 BTRFS_EXTENDED_PROFILE_MASK;
2313
2314 if (bargs->profiles & chunk_type)
2315 return 0;
2316
2317 return 1;
2318 }
2319
2320 static u64 div_factor_fine(u64 num, int factor)
2321 {
2322 if (factor <= 0)
2323 return 0;
2324 if (factor >= 100)
2325 return num;
2326
2327 num *= factor;
2328 do_div(num, 100);
2329 return num;
2330 }
2331
2332 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2333 struct btrfs_balance_args *bargs)
2334 {
2335 struct btrfs_block_group_cache *cache;
2336 u64 chunk_used, user_thresh;
2337 int ret = 1;
2338
2339 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2340 chunk_used = btrfs_block_group_used(&cache->item);
2341
2342 user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
2343 if (chunk_used < user_thresh)
2344 ret = 0;
2345
2346 btrfs_put_block_group(cache);
2347 return ret;
2348 }
2349
2350 static int chunk_devid_filter(struct extent_buffer *leaf,
2351 struct btrfs_chunk *chunk,
2352 struct btrfs_balance_args *bargs)
2353 {
2354 struct btrfs_stripe *stripe;
2355 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2356 int i;
2357
2358 for (i = 0; i < num_stripes; i++) {
2359 stripe = btrfs_stripe_nr(chunk, i);
2360 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2361 return 0;
2362 }
2363
2364 return 1;
2365 }
2366
2367 /* [pstart, pend) */
2368 static int chunk_drange_filter(struct extent_buffer *leaf,
2369 struct btrfs_chunk *chunk,
2370 u64 chunk_offset,
2371 struct btrfs_balance_args *bargs)
2372 {
2373 struct btrfs_stripe *stripe;
2374 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2375 u64 stripe_offset;
2376 u64 stripe_length;
2377 int factor;
2378 int i;
2379
2380 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2381 return 0;
2382
2383 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2384 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2385 factor = 2;
2386 else
2387 factor = 1;
2388 factor = num_stripes / factor;
2389
2390 for (i = 0; i < num_stripes; i++) {
2391 stripe = btrfs_stripe_nr(chunk, i);
2392 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2393 continue;
2394
2395 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2396 stripe_length = btrfs_chunk_length(leaf, chunk);
2397 do_div(stripe_length, factor);
2398
2399 if (stripe_offset < bargs->pend &&
2400 stripe_offset + stripe_length > bargs->pstart)
2401 return 0;
2402 }
2403
2404 return 1;
2405 }
2406
2407 /* [vstart, vend) */
2408 static int chunk_vrange_filter(struct extent_buffer *leaf,
2409 struct btrfs_chunk *chunk,
2410 u64 chunk_offset,
2411 struct btrfs_balance_args *bargs)
2412 {
2413 if (chunk_offset < bargs->vend &&
2414 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2415 /* at least part of the chunk is inside this vrange */
2416 return 0;
2417
2418 return 1;
2419 }
2420
2421 static int chunk_soft_convert_filter(u64 chunk_type,
2422 struct btrfs_balance_args *bargs)
2423 {
2424 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2425 return 0;
2426
2427 chunk_type = chunk_to_extended(chunk_type) &
2428 BTRFS_EXTENDED_PROFILE_MASK;
2429
2430 if (bargs->target == chunk_type)
2431 return 1;
2432
2433 return 0;
2434 }
2435
2436 static int should_balance_chunk(struct btrfs_root *root,
2437 struct extent_buffer *leaf,
2438 struct btrfs_chunk *chunk, u64 chunk_offset)
2439 {
2440 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2441 struct btrfs_balance_args *bargs = NULL;
2442 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2443
2444 /* type filter */
2445 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2446 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2447 return 0;
2448 }
2449
2450 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2451 bargs = &bctl->data;
2452 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2453 bargs = &bctl->sys;
2454 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2455 bargs = &bctl->meta;
2456
2457 /* profiles filter */
2458 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2459 chunk_profiles_filter(chunk_type, bargs)) {
2460 return 0;
2461 }
2462
2463 /* usage filter */
2464 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2465 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2466 return 0;
2467 }
2468
2469 /* devid filter */
2470 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2471 chunk_devid_filter(leaf, chunk, bargs)) {
2472 return 0;
2473 }
2474
2475 /* drange filter, makes sense only with devid filter */
2476 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2477 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2478 return 0;
2479 }
2480
2481 /* vrange filter */
2482 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2483 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2484 return 0;
2485 }
2486
2487 /* soft profile changing mode */
2488 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2489 chunk_soft_convert_filter(chunk_type, bargs)) {
2490 return 0;
2491 }
2492
2493 return 1;
2494 }
2495
2496 static u64 div_factor(u64 num, int factor)
2497 {
2498 if (factor == 10)
2499 return num;
2500 num *= factor;
2501 do_div(num, 10);
2502 return num;
2503 }
2504
2505 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2506 {
2507 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2508 struct btrfs_root *chunk_root = fs_info->chunk_root;
2509 struct btrfs_root *dev_root = fs_info->dev_root;
2510 struct list_head *devices;
2511 struct btrfs_device *device;
2512 u64 old_size;
2513 u64 size_to_free;
2514 struct btrfs_chunk *chunk;
2515 struct btrfs_path *path;
2516 struct btrfs_key key;
2517 struct btrfs_key found_key;
2518 struct btrfs_trans_handle *trans;
2519 struct extent_buffer *leaf;
2520 int slot;
2521 int ret;
2522 int enospc_errors = 0;
2523 bool counting = true;
2524
2525 /* step one make some room on all the devices */
2526 devices = &fs_info->fs_devices->devices;
2527 list_for_each_entry(device, devices, dev_list) {
2528 old_size = device->total_bytes;
2529 size_to_free = div_factor(old_size, 1);
2530 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2531 if (!device->writeable ||
2532 device->total_bytes - device->bytes_used > size_to_free)
2533 continue;
2534
2535 ret = btrfs_shrink_device(device, old_size - size_to_free);
2536 if (ret == -ENOSPC)
2537 break;
2538 BUG_ON(ret);
2539
2540 trans = btrfs_start_transaction(dev_root, 0);
2541 BUG_ON(IS_ERR(trans));
2542
2543 ret = btrfs_grow_device(trans, device, old_size);
2544 BUG_ON(ret);
2545
2546 btrfs_end_transaction(trans, dev_root);
2547 }
2548
2549 /* step two, relocate all the chunks */
2550 path = btrfs_alloc_path();
2551 if (!path) {
2552 ret = -ENOMEM;
2553 goto error;
2554 }
2555
2556 /* zero out stat counters */
2557 spin_lock(&fs_info->balance_lock);
2558 memset(&bctl->stat, 0, sizeof(bctl->stat));
2559 spin_unlock(&fs_info->balance_lock);
2560 again:
2561 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2562 key.offset = (u64)-1;
2563 key.type = BTRFS_CHUNK_ITEM_KEY;
2564
2565 while (1) {
2566 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2567 atomic_read(&fs_info->balance_cancel_req)) {
2568 ret = -ECANCELED;
2569 goto error;
2570 }
2571
2572 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2573 if (ret < 0)
2574 goto error;
2575
2576 /*
2577 * this shouldn't happen, it means the last relocate
2578 * failed
2579 */
2580 if (ret == 0)
2581 BUG(); /* FIXME break ? */
2582
2583 ret = btrfs_previous_item(chunk_root, path, 0,
2584 BTRFS_CHUNK_ITEM_KEY);
2585 if (ret) {
2586 ret = 0;
2587 break;
2588 }
2589
2590 leaf = path->nodes[0];
2591 slot = path->slots[0];
2592 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2593
2594 if (found_key.objectid != key.objectid)
2595 break;
2596
2597 /* chunk zero is special */
2598 if (found_key.offset == 0)
2599 break;
2600
2601 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2602
2603 if (!counting) {
2604 spin_lock(&fs_info->balance_lock);
2605 bctl->stat.considered++;
2606 spin_unlock(&fs_info->balance_lock);
2607 }
2608
2609 ret = should_balance_chunk(chunk_root, leaf, chunk,
2610 found_key.offset);
2611 btrfs_release_path(path);
2612 if (!ret)
2613 goto loop;
2614
2615 if (counting) {
2616 spin_lock(&fs_info->balance_lock);
2617 bctl->stat.expected++;
2618 spin_unlock(&fs_info->balance_lock);
2619 goto loop;
2620 }
2621
2622 ret = btrfs_relocate_chunk(chunk_root,
2623 chunk_root->root_key.objectid,
2624 found_key.objectid,
2625 found_key.offset);
2626 if (ret && ret != -ENOSPC)
2627 goto error;
2628 if (ret == -ENOSPC) {
2629 enospc_errors++;
2630 } else {
2631 spin_lock(&fs_info->balance_lock);
2632 bctl->stat.completed++;
2633 spin_unlock(&fs_info->balance_lock);
2634 }
2635 loop:
2636 key.offset = found_key.offset - 1;
2637 }
2638
2639 if (counting) {
2640 btrfs_release_path(path);
2641 counting = false;
2642 goto again;
2643 }
2644 error:
2645 btrfs_free_path(path);
2646 if (enospc_errors) {
2647 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2648 enospc_errors);
2649 if (!ret)
2650 ret = -ENOSPC;
2651 }
2652
2653 return ret;
2654 }
2655
2656 /**
2657 * alloc_profile_is_valid - see if a given profile is valid and reduced
2658 * @flags: profile to validate
2659 * @extended: if true @flags is treated as an extended profile
2660 */
2661 static int alloc_profile_is_valid(u64 flags, int extended)
2662 {
2663 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
2664 BTRFS_BLOCK_GROUP_PROFILE_MASK);
2665
2666 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
2667
2668 /* 1) check that all other bits are zeroed */
2669 if (flags & ~mask)
2670 return 0;
2671
2672 /* 2) see if profile is reduced */
2673 if (flags == 0)
2674 return !extended; /* "0" is valid for usual profiles */
2675
2676 /* true if exactly one bit set */
2677 return (flags & (flags - 1)) == 0;
2678 }
2679
2680 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2681 {
2682 /* cancel requested || normal exit path */
2683 return atomic_read(&fs_info->balance_cancel_req) ||
2684 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2685 atomic_read(&fs_info->balance_cancel_req) == 0);
2686 }
2687
2688 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2689 {
2690 int ret;
2691
2692 unset_balance_control(fs_info);
2693 ret = del_balance_item(fs_info->tree_root);
2694 BUG_ON(ret);
2695 }
2696
2697 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2698 struct btrfs_ioctl_balance_args *bargs);
2699
2700 /*
2701 * Should be called with both balance and volume mutexes held
2702 */
2703 int btrfs_balance(struct btrfs_balance_control *bctl,
2704 struct btrfs_ioctl_balance_args *bargs)
2705 {
2706 struct btrfs_fs_info *fs_info = bctl->fs_info;
2707 u64 allowed;
2708 int mixed = 0;
2709 int ret;
2710
2711 if (btrfs_fs_closing(fs_info) ||
2712 atomic_read(&fs_info->balance_pause_req) ||
2713 atomic_read(&fs_info->balance_cancel_req)) {
2714 ret = -EINVAL;
2715 goto out;
2716 }
2717
2718 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2719 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
2720 mixed = 1;
2721
2722 /*
2723 * In case of mixed groups both data and meta should be picked,
2724 * and identical options should be given for both of them.
