projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Btrfs: cleanup duplicated division functions
[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 "compat.h"
29 #include "ctree.h"
30 #include "extent_map.h"
31 #include "disk-io.h"
32 #include "transaction.h"
33 #include "print-tree.h"
34 #include "volumes.h"
35 #include "async-thread.h"
36 #include "check-integrity.h"
37 #include "rcu-string.h"
38 #include "math.h"
39
40 static int init_first_rw_device(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root,
42 struct btrfs_device *device);
43 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
44 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
45 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
46
47 static DEFINE_MUTEX(uuid_mutex);
48 static LIST_HEAD(fs_uuids);
49
50 static void lock_chunks(struct btrfs_root *root)
51 {
52 mutex_lock(&root->fs_info->chunk_mutex);
53 }
54
55 static void unlock_chunks(struct btrfs_root *root)
56 {
57 mutex_unlock(&root->fs_info->chunk_mutex);
58 }
59
60 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
61 {
62 struct btrfs_device *device;
63 WARN_ON(fs_devices->opened);
64 while (!list_empty(&fs_devices->devices)) {
65 device = list_entry(fs_devices->devices.next,
66 struct btrfs_device, dev_list);
67 list_del(&device->dev_list);
68 rcu_string_free(device->name);
69 kfree(device);
70 }
71 kfree(fs_devices);
72 }
73
74 void btrfs_cleanup_fs_uuids(void)
75 {
76 struct btrfs_fs_devices *fs_devices;
77
78 while (!list_empty(&fs_uuids)) {
79 fs_devices = list_entry(fs_uuids.next,
80 struct btrfs_fs_devices, list);
81 list_del(&fs_devices->list);
82 free_fs_devices(fs_devices);
83 }
84 }
85
86 static noinline struct btrfs_device *__find_device(struct list_head *head,
87 u64 devid, u8 *uuid)
88 {
89 struct btrfs_device *dev;
90
91 list_for_each_entry(dev, head, dev_list) {
92 if (dev->devid == devid &&
93 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
94 return dev;
95 }
96 }
97 return NULL;
98 }
99
100 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
101 {
102 struct btrfs_fs_devices *fs_devices;
103
104 list_for_each_entry(fs_devices, &fs_uuids, list) {
105 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
106 return fs_devices;
107 }
108 return NULL;
109 }
110
111 static void requeue_list(struct btrfs_pending_bios *pending_bios,
112 struct bio *head, struct bio *tail)
113 {
114
115 struct bio *old_head;
116
117 old_head = pending_bios->head;
118 pending_bios->head = head;
119 if (pending_bios->tail)
120 tail->bi_next = old_head;
121 else
122 pending_bios->tail = tail;
123 }
124
125 /*
126 * we try to collect pending bios for a device so we don't get a large
127 * number of procs sending bios down to the same device. This greatly
128 * improves the schedulers ability to collect and merge the bios.
129 *
130 * But, it also turns into a long list of bios to process and that is sure
131 * to eventually make the worker thread block. The solution here is to
132 * make some progress and then put this work struct back at the end of
133 * the list if the block device is congested. This way, multiple devices
134 * can make progress from a single worker thread.
135 */
136 static noinline void run_scheduled_bios(struct btrfs_device *device)
137 {
138 struct bio *pending;
139 struct backing_dev_info *bdi;
140 struct btrfs_fs_info *fs_info;
141 struct btrfs_pending_bios *pending_bios;
142 struct bio *tail;
143 struct bio *cur;
144 int again = 0;
145 unsigned long num_run;
146 unsigned long batch_run = 0;
147 unsigned long limit;
148 unsigned long last_waited = 0;
149 int force_reg = 0;
150 int sync_pending = 0;
151 struct blk_plug plug;
152
153 /*
154 * this function runs all the bios we've collected for
155 * a particular device. We don't want to wander off to
156 * another device without first sending all of these down.
157 * So, setup a plug here and finish it off before we return
158 */
159 blk_start_plug(&plug);
160
161 bdi = blk_get_backing_dev_info(device->bdev);
162 fs_info = device->dev_root->fs_info;
163 limit = btrfs_async_submit_limit(fs_info);
164 limit = limit * 2 / 3;
165
166 loop:
167 spin_lock(&device->io_lock);
168
169 loop_lock:
170 num_run = 0;
171
172 /* take all the bios off the list at once and process them
173 * later on (without the lock held). But, remember the
174 * tail and other pointers so the bios can be properly reinserted
175 * into the list if we hit congestion
176 */
177 if (!force_reg && device->pending_sync_bios.head) {
178 pending_bios = &device->pending_sync_bios;
179 force_reg = 1;
180 } else {
181 pending_bios = &device->pending_bios;
182 force_reg = 0;
183 }
184
185 pending = pending_bios->head;
186 tail = pending_bios->tail;
187 WARN_ON(pending && !tail);
188
189 /*
190 * if pending was null this time around, no bios need processing
191 * at all and we can stop. Otherwise it'll loop back up again
192 * and do an additional check so no bios are missed.
193 *
194 * device->running_pending is used to synchronize with the
195 * schedule_bio code.
196 */
197 if (device->pending_sync_bios.head == NULL &&
198 device->pending_bios.head == NULL) {
199 again = 0;
200 device->running_pending = 0;
201 } else {
202 again = 1;
203 device->running_pending = 1;
204 }
205
206 pending_bios->head = NULL;
207 pending_bios->tail = NULL;
208
209 spin_unlock(&device->io_lock);
210
211 while (pending) {
212
213 rmb();
214 /* we want to work on both lists, but do more bios on the
215 * sync list than the regular list
216 */
217 if ((num_run > 32 &&
218 pending_bios != &device->pending_sync_bios &&
219 device->pending_sync_bios.head) ||
220 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
221 device->pending_bios.head)) {
222 spin_lock(&device->io_lock);
223 requeue_list(pending_bios, pending, tail);
224 goto loop_lock;
225 }
226
227 cur = pending;
228 pending = pending->bi_next;
229 cur->bi_next = NULL;
230
231 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
232 waitqueue_active(&fs_info->async_submit_wait))
233 wake_up(&fs_info->async_submit_wait);
234
235 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
236
237 /*
238 * if we're doing the sync list, record that our
239 * plug has some sync requests on it
240 *
241 * If we're doing the regular list and there are
242 * sync requests sitting around, unplug before
243 * we add more
244 */
245 if (pending_bios == &device->pending_sync_bios) {
246 sync_pending = 1;
247 } else if (sync_pending) {
248 blk_finish_plug(&plug);
249 blk_start_plug(&plug);
250 sync_pending = 0;
251 }
252
253 btrfsic_submit_bio(cur->bi_rw, cur);
254 num_run++;
255 batch_run++;
256 if (need_resched())
257 cond_resched();
258
259 /*
260 * we made progress, there is more work to do and the bdi
261 * is now congested. Back off and let other work structs
262 * run instead
263 */
264 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
265 fs_info->fs_devices->open_devices > 1) {
266 struct io_context *ioc;
267
268 ioc = current->io_context;
269
270 /*
271 * the main goal here is that we don't want to
272 * block if we're going to be able to submit
273 * more requests without blocking.
274 *
275 * This code does two great things, it pokes into
276 * the elevator code from a filesystem _and_
277 * it makes assumptions about how batching works.
278 */
279 if (ioc && ioc->nr_batch_requests > 0 &&
280 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
281 (last_waited == 0 ||
282 ioc->last_waited == last_waited)) {
283 /*
284 * we want to go through our batch of
285 * requests and stop. So, we copy out
286 * the ioc->last_waited time and test
287 * against it before looping
288 */
289 last_waited = ioc->last_waited;
290 if (need_resched())
291 cond_resched();
292 continue;
293 }
294 spin_lock(&device->io_lock);
295 requeue_list(pending_bios, pending, tail);
296 device->running_pending = 1;
297
298 spin_unlock(&device->io_lock);
299 btrfs_requeue_work(&device->work);
300 goto done;
301 }
302 /* unplug every 64 requests just for good measure */
303 if (batch_run % 64 == 0) {
304 blk_finish_plug(&plug);
305 blk_start_plug(&plug);
306 sync_pending = 0;
307 }
308 }
309
310 cond_resched();
311 if (again)
312 goto loop;
313
314 spin_lock(&device->io_lock);
315 if (device->pending_bios.head || device->pending_sync_bios.head)
316 goto loop_lock;
317 spin_unlock(&device->io_lock);
318
319 done:
320 blk_finish_plug(&plug);
321 }
322
323 static void pending_bios_fn(struct btrfs_work *work)
324 {
325 struct btrfs_device *device;
326
327 device = container_of(work, struct btrfs_device, work);
328 run_scheduled_bios(device);
329 }
330
331 static noinline int device_list_add(const char *path,
332 struct btrfs_super_block *disk_super,
333 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
334 {
335 struct btrfs_device *device;
336 struct btrfs_fs_devices *fs_devices;
337 struct rcu_string *name;
338 u64 found_transid = btrfs_super_generation(disk_super);
339
340 fs_devices = find_fsid(disk_super->fsid);
341 if (!fs_devices) {
342 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
343 if (!fs_devices)
344 return -ENOMEM;
345 INIT_LIST_HEAD(&fs_devices->devices);
346 INIT_LIST_HEAD(&fs_devices->alloc_list);
347 list_add(&fs_devices->list, &fs_uuids);
348 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
349 fs_devices->latest_devid = devid;
350 fs_devices->latest_trans = found_transid;
351 mutex_init(&fs_devices->device_list_mutex);
352 device = NULL;
353 } else {
354 device = __find_device(&fs_devices->devices, devid,
355 disk_super->dev_item.uuid);
356 }
357 if (!device) {
358 if (fs_devices->opened)
359 return -EBUSY;
360
361 device = kzalloc(sizeof(*device), GFP_NOFS);
362 if (!device) {
363 /* we can safely leave the fs_devices entry around */
364 return -ENOMEM;
365 }
366 device->devid = devid;
367 device->dev_stats_valid = 0;
368 device->work.func = pending_bios_fn;
369 memcpy(device->uuid, disk_super->dev_item.uuid,
370 BTRFS_UUID_SIZE);
371 spin_lock_init(&device->io_lock);
372
373 name = rcu_string_strdup(path, GFP_NOFS);
374 if (!name) {
375 kfree(device);
376 return -ENOMEM;
377 }
378 rcu_assign_pointer(device->name, name);
379 INIT_LIST_HEAD(&device->dev_alloc_list);
380
381 /* init readahead state */
382 spin_lock_init(&device->reada_lock);
383 device->reada_curr_zone = NULL;
384 atomic_set(&device->reada_in_flight, 0);
385 device->reada_next = 0;
386 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
387 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
388
389 mutex_lock(&fs_devices->device_list_mutex);
390 list_add_rcu(&device->dev_list, &fs_devices->devices);
391 mutex_unlock(&fs_devices->device_list_mutex);
392
393 device->fs_devices = fs_devices;
394 fs_devices->num_devices++;
395 } else if (!device->name || strcmp(device->name->str, path)) {
396 name = rcu_string_strdup(path, GFP_NOFS);
397 if (!name)
398 return -ENOMEM;
399 rcu_string_free(device->name);
400 rcu_assign_pointer(device->name, name);
401 if (device->missing) {
402 fs_devices->missing_devices--;
403 device->missing = 0;
404 }
405 }
406
407 if (found_transid > fs_devices->latest_trans) {
408 fs_devices->latest_devid = devid;
409 fs_devices->latest_trans = found_transid;
410 }
411 *fs_devices_ret = fs_devices;
412 return 0;
413 }
414
415 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
416 {
417 struct btrfs_fs_devices *fs_devices;
418 struct btrfs_device *device;
419 struct btrfs_device *orig_dev;
420
421 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
422 if (!fs_devices)
423 return ERR_PTR(-ENOMEM);
424
425 INIT_LIST_HEAD(&fs_devices->devices);
426 INIT_LIST_HEAD(&fs_devices->alloc_list);
427 INIT_LIST_HEAD(&fs_devices->list);
428 mutex_init(&fs_devices->device_list_mutex);
429 fs_devices->latest_devid = orig->latest_devid;
430 fs_devices->latest_trans = orig->latest_trans;
431 fs_devices->total_devices = orig->total_devices;
432 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
433
434 /* We have held the volume lock, it is safe to get the devices. */
435 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
436 struct rcu_string *name;
437
438 device = kzalloc(sizeof(*device), GFP_NOFS);
439 if (!device)
440 goto error;
441
442 /*
443 * This is ok to do without rcu read locked because we hold the
444 * uuid mutex so nothing we touch in here is going to disappear.