2725 */
2726 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
2727 if (mixed && (bctl->flags & allowed)) {
2728 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
2729 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
2730 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
2731 printk(KERN_ERR "btrfs: with mixed groups data and "
2732 "metadata balance options must be the same\n");
2733 ret = -EINVAL;
2734 goto out;
2735 }
2736 }
2737
2738 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2739 if (fs_info->fs_devices->num_devices == 1)
2740 allowed |= BTRFS_BLOCK_GROUP_DUP;
2741 else if (fs_info->fs_devices->num_devices < 4)
2742 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
2743 else
2744 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2745 BTRFS_BLOCK_GROUP_RAID10);
2746
2747 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2748 (!alloc_profile_is_valid(bctl->data.target, 1) ||
2749 (bctl->data.target & ~allowed))) {
2750 printk(KERN_ERR "btrfs: unable to start balance with target "
2751 "data profile %llu\n",
2752 (unsigned long long)bctl->data.target);
2753 ret = -EINVAL;
2754 goto out;
2755 }
2756 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2757 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
2758 (bctl->meta.target & ~allowed))) {
2759 printk(KERN_ERR "btrfs: unable to start balance with target "
2760 "metadata profile %llu\n",
2761 (unsigned long long)bctl->meta.target);
2762 ret = -EINVAL;
2763 goto out;
2764 }
2765 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2766 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
2767 (bctl->sys.target & ~allowed))) {
2768 printk(KERN_ERR "btrfs: unable to start balance with target "
2769 "system profile %llu\n",
2770 (unsigned long long)bctl->sys.target);
2771 ret = -EINVAL;
2772 goto out;
2773 }
2774
2775 /* allow dup'ed data chunks only in mixed mode */
2776 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2777 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
2778 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
2779 ret = -EINVAL;
2780 goto out;
2781 }
2782
2783 /* allow to reduce meta or sys integrity only if force set */
2784 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
2785 BTRFS_BLOCK_GROUP_RAID10;
2786 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2787 (fs_info->avail_system_alloc_bits & allowed) &&
2788 !(bctl->sys.target & allowed)) ||
2789 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2790 (fs_info->avail_metadata_alloc_bits & allowed) &&
2791 !(bctl->meta.target & allowed))) {
2792 if (bctl->flags & BTRFS_BALANCE_FORCE) {
2793 printk(KERN_INFO "btrfs: force reducing metadata "
2794 "integrity\n");
2795 } else {
2796 printk(KERN_ERR "btrfs: balance will reduce metadata "
2797 "integrity, use force if you want this\n");
2798 ret = -EINVAL;
2799 goto out;
2800 }
2801 }
2802
2803 ret = insert_balance_item(fs_info->tree_root, bctl);
2804 if (ret && ret != -EEXIST)
2805 goto out;
2806
2807 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
2808 BUG_ON(ret == -EEXIST);
2809 set_balance_control(bctl);
2810 } else {
2811 BUG_ON(ret != -EEXIST);
2812 spin_lock(&fs_info->balance_lock);
2813 update_balance_args(bctl);
2814 spin_unlock(&fs_info->balance_lock);
2815 }
2816
2817 atomic_inc(&fs_info->balance_running);
2818 mutex_unlock(&fs_info->balance_mutex);
2819
2820 ret = __btrfs_balance(fs_info);
2821
2822 mutex_lock(&fs_info->balance_mutex);
2823 atomic_dec(&fs_info->balance_running);
2824
2825 if (bargs) {
2826 memset(bargs, 0, sizeof(*bargs));
2827 update_ioctl_balance_args(fs_info, 0, bargs);
2828 }
2829
2830 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
2831 balance_need_close(fs_info)) {
2832 __cancel_balance(fs_info);
2833 }
2834
2835 wake_up(&fs_info->balance_wait_q);
2836
2837 return ret;
2838 out:
2839 if (bctl->flags & BTRFS_BALANCE_RESUME)
2840 __cancel_balance(fs_info);
2841 else
2842 kfree(bctl);
2843 return ret;
2844 }
2845
2846 static int balance_kthread(void *data)
2847 {
2848 struct btrfs_fs_info *fs_info = data;
2849 int ret = 0;
2850
2851 mutex_lock(&fs_info->volume_mutex);
2852 mutex_lock(&fs_info->balance_mutex);
2853
2854 if (fs_info->balance_ctl) {
2855 printk(KERN_INFO "btrfs: continuing balance\n");
2856 ret = btrfs_balance(fs_info->balance_ctl, NULL);
2857 }
2858
2859 mutex_unlock(&fs_info->balance_mutex);
2860 mutex_unlock(&fs_info->volume_mutex);
2861
2862 return ret;
2863 }
2864
2865 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
2866 {
2867 struct task_struct *tsk;
2868
2869 spin_lock(&fs_info->balance_lock);
2870 if (!fs_info->balance_ctl) {
2871 spin_unlock(&fs_info->balance_lock);
2872 return 0;
2873 }
2874 spin_unlock(&fs_info->balance_lock);
2875
2876 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
2877 printk(KERN_INFO "btrfs: force skipping balance\n");
2878 return 0;
2879 }
2880
2881 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
2882 if (IS_ERR(tsk))
2883 return PTR_ERR(tsk);
2884
2885 return 0;
2886 }
2887
2888 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
2889 {
2890 struct btrfs_balance_control *bctl;
2891 struct btrfs_balance_item *item;
2892 struct btrfs_disk_balance_args disk_bargs;
2893 struct btrfs_path *path;
2894 struct extent_buffer *leaf;
2895 struct btrfs_key key;
2896 int ret;
2897
2898 path = btrfs_alloc_path();
2899 if (!path)
2900 return -ENOMEM;
2901
2902 key.objectid = BTRFS_BALANCE_OBJECTID;
2903 key.type = BTRFS_BALANCE_ITEM_KEY;
2904 key.offset = 0;
2905
2906 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2907 if (ret < 0)
2908 goto out;
2909 if (ret > 0) { /* ret = -ENOENT; */
2910 ret = 0;
2911 goto out;
2912 }
2913
2914 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
2915 if (!bctl) {
2916 ret = -ENOMEM;
2917 goto out;
2918 }
2919
2920 leaf = path->nodes[0];
2921 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2922
2923 bctl->fs_info = fs_info;
2924 bctl->flags = btrfs_balance_flags(leaf, item);
2925 bctl->flags |= BTRFS_BALANCE_RESUME;
2926
2927 btrfs_balance_data(leaf, item, &disk_bargs);
2928 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
2929 btrfs_balance_meta(leaf, item, &disk_bargs);
2930 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
2931 btrfs_balance_sys(leaf, item, &disk_bargs);
2932 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
2933
2934 mutex_lock(&fs_info->volume_mutex);
2935 mutex_lock(&fs_info->balance_mutex);
2936
2937 set_balance_control(bctl);
2938
2939 mutex_unlock(&fs_info->balance_mutex);
2940 mutex_unlock(&fs_info->volume_mutex);
2941 out:
2942 btrfs_free_path(path);
2943 return ret;
2944 }
2945
2946 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
2947 {
2948 int ret = 0;
2949
2950 mutex_lock(&fs_info->balance_mutex);
2951 if (!fs_info->balance_ctl) {
2952 mutex_unlock(&fs_info->balance_mutex);
2953 return -ENOTCONN;
2954 }
2955
2956 if (atomic_read(&fs_info->balance_running)) {
2957 atomic_inc(&fs_info->balance_pause_req);
2958 mutex_unlock(&fs_info->balance_mutex);
2959
2960 wait_event(fs_info->balance_wait_q,
2961 atomic_read(&fs_info->balance_running) == 0);
2962
2963 mutex_lock(&fs_info->balance_mutex);
2964 /* we are good with balance_ctl ripped off from under us */
2965 BUG_ON(atomic_read(&fs_info->balance_running));
2966 atomic_dec(&fs_info->balance_pause_req);
2967 } else {
2968 ret = -ENOTCONN;
2969 }
2970
2971 mutex_unlock(&fs_info->balance_mutex);
2972 return ret;
2973 }
2974
2975 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
2976 {
2977 mutex_lock(&fs_info->balance_mutex);
2978 if (!fs_info->balance_ctl) {
2979 mutex_unlock(&fs_info->balance_mutex);
2980 return -ENOTCONN;
2981 }
2982
2983 atomic_inc(&fs_info->balance_cancel_req);
2984 /*
2985 * if we are running just wait and return, balance item is
2986 * deleted in btrfs_balance in this case
2987 */
2988 if (atomic_read(&fs_info->balance_running)) {
2989 mutex_unlock(&fs_info->balance_mutex);
2990 wait_event(fs_info->balance_wait_q,
2991 atomic_read(&fs_info->balance_running) == 0);
2992 mutex_lock(&fs_info->balance_mutex);
2993 } else {
2994 /* __cancel_balance needs volume_mutex */
2995 mutex_unlock(&fs_info->balance_mutex);
2996 mutex_lock(&fs_info->volume_mutex);
2997 mutex_lock(&fs_info->balance_mutex);
2998
2999 if (fs_info->balance_ctl)
3000 __cancel_balance(fs_info);
3001
3002 mutex_unlock(&fs_info->volume_mutex);
3003 }
3004
3005 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3006 atomic_dec(&fs_info->balance_cancel_req);
3007 mutex_unlock(&fs_info->balance_mutex);
3008 return 0;
3009 }
3010
3011 /*
3012 * shrinking a device means finding all of the device extents past
3013 * the new size, and then following the back refs to the chunks.
3014 * The chunk relocation code actually frees the device extent
3015 */
3016 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3017 {
3018 struct btrfs_trans_handle *trans;
3019 struct btrfs_root *root = device->dev_root;
3020 struct btrfs_dev_extent *dev_extent = NULL;
3021 struct btrfs_path *path;
3022 u64 length;
3023 u64 chunk_tree;
3024 u64 chunk_objectid;
3025 u64 chunk_offset;
3026 int ret;
3027 int slot;
3028 int failed = 0;
3029 bool retried = false;
3030 struct extent_buffer *l;
3031 struct btrfs_key key;
3032 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3033 u64 old_total = btrfs_super_total_bytes(super_copy);
3034 u64 old_size = device->total_bytes;
3035 u64 diff = device->total_bytes - new_size;
3036
3037 if (new_size >= device->total_bytes)
3038 return -EINVAL;
3039
3040 path = btrfs_alloc_path();
3041 if (!path)
3042 return -ENOMEM;
3043
3044 path->reada = 2;
3045
3046 lock_chunks(root);
3047
3048 device->total_bytes = new_size;
3049 if (device->writeable) {
3050 device->fs_devices->total_rw_bytes -= diff;
3051 spin_lock(&root->fs_info->free_chunk_lock);
3052 root->fs_info->free_chunk_space -= diff;
3053 spin_unlock(&root->fs_info->free_chunk_lock);
3054 }
3055 unlock_chunks(root);
3056
3057 again:
3058 key.objectid = device->devid;
3059 key.offset = (u64)-1;
3060 key.type = BTRFS_DEV_EXTENT_KEY;
3061
3062 do {
3063 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3064 if (ret < 0)
3065 goto done;
3066
3067 ret = btrfs_previous_item(root, path, 0, key.type);
3068 if (ret < 0)
3069 goto done;
3070 if (ret) {
3071 ret = 0;
3072 btrfs_release_path(path);
3073 break;
3074 }
3075
3076 l = path->nodes[0];
3077 slot = path->slots[0];
3078 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3079
3080 if (key.objectid != device->devid) {
3081 btrfs_release_path(path);
3082 break;
3083 }
3084
3085 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3086 length = btrfs_dev_extent_length(l, dev_extent);
3087
3088 if (key.offset + length <= new_size) {
3089 btrfs_release_path(path);
3090 break;
3091 }
3092
3093 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3094 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3095 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3096 btrfs_release_path(path);
3097
3098 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3099 chunk_offset);
3100 if (ret && ret != -ENOSPC)
3101 goto done;
3102 if (ret == -ENOSPC)
3103 failed++;
3104 } while (key.offset-- > 0);
3105
3106 if (failed && !retried) {
3107 failed = 0;
3108 retried = true;
3109 goto again;
3110 } else if (failed && retried) {
3111 ret = -ENOSPC;
3112 lock_chunks(root);
3113
3114 device->total_bytes = old_size;
3115 if (device->writeable)
3116 device->fs_devices->total_rw_bytes += diff;
3117 spin_lock(&root->fs_info->free_chunk_lock);
3118 root->fs_info->free_chunk_space += diff;
3119 spin_unlock(&root->fs_info->free_chunk_lock);
3120 unlock_chunks(root);
3121 goto done;
3122 }
3123
3124 /* Shrinking succeeded, else we would be at "done". */
3125 trans = btrfs_start_transaction(root, 0);
3126 if (IS_ERR(trans)) {
3127 ret = PTR_ERR(trans);
3128 goto done;
3129 }
3130
3131 lock_chunks(root);
3132
3133 device->disk_total_bytes = new_size;
3134 /* Now btrfs_update_device() will change the on-disk size. */
3135 ret = btrfs_update_device(trans, device);
3136 if (ret) {
3137 unlock_chunks(root);
3138 btrfs_end_transaction(trans, root);
3139 goto done;
3140 }
3141 WARN_ON(diff > old_total);
3142 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3143 unlock_chunks(root);
3144 btrfs_end_transaction(trans, root);
3145 done:
3146 btrfs_free_path(path);
3147 return ret;
3148 }
3149
3150 static int btrfs_add_system_chunk(struct btrfs_root *root,
3151 struct btrfs_key *key,
3152 struct btrfs_chunk *chunk, int item_size)
3153 {
3154 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3155 struct btrfs_disk_key disk_key;
3156 u32 array_size;
3157 u8 *ptr;
3158
3159 array_size = btrfs_super_sys_array_size(super_copy);
3160 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3161 return -EFBIG;
3162
3163 ptr = super_copy->sys_chunk_array + array_size;
3164 btrfs_cpu_key_to_disk(&disk_key, key);
3165 memcpy(ptr, &disk_key, sizeof(disk_key));
3166 ptr += sizeof(disk_key);
3167 memcpy(ptr, chunk, item_size);
3168 item_size += sizeof(disk_key);
3169 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3170 return 0;
3171 }
3172
3173 /*
3174 * sort the devices in descending order by max_avail, total_avail
3175 */
3176 static int btrfs_cmp_device_info(const void *a, const void *b)
3177 {
3178 const struct btrfs_device_info *di_a = a;
3179 const struct btrfs_device_info *di_b = b;
3180
3181 if (di_a->max_avail > di_b->max_avail)
3182 return -1;
3183 if (di_a->max_avail < di_b->max_avail)
3184 return 1;
3185 if (di_a->total_avail > di_b->total_avail)
3186 return -1;
3187 if (di_a->total_avail < di_b->total_avail)
3188 return 1;
3189 return 0;
3190 }
3191
3192 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3193 struct btrfs_root *extent_root,
3194 struct map_lookup **map_ret,
3195 u64 *num_bytes_out, u64 *stripe_size_out,
3196 u64 start, u64 type)
3197 {
3198 struct btrfs_fs_info *info = extent_root->fs_info;
3199 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3200 struct list_head *cur;
3201 struct map_lookup *map = NULL;
3202 struct extent_map_tree *em_tree;
3203 struct extent_map *em;
3204 struct btrfs_device_info *devices_info = NULL;
3205 u64 total_avail;
3206 int num_stripes; /* total number of stripes to allocate */
3207 int sub_stripes; /* sub_stripes info for map */
3208 int dev_stripes; /* stripes per dev */
3209 int devs_max; /* max devs to use */
3210 int devs_min; /* min devs needed */
3211 int devs_increment; /* ndevs has to be a multiple of this */
3212 int ncopies; /* how many copies to data has */
3213 int ret;
3214 u64 max_stripe_size;
3215 u64 max_chunk_size;
3216 u64 stripe_size;
3217 u64 num_bytes;
3218 int ndevs;
3219 int i;
3220 int j;
3221
3222 BUG_ON(!alloc_profile_is_valid(type, 0));
3223
3224 if (list_empty(&fs_devices->alloc_list))
3225 return -ENOSPC;
3226
3227 sub_stripes = 1;
3228 dev_stripes = 1;
3229 devs_increment = 1;
3230 ncopies = 1;
3231 devs_max = 0; /* 0 == as many as possible */
3232 devs_min = 1;
3233
3234 /*
3235 * define the properties of each RAID type.
3236 * FIXME: move this to a global table and use it in all RAID
3237 * calculation code
3238 */
3239 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
3240 dev_stripes = 2;
3241 ncopies = 2;
3242 devs_max = 1;
3243 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
3244 devs_min = 2;
3245 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
3246 devs_increment = 2;
3247 ncopies = 2;
3248 devs_max = 2;
3249 devs_min = 2;
3250 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
3251 sub_stripes = 2;
3252 devs_increment = 2;
3253 ncopies = 2;
3254 devs_min = 4;
3255 } else {
3256 devs_max = 1;
3257 }
3258
3259 if (type & BTRFS_BLOCK_GROUP_DATA) {
3260 max_stripe_size = 1024 * 1024 * 1024;
3261 max_chunk_size = 10 * max_stripe_size;
3262 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3263 /* for larger filesystems, use larger metadata chunks */
3264 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3265 max_stripe_size = 1024 * 1024 * 1024;
3266 else
3267 max_stripe_size = 256 * 1024 * 1024;
3268 max_chunk_size = max_stripe_size;
3269 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3270 max_stripe_size = 32 * 1024 * 1024;
3271 max_chunk_size = 2 * max_stripe_size;
3272 } else {
3273 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3274 type);
3275 BUG_ON(1);
3276 }
3277
3278 /* we don't want a chunk larger than 10% of writeable space */
3279 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3280 max_chunk_size);
3281
3282 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3283 GFP_NOFS);
3284 if (!devices_info)
3285 return -ENOMEM;
3286
3287 cur = fs_devices->alloc_list.next;
3288
3289 /*
3290 * in the first pass through the devices list, we gather information
3291 * about the available holes on each device.