445 */
446 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
447 if (!name) {
448 kfree(device);
449 goto error;
450 }
451 rcu_assign_pointer(device->name, name);
452
453 device->devid = orig_dev->devid;
454 device->work.func = pending_bios_fn;
455 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
456 spin_lock_init(&device->io_lock);
457 INIT_LIST_HEAD(&device->dev_list);
458 INIT_LIST_HEAD(&device->dev_alloc_list);
459
460 list_add(&device->dev_list, &fs_devices->devices);
461 device->fs_devices = fs_devices;
462 fs_devices->num_devices++;
463 }
464 return fs_devices;
465 error:
466 free_fs_devices(fs_devices);
467 return ERR_PTR(-ENOMEM);
468 }
469
470 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
471 {
472 struct btrfs_device *device, *next;
473
474 struct block_device *latest_bdev = NULL;
475 u64 latest_devid = 0;
476 u64 latest_transid = 0;
477
478 mutex_lock(&uuid_mutex);
479 again:
480 /* This is the initialized path, it is safe to release the devices. */
481 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
482 if (device->in_fs_metadata) {
483 if (!latest_transid ||
484 device->generation > latest_transid) {
485 latest_devid = device->devid;
486 latest_transid = device->generation;
487 latest_bdev = device->bdev;
488 }
489 continue;
490 }
491
492 if (device->bdev) {
493 blkdev_put(device->bdev, device->mode);
494 device->bdev = NULL;
495 fs_devices->open_devices--;
496 }
497 if (device->writeable) {
498 list_del_init(&device->dev_alloc_list);
499 device->writeable = 0;
500 fs_devices->rw_devices--;
501 }
502 list_del_init(&device->dev_list);
503 fs_devices->num_devices--;
504 rcu_string_free(device->name);
505 kfree(device);
506 }
507
508 if (fs_devices->seed) {
509 fs_devices = fs_devices->seed;
510 goto again;
511 }
512
513 fs_devices->latest_bdev = latest_bdev;
514 fs_devices->latest_devid = latest_devid;
515 fs_devices->latest_trans = latest_transid;
516
517 mutex_unlock(&uuid_mutex);
518 }
519
520 static void __free_device(struct work_struct *work)
521 {
522 struct btrfs_device *device;
523
524 device = container_of(work, struct btrfs_device, rcu_work);
525
526 if (device->bdev)
527 blkdev_put(device->bdev, device->mode);
528
529 rcu_string_free(device->name);
530 kfree(device);
531 }
532
533 static void free_device(struct rcu_head *head)
534 {
535 struct btrfs_device *device;
536
537 device = container_of(head, struct btrfs_device, rcu);
538
539 INIT_WORK(&device->rcu_work, __free_device);
540 schedule_work(&device->rcu_work);
541 }
542
543 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
544 {
545 struct btrfs_device *device;
546
547 if (--fs_devices->opened > 0)
548 return 0;
549
550 mutex_lock(&fs_devices->device_list_mutex);
551 list_for_each_entry(device, &fs_devices->devices, dev_list) {
552 struct btrfs_device *new_device;
553 struct rcu_string *name;
554
555 if (device->bdev)
556 fs_devices->open_devices--;
557
558 if (device->writeable) {
559 list_del_init(&device->dev_alloc_list);
560 fs_devices->rw_devices--;
561 }
562
563 if (device->can_discard)
564 fs_devices->num_can_discard--;
565
566 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
567 BUG_ON(!new_device); /* -ENOMEM */
568 memcpy(new_device, device, sizeof(*new_device));
569
570 /* Safe because we are under uuid_mutex */
571 if (device->name) {
572 name = rcu_string_strdup(device->name->str, GFP_NOFS);
573 BUG_ON(device->name && !name); /* -ENOMEM */
574 rcu_assign_pointer(new_device->name, name);
575 }
576 new_device->bdev = NULL;
577 new_device->writeable = 0;
578 new_device->in_fs_metadata = 0;
579 new_device->can_discard = 0;
580 list_replace_rcu(&device->dev_list, &new_device->dev_list);
581
582 call_rcu(&device->rcu, free_device);
583 }
584 mutex_unlock(&fs_devices->device_list_mutex);
585
586 WARN_ON(fs_devices->open_devices);
587 WARN_ON(fs_devices->rw_devices);
588 fs_devices->opened = 0;
589 fs_devices->seeding = 0;
590
591 return 0;
592 }
593
594 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
595 {
596 struct btrfs_fs_devices *seed_devices = NULL;
597 int ret;
598
599 mutex_lock(&uuid_mutex);
600 ret = __btrfs_close_devices(fs_devices);
601 if (!fs_devices->opened) {
602 seed_devices = fs_devices->seed;
603 fs_devices->seed = NULL;
604 }
605 mutex_unlock(&uuid_mutex);
606
607 while (seed_devices) {
608 fs_devices = seed_devices;
609 seed_devices = fs_devices->seed;
610 __btrfs_close_devices(fs_devices);
611 free_fs_devices(fs_devices);
612 }
613 return ret;
614 }
615
616 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
617 fmode_t flags, void *holder)
618 {
619 struct request_queue *q;
620 struct block_device *bdev;
621 struct list_head *head = &fs_devices->devices;
622 struct btrfs_device *device;
623 struct block_device *latest_bdev = NULL;
624 struct buffer_head *bh;
625 struct btrfs_super_block *disk_super;
626 u64 latest_devid = 0;
627 u64 latest_transid = 0;
628 u64 devid;
629 int seeding = 1;
630 int ret = 0;
631
632 flags |= FMODE_EXCL;
633
634 list_for_each_entry(device, head, dev_list) {
635 if (device->bdev)
636 continue;
637 if (!device->name)
638 continue;
639
640 bdev = blkdev_get_by_path(device->name->str, flags, holder);
641 if (IS_ERR(bdev)) {
642 printk(KERN_INFO "btrfs: open %s failed\n", device->name->str);
643 goto error;
644 }
645 filemap_write_and_wait(bdev->bd_inode->i_mapping);
646 invalidate_bdev(bdev);
647 set_blocksize(bdev, 4096);
648
649 bh = btrfs_read_dev_super(bdev);
650 if (!bh)
651 goto error_close;
652
653 disk_super = (struct btrfs_super_block *)bh->b_data;
654 devid = btrfs_stack_device_id(&disk_super->dev_item);
655 if (devid != device->devid)
656 goto error_brelse;
657
658 if (memcmp(device->uuid, disk_super->dev_item.uuid,
659 BTRFS_UUID_SIZE))
660 goto error_brelse;
661
662 device->generation = btrfs_super_generation(disk_super);
663 if (!latest_transid || device->generation > latest_transid) {
664 latest_devid = devid;
665 latest_transid = device->generation;
666 latest_bdev = bdev;
667 }
668
669 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
670 device->writeable = 0;
671 } else {
672 device->writeable = !bdev_read_only(bdev);
673 seeding = 0;
674 }
675
676 q = bdev_get_queue(bdev);
677 if (blk_queue_discard(q)) {
678 device->can_discard = 1;
679 fs_devices->num_can_discard++;
680 }
681
682 device->bdev = bdev;
683 device->in_fs_metadata = 0;
684 device->mode = flags;
685
686 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
687 fs_devices->rotating = 1;
688
689 fs_devices->open_devices++;
690 if (device->writeable) {
691 fs_devices->rw_devices++;
692 list_add(&device->dev_alloc_list,
693 &fs_devices->alloc_list);
694 }
695 brelse(bh);
696 continue;
697
698 error_brelse:
699 brelse(bh);
700 error_close:
701 blkdev_put(bdev, flags);
702 error:
703 continue;
704 }
705 if (fs_devices->open_devices == 0) {
706 ret = -EINVAL;
707 goto out;
708 }
709 fs_devices->seeding = seeding;
710 fs_devices->opened = 1;
711 fs_devices->latest_bdev = latest_bdev;
712 fs_devices->latest_devid = latest_devid;
713 fs_devices->latest_trans = latest_transid;
714 fs_devices->total_rw_bytes = 0;
715 out:
716 return ret;
717 }
718
719 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
720 fmode_t flags, void *holder)
721 {
722 int ret;
723
724 mutex_lock(&uuid_mutex);
725 if (fs_devices->opened) {
726 fs_devices->opened++;
727 ret = 0;
728 } else {
729 ret = __btrfs_open_devices(fs_devices, flags, holder);
730 }
731 mutex_unlock(&uuid_mutex);
732 return ret;
733 }
734
735 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
736 struct btrfs_fs_devices **fs_devices_ret)
737 {
738 struct btrfs_super_block *disk_super;
739 struct block_device *bdev;
740 struct buffer_head *bh;
741 int ret;
742 u64 devid;
743 u64 transid;
744 u64 total_devices;
745
746 flags |= FMODE_EXCL;
747 bdev = blkdev_get_by_path(path, flags, holder);
748
749 if (IS_ERR(bdev)) {
750 ret = PTR_ERR(bdev);
751 goto error;
752 }
753
754 mutex_lock(&uuid_mutex);
755 ret = set_blocksize(bdev, 4096);
756 if (ret)
757 goto error_close;
758 bh = btrfs_read_dev_super(bdev);
759 if (!bh) {
760 ret = -EINVAL;
761 goto error_close;
762 }
763 disk_super = (struct btrfs_super_block *)bh->b_data;
764 devid = btrfs_stack_device_id(&disk_super->dev_item);
765 transid = btrfs_super_generation(disk_super);
766 total_devices = btrfs_super_num_devices(disk_super);
767 if (disk_super->label[0])
768 printk(KERN_INFO "device label %s ", disk_super->label);
769 else
770 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
771 printk(KERN_CONT "devid %llu transid %llu %s\n",
772 (unsigned long long)devid, (unsigned long long)transid, path);
773 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
774 if (!ret && fs_devices_ret)
775 (*fs_devices_ret)->total_devices = total_devices;
776 brelse(bh);
777 error_close:
778 mutex_unlock(&uuid_mutex);
779 blkdev_put(bdev, flags);
780 error:
781 return ret;
782 }
783
784 /* helper to account the used device space in the range */
785 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
786 u64 end, u64 *length)
787 {
788 struct btrfs_key key;
789 struct btrfs_root *root = device->dev_root;
790 struct btrfs_dev_extent *dev_extent;
791 struct btrfs_path *path;
792 u64 extent_end;
793 int ret;
794 int slot;
795 struct extent_buffer *l;
796
797 *length = 0;
798
799 if (start >= device->total_bytes)
800 return 0;
801
802 path = btrfs_alloc_path();
803 if (!path)
804 return -ENOMEM;
805 path->reada = 2;
806
807 key.objectid = device->devid;
808 key.offset = start;
809 key.type = BTRFS_DEV_EXTENT_KEY;
810
811 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
812 if (ret < 0)
813 goto out;
814 if (ret > 0) {
815 ret = btrfs_previous_item(root, path, key.objectid, key.type);
816 if (ret < 0)
817 goto out;
818 }
819
820 while (1) {
821 l = path->nodes[0];
822 slot = path->slots[0];
823 if (slot >= btrfs_header_nritems(l)) {
824 ret = btrfs_next_leaf(root, path);
825 if (ret == 0)
826 continue;
827 if (ret < 0)
828 goto out;
829
830 break;
831 }
832 btrfs_item_key_to_cpu(l, &key, slot);
833
834 if (key.objectid < device->devid)
835 goto next;
836
837 if (key.objectid > device->devid)
838 break;
839
840 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
841 goto next;
842
843 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
844 extent_end = key.offset + btrfs_dev_extent_length(l,
845 dev_extent);
846 if (key.offset <= start && extent_end > end) {
847 *length = end - start + 1;
848 break;
849 } else if (key.offset <= start && extent_end > start)
850 *length += extent_end - start;
851 else if (key.offset > start && extent_end <= end)
852 *length += extent_end - key.offset;
853 else if (key.offset > start && key.offset <= end) {
854 *length += end - key.offset + 1;
855 break;
856 } else if (key.offset > end)
857 break;
858
859 next:
860 path->slots[0]++;
861 }
862 ret = 0;
863 out:
864 btrfs_free_path(path);
865 return ret;
866 }
867
868 /*
869 * find_free_dev_extent - find free space in the specified device
870 * @device: the device which we search the free space in
871 * @num_bytes: the size of the free space that we need
872 * @start: store the start of the free space.
873 * @len: the size of the free space. that we find, or the size of the max
874 * free space if we don't find suitable free space
875 *
876 * this uses a pretty simple search, the expectation is that it is
877 * called very infrequently and that a given device has a small number
878 * of extents
879 *
880 * @start is used to store the start of the free space if we find. But if we
881 * don't find suitable free space, it will be used to store the start position
882 * of the max free space.
883 *
884 * @len is used to store the size of the free space that we find.
885 * But if we don't find suitable free space, it is used to store the size of
886 * the max free space.
887 */
888 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
889 u64 *start, u64 *len)
890 {
891 struct btrfs_key key;
892 struct btrfs_root *root = device->dev_root;
893 struct btrfs_dev_extent *dev_extent;
894 struct btrfs_path *path;
895 u64 hole_size;
896 u64 max_hole_start;
897 u64 max_hole_size;
898 u64 extent_end;
899 u64 search_start;
900 u64 search_end = device->total_bytes;
901 int ret;
902 int slot;
903 struct extent_buffer *l;
904
905 /* FIXME use last free of some kind */
906
907 /* we don't want to overwrite the superblock on the drive,
908 * so we make sure to start at an offset of at least 1MB
909 */
910 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
911
912 max_hole_start = search_start;
913 max_hole_size = 0;
914 hole_size = 0;
915
916 if (search_start >= search_end) {
917 ret = -ENOSPC;
918 goto error;
919 }
920
921 path = btrfs_alloc_path();
922 if (!path) {
923 ret = -ENOMEM;
924 goto error;
925 }
926 path->reada = 2;
927
928 key.objectid = device->devid;
929 key.offset = search_start;
930 key.type = BTRFS_DEV_EXTENT_KEY;
931
932 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
933 if (ret < 0)
934 goto out;
935 if (ret > 0) {
936 ret = btrfs_previous_item(root, path, key.objectid, key.type);
937 if (ret < 0)
938 goto out;
939 }
940
941 while (1) {
942 l = path->nodes[0];
943 slot = path->slots[0];
944 if (slot >= btrfs_header_nritems(l)) {
945 ret = btrfs_next_leaf(root, path);
946 if (ret == 0)
947 continue;
948 if (ret < 0)
949 goto out;
950
951 break;
952 }
953 btrfs_item_key_to_cpu(l, &key, slot);
954
955 if (key.objectid < device->devid)
956 goto next;
957
958 if (key.objectid > device->devid)
959 break;
960
961 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
962 goto next;
963
964 if (key.offset > search_start) {
965 hole_size = key.offset - search_start;
966
967 if (hole_size > max_hole_size) {
968 max_hole_start = search_start;
969 max_hole_size = hole_size;
970 }
971
972 /*
973 * If this free space is greater than which we need,
974 * it must be the max free space that we have found
975 * until now, so max_hole_start must point to the start
976 * of this free space and the length of this free space
977 * is stored in max_hole_size. Thus, we return
978 * max_hole_start and max_hole_size and go back to the
979 * caller.
980 */
981 if (hole_size >= num_bytes) {
982 ret = 0;
983 goto out;
984 }
985 }
986
987 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
988 extent_end = key.offset + btrfs_dev_extent_length(l,
989 dev_extent);
990 if (extent_end > search_start)
991 search_start = extent_end;
992 next:
993 path->slots[0]++;
994 cond_resched();
995 }
996
997 /*
998 * At this point, search_start should be the end of
999 * allocated dev extents, and when shrinking the device,
1000 * search_end may be smaller than search_start.
1001 */
1002 if (search_end > search_start)
1003 hole_size = search_end - search_start;
1004
1005 if (hole_size > max_hole_size) {
1006 max_hole_start = search_start;
1007 max_hole_size = hole_size;
1008 }
1009
1010 /* See above. */
1011 if (hole_size < num_bytes)
1012 ret = -ENOSPC;
1013 else
1014 ret = 0;
1015
1016 out:
1017 btrfs_free_path(path);
1018 error:
1019 *start = max_hole_start;
1020 if (len)
1021 *len = max_hole_size;
1022 return ret;
1023 }
1024
1025 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1026 struct btrfs_device *device,
1027 u64 start)
1028 {
1029 int ret;
1030 struct btrfs_path *path;
1031 struct btrfs_root *root = device->dev_root;
1032 struct btrfs_key key;
1033 struct btrfs_key found_key;
1034 struct extent_buffer *leaf = NULL;
1035 struct btrfs_dev_extent *extent = NULL;
1036
1037 path = btrfs_alloc_path();
1038 if (!path)
1039 return -ENOMEM;
1040
1041 key.objectid = device->devid;
1042 key.offset = start;
1043 key.type = BTRFS_DEV_EXTENT_KEY;
1044 again:
1045 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1046 if (ret > 0) {
1047 ret = btrfs_previous_item(root, path, key.objectid,
1048 BTRFS_DEV_EXTENT_KEY);
1049 if (ret)
1050 goto out;
1051 leaf = path->nodes[0];
1052 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1053 extent = btrfs_item_ptr(leaf, path->slots[0],
1054 struct btrfs_dev_extent);
1055 BUG_ON(found_key.offset > start || found_key.offset +
1056 btrfs_dev_extent_length(leaf, extent) < start);
1057 key = found_key;
1058 btrfs_release_path(path);
1059 goto again;
1060 } else if (ret == 0) {
1061 leaf = path->nodes[0];
1062 extent = btrfs_item_ptr(leaf, path->slots[0],
1063 struct btrfs_dev_extent);
1064 } else {
1065 btrfs_error(root->fs_info, ret, "Slot search failed");
1066 goto out;
1067 }
1068
1069 if (device->bytes_used > 0) {
1070 u64 len = btrfs_dev_extent_length(leaf, extent);
1071 device->bytes_used -= len;
1072 spin_lock(&root->fs_info->free_chunk_lock);
1073 root->fs_info->free_chunk_space += len;
1074 spin_unlock(&root->fs_info->free_chunk_lock);
1075 }
1076 ret = btrfs_del_item(trans, root, path);
1077 if (ret) {
1078 btrfs_error(root->fs_info, ret,
1079 "Failed to remove dev extent item");
1080 }
1081 out:
1082 btrfs_free_path(path);
1083 return ret;
1084 }
1085
1086 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1087 struct btrfs_device *device,
1088 u64 chunk_tree, u64 chunk_objectid,
1089 u64 chunk_offset, u64 start, u64 num_bytes)
1090 {
1091 int ret;
1092 struct btrfs_path *path;
1093 struct btrfs_root *root = device->dev_root;
1094 struct btrfs_dev_extent *extent;
1095 struct extent_buffer *leaf;
1096 struct btrfs_key key;
1097
1098 WARN_ON(!device->in_fs_metadata);
1099 path = btrfs_alloc_path();
1100 if (!path)
1101 return -ENOMEM;
1102
1103 key.objectid = device->devid;
1104 key.offset = start;
1105 key.type = BTRFS_DEV_EXTENT_KEY;
1106 ret = btrfs_insert_empty_item(trans, root, path, &key,
1107 sizeof(*extent));
1108 if (ret)
1109 goto out;
1110
1111 leaf = path->nodes[0];
1112 extent = btrfs_item_ptr(leaf, path->slots[0],
1113 struct btrfs_dev_extent);
1114 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1115 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1116 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1117
1118 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1119 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1120 BTRFS_UUID_SIZE);
1121
1122 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1123 btrfs_mark_buffer_dirty(leaf);
1124 out:
1125 btrfs_free_path(path);
1126 return ret;
1127 }
1128
1129 static noinline int find_next_chunk(struct btrfs_root *root,
1130 u64 objectid, u64 *offset)
1131 {
1132 struct btrfs_path *path;
1133 int ret;
1134 struct btrfs_key key;
1135 struct btrfs_chunk *chunk;
1136 struct btrfs_key found_key;
1137
1138 path = btrfs_alloc_path();
1139 if (!path)
1140 return -ENOMEM;
1141
1142 key.objectid = objectid;
1143 key.offset = (u64)-1;
1144 key.type = BTRFS_CHUNK_ITEM_KEY;
1145
1146 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1147 if (ret < 0)
1148 goto error;
1149
1150 BUG_ON(ret == 0); /* Corruption */
1151
1152 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1153 if (ret) {
1154 *offset = 0;
1155 } else {
1156 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1157 path->slots[0]);
1158 if (found_key.objectid != objectid)
1159 *offset = 0;
1160 else {
1161 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1162 struct btrfs_chunk);
1163 *offset = found_key.offset +
1164 btrfs_chunk_length(path->nodes[0], chunk);
1165 }
1166 }
1167 ret = 0;
1168 error:
1169 btrfs_free_path(path);
1170 return ret;
1171 }
1172
1173 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1174 {
1175 int ret;
1176 struct btrfs_key key;
1177 struct btrfs_key found_key;
1178 struct btrfs_path *path;
1179
1180 root = root->fs_info->chunk_root;
1181
1182 path = btrfs_alloc_path();
1183 if (!path)
1184 return -ENOMEM;
1185
1186 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1187 key.type = BTRFS_DEV_ITEM_KEY;
1188 key.offset = (u64)-1;
1189
1190 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1191 if (ret < 0)
1192 goto error;
1193
1194 BUG_ON(ret == 0); /* Corruption */
1195
1196 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1197 BTRFS_DEV_ITEM_KEY);
1198 if (ret) {
1199 *objectid = 1;
1200 } else {
1201 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1202 path->slots[0]);
1203 *objectid = found_key.offset + 1;
1204 }
1205 ret = 0;
1206 error:
1207 btrfs_free_path(path);
1208 return ret;
1209 }
1210
1211 /*
1212 * the device information is stored in the chunk root
1213 * the btrfs_device struct should be fully filled in
1214 */
1215 int btrfs_add_device(struct btrfs_trans_handle *trans,
1216 struct btrfs_root *root,
1217 struct btrfs_device *device)
1218 {
1219 int ret;
1220 struct btrfs_path *path;
1221 struct btrfs_dev_item *dev_item;
1222 struct extent_buffer *leaf;
1223 struct btrfs_key key;
1224 unsigned long ptr;
1225
1226 root = root->fs_info->chunk_root;
1227
1228 path = btrfs_alloc_path();
1229 if (!path)
1230 return -ENOMEM;
1231
1232 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1233 key.type = BTRFS_DEV_ITEM_KEY;
1234 key.offset = device->devid;
1235
1236 ret = btrfs_insert_empty_item(trans, root, path, &key,
1237 sizeof(*dev_item));
1238 if (ret)
1239 goto out;
1240
1241 leaf = path->nodes[0];
1242 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1243
1244 btrfs_set_device_id(leaf, dev_item, device->devid);
1245 btrfs_set_device_generation(leaf, dev_item, 0);
1246 btrfs_set_device_type(leaf, dev_item, device->type);
1247 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1248 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1249 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1250 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1251 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1252 btrfs_set_device_group(leaf, dev_item, 0);
1253 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1254 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1255 btrfs_set_device_start_offset(leaf, dev_item, 0);
1256
1257 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1258 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1259 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1260 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1261 btrfs_mark_buffer_dirty(leaf);
1262
1263 ret = 0;
1264 out:
1265 btrfs_free_path(path);
1266 return ret;
1267 }
1268
1269 static int btrfs_rm_dev_item(struct btrfs_root *root,
1270 struct btrfs_device *device)
1271 {
1272 int ret;
1273 struct btrfs_path *path;
1274 struct btrfs_key key;
1275 struct btrfs_trans_handle *trans;
1276
1277 root = root->fs_info->chunk_root;
1278
1279 path = btrfs_alloc_path();
1280 if (!path)
1281 return -ENOMEM;
1282
1283 trans = btrfs_start_transaction(root, 0);
1284 if (IS_ERR(trans)) {
1285 btrfs_free_path(path);
1286 return PTR_ERR(trans);
1287 }
1288 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1289 key.type = BTRFS_DEV_ITEM_KEY;
1290 key.offset = device->devid;
1291 lock_chunks(root);
1292
1293 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1294 if (ret < 0)
1295 goto out;
1296
1297 if (ret > 0) {
1298 ret = -ENOENT;
1299 goto out;
1300 }
1301
1302 ret = btrfs_del_item(trans, root, path);
1303 if (ret)
1304 goto out;
1305 out:
1306 btrfs_free_path(path);
1307 unlock_chunks(root);
1308 btrfs_commit_transaction(trans, root);
1309 return ret;
1310 }
1311
1312 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1313 {
1314 struct btrfs_device *device;
1315 struct btrfs_device *next_device;
1316 struct block_device *bdev;
1317 struct buffer_head *bh = NULL;
1318 struct btrfs_super_block *disk_super;
1319 struct btrfs_fs_devices *cur_devices;
1320 u64 all_avail;
1321 u64 devid;
1322 u64 num_devices;
1323 u8 *dev_uuid;
1324 int ret = 0;
1325 bool clear_super = false;
1326
1327 mutex_lock(&uuid_mutex);
1328
1329 all_avail = root->fs_info->avail_data_alloc_bits |
1330 root->fs_info->avail_system_alloc_bits |
1331 root->fs_info->avail_metadata_alloc_bits;
1332
1333 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1334 root->fs_info->fs_devices->num_devices <= 4) {
1335 printk(KERN_ERR "btrfs: unable to go below four devices "
1336 "on raid10\n");
1337 ret = -EINVAL;
1338 goto out;
1339 }
1340
1341 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1342 root->fs_info->fs_devices->num_devices <= 2) {
1343 printk(KERN_ERR "btrfs: unable to go below two "
1344 "devices on raid1\n");
1345 ret = -EINVAL;
1346 goto out;
1347 }
1348
1349 if (strcmp(device_path, "missing") == 0) {
1350 struct list_head *devices;
1351 struct btrfs_device *tmp;
1352
1353 device = NULL;
1354 devices = &root->fs_info->fs_devices->devices;
1355 /*
1356 * It is safe to read the devices since the volume_mutex
1357 * is held.
1358 */
1359 list_for_each_entry(tmp, devices, dev_list) {
1360 if (tmp->in_fs_metadata && !tmp->bdev) {
1361 device = tmp;
1362 break;
1363 }
1364 }
1365 bdev = NULL;
1366 bh = NULL;
1367 disk_super = NULL;
1368 if (!device) {
1369 printk(KERN_ERR "btrfs: no missing devices found to "
1370 "remove\n");
1371 goto out;
1372 }
1373 } else {
1374 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1375 root->fs_info->bdev_holder);
1376 if (IS_ERR(bdev)) {
1377 ret = PTR_ERR(bdev);
1378 goto out;
1379 }
1380
1381 set_blocksize(bdev, 4096);
1382 invalidate_bdev(bdev);
1383 bh = btrfs_read_dev_super(bdev);
1384 if (!bh) {
1385 ret = -EINVAL;
1386 goto error_close;
1387 }
1388 disk_super = (struct btrfs_super_block *)bh->b_data;
1389 devid = btrfs_stack_device_id(&disk_super->dev_item);
1390 dev_uuid = disk_super->dev_item.uuid;
1391 device = btrfs_find_device(root, devid, dev_uuid,
1392 disk_super->fsid);
1393 if (!device) {
1394 ret = -ENOENT;
1395 goto error_brelse;
1396 }
1397 }
1398
1399 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1400 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1401 "device\n");
1402 ret = -EINVAL;
1403 goto error_brelse;
1404 }
1405
1406 if (device->writeable) {
1407 lock_chunks(root);
1408 list_del_init(&device->dev_alloc_list);
1409 unlock_chunks(root);
1410 root->fs_info->fs_devices->rw_devices--;
1411 clear_super = true;
1412 }
1413
1414 ret = btrfs_shrink_device(device, 0);
1415 if (ret)
1416 goto error_undo;
1417
1418 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1419 if (ret)
1420 goto error_undo;
1421
1422 spin_lock(&root->fs_info->free_chunk_lock);
1423 root->fs_info->free_chunk_space = device->total_bytes -
1424 device->bytes_used;
1425 spin_unlock(&root->fs_info->free_chunk_lock);
1426
1427 device->in_fs_metadata = 0;
1428 btrfs_scrub_cancel_dev(root, device);
1429
1430 /*
1431 * the device list mutex makes sure that we don't change
1432 * the device list while someone else is writing out all
1433 * the device supers.
1434 */
1435
1436 cur_devices = device->fs_devices;
1437 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1438 list_del_rcu(&device->dev_list);
1439
1440 device->fs_devices->num_devices--;
1441 device->fs_devices->total_devices--;
1442
1443 if (device->missing)
1444 root->fs_info->fs_devices->missing_devices--;
1445
1446 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1447 struct btrfs_device, dev_list);
1448 if (device->bdev == root->fs_info->sb->s_bdev)
1449 root->fs_info->sb->s_bdev = next_device->bdev;
1450 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1451 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1452
1453 if (device->bdev)
1454 device->fs_devices->open_devices--;
1455
1456 call_rcu(&device->rcu, free_device);
1457 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1458
1459 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1460 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1461
1462 if (cur_devices->open_devices == 0) {
1463 struct btrfs_fs_devices *fs_devices;
1464 fs_devices = root->fs_info->fs_devices;
1465 while (fs_devices) {
1466 if (fs_devices->seed == cur_devices)
1467 break;
1468 fs_devices = fs_devices->seed;
1469 }
1470 fs_devices->seed = cur_devices->seed;
1471 cur_devices->seed = NULL;
1472 lock_chunks(root);
1473 __btrfs_close_devices(cur_devices);
1474 unlock_chunks(root);
1475 free_fs_devices(cur_devices);
1476 }
1477
1478 root->fs_info->num_tolerated_disk_barrier_failures =
1479 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1480
1481 /*
1482 * at this point, the device is zero sized. We want to
1483 * remove it from the devices list and zero out the old super
1484 */
1485 if (clear_super) {
1486 /* make sure this device isn't detected as part of
1487 * the FS anymore
1488 */
1489 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1490 set_buffer_dirty(bh);
1491 sync_dirty_buffer(bh);
1492 }
1493
1494 ret = 0;
1495
1496 error_brelse:
1497 brelse(bh);
1498 error_close:
1499 if (bdev)
1500 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1501 out:
1502 mutex_unlock(&uuid_mutex);
1503 return ret;
1504 error_undo:
1505 if (device->writeable) {
1506 lock_chunks(root);
1507 list_add(&device->dev_alloc_list,
1508 &root->fs_info->fs_devices->alloc_list);
1509 unlock_chunks(root);
1510 root->fs_info->fs_devices->rw_devices++;
1511 }
1512 goto error_brelse;
1513 }
1514
1515 /*
1516 * does all the dirty work required for changing file system's UUID.
1517 */
1518 static int btrfs_prepare_sprout(struct btrfs_root *root)
1519 {
1520 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1521 struct btrfs_fs_devices *old_devices;
1522 struct btrfs_fs_devices *seed_devices;
1523 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1524 struct btrfs_device *device;
1525 u64 super_flags;
1526
1527 BUG_ON(!mutex_is_locked(&uuid_mutex));
1528 if (!fs_devices->seeding)
1529 return -EINVAL;
1530
1531 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1532 if (!seed_devices)
1533 return -ENOMEM;
1534
1535 old_devices = clone_fs_devices(fs_devices);
1536 if (IS_ERR(old_devices)) {
1537 kfree(seed_devices);
1538 return PTR_ERR(old_devices);
1539 }
1540
1541 list_add(&old_devices->list, &fs_uuids);
1542
1543 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1544 seed_devices->opened = 1;
1545 INIT_LIST_HEAD(&seed_devices->devices);
1546 INIT_LIST_HEAD(&seed_devices->alloc_list);
1547 mutex_init(&seed_devices->device_list_mutex);
1548
1549 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1550 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1551 synchronize_rcu);
1552 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1553
1554 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1555 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1556 device->fs_devices = seed_devices;
1557 }
1558
1559 fs_devices->seeding = 0;
1560 fs_devices->num_devices = 0;
1561 fs_devices->open_devices = 0;
1562 fs_devices->total_devices = 0;
1563 fs_devices->seed = seed_devices;
1564
1565 generate_random_uuid(fs_devices->fsid);
1566 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1567 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1568 super_flags = btrfs_super_flags(disk_super) &
1569 ~BTRFS_SUPER_FLAG_SEEDING;
1570 btrfs_set_super_flags(disk_super, super_flags);
1571
1572 return 0;
1573 }
1574
1575 /*
1576 * strore the expected generation for seed devices in device items.
1577 */
1578 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1579 struct btrfs_root *root)
1580 {
1581 struct btrfs_path *path;
1582 struct extent_buffer *leaf;
1583 struct btrfs_dev_item *dev_item;
1584 struct btrfs_device *device;
1585 struct btrfs_key key;
1586 u8 fs_uuid[BTRFS_UUID_SIZE];
1587 u8 dev_uuid[BTRFS_UUID_SIZE];
1588 u64 devid;
1589 int ret;
1590
1591 path = btrfs_alloc_path();
1592 if (!path)
1593 return -ENOMEM;
1594
1595 root = root->fs_info->chunk_root;
1596 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1597 key.offset = 0;
1598 key.type = BTRFS_DEV_ITEM_KEY;
1599
1600 while (1) {
1601 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1602 if (ret < 0)
1603 goto error;
1604
1605 leaf = path->nodes[0];
1606 next_slot:
1607 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1608 ret = btrfs_next_leaf(root, path);
1609 if (ret > 0)
1610 break;
1611 if (ret < 0)
1612 goto error;
1613 leaf = path->nodes[0];
1614 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1615 btrfs_release_path(path);
1616 continue;
1617 }
1618
1619 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1620 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1621 key.type != BTRFS_DEV_ITEM_KEY)
1622 break;
1623
1624 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1625 struct btrfs_dev_item);
1626 devid = btrfs_device_id(leaf, dev_item);
1627 read_extent_buffer(leaf, dev_uuid,
1628 (unsigned long)btrfs_device_uuid(dev_item),
1629 BTRFS_UUID_SIZE);
1630 read_extent_buffer(leaf, fs_uuid,
1631 (unsigned long)btrfs_device_fsid(dev_item),
1632 BTRFS_UUID_SIZE);
1633 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1634 BUG_ON(!device); /* Logic error */
1635
1636 if (device->fs_devices->seeding) {
1637 btrfs_set_device_generation(leaf, dev_item,
1638 device->generation);
1639 btrfs_mark_buffer_dirty(leaf);
1640 }
1641
1642 path->slots[0]++;
1643 goto next_slot;
1644 }
1645 ret = 0;
1646 error:
1647 btrfs_free_path(path);
1648 return ret;
1649 }
1650
1651 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1652 {
1653 struct request_queue *q;
1654 struct btrfs_trans_handle *trans;
1655 struct btrfs_device *device;
1656 struct block_device *bdev;
1657 struct list_head *devices;
1658 struct super_block *sb = root->fs_info->sb;
1659 struct rcu_string *name;
1660 u64 total_bytes;
1661 int seeding_dev = 0;
1662 int ret = 0;
1663
1664 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1665 return -EROFS;
1666
1667 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1668 root->fs_info->bdev_holder);
1669 if (IS_ERR(bdev))
1670 return PTR_ERR(bdev);
1671
1672 if (root->fs_info->fs_devices->seeding) {
1673 seeding_dev = 1;
1674 down_write(&sb->s_umount);
1675 mutex_lock(&uuid_mutex);
1676 }
1677
1678 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1679
1680 devices = &root->fs_info->fs_devices->devices;
1681 /*
1682 * we have the volume lock, so we don't need the extra
1683 * device list mutex while reading the list here.