3292 */
3293 ndevs = 0;
3294 while (cur != &fs_devices->alloc_list) {
3295 struct btrfs_device *device;
3296 u64 max_avail;
3297 u64 dev_offset;
3298
3299 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3300
3301 cur = cur->next;
3302
3303 if (!device->writeable) {
3304 printk(KERN_ERR
3305 "btrfs: read-only device in alloc_list\n");
3306 WARN_ON(1);
3307 continue;
3308 }
3309
3310 if (!device->in_fs_metadata)
3311 continue;
3312
3313 if (device->total_bytes > device->bytes_used)
3314 total_avail = device->total_bytes - device->bytes_used;
3315 else
3316 total_avail = 0;
3317
3318 /* If there is no space on this device, skip it. */
3319 if (total_avail == 0)
3320 continue;
3321
3322 ret = find_free_dev_extent(device,
3323 max_stripe_size * dev_stripes,
3324 &dev_offset, &max_avail);
3325 if (ret && ret != -ENOSPC)
3326 goto error;
3327
3328 if (ret == 0)
3329 max_avail = max_stripe_size * dev_stripes;
3330
3331 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3332 continue;
3333
3334 devices_info[ndevs].dev_offset = dev_offset;
3335 devices_info[ndevs].max_avail = max_avail;
3336 devices_info[ndevs].total_avail = total_avail;
3337 devices_info[ndevs].dev = device;
3338 ++ndevs;
3339 }
3340
3341 /*
3342 * now sort the devices by hole size / available space
3343 */
3344 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3345 btrfs_cmp_device_info, NULL);
3346
3347 /* round down to number of usable stripes */
3348 ndevs -= ndevs % devs_increment;
3349
3350 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3351 ret = -ENOSPC;
3352 goto error;
3353 }
3354
3355 if (devs_max && ndevs > devs_max)
3356 ndevs = devs_max;
3357 /*
3358 * the primary goal is to maximize the number of stripes, so use as many
3359 * devices as possible, even if the stripes are not maximum sized.
3360 */
3361 stripe_size = devices_info[ndevs-1].max_avail;
3362 num_stripes = ndevs * dev_stripes;
3363
3364 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3365 stripe_size = max_chunk_size * ncopies;
3366 do_div(stripe_size, ndevs);
3367 }
3368
3369 do_div(stripe_size, dev_stripes);
3370
3371 /* align to BTRFS_STRIPE_LEN */
3372 do_div(stripe_size, BTRFS_STRIPE_LEN);
3373 stripe_size *= BTRFS_STRIPE_LEN;
3374
3375 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3376 if (!map) {
3377 ret = -ENOMEM;
3378 goto error;
3379 }
3380 map->num_stripes = num_stripes;
3381
3382 for (i = 0; i < ndevs; ++i) {
3383 for (j = 0; j < dev_stripes; ++j) {
3384 int s = i * dev_stripes + j;
3385 map->stripes[s].dev = devices_info[i].dev;
3386 map->stripes[s].physical = devices_info[i].dev_offset +
3387 j * stripe_size;
3388 }
3389 }
3390 map->sector_size = extent_root->sectorsize;
3391 map->stripe_len = BTRFS_STRIPE_LEN;
3392 map->io_align = BTRFS_STRIPE_LEN;
3393 map->io_width = BTRFS_STRIPE_LEN;
3394 map->type = type;
3395 map->sub_stripes = sub_stripes;
3396
3397 *map_ret = map;
3398 num_bytes = stripe_size * (num_stripes / ncopies);
3399
3400 *stripe_size_out = stripe_size;
3401 *num_bytes_out = num_bytes;
3402
3403 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3404
3405 em = alloc_extent_map();
3406 if (!em) {
3407 ret = -ENOMEM;
3408 goto error;
3409 }
3410 em->bdev = (struct block_device *)map;
3411 em->start = start;
3412 em->len = num_bytes;
3413 em->block_start = 0;
3414 em->block_len = em->len;
3415
3416 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3417 write_lock(&em_tree->lock);
3418 ret = add_extent_mapping(em_tree, em);
3419 write_unlock(&em_tree->lock);
3420 free_extent_map(em);
3421 if (ret)
3422 goto error;
3423
3424 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3425 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3426 start, num_bytes);
3427 if (ret)
3428 goto error;
3429
3430 for (i = 0; i < map->num_stripes; ++i) {
3431 struct btrfs_device *device;
3432 u64 dev_offset;
3433
3434 device = map->stripes[i].dev;
3435 dev_offset = map->stripes[i].physical;
3436
3437 ret = btrfs_alloc_dev_extent(trans, device,
3438 info->chunk_root->root_key.objectid,
3439 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3440 start, dev_offset, stripe_size);
3441 if (ret) {
3442 btrfs_abort_transaction(trans, extent_root, ret);
3443 goto error;
3444 }
3445 }
3446
3447 kfree(devices_info);
3448 return 0;
3449
3450 error:
3451 kfree(map);
3452 kfree(devices_info);
3453 return ret;
3454 }
3455
3456 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3457 struct btrfs_root *extent_root,
3458 struct map_lookup *map, u64 chunk_offset,
3459 u64 chunk_size, u64 stripe_size)
3460 {
3461 u64 dev_offset;
3462 struct btrfs_key key;
3463 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3464 struct btrfs_device *device;
3465 struct btrfs_chunk *chunk;
3466 struct btrfs_stripe *stripe;
3467 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3468 int index = 0;
3469 int ret;
3470
3471 chunk = kzalloc(item_size, GFP_NOFS);
3472 if (!chunk)
3473 return -ENOMEM;
3474
3475 index = 0;
3476 while (index < map->num_stripes) {
3477 device = map->stripes[index].dev;
3478 device->bytes_used += stripe_size;
3479 ret = btrfs_update_device(trans, device);
3480 if (ret)
3481 goto out_free;
3482 index++;
3483 }
3484
3485 spin_lock(&extent_root->fs_info->free_chunk_lock);
3486 extent_root->fs_info->free_chunk_space -= (stripe_size *
3487 map->num_stripes);
3488 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3489
3490 index = 0;
3491 stripe = &chunk->stripe;
3492 while (index < map->num_stripes) {
3493 device = map->stripes[index].dev;
3494 dev_offset = map->stripes[index].physical;
3495
3496 btrfs_set_stack_stripe_devid(stripe, device->devid);
3497 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3498 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3499 stripe++;
3500 index++;
3501 }
3502
3503 btrfs_set_stack_chunk_length(chunk, chunk_size);
3504 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3505 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3506 btrfs_set_stack_chunk_type(chunk, map->type);
3507 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3508 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3509 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3510 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3511 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3512
3513 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3514 key.type = BTRFS_CHUNK_ITEM_KEY;
3515 key.offset = chunk_offset;
3516
3517 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3518
3519 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3520 /*
3521 * TODO: Cleanup of inserted chunk root in case of
3522 * failure.
3523 */
3524 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3525 item_size);
3526 }
3527
3528 out_free:
3529 kfree(chunk);
3530 return ret;
3531 }
3532
3533 /*
3534 * Chunk allocation falls into two parts. The first part does works
3535 * that make the new allocated chunk useable, but not do any operation
3536 * that modifies the chunk tree. The second part does the works that
3537 * require modifying the chunk tree. This division is important for the
3538 * bootstrap process of adding storage to a seed btrfs.
3539 */
3540 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3541 struct btrfs_root *extent_root, u64 type)
3542 {
3543 u64 chunk_offset;
3544 u64 chunk_size;
3545 u64 stripe_size;
3546 struct map_lookup *map;
3547 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3548 int ret;
3549
3550 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3551 &chunk_offset);
3552 if (ret)
3553 return ret;
3554
3555 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3556 &stripe_size, chunk_offset, type);
3557 if (ret)
3558 return ret;
3559
3560 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3561 chunk_size, stripe_size);
3562 if (ret)
3563 return ret;
3564 return 0;
3565 }
3566
3567 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3568 struct btrfs_root *root,
3569 struct btrfs_device *device)
3570 {
3571 u64 chunk_offset;
3572 u64 sys_chunk_offset;
3573 u64 chunk_size;
3574 u64 sys_chunk_size;
3575 u64 stripe_size;
3576 u64 sys_stripe_size;
3577 u64 alloc_profile;
3578 struct map_lookup *map;
3579 struct map_lookup *sys_map;
3580 struct btrfs_fs_info *fs_info = root->fs_info;
3581 struct btrfs_root *extent_root = fs_info->extent_root;
3582 int ret;
3583
3584 ret = find_next_chunk(fs_info->chunk_root,
3585 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3586 if (ret)
3587 return ret;
3588
3589 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3590 fs_info->avail_metadata_alloc_bits;
3591 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3592
3593 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3594 &stripe_size, chunk_offset, alloc_profile);
3595 if (ret)
3596 return ret;
3597
3598 sys_chunk_offset = chunk_offset + chunk_size;
3599
3600 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3601 fs_info->avail_system_alloc_bits;
3602 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3603
3604 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3605 &sys_chunk_size, &sys_stripe_size,
3606 sys_chunk_offset, alloc_profile);
3607 if (ret)
3608 goto abort;
3609
3610 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3611 if (ret)
3612 goto abort;
3613
3614 /*
3615 * Modifying chunk tree needs allocating new blocks from both
3616 * system block group and metadata block group. So we only can
3617 * do operations require modifying the chunk tree after both
3618 * block groups were created.