1684 */
1685 list_for_each_entry(device, devices, dev_list) {
1686 if (device->bdev == bdev) {
1687 ret = -EEXIST;
1688 goto error;
1689 }
1690 }
1691
1692 device = kzalloc(sizeof(*device), GFP_NOFS);
1693 if (!device) {
1694 /* we can safely leave the fs_devices entry around */
1695 ret = -ENOMEM;
1696 goto error;
1697 }
1698
1699 name = rcu_string_strdup(device_path, GFP_NOFS);
1700 if (!name) {
1701 kfree(device);
1702 ret = -ENOMEM;
1703 goto error;
1704 }
1705 rcu_assign_pointer(device->name, name);
1706
1707 ret = find_next_devid(root, &device->devid);
1708 if (ret) {
1709 rcu_string_free(device->name);
1710 kfree(device);
1711 goto error;
1712 }
1713
1714 trans = btrfs_start_transaction(root, 0);
1715 if (IS_ERR(trans)) {
1716 rcu_string_free(device->name);
1717 kfree(device);
1718 ret = PTR_ERR(trans);
1719 goto error;
1720 }
1721
1722 lock_chunks(root);
1723
1724 q = bdev_get_queue(bdev);
1725 if (blk_queue_discard(q))
1726 device->can_discard = 1;
1727 device->writeable = 1;
1728 device->work.func = pending_bios_fn;
1729 generate_random_uuid(device->uuid);
1730 spin_lock_init(&device->io_lock);
1731 device->generation = trans->transid;
1732 device->io_width = root->sectorsize;
1733 device->io_align = root->sectorsize;
1734 device->sector_size = root->sectorsize;
1735 device->total_bytes = i_size_read(bdev->bd_inode);
1736 device->disk_total_bytes = device->total_bytes;
1737 device->dev_root = root->fs_info->dev_root;
1738 device->bdev = bdev;
1739 device->in_fs_metadata = 1;
1740 device->mode = FMODE_EXCL;
1741 set_blocksize(device->bdev, 4096);
1742
1743 if (seeding_dev) {
1744 sb->s_flags &= ~MS_RDONLY;
1745 ret = btrfs_prepare_sprout(root);
1746 BUG_ON(ret); /* -ENOMEM */
1747 }
1748
1749 device->fs_devices = root->fs_info->fs_devices;
1750
1751 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1752 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1753 list_add(&device->dev_alloc_list,
1754 &root->fs_info->fs_devices->alloc_list);
1755 root->fs_info->fs_devices->num_devices++;
1756 root->fs_info->fs_devices->open_devices++;
1757 root->fs_info->fs_devices->rw_devices++;
1758 root->fs_info->fs_devices->total_devices++;
1759 if (device->can_discard)
1760 root->fs_info->fs_devices->num_can_discard++;
1761 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1762
1763 spin_lock(&root->fs_info->free_chunk_lock);
1764 root->fs_info->free_chunk_space += device->total_bytes;
1765 spin_unlock(&root->fs_info->free_chunk_lock);
1766
1767 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1768 root->fs_info->fs_devices->rotating = 1;
1769
1770 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1771 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1772 total_bytes + device->total_bytes);
1773
1774 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1775 btrfs_set_super_num_devices(root->fs_info->super_copy,
1776 total_bytes + 1);
1777 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1778
1779 if (seeding_dev) {
1780 ret = init_first_rw_device(trans, root, device);
1781 if (ret) {
1782 btrfs_abort_transaction(trans, root, ret);
1783 goto error_trans;
1784 }
1785 ret = btrfs_finish_sprout(trans, root);
1786 if (ret) {
1787 btrfs_abort_transaction(trans, root, ret);
1788 goto error_trans;
1789 }
1790 } else {
1791 ret = btrfs_add_device(trans, root, device);
1792 if (ret) {
1793 btrfs_abort_transaction(trans, root, ret);
1794 goto error_trans;
1795 }
1796 }
1797
1798 /*
1799 * we've got more storage, clear any full flags on the space
1800 * infos
1801 */
1802 btrfs_clear_space_info_full(root->fs_info);
1803
1804 unlock_chunks(root);
1805 root->fs_info->num_tolerated_disk_barrier_failures =
1806 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1807 ret = btrfs_commit_transaction(trans, root);
1808
1809 if (seeding_dev) {
1810 mutex_unlock(&uuid_mutex);
1811 up_write(&sb->s_umount);
1812
1813 if (ret) /* transaction commit */
1814 return ret;
1815
1816 ret = btrfs_relocate_sys_chunks(root);
1817 if (ret < 0)
1818 btrfs_error(root->fs_info, ret,
1819 "Failed to relocate sys chunks after "
1820 "device initialization. This can be fixed "
1821 "using the \"btrfs balance\" command.");
1822 trans = btrfs_attach_transaction(root);
1823 if (IS_ERR(trans)) {
1824 if (PTR_ERR(trans) == -ENOENT)
1825 return 0;
1826 return PTR_ERR(trans);
1827 }
1828 ret = btrfs_commit_transaction(trans, root);
1829 }
1830
1831 return ret;
1832
1833 error_trans:
1834 unlock_chunks(root);
1835 btrfs_end_transaction(trans, root);
1836 rcu_string_free(device->name);
1837 kfree(device);
1838 error:
1839 blkdev_put(bdev, FMODE_EXCL);
1840 if (seeding_dev) {
1841 mutex_unlock(&uuid_mutex);
1842 up_write(&sb->s_umount);
1843 }
1844 return ret;
1845 }
1846
1847 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1848 struct btrfs_device *device)
1849 {
1850 int ret;
1851 struct btrfs_path *path;
1852 struct btrfs_root *root;
1853 struct btrfs_dev_item *dev_item;
1854 struct extent_buffer *leaf;
1855 struct btrfs_key key;
1856
1857 root = device->dev_root->fs_info->chunk_root;
1858
1859 path = btrfs_alloc_path();
1860 if (!path)
1861 return -ENOMEM;
1862
1863 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1864 key.type = BTRFS_DEV_ITEM_KEY;
1865 key.offset = device->devid;
1866
1867 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1868 if (ret < 0)
1869 goto out;
1870
1871 if (ret > 0) {
1872 ret = -ENOENT;
1873 goto out;
1874 }
1875
1876 leaf = path->nodes[0];
1877 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1878
1879 btrfs_set_device_id(leaf, dev_item, device->devid);
1880 btrfs_set_device_type(leaf, dev_item, device->type);
1881 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1882 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1883 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1884 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1885 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1886 btrfs_mark_buffer_dirty(leaf);
1887
1888 out:
1889 btrfs_free_path(path);
1890 return ret;
1891 }
1892
1893 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1894 struct btrfs_device *device, u64 new_size)
1895 {
1896 struct btrfs_super_block *super_copy =
1897 device->dev_root->fs_info->super_copy;
1898 u64 old_total = btrfs_super_total_bytes(super_copy);
1899 u64 diff = new_size - device->total_bytes;
1900
1901 if (!device->writeable)
1902 return -EACCES;
1903 if (new_size <= device->total_bytes)
1904 return -EINVAL;
1905
1906 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1907 device->fs_devices->total_rw_bytes += diff;
1908
1909 device->total_bytes = new_size;
1910 device->disk_total_bytes = new_size;
1911 btrfs_clear_space_info_full(device->dev_root->fs_info);
1912
1913 return btrfs_update_device(trans, device);
1914 }
1915
1916 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1917 struct btrfs_device *device, u64 new_size)
1918 {
1919 int ret;
1920 lock_chunks(device->dev_root);
1921 ret = __btrfs_grow_device(trans, device, new_size);
1922 unlock_chunks(device->dev_root);
1923 return ret;
1924 }
1925
1926 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1927 struct btrfs_root *root,
1928 u64 chunk_tree, u64 chunk_objectid,
1929 u64 chunk_offset)
1930 {
1931 int ret;
1932 struct btrfs_path *path;
1933 struct btrfs_key key;
1934
1935 root = root->fs_info->chunk_root;
1936 path = btrfs_alloc_path();
1937 if (!path)
1938 return -ENOMEM;
1939
1940 key.objectid = chunk_objectid;
1941 key.offset = chunk_offset;
1942 key.type = BTRFS_CHUNK_ITEM_KEY;
1943
1944 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1945 if (ret < 0)
1946 goto out;
1947 else if (ret > 0) { /* Logic error or corruption */
1948 btrfs_error(root->fs_info, -ENOENT,
1949 "Failed lookup while freeing chunk.");
1950 ret = -ENOENT;
1951 goto out;
1952 }
1953
1954 ret = btrfs_del_item(trans, root, path);
1955 if (ret < 0)
1956 btrfs_error(root->fs_info, ret,
1957 "Failed to delete chunk item.");
1958 out:
1959 btrfs_free_path(path);
1960 return ret;
1961 }
1962
1963 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1964 chunk_offset)
1965 {
1966 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1967 struct btrfs_disk_key *disk_key;
1968 struct btrfs_chunk *chunk;
1969 u8 *ptr;
1970 int ret = 0;
1971 u32 num_stripes;
1972 u32 array_size;
1973 u32 len = 0;
1974 u32 cur;
1975 struct btrfs_key key;
1976
1977 array_size = btrfs_super_sys_array_size(super_copy);
1978
1979 ptr = super_copy->sys_chunk_array;
1980 cur = 0;
1981
1982 while (cur < array_size) {
1983 disk_key = (struct btrfs_disk_key *)ptr;
1984 btrfs_disk_key_to_cpu(&key, disk_key);
1985
1986 len = sizeof(*disk_key);
1987
1988 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1989 chunk = (struct btrfs_chunk *)(ptr + len);
1990 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1991 len += btrfs_chunk_item_size(num_stripes);
1992 } else {
1993 ret = -EIO;
1994 break;
1995 }
1996 if (key.objectid == chunk_objectid &&
1997 key.offset == chunk_offset) {
1998 memmove(ptr, ptr + len, array_size - (cur + len));
1999 array_size -= len;
2000 btrfs_set_super_sys_array_size(super_copy, array_size);
2001 } else {
2002 ptr += len;
2003 cur += len;
2004 }
2005 }
2006 return ret;
2007 }
2008
2009 static int btrfs_relocate_chunk(struct btrfs_root *root,
2010 u64 chunk_tree, u64 chunk_objectid,
2011 u64 chunk_offset)
2012 {
2013 struct extent_map_tree *em_tree;
2014 struct btrfs_root *extent_root;
2015 struct btrfs_trans_handle *trans;
2016 struct extent_map *em;
2017 struct map_lookup *map;
2018 int ret;
2019 int i;
2020
2021 root = root->fs_info->chunk_root;
2022 extent_root = root->fs_info->extent_root;
2023 em_tree = &root->fs_info->mapping_tree.map_tree;
2024
2025 ret = btrfs_can_relocate(extent_root, chunk_offset);
2026 if (ret)
2027 return -ENOSPC;
2028
2029 /* step one, relocate all the extents inside this chunk */
2030 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2031 if (ret)
2032 return ret;
2033
2034 trans = btrfs_start_transaction(root, 0);
2035 BUG_ON(IS_ERR(trans));
2036
2037 lock_chunks(root);
2038
2039 /*
2040 * step two, delete the device extents and the
2041 * chunk tree entries
2042 */
2043 read_lock(&em_tree->lock);
2044 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2045 read_unlock(&em_tree->lock);
2046
2047 BUG_ON(!em || em->start > chunk_offset ||
2048 em->start + em->len < chunk_offset);
2049 map = (struct map_lookup *)em->bdev;
2050
2051 for (i = 0; i < map->num_stripes; i++) {
2052 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2053 map->stripes[i].physical);
2054 BUG_ON(ret);
2055
2056 if (map->stripes[i].dev) {
2057 ret = btrfs_update_device(trans, map->stripes[i].dev);
2058 BUG_ON(ret);
2059 }
2060 }
2061 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2062 chunk_offset);
2063
2064 BUG_ON(ret);
2065
2066 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2067
2068 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2069 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2070 BUG_ON(ret);
2071 }
2072
2073 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2074 BUG_ON(ret);
2075
2076 write_lock(&em_tree->lock);
2077 remove_extent_mapping(em_tree, em);
2078 write_unlock(&em_tree->lock);
2079
2080 kfree(map);
2081 em->bdev = NULL;
2082
2083 /* once for the tree */
2084 free_extent_map(em);
2085 /* once for us */
2086 free_extent_map(em);
2087
2088 unlock_chunks(root);
2089 btrfs_end_transaction(trans, root);
2090 return 0;
2091 }
2092
2093 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2094 {
2095 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2096 struct btrfs_path *path;
2097 struct extent_buffer *leaf;
2098 struct btrfs_chunk *chunk;
2099 struct btrfs_key key;
2100 struct btrfs_key found_key;
2101 u64 chunk_tree = chunk_root->root_key.objectid;
2102 u64 chunk_type;
2103 bool retried = false;
2104 int failed = 0;
2105 int ret;
2106
2107 path = btrfs_alloc_path();
2108 if (!path)
2109 return -ENOMEM;
2110
2111 again:
2112 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2113 key.offset = (u64)-1;
2114 key.type = BTRFS_CHUNK_ITEM_KEY;
2115
2116 while (1) {
2117 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2118 if (ret < 0)
2119 goto error;
2120 BUG_ON(ret == 0); /* Corruption */
2121
2122 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2123 key.type);
2124 if (ret < 0)
2125 goto error;
2126 if (ret > 0)
2127 break;
2128
2129 leaf = path->nodes[0];
2130 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2131
2132 chunk = btrfs_item_ptr(leaf, path->slots[0],
2133 struct btrfs_chunk);
2134 chunk_type = btrfs_chunk_type(leaf, chunk);
2135 btrfs_release_path(path);
2136
2137 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2138 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2139 found_key.objectid,
2140 found_key.offset);
2141 if (ret == -ENOSPC)
2142 failed++;
2143 else if (ret)
2144 BUG();
2145 }
2146
2147 if (found_key.offset == 0)
2148 break;
2149 key.offset = found_key.offset - 1;
2150 }
2151 ret = 0;
2152 if (failed && !retried) {
2153 failed = 0;
2154 retried = true;
2155 goto again;
2156 } else if (failed && retried) {
2157 WARN_ON(1);
2158 ret = -ENOSPC;
2159 }
2160 error:
2161 btrfs_free_path(path);
2162 return ret;
2163 }
2164
2165 static int insert_balance_item(struct btrfs_root *root,
2166 struct btrfs_balance_control *bctl)
2167 {
2168 struct btrfs_trans_handle *trans;
2169 struct btrfs_balance_item *item;
2170 struct btrfs_disk_balance_args disk_bargs;
2171 struct btrfs_path *path;
2172 struct extent_buffer *leaf;
2173 struct btrfs_key key;
2174 int ret, err;
2175
2176 path = btrfs_alloc_path();
2177 if (!path)
2178 return -ENOMEM;
2179
2180 trans = btrfs_start_transaction(root, 0);
2181 if (IS_ERR(trans)) {
2182 btrfs_free_path(path);
2183 return PTR_ERR(trans);
2184 }
2185
2186 key.objectid = BTRFS_BALANCE_OBJECTID;
2187 key.type = BTRFS_BALANCE_ITEM_KEY;
2188 key.offset = 0;
2189
2190 ret = btrfs_insert_empty_item(trans, root, path, &key,
2191 sizeof(*item));
2192 if (ret)
2193 goto out;
2194
2195 leaf = path->nodes[0];
2196 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2197
2198 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2199
2200 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2201 btrfs_set_balance_data(leaf, item, &disk_bargs);
2202 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2203 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2204 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2205 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2206
2207 btrfs_set_balance_flags(leaf, item, bctl->flags);
2208
2209 btrfs_mark_buffer_dirty(leaf);
2210 out:
2211 btrfs_free_path(path);
2212 err = btrfs_commit_transaction(trans, root);
2213 if (err && !ret)
2214 ret = err;
2215 return ret;
2216 }
2217
2218 static int del_balance_item(struct btrfs_root *root)
2219 {
2220 struct btrfs_trans_handle *trans;
2221 struct btrfs_path *path;
2222 struct btrfs_key key;
2223 int ret, err;
2224
2225 path = btrfs_alloc_path();
2226 if (!path)
2227 return -ENOMEM;
2228
2229 trans = btrfs_start_transaction(root, 0);
2230 if (IS_ERR(trans)) {
2231 btrfs_free_path(path);
2232 return PTR_ERR(trans);
2233 }
2234
2235 key.objectid = BTRFS_BALANCE_OBJECTID;
2236 key.type = BTRFS_BALANCE_ITEM_KEY;
2237 key.offset = 0;
2238
2239 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2240 if (ret < 0)
2241 goto out;
2242 if (ret > 0) {
2243 ret = -ENOENT;
2244 goto out;
2245 }
2246
2247 ret = btrfs_del_item(trans, root, path);
2248 out:
2249 btrfs_free_path(path);
2250 err = btrfs_commit_transaction(trans, root);
2251 if (err && !ret)
2252 ret = err;
2253 return ret;
2254 }
2255
2256 /*
2257 * This is a heuristic used to reduce the number of chunks balanced on
2258 * resume after balance was interrupted.
2259 */
2260 static void update_balance_args(struct btrfs_balance_control *bctl)
2261 {
2262 /*
2263 * Turn on soft mode for chunk types that were being converted.
2264 */
2265 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2266 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2267 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2268 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2269 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2270 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2271
2272 /*
2273 * Turn on usage filter if is not already used. The idea is
2274 * that chunks that we have already balanced should be
2275 * reasonably full. Don't do it for chunks that are being
2276 * converted - that will keep us from relocating unconverted
2277 * (albeit full) chunks.
2278 */
2279 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2280 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2281 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2282 bctl->data.usage = 90;
2283 }
2284 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2285 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2286 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2287 bctl->sys.usage = 90;
2288 }
2289 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2290 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2291 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2292 bctl->meta.usage = 90;
2293 }
2294 }
2295
2296 /*
2297 * Should be called with both balance and volume mutexes held to
2298 * serialize other volume operations (add_dev/rm_dev/resize) with
2299 * restriper. Same goes for unset_balance_control.
2300 */
2301 static void set_balance_control(struct btrfs_balance_control *bctl)
2302 {
2303 struct btrfs_fs_info *fs_info = bctl->fs_info;
2304
2305 BUG_ON(fs_info->balance_ctl);
2306
2307 spin_lock(&fs_info->balance_lock);
2308 fs_info->balance_ctl = bctl;
2309 spin_unlock(&fs_info->balance_lock);
2310 }
2311
2312 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2313 {
2314 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2315
2316 BUG_ON(!fs_info->balance_ctl);
2317
2318 spin_lock(&fs_info->balance_lock);
2319 fs_info->balance_ctl = NULL;
2320 spin_unlock(&fs_info->balance_lock);
2321
2322 kfree(bctl);
2323 }
2324
2325 /*
2326 * Balance filters. Return 1 if chunk should be filtered out
2327 * (should not be balanced).
2328 */
2329 static int chunk_profiles_filter(u64 chunk_type,
2330 struct btrfs_balance_args *bargs)
2331 {
2332 chunk_type = chunk_to_extended(chunk_type) &
2333 BTRFS_EXTENDED_PROFILE_MASK;
2334
2335 if (bargs->profiles & chunk_type)
2336 return 0;
2337
2338 return 1;
2339 }
2340
2341 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2342 struct btrfs_balance_args *bargs)
2343 {
2344 struct btrfs_block_group_cache *cache;
2345 u64 chunk_used, user_thresh;
2346 int ret = 1;
2347
2348 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2349 chunk_used = btrfs_block_group_used(&cache->item);
2350
2351 user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
2352 if (chunk_used < user_thresh)
2353 ret = 0;
2354
2355 btrfs_put_block_group(cache);
2356 return ret;
2357 }
2358
2359 static int chunk_devid_filter(struct extent_buffer *leaf,
2360 struct btrfs_chunk *chunk,
2361 struct btrfs_balance_args *bargs)
2362 {
2363 struct btrfs_stripe *stripe;
2364 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2365 int i;
2366
2367 for (i = 0; i < num_stripes; i++) {
2368 stripe = btrfs_stripe_nr(chunk, i);
2369 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2370 return 0;
2371 }
2372
2373 return 1;
2374 }
2375
2376 /* [pstart, pend) */
2377 static int chunk_drange_filter(struct extent_buffer *leaf,
2378 struct btrfs_chunk *chunk,
2379 u64 chunk_offset,
2380 struct btrfs_balance_args *bargs)
2381 {
2382 struct btrfs_stripe *stripe;
2383 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2384 u64 stripe_offset;
2385 u64 stripe_length;
2386 int factor;
2387 int i;
2388
2389 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2390 return 0;
2391
2392 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2393 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2394 factor = 2;
2395 else
2396 factor = 1;
2397 factor = num_stripes / factor;
2398
2399 for (i = 0; i < num_stripes; i++) {
2400 stripe = btrfs_stripe_nr(chunk, i);
2401 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2402 continue;
2403
2404 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2405 stripe_length = btrfs_chunk_length(leaf, chunk);
2406 do_div(stripe_length, factor);
2407
2408 if (stripe_offset < bargs->pend &&
2409 stripe_offset + stripe_length > bargs->pstart)
2410 return 0;
2411 }
2412
2413 return 1;
2414 }
2415
2416 /* [vstart, vend) */
2417 static int chunk_vrange_filter(struct extent_buffer *leaf,
2418 struct btrfs_chunk *chunk,
2419 u64 chunk_offset,
2420 struct btrfs_balance_args *bargs)
2421 {
2422 if (chunk_offset < bargs->vend &&
2423 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2424 /* at least part of the chunk is inside this vrange */
2425 return 0;
2426
2427 return 1;
2428 }
2429
2430 static int chunk_soft_convert_filter(u64 chunk_type,
2431 struct btrfs_balance_args *bargs)
2432 {
2433 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2434 return 0;
2435
2436 chunk_type = chunk_to_extended(chunk_type) &
2437 BTRFS_EXTENDED_PROFILE_MASK;
2438
2439 if (bargs->target == chunk_type)
2440 return 1;
2441
2442 return 0;
2443 }
2444
2445 static int should_balance_chunk(struct btrfs_root *root,
2446 struct extent_buffer *leaf,
2447 struct btrfs_chunk *chunk, u64 chunk_offset)
2448 {
2449 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2450 struct btrfs_balance_args *bargs = NULL;
2451 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2452
2453 /* type filter */
2454 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2455 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2456 return 0;
2457 }
2458
2459 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2460 bargs = &bctl->data;
2461 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2462 bargs = &bctl->sys;
2463 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2464 bargs = &bctl->meta;
2465
2466 /* profiles filter */
2467 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2468 chunk_profiles_filter(chunk_type, bargs)) {
2469 return 0;
2470 }
2471
2472 /* usage filter */
2473 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2474 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2475 return 0;
2476 }
2477
2478 /* devid filter */
2479 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2480 chunk_devid_filter(leaf, chunk, bargs)) {
2481 return 0;
2482 }
2483
2484 /* drange filter, makes sense only with devid filter */
2485 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2486 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2487 return 0;
2488 }
2489
2490 /* vrange filter */
2491 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2492 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2493 return 0;
2494 }
2495
2496 /* soft profile changing mode */
2497 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2498 chunk_soft_convert_filter(chunk_type, bargs)) {
2499 return 0;
2500 }
2501
2502 return 1;
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 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
2804 int num_tolerated_disk_barrier_failures;
2805 u64 target = bctl->sys.target;
2806
2807 num_tolerated_disk_barrier_failures =
2808 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2809 if (num_tolerated_disk_barrier_failures > 0 &&
2810 (target &
2811 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
2812 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
2813 num_tolerated_disk_barrier_failures = 0;
2814 else if (num_tolerated_disk_barrier_failures > 1 &&
2815 (target &
2816 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
2817 num_tolerated_disk_barrier_failures = 1;
2818
2819 fs_info->num_tolerated_disk_barrier_failures =
2820 num_tolerated_disk_barrier_failures;
2821 }
2822
2823 ret = insert_balance_item(fs_info->tree_root, bctl);
2824 if (ret && ret != -EEXIST)
2825 goto out;
2826
2827 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
2828 BUG_ON(ret == -EEXIST);
2829 set_balance_control(bctl);
2830 } else {
2831 BUG_ON(ret != -EEXIST);
2832 spin_lock(&fs_info->balance_lock);
2833 update_balance_args(bctl);
2834 spin_unlock(&fs_info->balance_lock);
2835 }
2836
2837 atomic_inc(&fs_info->balance_running);
2838 mutex_unlock(&fs_info->balance_mutex);
2839
2840 ret = __btrfs_balance(fs_info);
2841
2842 mutex_lock(&fs_info->balance_mutex);
2843 atomic_dec(&fs_info->balance_running);
2844
2845 if (bargs) {
2846 memset(bargs, 0, sizeof(*bargs));
2847 update_ioctl_balance_args(fs_info, 0, bargs);
2848 }
2849
2850 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
2851 balance_need_close(fs_info)) {
2852 __cancel_balance(fs_info);
2853 }
2854
2855 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
2856 fs_info->num_tolerated_disk_barrier_failures =
2857 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
2858 }
2859
2860 wake_up(&fs_info->balance_wait_q);
2861
2862 return ret;
2863 out:
2864 if (bctl->flags & BTRFS_BALANCE_RESUME)
2865 __cancel_balance(fs_info);
2866 else
2867 kfree(bctl);
2868 return ret;
2869 }
2870
2871 static int balance_kthread(void *data)
2872 {
2873 struct btrfs_fs_info *fs_info = data;
2874 int ret = 0;
2875
2876 mutex_lock(&fs_info->volume_mutex);
2877 mutex_lock(&fs_info->balance_mutex);
2878
2879 if (fs_info->balance_ctl) {
2880 printk(KERN_INFO "btrfs: continuing balance\n");
2881 ret = btrfs_balance(fs_info->balance_ctl, NULL);
2882 }
2883
2884 mutex_unlock(&fs_info->balance_mutex);
2885 mutex_unlock(&fs_info->volume_mutex);
2886
2887 return ret;
2888 }
2889
2890 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
2891 {
2892 struct task_struct *tsk;
2893
2894 spin_lock(&fs_info->balance_lock);
2895 if (!fs_info->balance_ctl) {
2896 spin_unlock(&fs_info->balance_lock);
2897 return 0;
2898 }
2899 spin_unlock(&fs_info->balance_lock);
2900
2901 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
2902 printk(KERN_INFO "btrfs: force skipping balance\n");
2903 return 0;
2904 }
2905
2906 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
2907 if (IS_ERR(tsk))
2908 return PTR_ERR(tsk);
2909
2910 return 0;
2911 }
2912
2913 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
2914 {
2915 struct btrfs_balance_control *bctl;
2916 struct btrfs_balance_item *item;
2917 struct btrfs_disk_balance_args disk_bargs;
2918 struct btrfs_path *path;
2919 struct extent_buffer *leaf;
2920 struct btrfs_key key;
2921 int ret;
2922
2923 path = btrfs_alloc_path();
2924 if (!path)
2925 return -ENOMEM;
2926
2927 key.objectid = BTRFS_BALANCE_OBJECTID;
2928 key.type = BTRFS_BALANCE_ITEM_KEY;
2929 key.offset = 0;
2930
2931 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
2932 if (ret < 0)
2933 goto out;
2934 if (ret > 0) { /* ret = -ENOENT; */
2935 ret = 0;
2936 goto out;
2937 }
2938
2939 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
2940 if (!bctl) {
2941 ret = -ENOMEM;
2942 goto out;
2943 }
2944
2945 leaf = path->nodes[0];
2946 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2947
2948 bctl->fs_info = fs_info;
2949 bctl->flags = btrfs_balance_flags(leaf, item);
2950 bctl->flags |= BTRFS_BALANCE_RESUME;
2951
2952 btrfs_balance_data(leaf, item, &disk_bargs);
2953 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
2954 btrfs_balance_meta(leaf, item, &disk_bargs);
2955 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
2956 btrfs_balance_sys(leaf, item, &disk_bargs);
2957 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
2958
2959 mutex_lock(&fs_info->volume_mutex);
2960 mutex_lock(&fs_info->balance_mutex);
2961
2962 set_balance_control(bctl);
2963
2964 mutex_unlock(&fs_info->balance_mutex);
2965 mutex_unlock(&fs_info->volume_mutex);
2966 out:
2967 btrfs_free_path(path);
2968 return ret;
2969 }
2970
2971 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
2972 {
2973 int ret = 0;
2974
2975 mutex_lock(&fs_info->balance_mutex);
2976 if (!fs_info->balance_ctl) {
2977 mutex_unlock(&fs_info->balance_mutex);
2978 return -ENOTCONN;
2979 }
2980
2981 if (atomic_read(&fs_info->balance_running)) {
2982 atomic_inc(&fs_info->balance_pause_req);
2983 mutex_unlock(&fs_info->balance_mutex);
2984
2985 wait_event(fs_info->balance_wait_q,
2986 atomic_read(&fs_info->balance_running) == 0);
2987
2988 mutex_lock(&fs_info->balance_mutex);
2989 /* we are good with balance_ctl ripped off from under us */
2990 BUG_ON(atomic_read(&fs_info->balance_running));
2991 atomic_dec(&fs_info->balance_pause_req);
2992 } else {
2993 ret = -ENOTCONN;
2994 }
2995
2996 mutex_unlock(&fs_info->balance_mutex);
2997 return ret;
2998 }
2999
3000 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3001 {
3002 mutex_lock(&fs_info->balance_mutex);
3003 if (!fs_info->balance_ctl) {
3004 mutex_unlock(&fs_info->balance_mutex);
3005 return -ENOTCONN;
3006 }
3007
3008 atomic_inc(&fs_info->balance_cancel_req);
3009 /*
3010 * if we are running just wait and return, balance item is
3011 * deleted in btrfs_balance in this case
3012 */
3013 if (atomic_read(&fs_info->balance_running)) {
3014 mutex_unlock(&fs_info->balance_mutex);
3015 wait_event(fs_info->balance_wait_q,
3016 atomic_read(&fs_info->balance_running) == 0);
3017 mutex_lock(&fs_info->balance_mutex);
3018 } else {
3019 /* __cancel_balance needs volume_mutex */
3020 mutex_unlock(&fs_info->balance_mutex);
3021 mutex_lock(&fs_info->volume_mutex);
3022 mutex_lock(&fs_info->balance_mutex);
3023
3024 if (fs_info->balance_ctl)
3025 __cancel_balance(fs_info);
3026
3027 mutex_unlock(&fs_info->volume_mutex);
3028 }
3029
3030 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3031 atomic_dec(&fs_info->balance_cancel_req);
3032 mutex_unlock(&fs_info->balance_mutex);
3033 return 0;
3034 }
3035
3036 /*
3037 * shrinking a device means finding all of the device extents past
3038 * the new size, and then following the back refs to the chunks.
3039 * The chunk relocation code actually frees the device extent
3040 */
3041 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3042 {
3043 struct btrfs_trans_handle *trans;
3044 struct btrfs_root *root = device->dev_root;
3045 struct btrfs_dev_extent *dev_extent = NULL;
3046 struct btrfs_path *path;
3047 u64 length;
3048 u64 chunk_tree;
3049 u64 chunk_objectid;
3050 u64 chunk_offset;
3051 int ret;
3052 int slot;
3053 int failed = 0;
3054 bool retried = false;
3055 struct extent_buffer *l;
3056 struct btrfs_key key;
3057 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3058 u64 old_total = btrfs_super_total_bytes(super_copy);
3059 u64 old_size = device->total_bytes;
3060 u64 diff = device->total_bytes - new_size;
3061
3062 if (new_size >= device->total_bytes)
3063 return -EINVAL;
3064
3065 path = btrfs_alloc_path();
3066 if (!path)
3067 return -ENOMEM;
3068
3069 path->reada = 2;
3070
3071 lock_chunks(root);
3072
3073 device->total_bytes = new_size;
3074 if (device->writeable) {
3075 device->fs_devices->total_rw_bytes -= diff;
3076 spin_lock(&root->fs_info->free_chunk_lock);
3077 root->fs_info->free_chunk_space -= diff;
3078 spin_unlock(&root->fs_info->free_chunk_lock);
3079 }
3080 unlock_chunks(root);
3081
3082 again:
3083 key.objectid = device->devid;
3084 key.offset = (u64)-1;
3085 key.type = BTRFS_DEV_EXTENT_KEY;
3086
3087 do {
3088 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3089 if (ret < 0)
3090 goto done;
3091
3092 ret = btrfs_previous_item(root, path, 0, key.type);
3093 if (ret < 0)
3094 goto done;
3095 if (ret) {
3096 ret = 0;
3097 btrfs_release_path(path);
3098 break;
3099 }
3100
3101 l = path->nodes[0];
3102 slot = path->slots[0];
3103 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3104
3105 if (key.objectid != device->devid) {
3106 btrfs_release_path(path);
3107 break;
3108 }
3109
3110 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3111 length = btrfs_dev_extent_length(l, dev_extent);
3112
3113 if (key.offset + length <= new_size) {
3114 btrfs_release_path(path);
3115 break;
3116 }
3117
3118 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3119 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3120 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3121 btrfs_release_path(path);
3122
3123 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3124 chunk_offset);
3125 if (ret && ret != -ENOSPC)
3126 goto done;
3127 if (ret == -ENOSPC)
3128 failed++;
3129 } while (key.offset-- > 0);
3130
3131 if (failed && !retried) {
3132 failed = 0;
3133 retried = true;
3134 goto again;
3135 } else if (failed && retried) {
3136 ret = -ENOSPC;
3137 lock_chunks(root);
3138
3139 device->total_bytes = old_size;
3140 if (device->writeable)
3141 device->fs_devices->total_rw_bytes += diff;
3142 spin_lock(&root->fs_info->free_chunk_lock);
3143 root->fs_info->free_chunk_space += diff;
3144 spin_unlock(&root->fs_info->free_chunk_lock);
3145 unlock_chunks(root);
3146 goto done;
3147 }
3148
3149 /* Shrinking succeeded, else we would be at "done". */
3150 trans = btrfs_start_transaction(root, 0);
3151 if (IS_ERR(trans)) {
3152 ret = PTR_ERR(trans);
3153 goto done;
3154 }
3155
3156 lock_chunks(root);
3157
3158 device->disk_total_bytes = new_size;
3159 /* Now btrfs_update_device() will change the on-disk size. */
3160 ret = btrfs_update_device(trans, device);
3161 if (ret) {
3162 unlock_chunks(root);
3163 btrfs_end_transaction(trans, root);
3164 goto done;
3165 }
3166 WARN_ON(diff > old_total);
3167 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3168 unlock_chunks(root);
3169 btrfs_end_transaction(trans, root);
3170 done:
3171 btrfs_free_path(path);
3172 return ret;
3173 }
3174
3175 static int btrfs_add_system_chunk(struct btrfs_root *root,
3176 struct btrfs_key *key,
3177 struct btrfs_chunk *chunk, int item_size)
3178 {
3179 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3180 struct btrfs_disk_key disk_key;
3181 u32 array_size;
3182 u8 *ptr;
3183
3184 array_size = btrfs_super_sys_array_size(super_copy);
3185 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3186 return -EFBIG;
3187
3188 ptr = super_copy->sys_chunk_array + array_size;
3189 btrfs_cpu_key_to_disk(&disk_key, key);
3190 memcpy(ptr, &disk_key, sizeof(disk_key));
3191 ptr += sizeof(disk_key);
3192 memcpy(ptr, chunk, item_size);
3193 item_size += sizeof(disk_key);
3194 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3195 return 0;
3196 }
3197
3198 /*
3199 * sort the devices in descending order by max_avail, total_avail
3200 */
3201 static int btrfs_cmp_device_info(const void *a, const void *b)
3202 {
3203 const struct btrfs_device_info *di_a = a;
3204 const struct btrfs_device_info *di_b = b;
3205
3206 if (di_a->max_avail > di_b->max_avail)
3207 return -1;
3208 if (di_a->max_avail < di_b->max_avail)
3209 return 1;
3210 if (di_a->total_avail > di_b->total_avail)
3211 return -1;
3212 if (di_a->total_avail < di_b->total_avail)
3213 return 1;
3214 return 0;
3215 }
3216
3217 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3218 struct btrfs_root *extent_root,
3219 struct map_lookup **map_ret,
3220 u64 *num_bytes_out, u64 *stripe_size_out,
3221 u64 start, u64 type)
3222 {
3223 struct btrfs_fs_info *info = extent_root->fs_info;
3224 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3225 struct list_head *cur;
3226 struct map_lookup *map = NULL;
3227 struct extent_map_tree *em_tree;
3228 struct extent_map *em;
3229 struct btrfs_device_info *devices_info = NULL;
3230 u64 total_avail;
3231 int num_stripes; /* total number of stripes to allocate */
3232 int sub_stripes; /* sub_stripes info for map */
3233 int dev_stripes; /* stripes per dev */
3234 int devs_max; /* max devs to use */
3235 int devs_min; /* min devs needed */
3236 int devs_increment; /* ndevs has to be a multiple of this */
3237 int ncopies; /* how many copies to data has */
3238 int ret;
3239 u64 max_stripe_size;
3240 u64 max_chunk_size;
3241 u64 stripe_size;
3242 u64 num_bytes;
3243 int ndevs;
3244 int i;
3245 int j;
3246
3247 BUG_ON(!alloc_profile_is_valid(type, 0));
3248
3249 if (list_empty(&fs_devices->alloc_list))
3250 return -ENOSPC;
3251
3252 sub_stripes = 1;
3253 dev_stripes = 1;
3254 devs_increment = 1;
3255 ncopies = 1;
3256 devs_max = 0; /* 0 == as many as possible */
3257 devs_min = 1;
3258
3259 /*
3260 * define the properties of each RAID type.