3619 */
3620 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3621 chunk_size, stripe_size);
3622 if (ret)
3623 goto abort;
3624
3625 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3626 sys_chunk_offset, sys_chunk_size,
3627 sys_stripe_size);
3628 if (ret)
3629 goto abort;
3630
3631 return 0;
3632
3633 abort:
3634 btrfs_abort_transaction(trans, root, ret);
3635 return ret;
3636 }
3637
3638 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3639 {
3640 struct extent_map *em;
3641 struct map_lookup *map;
3642 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3643 int readonly = 0;
3644 int i;
3645
3646 read_lock(&map_tree->map_tree.lock);
3647 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3648 read_unlock(&map_tree->map_tree.lock);
3649 if (!em)
3650 return 1;
3651
3652 if (btrfs_test_opt(root, DEGRADED)) {
3653 free_extent_map(em);
3654 return 0;
3655 }
3656
3657 map = (struct map_lookup *)em->bdev;
3658 for (i = 0; i < map->num_stripes; i++) {
3659 if (!map->stripes[i].dev->writeable) {
3660 readonly = 1;
3661 break;
3662 }
3663 }
3664 free_extent_map(em);
3665 return readonly;
3666 }
3667
3668 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3669 {
3670 extent_map_tree_init(&tree->map_tree);
3671 }
3672
3673 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3674 {
3675 struct extent_map *em;
3676
3677 while (1) {
3678 write_lock(&tree->map_tree.lock);
3679 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3680 if (em)
3681 remove_extent_mapping(&tree->map_tree, em);
3682 write_unlock(&tree->map_tree.lock);
3683 if (!em)
3684 break;
3685 kfree(em->bdev);
3686 /* once for us */
3687 free_extent_map(em);
3688 /* once for the tree */
3689 free_extent_map(em);
3690 }
3691 }
3692
3693 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
3694 {
3695 struct extent_map *em;
3696 struct map_lookup *map;
3697 struct extent_map_tree *em_tree = &map_tree->map_tree;
3698 int ret;
3699
3700 read_lock(&em_tree->lock);
3701 em = lookup_extent_mapping(em_tree, logical, len);
3702 read_unlock(&em_tree->lock);
3703 BUG_ON(!em);
3704
3705 BUG_ON(em->start > logical || em->start + em->len < logical);
3706 map = (struct map_lookup *)em->bdev;
3707 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
3708 ret = map->num_stripes;
3709 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3710 ret = map->sub_stripes;
3711 else
3712 ret = 1;
3713 free_extent_map(em);
3714 return ret;
3715 }
3716
3717 static int find_live_mirror(struct map_lookup *map, int first, int num,
3718 int optimal)
3719 {
3720 int i;
3721 if (map->stripes[optimal].dev->bdev)
3722 return optimal;
3723 for (i = first; i < first + num; i++) {
3724 if (map->stripes[i].dev->bdev)
3725 return i;
3726 }
3727 /* we couldn't find one that doesn't fail. Just return something
3728 * and the io error handling code will clean up eventually
3729 */
3730 return optimal;
3731 }
3732
3733 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3734 u64 logical, u64 *length,
3735 struct btrfs_bio **bbio_ret,
3736 int mirror_num)
3737 {
3738 struct extent_map *em;
3739 struct map_lookup *map;
3740 struct extent_map_tree *em_tree = &map_tree->map_tree;
3741 u64 offset;
3742 u64 stripe_offset;
3743 u64 stripe_end_offset;
3744 u64 stripe_nr;
3745 u64 stripe_nr_orig;
3746 u64 stripe_nr_end;
3747 int stripe_index;
3748 int i;
3749 int ret = 0;
3750 int num_stripes;
3751 int max_errors = 0;
3752 struct btrfs_bio *bbio = NULL;
3753
3754 read_lock(&em_tree->lock);
3755 em = lookup_extent_mapping(em_tree, logical, *length);
3756 read_unlock(&em_tree->lock);
3757
3758 if (!em) {
3759 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
3760 (unsigned long long)logical,
3761 (unsigned long long)*length);
3762 BUG();
3763 }
3764
3765 BUG_ON(em->start > logical || em->start + em->len < logical);
3766 map = (struct map_lookup *)em->bdev;
3767 offset = logical - em->start;
3768
3769 if (mirror_num > map->num_stripes)
3770 mirror_num = 0;
3771
3772 stripe_nr = offset;
3773 /*
3774 * stripe_nr counts the total number of stripes we have to stride
3775 * to get to this block
3776 */
3777 do_div(stripe_nr, map->stripe_len);
3778
3779 stripe_offset = stripe_nr * map->stripe_len;
3780 BUG_ON(offset < stripe_offset);
3781
3782 /* stripe_offset is the offset of this block in its stripe*/
3783 stripe_offset = offset - stripe_offset;
3784
3785 if (rw & REQ_DISCARD)
3786 *length = min_t(u64, em->len - offset, *length);
3787 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3788 /* we limit the length of each bio to what fits in a stripe */
3789 *length = min_t(u64, em->len - offset,
3790 map->stripe_len - stripe_offset);
3791 } else {
3792 *length = em->len - offset;
3793 }
3794
3795 if (!bbio_ret)
3796 goto out;
3797
3798 num_stripes = 1;
3799 stripe_index = 0;
3800 stripe_nr_orig = stripe_nr;
3801 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3802 (~(map->stripe_len - 1));
3803 do_div(stripe_nr_end, map->stripe_len);
3804 stripe_end_offset = stripe_nr_end * map->stripe_len -
3805 (offset + *length);
3806 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3807 if (rw & REQ_DISCARD)
3808 num_stripes = min_t(u64, map->num_stripes,
3809 stripe_nr_end - stripe_nr_orig);
3810 stripe_index = do_div(stripe_nr, map->num_stripes);
3811 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3812 if (rw & (REQ_WRITE | REQ_DISCARD))
3813 num_stripes = map->num_stripes;
3814 else if (mirror_num)
3815 stripe_index = mirror_num - 1;
3816 else {
3817 stripe_index = find_live_mirror(map, 0,
3818 map->num_stripes,
3819 current->pid % map->num_stripes);
3820 mirror_num = stripe_index + 1;
3821 }
3822
3823 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3824 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3825 num_stripes = map->num_stripes;
3826 } else if (mirror_num) {
3827 stripe_index = mirror_num - 1;
3828 } else {
3829 mirror_num = 1;
3830 }
3831
3832 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3833 int factor = map->num_stripes / map->sub_stripes;
3834
3835 stripe_index = do_div(stripe_nr, factor);
3836 stripe_index *= map->sub_stripes;
3837
3838 if (rw & REQ_WRITE)
3839 num_stripes = map->sub_stripes;
3840 else if (rw & REQ_DISCARD)
3841 num_stripes = min_t(u64, map->sub_stripes *
3842 (stripe_nr_end - stripe_nr_orig),
3843 map->num_stripes);
3844 else if (mirror_num)
3845 stripe_index += mirror_num - 1;
3846 else {
3847 int old_stripe_index = stripe_index;
3848 stripe_index = find_live_mirror(map, stripe_index,
3849 map->sub_stripes, stripe_index +
3850 current->pid % map->sub_stripes);
3851 mirror_num = stripe_index - old_stripe_index + 1;
3852 }
3853 } else {
3854 /*
3855 * after this do_div call, stripe_nr is the number of stripes
3856 * on this device we have to walk to find the data, and
3857 * stripe_index is the number of our device in the stripe array
3858 */
3859 stripe_index = do_div(stripe_nr, map->num_stripes);
3860 mirror_num = stripe_index + 1;
3861 }
3862 BUG_ON(stripe_index >= map->num_stripes);
3863
3864 bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
3865 if (!bbio) {
3866 ret = -ENOMEM;
3867 goto out;
3868 }
3869 atomic_set(&bbio->error, 0);
3870
3871 if (rw & REQ_DISCARD) {
3872 int factor = 0;
3873 int sub_stripes = 0;
3874 u64 stripes_per_dev = 0;
3875 u32 remaining_stripes = 0;
3876 u32 last_stripe = 0;
3877
3878 if (map->type &
3879 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
3880 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3881 sub_stripes = 1;
3882 else
3883 sub_stripes = map->sub_stripes;
3884
3885 factor = map->num_stripes / sub_stripes;
3886 stripes_per_dev = div_u64_rem(stripe_nr_end -
3887 stripe_nr_orig,
3888 factor,
3889 &remaining_stripes);
3890 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
3891 last_stripe *= sub_stripes;
3892 }
3893
3894 for (i = 0; i < num_stripes; i++) {
3895 bbio->stripes[i].physical =
3896 map->stripes[stripe_index].physical +
3897 stripe_offset + stripe_nr * map->stripe_len;
3898 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3899
3900 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3901 BTRFS_BLOCK_GROUP_RAID10)) {
3902 bbio->stripes[i].length = stripes_per_dev *
3903 map->stripe_len;
3904
3905 if (i / sub_stripes < remaining_stripes)
3906 bbio->stripes[i].length +=
3907 map->stripe_len;
3908
3909 /*
3910 * Special for the first stripe and
3911 * the last stripe:
3912 *
3913 * |-------|...|-------|
3914 * |----------|
3915 * off end_off
3916 */
3917 if (i < sub_stripes)
3918 bbio->stripes[i].length -=
3919 stripe_offset;
3920
3921 if (stripe_index >= last_stripe &&
3922 stripe_index <= (last_stripe +
3923 sub_stripes - 1))
3924 bbio->stripes[i].length -=
3925 stripe_end_offset;
3926
3927 if (i == sub_stripes - 1)
3928 stripe_offset = 0;
3929 } else
3930 bbio->stripes[i].length = *length;
3931
3932 stripe_index++;
3933 if (stripe_index == map->num_stripes) {
3934 /* This could only happen for RAID0/10 */
3935 stripe_index = 0;
3936 stripe_nr++;
3937 }
3938 }
3939 } else {
3940 for (i = 0; i < num_stripes; i++) {
3941 bbio->stripes[i].physical =
3942 map->stripes[stripe_index].physical +
3943 stripe_offset +
3944 stripe_nr * map->stripe_len;
3945 bbio->stripes[i].dev =
3946 map->stripes[stripe_index].dev;
3947 stripe_index++;
3948 }
3949 }
3950
3951 if (rw & REQ_WRITE) {
3952 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
3953 BTRFS_BLOCK_GROUP_RAID10 |
3954 BTRFS_BLOCK_GROUP_DUP)) {
3955 max_errors = 1;
3956 }
3957 }
3958
3959 *bbio_ret = bbio;
3960 bbio->num_stripes = num_stripes;
3961 bbio->max_errors = max_errors;
3962 bbio->mirror_num = mirror_num;
3963 out:
3964 free_extent_map(em);
3965 return ret;
3966 }
3967
3968 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3969 u64 logical, u64 *length,
3970 struct btrfs_bio **bbio_ret, int mirror_num)
3971 {
3972 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
3973 mirror_num);
3974 }
3975
3976 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3977 u64 chunk_start, u64 physical, u64 devid,
3978 u64 **logical, int *naddrs, int *stripe_len)
3979 {
3980 struct extent_map_tree *em_tree = &map_tree->map_tree;
3981 struct extent_map *em;
3982 struct map_lookup *map;
3983 u64 *buf;
3984 u64 bytenr;
3985 u64 length;
3986 u64 stripe_nr;
3987 int i, j, nr = 0;
3988
3989 read_lock(&em_tree->lock);
3990 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3991 read_unlock(&em_tree->lock);
3992
3993 BUG_ON(!em || em->start != chunk_start);
3994 map = (struct map_lookup *)em->bdev;
3995
3996 length = em->len;
3997 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3998 do_div(length, map->num_stripes / map->sub_stripes);
3999 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4000 do_div(length, map->num_stripes);
4001
4002 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4003 BUG_ON(!buf); /* -ENOMEM */
4004
4005 for (i = 0; i < map->num_stripes; i++) {
4006 if (devid && map->stripes[i].dev->devid != devid)
4007 continue;
4008 if (map->stripes[i].physical > physical ||
4009 map->stripes[i].physical + length <= physical)
4010 continue;
4011
4012 stripe_nr = physical - map->stripes[i].physical;
4013 do_div(stripe_nr, map->stripe_len);
4014
4015 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4016 stripe_nr = stripe_nr * map->num_stripes + i;
4017 do_div(stripe_nr, map->sub_stripes);
4018 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4019 stripe_nr = stripe_nr * map->num_stripes + i;
4020 }
4021 bytenr = chunk_start + stripe_nr * map->stripe_len;
4022 WARN_ON(nr >= map->num_stripes);
4023 for (j = 0; j < nr; j++) {
4024 if (buf[j] == bytenr)
4025 break;
4026 }
4027 if (j == nr) {
4028 WARN_ON(nr >= map->num_stripes);
4029 buf[nr++] = bytenr;
4030 }
4031 }
4032
4033 *logical = buf;
4034 *naddrs = nr;
4035 *stripe_len = map->stripe_len;
4036
4037 free_extent_map(em);
4038 return 0;
4039 }
4040
4041 static void *merge_stripe_index_into_bio_private(void *bi_private,
4042 unsigned int stripe_index)
4043 {
4044 /*
4045 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4046 * at most 1.