3261 * FIXME: move this to a global table and use it in all RAID
3262 * calculation code
3263 */
3264 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
3265 dev_stripes = 2;
3266 ncopies = 2;
3267 devs_max = 1;
3268 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
3269 devs_min = 2;
3270 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
3271 devs_increment = 2;
3272 ncopies = 2;
3273 devs_max = 2;
3274 devs_min = 2;
3275 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
3276 sub_stripes = 2;
3277 devs_increment = 2;
3278 ncopies = 2;
3279 devs_min = 4;
3280 } else {
3281 devs_max = 1;
3282 }
3283
3284 if (type & BTRFS_BLOCK_GROUP_DATA) {
3285 max_stripe_size = 1024 * 1024 * 1024;
3286 max_chunk_size = 10 * max_stripe_size;
3287 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3288 /* for larger filesystems, use larger metadata chunks */
3289 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3290 max_stripe_size = 1024 * 1024 * 1024;
3291 else
3292 max_stripe_size = 256 * 1024 * 1024;
3293 max_chunk_size = max_stripe_size;
3294 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3295 max_stripe_size = 32 * 1024 * 1024;
3296 max_chunk_size = 2 * max_stripe_size;
3297 } else {
3298 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3299 type);
3300 BUG_ON(1);
3301 }
3302
3303 /* we don't want a chunk larger than 10% of writeable space */
3304 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3305 max_chunk_size);
3306
3307 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3308 GFP_NOFS);
3309 if (!devices_info)
3310 return -ENOMEM;
3311
3312 cur = fs_devices->alloc_list.next;
3313
3314 /*
3315 * in the first pass through the devices list, we gather information
3316 * about the available holes on each device.
3317 */
3318 ndevs = 0;
3319 while (cur != &fs_devices->alloc_list) {
3320 struct btrfs_device *device;
3321 u64 max_avail;
3322 u64 dev_offset;
3323
3324 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3325
3326 cur = cur->next;
3327
3328 if (!device->writeable) {
3329 printk(KERN_ERR
3330 "btrfs: read-only device in alloc_list\n");
3331 WARN_ON(1);
3332 continue;
3333 }
3334
3335 if (!device->in_fs_metadata)
3336 continue;
3337
3338 if (device->total_bytes > device->bytes_used)
3339 total_avail = device->total_bytes - device->bytes_used;
3340 else
3341 total_avail = 0;
3342
3343 /* If there is no space on this device, skip it. */
3344 if (total_avail == 0)
3345 continue;
3346
3347 ret = find_free_dev_extent(device,
3348 max_stripe_size * dev_stripes,
3349 &dev_offset, &max_avail);
3350 if (ret && ret != -ENOSPC)
3351 goto error;
3352
3353 if (ret == 0)
3354 max_avail = max_stripe_size * dev_stripes;
3355
3356 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3357 continue;
3358
3359 devices_info[ndevs].dev_offset = dev_offset;
3360 devices_info[ndevs].max_avail = max_avail;
3361 devices_info[ndevs].total_avail = total_avail;
3362 devices_info[ndevs].dev = device;
3363 ++ndevs;
3364 }
3365
3366 /*
3367 * now sort the devices by hole size / available space
3368 */
3369 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3370 btrfs_cmp_device_info, NULL);
3371
3372 /* round down to number of usable stripes */
3373 ndevs -= ndevs % devs_increment;
3374
3375 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3376 ret = -ENOSPC;
3377 goto error;
3378 }
3379
3380 if (devs_max && ndevs > devs_max)
3381 ndevs = devs_max;
3382 /*
3383 * the primary goal is to maximize the number of stripes, so use as many
3384 * devices as possible, even if the stripes are not maximum sized.
3385 */
3386 stripe_size = devices_info[ndevs-1].max_avail;
3387 num_stripes = ndevs * dev_stripes;
3388
3389 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3390 stripe_size = max_chunk_size * ncopies;
3391 do_div(stripe_size, ndevs);
3392 }
3393
3394 do_div(stripe_size, dev_stripes);
3395
3396 /* align to BTRFS_STRIPE_LEN */
3397 do_div(stripe_size, BTRFS_STRIPE_LEN);
3398 stripe_size *= BTRFS_STRIPE_LEN;
3399
3400 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3401 if (!map) {
3402 ret = -ENOMEM;
3403 goto error;
3404 }
3405 map->num_stripes = num_stripes;
3406
3407 for (i = 0; i < ndevs; ++i) {
3408 for (j = 0; j < dev_stripes; ++j) {
3409 int s = i * dev_stripes + j;
3410 map->stripes[s].dev = devices_info[i].dev;
3411 map->stripes[s].physical = devices_info[i].dev_offset +
3412 j * stripe_size;
3413 }
3414 }
3415 map->sector_size = extent_root->sectorsize;
3416 map->stripe_len = BTRFS_STRIPE_LEN;
3417 map->io_align = BTRFS_STRIPE_LEN;
3418 map->io_width = BTRFS_STRIPE_LEN;
3419 map->type = type;
3420 map->sub_stripes = sub_stripes;
3421
3422 *map_ret = map;
3423 num_bytes = stripe_size * (num_stripes / ncopies);
3424
3425 *stripe_size_out = stripe_size;
3426 *num_bytes_out = num_bytes;
3427
3428 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3429
3430 em = alloc_extent_map();
3431 if (!em) {
3432 ret = -ENOMEM;
3433 goto error;
3434 }
3435 em->bdev = (struct block_device *)map;
3436 em->start = start;
3437 em->len = num_bytes;
3438 em->block_start = 0;
3439 em->block_len = em->len;
3440
3441 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3442 write_lock(&em_tree->lock);
3443 ret = add_extent_mapping(em_tree, em);
3444 write_unlock(&em_tree->lock);
3445 free_extent_map(em);
3446 if (ret)
3447 goto error;
3448
3449 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3450 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3451 start, num_bytes);
3452 if (ret)
3453 goto error;
3454
3455 for (i = 0; i < map->num_stripes; ++i) {
3456 struct btrfs_device *device;
3457 u64 dev_offset;
3458
3459 device = map->stripes[i].dev;
3460 dev_offset = map->stripes[i].physical;
3461
3462 ret = btrfs_alloc_dev_extent(trans, device,
3463 info->chunk_root->root_key.objectid,
3464 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3465 start, dev_offset, stripe_size);
3466 if (ret) {
3467 btrfs_abort_transaction(trans, extent_root, ret);
3468 goto error;
3469 }
3470 }
3471
3472 kfree(devices_info);
3473 return 0;
3474
3475 error:
3476 kfree(map);
3477 kfree(devices_info);
3478 return ret;
3479 }
3480
3481 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3482 struct btrfs_root *extent_root,
3483 struct map_lookup *map, u64 chunk_offset,
3484 u64 chunk_size, u64 stripe_size)
3485 {
3486 u64 dev_offset;
3487 struct btrfs_key key;
3488 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3489 struct btrfs_device *device;
3490 struct btrfs_chunk *chunk;
3491 struct btrfs_stripe *stripe;
3492 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3493 int index = 0;
3494 int ret;
3495
3496 chunk = kzalloc(item_size, GFP_NOFS);
3497 if (!chunk)
3498 return -ENOMEM;
3499
3500 index = 0;
3501 while (index < map->num_stripes) {
3502 device = map->stripes[index].dev;
3503 device->bytes_used += stripe_size;
3504 ret = btrfs_update_device(trans, device);
3505 if (ret)
3506 goto out_free;
3507 index++;
3508 }
3509
3510 spin_lock(&extent_root->fs_info->free_chunk_lock);
3511 extent_root->fs_info->free_chunk_space -= (stripe_size *
3512 map->num_stripes);
3513 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3514
3515 index = 0;
3516 stripe = &chunk->stripe;
3517 while (index < map->num_stripes) {
3518 device = map->stripes[index].dev;
3519 dev_offset = map->stripes[index].physical;
3520
3521 btrfs_set_stack_stripe_devid(stripe, device->devid);
3522 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3523 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3524 stripe++;
3525 index++;
3526 }
3527
3528 btrfs_set_stack_chunk_length(chunk, chunk_size);
3529 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3530 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3531 btrfs_set_stack_chunk_type(chunk, map->type);
3532 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3533 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3534 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3535 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3536 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3537
3538 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3539 key.type = BTRFS_CHUNK_ITEM_KEY;
3540 key.offset = chunk_offset;
3541
3542 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3543
3544 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3545 /*
3546 * TODO: Cleanup of inserted chunk root in case of
3547 * failure.
3548 */
3549 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3550 item_size);
3551 }
3552
3553 out_free:
3554 kfree(chunk);
3555 return ret;
3556 }
3557
3558 /*
3559 * Chunk allocation falls into two parts. The first part does works
3560 * that make the new allocated chunk useable, but not do any operation
3561 * that modifies the chunk tree. The second part does the works that
3562 * require modifying the chunk tree. This division is important for the
3563 * bootstrap process of adding storage to a seed btrfs.
3564 */
3565 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3566 struct btrfs_root *extent_root, u64 type)
3567 {
3568 u64 chunk_offset;
3569 u64 chunk_size;
3570 u64 stripe_size;
3571 struct map_lookup *map;
3572 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3573 int ret;
3574
3575 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3576 &chunk_offset);
3577 if (ret)
3578 return ret;
3579
3580 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3581 &stripe_size, chunk_offset, type);
3582 if (ret)
3583 return ret;
3584
3585 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3586 chunk_size, stripe_size);
3587 if (ret)
3588 return ret;
3589 return 0;
3590 }
3591
3592 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3593 struct btrfs_root *root,
3594 struct btrfs_device *device)
3595 {
3596 u64 chunk_offset;
3597 u64 sys_chunk_offset;
3598 u64 chunk_size;
3599 u64 sys_chunk_size;
3600 u64 stripe_size;
3601 u64 sys_stripe_size;
3602 u64 alloc_profile;
3603 struct map_lookup *map;
3604 struct map_lookup *sys_map;
3605 struct btrfs_fs_info *fs_info = root->fs_info;
3606 struct btrfs_root *extent_root = fs_info->extent_root;
3607 int ret;
3608
3609 ret = find_next_chunk(fs_info->chunk_root,
3610 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3611 if (ret)
3612 return ret;
3613
3614 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3615 fs_info->avail_metadata_alloc_bits;
3616 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3617
3618 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3619 &stripe_size, chunk_offset, alloc_profile);
3620 if (ret)
3621 return ret;
3622
3623 sys_chunk_offset = chunk_offset + chunk_size;
3624
3625 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3626 fs_info->avail_system_alloc_bits;
3627 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3628
3629 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3630 &sys_chunk_size, &sys_stripe_size,
3631 sys_chunk_offset, alloc_profile);
3632 if (ret) {
3633 btrfs_abort_transaction(trans, root, ret);
3634 goto out;
3635 }
3636
3637 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3638 if (ret) {
3639 btrfs_abort_transaction(trans, root, ret);
3640 goto out;
3641 }
3642
3643 /*
3644 * Modifying chunk tree needs allocating new blocks from both
3645 * system block group and metadata block group. So we only can
3646 * do operations require modifying the chunk tree after both
3647 * block groups were created.
3648 */
3649 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3650 chunk_size, stripe_size);
3651 if (ret) {
3652 btrfs_abort_transaction(trans, root, ret);
3653 goto out;
3654 }
3655
3656 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3657 sys_chunk_offset, sys_chunk_size,
3658 sys_stripe_size);
3659 if (ret)
3660 btrfs_abort_transaction(trans, root, ret);
3661
3662 out:
3663
3664 return ret;
3665 }
3666
3667 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3668 {
3669 struct extent_map *em;
3670 struct map_lookup *map;
3671 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3672 int readonly = 0;
3673 int i;
3674
3675 read_lock(&map_tree->map_tree.lock);
3676 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3677 read_unlock(&map_tree->map_tree.lock);
3678 if (!em)
3679 return 1;
3680
3681 if (btrfs_test_opt(root, DEGRADED)) {
3682 free_extent_map(em);
3683 return 0;
3684 }
3685
3686 map = (struct map_lookup *)em->bdev;
3687 for (i = 0; i < map->num_stripes; i++) {
3688 if (!map->stripes[i].dev->writeable) {
3689 readonly = 1;
3690 break;
3691 }
3692 }
3693 free_extent_map(em);
3694 return readonly;
3695 }
3696
3697 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3698 {
3699 extent_map_tree_init(&tree->map_tree);
3700 }
3701
3702 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3703 {
3704 struct extent_map *em;
3705
3706 while (1) {
3707 write_lock(&tree->map_tree.lock);
3708 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3709 if (em)
3710 remove_extent_mapping(&tree->map_tree, em);
3711 write_unlock(&tree->map_tree.lock);
3712 if (!em)
3713 break;
3714 kfree(em->bdev);
3715 /* once for us */
3716 free_extent_map(em);
3717 /* once for the tree */
3718 free_extent_map(em);
3719 }
3720 }
3721
3722 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
3723 {
3724 struct extent_map *em;
3725 struct map_lookup *map;
3726 struct extent_map_tree *em_tree = &map_tree->map_tree;
3727 int ret;
3728
3729 read_lock(&em_tree->lock);
3730 em = lookup_extent_mapping(em_tree, logical, len);
3731 read_unlock(&em_tree->lock);
3732 BUG_ON(!em);
3733
3734 BUG_ON(em->start > logical || em->start + em->len < logical);
3735 map = (struct map_lookup *)em->bdev;
3736 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
3737 ret = map->num_stripes;
3738 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3739 ret = map->sub_stripes;
3740 else
3741 ret = 1;
3742 free_extent_map(em);
3743 return ret;
3744 }
3745
3746 static int find_live_mirror(struct map_lookup *map, int first, int num,
3747 int optimal)
3748 {
3749 int i;
3750 if (map->stripes[optimal].dev->bdev)
3751 return optimal;
3752 for (i = first; i < first + num; i++) {
3753 if (map->stripes[i].dev->bdev)
3754 return i;
3755 }
3756 /* we couldn't find one that doesn't fail. Just return something
3757 * and the io error handling code will clean up eventually
3758 */
3759 return optimal;
3760 }
3761
3762 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3763 u64 logical, u64 *length,
3764 struct btrfs_bio **bbio_ret,
3765 int mirror_num)
3766 {
3767 struct extent_map *em;
3768 struct map_lookup *map;
3769 struct extent_map_tree *em_tree = &map_tree->map_tree;
3770 u64 offset;
3771 u64 stripe_offset;
3772 u64 stripe_end_offset;
3773 u64 stripe_nr;
3774 u64 stripe_nr_orig;
3775 u64 stripe_nr_end;
3776 int stripe_index;
3777 int i;
3778 int ret = 0;
3779 int num_stripes;
3780 int max_errors = 0;
3781 struct btrfs_bio *bbio = NULL;
3782
3783 read_lock(&em_tree->lock);
3784 em = lookup_extent_mapping(em_tree, logical, *length);
3785 read_unlock(&em_tree->lock);
3786
3787 if (!em) {
3788 printk(KERN_CRIT "btrfs: unable to find logical %llu len %llu\n",
3789 (unsigned long long)logical,
3790 (unsigned long long)*length);
3791 BUG();
3792 }
3793
3794 BUG_ON(em->start > logical || em->start + em->len < logical);
3795 map = (struct map_lookup *)em->bdev;
3796 offset = logical - em->start;
3797
3798 if (mirror_num > map->num_stripes)
3799 mirror_num = 0;
3800
3801 stripe_nr = offset;
3802 /*
3803 * stripe_nr counts the total number of stripes we have to stride
3804 * to get to this block
3805 */
3806 do_div(stripe_nr, map->stripe_len);
3807
3808 stripe_offset = stripe_nr * map->stripe_len;
3809 BUG_ON(offset < stripe_offset);
3810
3811 /* stripe_offset is the offset of this block in its stripe*/
3812 stripe_offset = offset - stripe_offset;
3813
3814 if (rw & REQ_DISCARD)
3815 *length = min_t(u64, em->len - offset, *length);
3816 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3817 /* we limit the length of each bio to what fits in a stripe */
3818 *length = min_t(u64, em->len - offset,
3819 map->stripe_len - stripe_offset);
3820 } else {
3821 *length = em->len - offset;
3822 }
3823
3824 if (!bbio_ret)
3825 goto out;
3826
3827 num_stripes = 1;
3828 stripe_index = 0;
3829 stripe_nr_orig = stripe_nr;
3830 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3831 (~(map->stripe_len - 1));
3832 do_div(stripe_nr_end, map->stripe_len);
3833 stripe_end_offset = stripe_nr_end * map->stripe_len -
3834 (offset + *length);
3835 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3836 if (rw & REQ_DISCARD)
3837 num_stripes = min_t(u64, map->num_stripes,
3838 stripe_nr_end - stripe_nr_orig);
3839 stripe_index = do_div(stripe_nr, map->num_stripes);
3840 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3841 if (rw & (REQ_WRITE | REQ_DISCARD))
3842 num_stripes = map->num_stripes;
3843 else if (mirror_num)
3844 stripe_index = mirror_num - 1;
3845 else {
3846 stripe_index = find_live_mirror(map, 0,
3847 map->num_stripes,
3848 current->pid % map->num_stripes);
3849 mirror_num = stripe_index + 1;
3850 }
3851
3852 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3853 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3854 num_stripes = map->num_stripes;
3855 } else if (mirror_num) {
3856 stripe_index = mirror_num - 1;
3857 } else {
3858 mirror_num = 1;
3859 }
3860
3861 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3862 int factor = map->num_stripes / map->sub_stripes;
3863
3864 stripe_index = do_div(stripe_nr, factor);
3865 stripe_index *= map->sub_stripes;
3866
3867 if (rw & REQ_WRITE)
3868 num_stripes = map->sub_stripes;
3869 else if (rw & REQ_DISCARD)
3870 num_stripes = min_t(u64, map->sub_stripes *
3871 (stripe_nr_end - stripe_nr_orig),
3872 map->num_stripes);
3873 else if (mirror_num)
3874 stripe_index += mirror_num - 1;
3875 else {
3876 int old_stripe_index = stripe_index;
3877 stripe_index = find_live_mirror(map, stripe_index,
3878 map->sub_stripes, stripe_index +
3879 current->pid % map->sub_stripes);
3880 mirror_num = stripe_index - old_stripe_index + 1;
3881 }
3882 } else {
3883 /*
3884 * after this do_div call, stripe_nr is the number of stripes
3885 * on this device we have to walk to find the data, and
3886 * stripe_index is the number of our device in the stripe array
3887 */
3888 stripe_index = do_div(stripe_nr, map->num_stripes);
3889 mirror_num = stripe_index + 1;
3890 }
3891 BUG_ON(stripe_index >= map->num_stripes);
3892
3893 bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
3894 if (!bbio) {
3895 ret = -ENOMEM;
3896 goto out;
3897 }
3898 atomic_set(&bbio->error, 0);
3899
3900 if (rw & REQ_DISCARD) {
3901 int factor = 0;
3902 int sub_stripes = 0;
3903 u64 stripes_per_dev = 0;
3904 u32 remaining_stripes = 0;
3905 u32 last_stripe = 0;
3906
3907 if (map->type &
3908 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
3909 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3910 sub_stripes = 1;
3911 else
3912 sub_stripes = map->sub_stripes;
3913
3914 factor = map->num_stripes / sub_stripes;
3915 stripes_per_dev = div_u64_rem(stripe_nr_end -
3916 stripe_nr_orig,
3917 factor,
3918 &remaining_stripes);
3919 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
3920 last_stripe *= sub_stripes;
3921 }
3922
3923 for (i = 0; i < num_stripes; i++) {
3924 bbio->stripes[i].physical =
3925 map->stripes[stripe_index].physical +
3926 stripe_offset + stripe_nr * map->stripe_len;
3927 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3928
3929 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3930 BTRFS_BLOCK_GROUP_RAID10)) {
3931 bbio->stripes[i].length = stripes_per_dev *
3932 map->stripe_len;
3933
3934 if (i / sub_stripes < remaining_stripes)
3935 bbio->stripes[i].length +=
3936 map->stripe_len;
3937
3938 /*
3939 * Special for the first stripe and
3940 * the last stripe:
3941 *
3942 * |-------|...|-------|
3943 * |----------|
3944 * off end_off
3945 */
3946 if (i < sub_stripes)
3947 bbio->stripes[i].length -=
3948 stripe_offset;
3949
3950 if (stripe_index >= last_stripe &&
3951 stripe_index <= (last_stripe +
3952 sub_stripes - 1))
3953 bbio->stripes[i].length -=
3954 stripe_end_offset;
3955
3956 if (i == sub_stripes - 1)
3957 stripe_offset = 0;
3958 } else
3959 bbio->stripes[i].length = *length;
3960
3961 stripe_index++;
3962 if (stripe_index == map->num_stripes) {
3963 /* This could only happen for RAID0/10 */
3964 stripe_index = 0;
3965 stripe_nr++;
3966 }
3967 }
3968 } else {
3969 for (i = 0; i < num_stripes; i++) {
3970 bbio->stripes[i].physical =
3971 map->stripes[stripe_index].physical +
3972 stripe_offset +
3973 stripe_nr * map->stripe_len;
3974 bbio->stripes[i].dev =
3975 map->stripes[stripe_index].dev;
3976 stripe_index++;
3977 }
3978 }
3979
3980 if (rw & REQ_WRITE) {
3981 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
3982 BTRFS_BLOCK_GROUP_RAID10 |
3983 BTRFS_BLOCK_GROUP_DUP)) {
3984 max_errors = 1;
3985 }
3986 }
3987
3988 *bbio_ret = bbio;
3989 bbio->num_stripes = num_stripes;
3990 bbio->max_errors = max_errors;
3991 bbio->mirror_num = mirror_num;
3992 out:
3993 free_extent_map(em);
3994 return ret;
3995 }
3996
3997 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3998 u64 logical, u64 *length,
3999 struct btrfs_bio **bbio_ret, int mirror_num)
4000 {
4001 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
4002 mirror_num);
4003 }
4004
4005 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4006 u64 chunk_start, u64 physical, u64 devid,
4007 u64 **logical, int *naddrs, int *stripe_len)
4008 {
4009 struct extent_map_tree *em_tree = &map_tree->map_tree;
4010 struct extent_map *em;
4011 struct map_lookup *map;
4012 u64 *buf;
4013 u64 bytenr;
4014 u64 length;
4015 u64 stripe_nr;
4016 int i, j, nr = 0;
4017
4018 read_lock(&em_tree->lock);
4019 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4020 read_unlock(&em_tree->lock);
4021
4022 BUG_ON(!em || em->start != chunk_start);
4023 map = (struct map_lookup *)em->bdev;
4024
4025 length = em->len;
4026 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4027 do_div(length, map->num_stripes / map->sub_stripes);
4028 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4029 do_div(length, map->num_stripes);
4030
4031 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4032 BUG_ON(!buf); /* -ENOMEM */
4033
4034 for (i = 0; i < map->num_stripes; i++) {
4035 if (devid && map->stripes[i].dev->devid != devid)
4036 continue;
4037 if (map->stripes[i].physical > physical ||
4038 map->stripes[i].physical + length <= physical)
4039 continue;
4040
4041 stripe_nr = physical - map->stripes[i].physical;
4042 do_div(stripe_nr, map->stripe_len);
4043
4044 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4045 stripe_nr = stripe_nr * map->num_stripes + i;
4046 do_div(stripe_nr, map->sub_stripes);
4047 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4048 stripe_nr = stripe_nr * map->num_stripes + i;
4049 }
4050 bytenr = chunk_start + stripe_nr * map->stripe_len;
4051 WARN_ON(nr >= map->num_stripes);
4052 for (j = 0; j < nr; j++) {
4053 if (buf[j] == bytenr)
4054 break;
4055 }
4056 if (j == nr) {
4057 WARN_ON(nr >= map->num_stripes);
4058 buf[nr++] = bytenr;
4059 }
4060 }
4061
4062 *logical = buf;
4063 *naddrs = nr;
4064 *stripe_len = map->stripe_len;
4065
4066 free_extent_map(em);
4067 return 0;
4068 }
4069
4070 static void *merge_stripe_index_into_bio_private(void *bi_private,
4071 unsigned int stripe_index)
4072 {
4073 /*
4074 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4075 * at most 1.
4076 * The alternative solution (instead of stealing bits from the
4077 * pointer) would be to allocate an intermediate structure
4078 * that contains the old private pointer plus the stripe_index.
4079 */
4080 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4081 BUG_ON(stripe_index > 3);
4082 return (void *)(((uintptr_t)bi_private) | stripe_index);
4083 }
4084
4085 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4086 {
4087 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4088 }
4089
4090 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4091 {
4092 return (unsigned int)((uintptr_t)bi_private) & 3;
4093 }
4094
4095 static void btrfs_end_bio(struct bio *bio, int err)
4096 {
4097 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4098 int is_orig_bio = 0;
4099
4100 if (err) {
4101 atomic_inc(&bbio->error);
4102 if (err == -EIO || err == -EREMOTEIO) {
4103 unsigned int stripe_index =
4104 extract_stripe_index_from_bio_private(
4105 bio->bi_private);
4106 struct btrfs_device *dev;
4107
4108 BUG_ON(stripe_index >= bbio->num_stripes);
4109 dev = bbio->stripes[stripe_index].dev;
4110 if (dev->bdev) {
4111 if (bio->bi_rw & WRITE)
4112 btrfs_dev_stat_inc(dev,
4113 BTRFS_DEV_STAT_WRITE_ERRS);
4114 else
4115 btrfs_dev_stat_inc(dev,
4116 BTRFS_DEV_STAT_READ_ERRS);
4117 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4118 btrfs_dev_stat_inc(dev,
4119 BTRFS_DEV_STAT_FLUSH_ERRS);
4120 btrfs_dev_stat_print_on_error(dev);
4121 }
4122 }
4123 }
4124
4125 if (bio == bbio->orig_bio)
4126 is_orig_bio = 1;
4127
4128 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4129 if (!is_orig_bio) {
4130 bio_put(bio);
4131 bio = bbio->orig_bio;
4132 }
4133 bio->bi_private = bbio->private;
4134 bio->bi_end_io = bbio->end_io;
4135 bio->bi_bdev = (struct block_device *)
4136 (unsigned long)bbio->mirror_num;
4137 /* only send an error to the higher layers if it is
4138 * beyond the tolerance of the multi-bio
4139 */
4140 if (atomic_read(&bbio->error) > bbio->max_errors) {
4141 err = -EIO;
4142 } else {
4143 /*
4144 * this bio is actually up to date, we didn't
4145 * go over the max number of errors
4146 */
4147 set_bit(BIO_UPTODATE, &bio->bi_flags);
4148 err = 0;
4149 }
4150 kfree(bbio);
4151
4152 bio_endio(bio, err);
4153 } else if (!is_orig_bio) {
4154 bio_put(bio);
4155 }
4156 }
4157
4158 struct async_sched {
4159 struct bio *bio;
4160 int rw;
4161 struct btrfs_fs_info *info;
4162 struct btrfs_work work;
4163 };
4164
4165 /*
4166 * see run_scheduled_bios for a description of why bios are collected for
4167 * async submit.
4168 *
4169 * This will add one bio to the pending list for a device and make sure
4170 * the work struct is scheduled.