4047 * The alternative solution (instead of stealing bits from the
4048 * pointer) would be to allocate an intermediate structure
4049 * that contains the old private pointer plus the stripe_index.
4050 */
4051 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4052 BUG_ON(stripe_index > 3);
4053 return (void *)(((uintptr_t)bi_private) | stripe_index);
4054 }
4055
4056 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4057 {
4058 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4059 }
4060
4061 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4062 {
4063 return (unsigned int)((uintptr_t)bi_private) & 3;
4064 }
4065
4066 static void btrfs_end_bio(struct bio *bio, int err)
4067 {
4068 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4069 int is_orig_bio = 0;
4070
4071 if (err) {
4072 atomic_inc(&bbio->error);
4073 if (err == -EIO || err == -EREMOTEIO) {
4074 unsigned int stripe_index =
4075 extract_stripe_index_from_bio_private(
4076 bio->bi_private);
4077 struct btrfs_device *dev;
4078
4079 BUG_ON(stripe_index >= bbio->num_stripes);
4080 dev = bbio->stripes[stripe_index].dev;
4081 if (dev->bdev) {
4082 if (bio->bi_rw & WRITE)
4083 btrfs_dev_stat_inc(dev,
4084 BTRFS_DEV_STAT_WRITE_ERRS);
4085 else
4086 btrfs_dev_stat_inc(dev,
4087 BTRFS_DEV_STAT_READ_ERRS);
4088 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4089 btrfs_dev_stat_inc(dev,
4090 BTRFS_DEV_STAT_FLUSH_ERRS);
4091 btrfs_dev_stat_print_on_error(dev);
4092 }
4093 }
4094 }
4095
4096 if (bio == bbio->orig_bio)
4097 is_orig_bio = 1;
4098
4099 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4100 if (!is_orig_bio) {
4101 bio_put(bio);
4102 bio = bbio->orig_bio;
4103 }
4104 bio->bi_private = bbio->private;
4105 bio->bi_end_io = bbio->end_io;
4106 bio->bi_bdev = (struct block_device *)
4107 (unsigned long)bbio->mirror_num;
4108 /* only send an error to the higher layers if it is
4109 * beyond the tolerance of the multi-bio
4110 */
4111 if (atomic_read(&bbio->error) > bbio->max_errors) {
4112 err = -EIO;
4113 } else {
4114 /*
4115 * this bio is actually up to date, we didn't
4116 * go over the max number of errors
4117 */
4118 set_bit(BIO_UPTODATE, &bio->bi_flags);
4119 err = 0;
4120 }
4121 kfree(bbio);
4122
4123 bio_endio(bio, err);
4124 } else if (!is_orig_bio) {
4125 bio_put(bio);
4126 }
4127 }
4128
4129 struct async_sched {
4130 struct bio *bio;
4131 int rw;
4132 struct btrfs_fs_info *info;
4133 struct btrfs_work work;
4134 };
4135
4136 /*
4137 * see run_scheduled_bios for a description of why bios are collected for
4138 * async submit.
4139 *
4140 * This will add one bio to the pending list for a device and make sure
4141 * the work struct is scheduled.
4142 */
4143 static noinline void schedule_bio(struct btrfs_root *root,
4144 struct btrfs_device *device,
4145 int rw, struct bio *bio)
4146 {
4147 int should_queue = 1;
4148 struct btrfs_pending_bios *pending_bios;
4149
4150 /* don't bother with additional async steps for reads, right now */
4151 if (!(rw & REQ_WRITE)) {
4152 bio_get(bio);
4153 btrfsic_submit_bio(rw, bio);
4154 bio_put(bio);
4155 return;
4156 }
4157
4158 /*
4159 * nr_async_bios allows us to reliably return congestion to the
4160 * higher layers. Otherwise, the async bio makes it appear we have
4161 * made progress against dirty pages when we've really just put it
4162 * on a queue for later
4163 */
4164 atomic_inc(&root->fs_info->nr_async_bios);
4165 WARN_ON(bio->bi_next);
4166 bio->bi_next = NULL;
4167 bio->bi_rw |= rw;
4168
4169 spin_lock(&device->io_lock);
4170 if (bio->bi_rw & REQ_SYNC)
4171 pending_bios = &device->pending_sync_bios;
4172 else
4173 pending_bios = &device->pending_bios;
4174
4175 if (pending_bios->tail)
4176 pending_bios->tail->bi_next = bio;
4177
4178 pending_bios->tail = bio;
4179 if (!pending_bios->head)
4180 pending_bios->head = bio;
4181 if (device->running_pending)
4182 should_queue = 0;
4183
4184 spin_unlock(&device->io_lock);
4185
4186 if (should_queue)
4187 btrfs_queue_worker(&root->fs_info->submit_workers,
4188 &device->work);
4189 }
4190
4191 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4192 int mirror_num, int async_submit)
4193 {
4194 struct btrfs_mapping_tree *map_tree;
4195 struct btrfs_device *dev;
4196 struct bio *first_bio = bio;
4197 u64 logical = (u64)bio->bi_sector << 9;
4198 u64 length = 0;
4199 u64 map_length;
4200 int ret;
4201 int dev_nr = 0;
4202 int total_devs = 1;
4203 struct btrfs_bio *bbio = NULL;
4204
4205 length = bio->bi_size;
4206 map_tree = &root->fs_info->mapping_tree;
4207 map_length = length;
4208
4209 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
4210 mirror_num);
4211 if (ret) /* -ENOMEM */
4212 return ret;
4213
4214 total_devs = bbio->num_stripes;
4215 if (map_length < length) {
4216 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
4217 "len %llu\n", (unsigned long long)logical,
4218 (unsigned long long)length,
4219 (unsigned long long)map_length);
4220 BUG();
4221 }
4222
4223 bbio->orig_bio = first_bio;
4224 bbio->private = first_bio->bi_private;
4225 bbio->end_io = first_bio->bi_end_io;
4226 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4227
4228 while (dev_nr < total_devs) {
4229 if (dev_nr < total_devs - 1) {
4230 bio = bio_clone(first_bio, GFP_NOFS);
4231 BUG_ON(!bio); /* -ENOMEM */
4232 } else {
4233 bio = first_bio;
4234 }
4235 bio->bi_private = bbio;
4236 bio->bi_private = merge_stripe_index_into_bio_private(
4237 bio->bi_private, (unsigned int)dev_nr);
4238 bio->bi_end_io = btrfs_end_bio;
4239 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
4240 dev = bbio->stripes[dev_nr].dev;
4241 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
4242 #ifdef DEBUG
4243 struct rcu_string *name;
4244
4245 rcu_read_lock();
4246 name = rcu_dereference(dev->name);
4247 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
4248 "(%s id %llu), size=%u\n", rw,
4249 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4250 name->str, dev->devid, bio->bi_size);
4251 rcu_read_unlock();
4252 #endif
4253 bio->bi_bdev = dev->bdev;
4254 if (async_submit)
4255 schedule_bio(root, dev, rw, bio);
4256 else
4257 btrfsic_submit_bio(rw, bio);
4258 } else {
4259 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
4260 bio->bi_sector = logical >> 9;
4261 bio_endio(bio, -EIO);
4262 }
4263 dev_nr++;
4264 }
4265 return 0;
4266 }
4267
4268 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
4269 u8 *uuid, u8 *fsid)
4270 {
4271 struct btrfs_device *device;
4272 struct btrfs_fs_devices *cur_devices;
4273
4274 cur_devices = root->fs_info->fs_devices;
4275 while (cur_devices) {
4276 if (!fsid ||
4277 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4278 device = __find_device(&cur_devices->devices,
4279 devid, uuid);
4280 if (device)
4281 return device;
4282 }
4283 cur_devices = cur_devices->seed;
4284 }
4285 return NULL;
4286 }
4287
4288 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4289 u64 devid, u8 *dev_uuid)
4290 {
4291 struct btrfs_device *device;
4292 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4293
4294 device = kzalloc(sizeof(*device), GFP_NOFS);
4295 if (!device)
4296 return NULL;
4297 list_add(&device->dev_list,
4298 &fs_devices->devices);
4299 device->dev_root = root->fs_info->dev_root;
4300 device->devid = devid;
4301 device->work.func = pending_bios_fn;
4302 device->fs_devices = fs_devices;
4303 device->missing = 1;
4304 fs_devices->num_devices++;
4305 fs_devices->missing_devices++;
4306 spin_lock_init(&device->io_lock);
4307 INIT_LIST_HEAD(&device->dev_alloc_list);
4308 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4309 return device;
4310 }
4311
4312 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4313 struct extent_buffer *leaf,
4314 struct btrfs_chunk *chunk)
4315 {
4316 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4317 struct map_lookup *map;
4318 struct extent_map *em;
4319 u64 logical;
4320 u64 length;
4321 u64 devid;
4322 u8 uuid[BTRFS_UUID_SIZE];
4323 int num_stripes;
4324 int ret;
4325 int i;
4326
4327 logical = key->offset;
4328 length = btrfs_chunk_length(leaf, chunk);
4329
4330 read_lock(&map_tree->map_tree.lock);
4331 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4332 read_unlock(&map_tree->map_tree.lock);
4333
4334 /* already mapped? */
4335 if (em && em->start <= logical && em->start + em->len > logical) {
4336 free_extent_map(em);
4337 return 0;
4338 } else if (em) {
4339 free_extent_map(em);
4340 }
4341
4342 em = alloc_extent_map();
4343 if (!em)
4344 return -ENOMEM;
4345 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4346 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4347 if (!map) {
4348 free_extent_map(em);
4349 return -ENOMEM;
4350 }
4351
4352 em->bdev = (struct block_device *)map;
4353 em->start = logical;
4354 em->len = length;
4355 em->block_start = 0;
4356 em->block_len = em->len;
4357
4358 map->num_stripes = num_stripes;
4359 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4360 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4361 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4362 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4363 map->type = btrfs_chunk_type(leaf, chunk);
4364 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4365 for (i = 0; i < num_stripes; i++) {
4366 map->stripes[i].physical =
4367 btrfs_stripe_offset_nr(leaf, chunk, i);
4368 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4369 read_extent_buffer(leaf, uuid, (unsigned long)
4370 btrfs_stripe_dev_uuid_nr(chunk, i),
4371 BTRFS_UUID_SIZE);
4372 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
4373 NULL);
4374 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
4375 kfree(map);
4376 free_extent_map(em);
4377 return -EIO;
4378 }
4379 if (!map->stripes[i].dev) {
4380 map->stripes[i].dev =
4381 add_missing_dev(root, devid, uuid);
4382 if (!map->stripes[i].dev) {
4383 kfree(map);
4384 free_extent_map(em);
4385 return -EIO;
4386 }
4387 }
4388 map->stripes[i].dev->in_fs_metadata = 1;
4389 }
4390
4391 write_lock(&map_tree->map_tree.lock);
4392 ret = add_extent_mapping(&map_tree->map_tree, em);
4393 write_unlock(&map_tree->map_tree.lock);
4394 BUG_ON(ret); /* Tree corruption */
4395 free_extent_map(em);
4396
4397 return 0;
4398 }
4399
4400 static void fill_device_from_item(struct extent_buffer *leaf,
4401 struct btrfs_dev_item *dev_item,
4402 struct btrfs_device *device)
4403 {
4404 unsigned long ptr;
4405
4406 device->devid = btrfs_device_id(leaf, dev_item);
4407 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
4408 device->total_bytes = device->disk_total_bytes;
4409 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
4410 device->type = btrfs_device_type(leaf, dev_item);
4411 device->io_align = btrfs_device_io_align(leaf, dev_item);
4412 device->io_width = btrfs_device_io_width(leaf, dev_item);
4413 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
4414
4415 ptr = (unsigned long)btrfs_device_uuid(dev_item);
4416 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
4417 }
4418
4419 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
4420 {
4421 struct btrfs_fs_devices *fs_devices;
4422 int ret;
4423
4424 BUG_ON(!mutex_is_locked(&uuid_mutex));
4425
4426 fs_devices = root->fs_info->fs_devices->seed;
4427 while (fs_devices) {
4428 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4429 ret = 0;
4430 goto out;
4431 }
4432 fs_devices = fs_devices->seed;
4433 }
4434
4435 fs_devices = find_fsid(fsid);
4436 if (!fs_devices) {
4437 ret = -ENOENT;
4438 goto out;
4439 }
4440
4441 fs_devices = clone_fs_devices(fs_devices);
4442 if (IS_ERR(fs_devices)) {
4443 ret = PTR_ERR(fs_devices);
4444 goto out;
4445 }
4446
4447 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
4448 root->fs_info->bdev_holder);
4449 if (ret) {
4450 free_fs_devices(fs_devices);
4451 goto out;
4452 }
4453
4454 if (!fs_devices->seeding) {
4455 __btrfs_close_devices(fs_devices);
4456 free_fs_devices(fs_devices);
4457 ret = -EINVAL;
4458 goto out;
4459 }
4460
4461 fs_devices->seed = root->fs_info->fs_devices->seed;
4462 root->fs_info->fs_devices->seed = fs_devices;
4463 out:
4464 return ret;
4465 }
4466
4467 static int read_one_dev(struct btrfs_root *root,
4468 struct extent_buffer *leaf,
4469 struct btrfs_dev_item *dev_item)
4470 {
4471 struct btrfs_device *device;
4472 u64 devid;
4473 int ret;
4474 u8 fs_uuid[BTRFS_UUID_SIZE];
4475 u8 dev_uuid[BTRFS_UUID_SIZE];
4476
4477 devid = btrfs_device_id(leaf, dev_item);
4478 read_extent_buffer(leaf, dev_uuid,
4479 (unsigned long)btrfs_device_uuid(dev_item),
4480 BTRFS_UUID_SIZE);
4481 read_extent_buffer(leaf, fs_uuid,
4482 (unsigned long)btrfs_device_fsid(dev_item),
4483 BTRFS_UUID_SIZE);
4484
4485 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
4486 ret = open_seed_devices(root, fs_uuid);
4487 if (ret && !btrfs_test_opt(root, DEGRADED))
4488 return ret;
4489 }
4490
4491 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
4492 if (!device || !device->bdev) {
4493 if (!btrfs_test_opt(root, DEGRADED))
4494 return -EIO;
4495
4496 if (!device) {
4497 printk(KERN_WARNING "warning devid %llu missing\n",
4498 (unsigned long long)devid);
4499 device = add_missing_dev(root, devid, dev_uuid);
4500 if (!device)
4501 return -ENOMEM;
4502 } else if (!device->missing) {
4503 /*
4504 * this happens when a device that was properly setup
4505 * in the device info lists suddenly goes bad.
4506 * device->bdev is NULL, and so we have to set
4507 * device->missing to one here
4508 */
4509 root->fs_info->fs_devices->missing_devices++;
4510 device->missing = 1;
4511 }
4512 }
4513
4514 if (device->fs_devices != root->fs_info->fs_devices) {
4515 BUG_ON(device->writeable);
4516 if (device->generation !=
4517 btrfs_device_generation(leaf, dev_item))
4518 return -EINVAL;
4519 }
4520
4521 fill_device_from_item(leaf, dev_item, device);
4522 device->dev_root = root->fs_info->dev_root;
4523 device->in_fs_metadata = 1;
4524 if (device->writeable) {
4525 device->fs_devices->total_rw_bytes += device->total_bytes;
4526 spin_lock(&root->fs_info->free_chunk_lock);
4527 root->fs_info->free_chunk_space += device->total_bytes -
4528 device->bytes_used;
4529 spin_unlock(&root->fs_info->free_chunk_lock);
4530 }
4531 ret = 0;
4532 return ret;
4533 }
4534
4535 int btrfs_read_sys_array(struct btrfs_root *root)
4536 {
4537 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4538 struct extent_buffer *sb;
4539 struct btrfs_disk_key *disk_key;
4540 struct btrfs_chunk *chunk;
4541 u8 *ptr;
4542 unsigned long sb_ptr;
4543 int ret = 0;
4544 u32 num_stripes;
4545 u32 array_size;
4546 u32 len = 0;
4547 u32 cur;
4548 struct btrfs_key key;
4549
4550 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
4551 BTRFS_SUPER_INFO_SIZE);
4552 if (!sb)
4553 return -ENOMEM;
4554 btrfs_set_buffer_uptodate(sb);
4555 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
4556 /*
4557 * The sb extent buffer is artifical and just used to read the system array.
4558 * btrfs_set_buffer_uptodate() call does not properly mark all it's
4559 * pages up-to-date when the page is larger: extent does not cover the
4560 * whole page and consequently check_page_uptodate does not find all
4561 * the page's extents up-to-date (the hole beyond sb),
4562 * write_extent_buffer then triggers a WARN_ON.
4563 *
4564 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
4565 * but sb spans only this function. Add an explicit SetPageUptodate call
4566 * to silence the warning eg. on PowerPC 64.
4567 */
4568 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
4569 SetPageUptodate(sb->pages[0]);
4570
4571 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
4572 array_size = btrfs_super_sys_array_size(super_copy);
4573
4574 ptr = super_copy->sys_chunk_array;
4575 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
4576 cur = 0;
4577
4578 while (cur < array_size) {
4579 disk_key = (struct btrfs_disk_key *)ptr;
4580 btrfs_disk_key_to_cpu(&key, disk_key);
4581
4582 len = sizeof(*disk_key); ptr += len;
4583 sb_ptr += len;
4584 cur += len;
4585
4586 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
4587 chunk = (struct btrfs_chunk *)sb_ptr;
4588 ret = read_one_chunk(root, &key, sb, chunk);
4589 if (ret)
4590 break;
4591 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
4592 len = btrfs_chunk_item_size(num_stripes);
4593 } else {
4594 ret = -EIO;
4595 break;
4596 }
4597 ptr += len;
4598 sb_ptr += len;
4599 cur += len;
4600 }
4601 free_extent_buffer(sb);
4602 return ret;
4603 }
4604
4605 struct btrfs_device *btrfs_find_device_for_logical(struct btrfs_root *root,
4606 u64 logical, int mirror_num)
4607 {
4608 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4609 int ret;
4610 u64 map_length = 0;
4611 struct btrfs_bio *bbio = NULL;
4612 struct btrfs_device *device;
4613
4614 BUG_ON(mirror_num == 0);
4615 ret = btrfs_map_block(map_tree, WRITE, logical, &map_length, &bbio,
4616 mirror_num);
4617 if (ret) {
4618 BUG_ON(bbio != NULL);
4619 return NULL;
4620 }
4621 BUG_ON(mirror_num != bbio->mirror_num);
4622 device = bbio->stripes[mirror_num - 1].dev;
4623 kfree(bbio);
4624 return device;
4625 }
4626
4627 int btrfs_read_chunk_tree(struct btrfs_root *root)
4628 {
4629 struct btrfs_path *path;
4630 struct extent_buffer *leaf;
4631 struct btrfs_key key;
4632 struct btrfs_key found_key;
4633 int ret;
4634 int slot;
4635
4636 root = root->fs_info->chunk_root;
4637
4638 path = btrfs_alloc_path();
4639 if (!path)
4640 return -ENOMEM;
4641
4642 mutex_lock(&uuid_mutex);
4643 lock_chunks(root);
4644
4645 /* first we search for all of the device items, and then we
4646 * read in all of the chunk items. This way we can create chunk
4647 * mappings that reference all of the devices that are afound
4648 */
4649 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
4650 key.offset = 0;
4651 key.type = 0;
4652 again:
4653 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4654 if (ret < 0)
4655 goto error;
4656 while (1) {
4657 leaf = path->nodes[0];
4658 slot = path->slots[0];
4659 if (slot >= btrfs_header_nritems(leaf)) {
4660 ret = btrfs_next_leaf(root, path);
4661 if (ret == 0)
4662 continue;
4663 if (ret < 0)
4664 goto error;
4665 break;
4666 }
4667 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4668 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4669 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
4670 break;
4671 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
4672 struct btrfs_dev_item *dev_item;
4673 dev_item = btrfs_item_ptr(leaf, slot,
4674 struct btrfs_dev_item);
4675 ret = read_one_dev(root, leaf, dev_item);
4676 if (ret)
4677 goto error;
4678 }
4679 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
4680 struct btrfs_chunk *chunk;
4681 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
4682 ret = read_one_chunk(root, &found_key, leaf, chunk);
4683 if (ret)
4684 goto error;
4685 }
4686 path->slots[0]++;
4687 }
4688 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4689 key.objectid = 0;
4690 btrfs_release_path(path);
4691 goto again;
4692 }
4693 ret = 0;
4694 error:
4695 unlock_chunks(root);
4696 mutex_unlock(&uuid_mutex);
4697
4698 btrfs_free_path(path);
4699 return ret;
4700 }
4701
4702 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
4703 {
4704 int i;
4705
4706 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4707 btrfs_dev_stat_reset(dev, i);
4708 }
4709
4710 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
4711 {
4712 struct btrfs_key key;
4713 struct btrfs_key found_key;
4714 struct btrfs_root *dev_root = fs_info->dev_root;
4715 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4716 struct extent_buffer *eb;
4717 int slot;
4718 int ret = 0;
4719 struct btrfs_device *device;
4720 struct btrfs_path *path = NULL;
4721 int i;
4722
4723 path = btrfs_alloc_path();
4724 if (!path) {
4725 ret = -ENOMEM;
4726 goto out;
4727 }
4728
4729 mutex_lock(&fs_devices->device_list_mutex);
4730 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4731 int item_size;
4732 struct btrfs_dev_stats_item *ptr;
4733
4734 key.objectid = 0;
4735 key.type = BTRFS_DEV_STATS_KEY;
4736 key.offset = device->devid;
4737 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
4738 if (ret) {
4739 printk_in_rcu(KERN_WARNING "btrfs: no dev_stats entry found for device %s (devid %llu) (OK on first mount after mkfs)\n",
4740 rcu_str_deref(device->name),
4741 (unsigned long long)device->devid);
4742 __btrfs_reset_dev_stats(device);
4743 device->dev_stats_valid = 1;
4744 btrfs_release_path(path);
4745 continue;
4746 }
4747 slot = path->slots[0];
4748 eb = path->nodes[0];
4749 btrfs_item_key_to_cpu(eb, &found_key, slot);
4750 item_size = btrfs_item_size_nr(eb, slot);
4751
4752 ptr = btrfs_item_ptr(eb, slot,
4753 struct btrfs_dev_stats_item);
4754
4755 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4756 if (item_size >= (1 + i) * sizeof(__le64))
4757 btrfs_dev_stat_set(device, i,
4758 btrfs_dev_stats_value(eb, ptr, i));
4759 else
4760 btrfs_dev_stat_reset(device, i);
4761 }
4762
4763 device->dev_stats_valid = 1;
4764 btrfs_dev_stat_print_on_load(device);
4765 btrfs_release_path(path);
4766 }
4767 mutex_unlock(&fs_devices->device_list_mutex);
4768
4769 out:
4770 btrfs_free_path(path);
4771 return ret < 0 ? ret : 0;
4772 }
4773
4774 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
4775 struct btrfs_root *dev_root,
4776 struct btrfs_device *device)
4777 {
4778 struct btrfs_path *path;
4779 struct btrfs_key key;
4780 struct extent_buffer *eb;
4781 struct btrfs_dev_stats_item *ptr;
4782 int ret;
4783 int i;
4784
4785 key.objectid = 0;
4786 key.type = BTRFS_DEV_STATS_KEY;
4787 key.offset = device->devid;
4788
4789 path = btrfs_alloc_path();
4790 BUG_ON(!path);
4791 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
4792 if (ret < 0) {
4793 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
4794 ret, rcu_str_deref(device->name));
4795 goto out;
4796 }
4797
4798 if (ret == 0 &&
4799 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
4800 /* need to delete old one and insert a new one */
4801 ret = btrfs_del_item(trans, dev_root, path);
4802 if (ret != 0) {
4803 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
4804 rcu_str_deref(device->name), ret);
4805 goto out;
4806 }
4807 ret = 1;
4808 }
4809
4810 if (ret == 1) {
4811 /* need to insert a new item */
4812 btrfs_release_path(path);
4813 ret = btrfs_insert_empty_item(trans, dev_root, path,
4814 &key, sizeof(*ptr));
4815 if (ret < 0) {
4816 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
4817 rcu_str_deref(device->name), ret);
4818 goto out;
4819 }
4820 }
4821
4822 eb = path->nodes[0];
4823 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
4824 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4825 btrfs_set_dev_stats_value(eb, ptr, i,
4826 btrfs_dev_stat_read(device, i));
4827 btrfs_mark_buffer_dirty(eb);
4828
4829 out:
4830 btrfs_free_path(path);
4831 return ret;
4832 }
4833
4834 /*
4835 * called from commit_transaction. Writes all changed device stats to disk.
4836 */
4837 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
4838 struct btrfs_fs_info *fs_info)
4839 {
4840 struct btrfs_root *dev_root = fs_info->dev_root;
4841 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4842 struct btrfs_device *device;
4843 int ret = 0;
4844
4845 mutex_lock(&fs_devices->device_list_mutex);
4846 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4847 if (!device->dev_stats_valid || !device->dev_stats_dirty)
4848 continue;
4849
4850 ret = update_dev_stat_item(trans, dev_root, device);
4851 if (!ret)
4852 device->dev_stats_dirty = 0;
4853 }
4854 mutex_unlock(&fs_devices->device_list_mutex);
4855
4856 return ret;
4857 }
4858
4859 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
4860 {
4861 btrfs_dev_stat_inc(dev, index);
4862 btrfs_dev_stat_print_on_error(dev);
4863 }
4864
4865 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
4866 {
4867 if (!dev->dev_stats_valid)
4868 return;
4869 printk_ratelimited_in_rcu(KERN_ERR
4870 "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,
4876 BTRFS_DEV_STAT_CORRUPTION_ERRS),
4877 btrfs_dev_stat_read(dev,
4878 BTRFS_DEV_STAT_GENERATION_ERRS));
4879 }
4880
4881 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
4882 {
4883 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4884 rcu_str_deref(dev->name),
4885 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4886 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4887 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4888 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
4889 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
4890 }
4891
4892 int btrfs_get_dev_stats(struct btrfs_root *root,
4893 struct btrfs_ioctl_get_dev_stats *stats,
4894 int reset_after_read)
4895 {
4896 struct btrfs_device *dev;
4897 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4898 int i;
4899
4900 mutex_lock(&fs_devices->device_list_mutex);
4901 dev = btrfs_find_device(root, stats->devid, NULL, NULL);
4902 mutex_unlock(&fs_devices->device_list_mutex);
4903
4904 if (!dev) {
4905 printk(KERN_WARNING
4906 "btrfs: get dev_stats failed, device not found\n");
4907 return -ENODEV;
4908 } else if (!dev->dev_stats_valid) {
4909 printk(KERN_WARNING
4910 "btrfs: get dev_stats failed, not yet valid\n");
4911 return -ENODEV;
4912 } else if (reset_after_read) {
4913 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4914 if (stats->nr_items > i)
4915 stats->values[i] =
4916 btrfs_dev_stat_read_and_reset(dev, i);
4917 else
4918 btrfs_dev_stat_reset(dev, i);
4919 }
4920 } else {
4921 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4922 if (stats->nr_items > i)
4923 stats->values[i] = btrfs_dev_stat_read(dev, i);
4924 }
4925 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
4926 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
4927 return 0;
4928 }
Linux kernel - Deliverables
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