4171 */
4172 static noinline void schedule_bio(struct btrfs_root *root,
4173 struct btrfs_device *device,
4174 int rw, struct bio *bio)
4175 {
4176 int should_queue = 1;
4177 struct btrfs_pending_bios *pending_bios;
4178
4179 /* don't bother with additional async steps for reads, right now */
4180 if (!(rw & REQ_WRITE)) {
4181 bio_get(bio);
4182 btrfsic_submit_bio(rw, bio);
4183 bio_put(bio);
4184 return;
4185 }
4186
4187 /*
4188 * nr_async_bios allows us to reliably return congestion to the
4189 * higher layers. Otherwise, the async bio makes it appear we have
4190 * made progress against dirty pages when we've really just put it
4191 * on a queue for later
4192 */
4193 atomic_inc(&root->fs_info->nr_async_bios);
4194 WARN_ON(bio->bi_next);
4195 bio->bi_next = NULL;
4196 bio->bi_rw |= rw;
4197
4198 spin_lock(&device->io_lock);
4199 if (bio->bi_rw & REQ_SYNC)
4200 pending_bios = &device->pending_sync_bios;
4201 else
4202 pending_bios = &device->pending_bios;
4203
4204 if (pending_bios->tail)
4205 pending_bios->tail->bi_next = bio;
4206
4207 pending_bios->tail = bio;
4208 if (!pending_bios->head)
4209 pending_bios->head = bio;
4210 if (device->running_pending)
4211 should_queue = 0;
4212
4213 spin_unlock(&device->io_lock);
4214
4215 if (should_queue)
4216 btrfs_queue_worker(&root->fs_info->submit_workers,
4217 &device->work);
4218 }
4219
4220 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4221 int mirror_num, int async_submit)
4222 {
4223 struct btrfs_mapping_tree *map_tree;
4224 struct btrfs_device *dev;
4225 struct bio *first_bio = bio;
4226 u64 logical = (u64)bio->bi_sector << 9;
4227 u64 length = 0;
4228 u64 map_length;
4229 int ret;
4230 int dev_nr = 0;
4231 int total_devs = 1;
4232 struct btrfs_bio *bbio = NULL;
4233
4234 length = bio->bi_size;
4235 map_tree = &root->fs_info->mapping_tree;
4236 map_length = length;
4237
4238 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
4239 mirror_num);
4240 if (ret) /* -ENOMEM */
4241 return ret;
4242
4243 total_devs = bbio->num_stripes;
4244 if (map_length < length) {
4245 printk(KERN_CRIT "btrfs: mapping failed logical %llu bio len %llu "
4246 "len %llu\n", (unsigned long long)logical,
4247 (unsigned long long)length,
4248 (unsigned long long)map_length);
4249 BUG();
4250 }
4251
4252 bbio->orig_bio = first_bio;
4253 bbio->private = first_bio->bi_private;
4254 bbio->end_io = first_bio->bi_end_io;
4255 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4256
4257 while (dev_nr < total_devs) {
4258 if (dev_nr < total_devs - 1) {
4259 bio = bio_clone(first_bio, GFP_NOFS);
4260 BUG_ON(!bio); /* -ENOMEM */
4261 } else {
4262 bio = first_bio;
4263 }
4264 bio->bi_private = bbio;
4265 bio->bi_private = merge_stripe_index_into_bio_private(
4266 bio->bi_private, (unsigned int)dev_nr);
4267 bio->bi_end_io = btrfs_end_bio;
4268 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
4269 dev = bbio->stripes[dev_nr].dev;
4270 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
4271 #ifdef DEBUG
4272 struct rcu_string *name;
4273
4274 rcu_read_lock();
4275 name = rcu_dereference(dev->name);
4276 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
4277 "(%s id %llu), size=%u\n", rw,
4278 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4279 name->str, dev->devid, bio->bi_size);
4280 rcu_read_unlock();
4281 #endif
4282 bio->bi_bdev = dev->bdev;
4283 if (async_submit)
4284 schedule_bio(root, dev, rw, bio);
4285 else
4286 btrfsic_submit_bio(rw, bio);
4287 } else {
4288 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
4289 bio->bi_sector = logical >> 9;
4290 bio_endio(bio, -EIO);
4291 }
4292 dev_nr++;
4293 }
4294 return 0;
4295 }
4296
4297 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
4298 u8 *uuid, u8 *fsid)
4299 {
4300 struct btrfs_device *device;
4301 struct btrfs_fs_devices *cur_devices;
4302
4303 cur_devices = root->fs_info->fs_devices;
4304 while (cur_devices) {
4305 if (!fsid ||
4306 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4307 device = __find_device(&cur_devices->devices,
4308 devid, uuid);
4309 if (device)
4310 return device;
4311 }
4312 cur_devices = cur_devices->seed;
4313 }
4314 return NULL;
4315 }
4316
4317 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4318 u64 devid, u8 *dev_uuid)
4319 {
4320 struct btrfs_device *device;
4321 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4322
4323 device = kzalloc(sizeof(*device), GFP_NOFS);
4324 if (!device)
4325 return NULL;
4326 list_add(&device->dev_list,
4327 &fs_devices->devices);
4328 device->dev_root = root->fs_info->dev_root;
4329 device->devid = devid;
4330 device->work.func = pending_bios_fn;
4331 device->fs_devices = fs_devices;
4332 device->missing = 1;
4333 fs_devices->num_devices++;
4334 fs_devices->missing_devices++;
4335 spin_lock_init(&device->io_lock);
4336 INIT_LIST_HEAD(&device->dev_alloc_list);
4337 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4338 return device;
4339 }
4340
4341 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4342 struct extent_buffer *leaf,
4343 struct btrfs_chunk *chunk)
4344 {
4345 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4346 struct map_lookup *map;
4347 struct extent_map *em;
4348 u64 logical;
4349 u64 length;
4350 u64 devid;
4351 u8 uuid[BTRFS_UUID_SIZE];
4352 int num_stripes;
4353 int ret;
4354 int i;
4355
4356 logical = key->offset;
4357 length = btrfs_chunk_length(leaf, chunk);
4358
4359 read_lock(&map_tree->map_tree.lock);
4360 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4361 read_unlock(&map_tree->map_tree.lock);
4362
4363 /* already mapped? */
4364 if (em && em->start <= logical && em->start + em->len > logical) {
4365 free_extent_map(em);
4366 return 0;
4367 } else if (em) {
4368 free_extent_map(em);
4369 }
4370
4371 em = alloc_extent_map();
4372 if (!em)
4373 return -ENOMEM;
4374 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4375 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4376 if (!map) {
4377 free_extent_map(em);
4378 return -ENOMEM;
4379 }
4380
4381 em->bdev = (struct block_device *)map;
4382 em->start = logical;
4383 em->len = length;
4384 em->block_start = 0;
4385 em->block_len = em->len;
4386
4387 map->num_stripes = num_stripes;
4388 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4389 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4390 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4391 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4392 map->type = btrfs_chunk_type(leaf, chunk);
4393 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4394 for (i = 0; i < num_stripes; i++) {
4395 map->stripes[i].physical =
4396 btrfs_stripe_offset_nr(leaf, chunk, i);
4397 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4398 read_extent_buffer(leaf, uuid, (unsigned long)
4399 btrfs_stripe_dev_uuid_nr(chunk, i),
4400 BTRFS_UUID_SIZE);
4401 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
4402 NULL);
4403 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
4404 kfree(map);
4405 free_extent_map(em);
4406 return -EIO;
4407 }
4408 if (!map->stripes[i].dev) {
4409 map->stripes[i].dev =
4410 add_missing_dev(root, devid, uuid);
4411 if (!map->stripes[i].dev) {
4412 kfree(map);
4413 free_extent_map(em);
4414 return -EIO;
4415 }
4416 }
4417 map->stripes[i].dev->in_fs_metadata = 1;
4418 }
4419
4420 write_lock(&map_tree->map_tree.lock);
4421 ret = add_extent_mapping(&map_tree->map_tree, em);
4422 write_unlock(&map_tree->map_tree.lock);
4423 BUG_ON(ret); /* Tree corruption */
4424 free_extent_map(em);
4425
4426 return 0;
4427 }
4428
4429 static void fill_device_from_item(struct extent_buffer *leaf,
4430 struct btrfs_dev_item *dev_item,
4431 struct btrfs_device *device)
4432 {
4433 unsigned long ptr;
4434
4435 device->devid = btrfs_device_id(leaf, dev_item);
4436 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
4437 device->total_bytes = device->disk_total_bytes;
4438 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
4439 device->type = btrfs_device_type(leaf, dev_item);
4440 device->io_align = btrfs_device_io_align(leaf, dev_item);
4441 device->io_width = btrfs_device_io_width(leaf, dev_item);
4442 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
4443
4444 ptr = (unsigned long)btrfs_device_uuid(dev_item);
4445 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
4446 }
4447
4448 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
4449 {
4450 struct btrfs_fs_devices *fs_devices;
4451 int ret;
4452
4453 BUG_ON(!mutex_is_locked(&uuid_mutex));
4454
4455 fs_devices = root->fs_info->fs_devices->seed;
4456 while (fs_devices) {
4457 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4458 ret = 0;
4459 goto out;
4460 }
4461 fs_devices = fs_devices->seed;
4462 }
4463
4464 fs_devices = find_fsid(fsid);
4465 if (!fs_devices) {
4466 ret = -ENOENT;
4467 goto out;
4468 }
4469
4470 fs_devices = clone_fs_devices(fs_devices);
4471 if (IS_ERR(fs_devices)) {
4472 ret = PTR_ERR(fs_devices);
4473 goto out;
4474 }
4475
4476 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
4477 root->fs_info->bdev_holder);
4478 if (ret) {
4479 free_fs_devices(fs_devices);
4480 goto out;
4481 }
4482
4483 if (!fs_devices->seeding) {
4484 __btrfs_close_devices(fs_devices);
4485 free_fs_devices(fs_devices);
4486 ret = -EINVAL;
4487 goto out;
4488 }
4489
4490 fs_devices->seed = root->fs_info->fs_devices->seed;
4491 root->fs_info->fs_devices->seed = fs_devices;
4492 out:
4493 return ret;
4494 }
4495
4496 static int read_one_dev(struct btrfs_root *root,
4497 struct extent_buffer *leaf,
4498 struct btrfs_dev_item *dev_item)
4499 {
4500 struct btrfs_device *device;
4501 u64 devid;
4502 int ret;
4503 u8 fs_uuid[BTRFS_UUID_SIZE];
4504 u8 dev_uuid[BTRFS_UUID_SIZE];
4505
4506 devid = btrfs_device_id(leaf, dev_item);
4507 read_extent_buffer(leaf, dev_uuid,
4508 (unsigned long)btrfs_device_uuid(dev_item),
4509 BTRFS_UUID_SIZE);
4510 read_extent_buffer(leaf, fs_uuid,
4511 (unsigned long)btrfs_device_fsid(dev_item),
4512 BTRFS_UUID_SIZE);
4513
4514 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
4515 ret = open_seed_devices(root, fs_uuid);
4516 if (ret && !btrfs_test_opt(root, DEGRADED))
4517 return ret;
4518 }
4519
4520 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
4521 if (!device || !device->bdev) {
4522 if (!btrfs_test_opt(root, DEGRADED))
4523 return -EIO;
4524
4525 if (!device) {
4526 printk(KERN_WARNING "warning devid %llu missing\n",
4527 (unsigned long long)devid);
4528 device = add_missing_dev(root, devid, dev_uuid);
4529 if (!device)
4530 return -ENOMEM;
4531 } else if (!device->missing) {
4532 /*
4533 * this happens when a device that was properly setup
4534 * in the device info lists suddenly goes bad.
4535 * device->bdev is NULL, and so we have to set
4536 * device->missing to one here
4537 */
4538 root->fs_info->fs_devices->missing_devices++;
4539 device->missing = 1;
4540 }
4541 }
4542
4543 if (device->fs_devices != root->fs_info->fs_devices) {
4544 BUG_ON(device->writeable);
4545 if (device->generation !=
4546 btrfs_device_generation(leaf, dev_item))
4547 return -EINVAL;
4548 }
4549
4550 fill_device_from_item(leaf, dev_item, device);
4551 device->dev_root = root->fs_info->dev_root;
4552 device->in_fs_metadata = 1;
4553 if (device->writeable) {
4554 device->fs_devices->total_rw_bytes += device->total_bytes;
4555 spin_lock(&root->fs_info->free_chunk_lock);
4556 root->fs_info->free_chunk_space += device->total_bytes -
4557 device->bytes_used;
4558 spin_unlock(&root->fs_info->free_chunk_lock);
4559 }
4560 ret = 0;
4561 return ret;
4562 }
4563
4564 int btrfs_read_sys_array(struct btrfs_root *root)
4565 {
4566 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4567 struct extent_buffer *sb;
4568 struct btrfs_disk_key *disk_key;
4569 struct btrfs_chunk *chunk;
4570 u8 *ptr;
4571 unsigned long sb_ptr;
4572 int ret = 0;
4573 u32 num_stripes;
4574 u32 array_size;
4575 u32 len = 0;
4576 u32 cur;
4577 struct btrfs_key key;
4578
4579 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
4580 BTRFS_SUPER_INFO_SIZE);
4581 if (!sb)
4582 return -ENOMEM;
4583 btrfs_set_buffer_uptodate(sb);
4584 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
4585 /*
4586 * The sb extent buffer is artifical and just used to read the system array.
4587 * btrfs_set_buffer_uptodate() call does not properly mark all it's
4588 * pages up-to-date when the page is larger: extent does not cover the
4589 * whole page and consequently check_page_uptodate does not find all
4590 * the page's extents up-to-date (the hole beyond sb),
4591 * write_extent_buffer then triggers a WARN_ON.
4592 *
4593 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
4594 * but sb spans only this function. Add an explicit SetPageUptodate call
4595 * to silence the warning eg. on PowerPC 64.
4596 */
4597 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
4598 SetPageUptodate(sb->pages[0]);
4599
4600 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
4601 array_size = btrfs_super_sys_array_size(super_copy);
4602
4603 ptr = super_copy->sys_chunk_array;
4604 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
4605 cur = 0;
4606
4607 while (cur < array_size) {
4608 disk_key = (struct btrfs_disk_key *)ptr;
4609 btrfs_disk_key_to_cpu(&key, disk_key);
4610
4611 len = sizeof(*disk_key); ptr += len;
4612 sb_ptr += len;
4613 cur += len;
4614
4615 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
4616 chunk = (struct btrfs_chunk *)sb_ptr;
4617 ret = read_one_chunk(root, &key, sb, chunk);
4618 if (ret)
4619 break;
4620 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
4621 len = btrfs_chunk_item_size(num_stripes);
4622 } else {
4623 ret = -EIO;
4624 break;
4625 }
4626 ptr += len;
4627 sb_ptr += len;
4628 cur += len;
4629 }
4630 free_extent_buffer(sb);
4631 return ret;
4632 }
4633
4634 int btrfs_read_chunk_tree(struct btrfs_root *root)
4635 {
4636 struct btrfs_path *path;
4637 struct extent_buffer *leaf;
4638 struct btrfs_key key;
4639 struct btrfs_key found_key;
4640 int ret;
4641 int slot;
4642
4643 root = root->fs_info->chunk_root;
4644
4645 path = btrfs_alloc_path();
4646 if (!path)
4647 return -ENOMEM;
4648
4649 mutex_lock(&uuid_mutex);
4650 lock_chunks(root);
4651
4652 /* first we search for all of the device items, and then we
4653 * read in all of the chunk items. This way we can create chunk
4654 * mappings that reference all of the devices that are afound
4655 */
4656 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
4657 key.offset = 0;
4658 key.type = 0;
4659 again:
4660 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4661 if (ret < 0)
4662 goto error;
4663 while (1) {
4664 leaf = path->nodes[0];
4665 slot = path->slots[0];
4666 if (slot >= btrfs_header_nritems(leaf)) {
4667 ret = btrfs_next_leaf(root, path);
4668 if (ret == 0)
4669 continue;
4670 if (ret < 0)
4671 goto error;
4672 break;
4673 }
4674 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4675 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4676 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
4677 break;
4678 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
4679 struct btrfs_dev_item *dev_item;
4680 dev_item = btrfs_item_ptr(leaf, slot,
4681 struct btrfs_dev_item);
4682 ret = read_one_dev(root, leaf, dev_item);
4683 if (ret)
4684 goto error;
4685 }
4686 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
4687 struct btrfs_chunk *chunk;
4688 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
4689 ret = read_one_chunk(root, &found_key, leaf, chunk);
4690 if (ret)
4691 goto error;
4692 }
4693 path->slots[0]++;
4694 }
4695 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4696 key.objectid = 0;
4697 btrfs_release_path(path);
4698 goto again;
4699 }
4700 ret = 0;
4701 error:
4702 unlock_chunks(root);
4703 mutex_unlock(&uuid_mutex);
4704
4705 btrfs_free_path(path);
4706 return ret;
4707 }
4708
4709 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
4710 {
4711 int i;
4712
4713 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4714 btrfs_dev_stat_reset(dev, i);
4715 }
4716
4717 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
4718 {
4719 struct btrfs_key key;
4720 struct btrfs_key found_key;
4721 struct btrfs_root *dev_root = fs_info->dev_root;
4722 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4723 struct extent_buffer *eb;
4724 int slot;
4725 int ret = 0;
4726 struct btrfs_device *device;
4727 struct btrfs_path *path = NULL;
4728 int i;
4729
4730 path = btrfs_alloc_path();
4731 if (!path) {
4732 ret = -ENOMEM;
4733 goto out;
4734 }
4735
4736 mutex_lock(&fs_devices->device_list_mutex);
4737 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4738 int item_size;
4739 struct btrfs_dev_stats_item *ptr;
4740
4741 key.objectid = 0;
4742 key.type = BTRFS_DEV_STATS_KEY;
4743 key.offset = device->devid;
4744 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
4745 if (ret) {
4746 __btrfs_reset_dev_stats(device);
4747 device->dev_stats_valid = 1;
4748 btrfs_release_path(path);
4749 continue;
4750 }
4751 slot = path->slots[0];
4752 eb = path->nodes[0];
4753 btrfs_item_key_to_cpu(eb, &found_key, slot);
4754 item_size = btrfs_item_size_nr(eb, slot);
4755
4756 ptr = btrfs_item_ptr(eb, slot,
4757 struct btrfs_dev_stats_item);
4758
4759 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4760 if (item_size >= (1 + i) * sizeof(__le64))
4761 btrfs_dev_stat_set(device, i,
4762 btrfs_dev_stats_value(eb, ptr, i));
4763 else
4764 btrfs_dev_stat_reset(device, i);
4765 }
4766
4767 device->dev_stats_valid = 1;
4768 btrfs_dev_stat_print_on_load(device);
4769 btrfs_release_path(path);
4770 }
4771 mutex_unlock(&fs_devices->device_list_mutex);
4772
4773 out:
4774 btrfs_free_path(path);
4775 return ret < 0 ? ret : 0;
4776 }
4777
4778 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
4779 struct btrfs_root *dev_root,
4780 struct btrfs_device *device)
4781 {
4782 struct btrfs_path *path;
4783 struct btrfs_key key;
4784 struct extent_buffer *eb;
4785 struct btrfs_dev_stats_item *ptr;
4786 int ret;
4787 int i;
4788
4789 key.objectid = 0;
4790 key.type = BTRFS_DEV_STATS_KEY;
4791 key.offset = device->devid;
4792
4793 path = btrfs_alloc_path();
4794 BUG_ON(!path);
4795 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
4796 if (ret < 0) {
4797 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
4798 ret, rcu_str_deref(device->name));
4799 goto out;
4800 }
4801
4802 if (ret == 0 &&
4803 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
4804 /* need to delete old one and insert a new one */
4805 ret = btrfs_del_item(trans, dev_root, path);
4806 if (ret != 0) {
4807 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
4808 rcu_str_deref(device->name), ret);
4809 goto out;
4810 }
4811 ret = 1;
4812 }
4813
4814 if (ret == 1) {
4815 /* need to insert a new item */
4816 btrfs_release_path(path);
4817 ret = btrfs_insert_empty_item(trans, dev_root, path,
4818 &key, sizeof(*ptr));
4819 if (ret < 0) {
4820 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
4821 rcu_str_deref(device->name), ret);
4822 goto out;
4823 }
4824 }
4825
4826 eb = path->nodes[0];
4827 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
4828 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4829 btrfs_set_dev_stats_value(eb, ptr, i,
4830 btrfs_dev_stat_read(device, i));
4831 btrfs_mark_buffer_dirty(eb);
4832
4833 out:
4834 btrfs_free_path(path);
4835 return ret;
4836 }
4837
4838 /*
4839 * called from commit_transaction. Writes all changed device stats to disk.
4840 */
4841 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
4842 struct btrfs_fs_info *fs_info)
4843 {
4844 struct btrfs_root *dev_root = fs_info->dev_root;
4845 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4846 struct btrfs_device *device;
4847 int ret = 0;
4848
4849 mutex_lock(&fs_devices->device_list_mutex);
4850 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4851 if (!device->dev_stats_valid || !device->dev_stats_dirty)
4852 continue;
4853
4854 ret = update_dev_stat_item(trans, dev_root, device);
4855 if (!ret)
4856 device->dev_stats_dirty = 0;
4857 }
4858 mutex_unlock(&fs_devices->device_list_mutex);
4859
4860 return ret;
4861 }
4862
4863 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
4864 {
4865 btrfs_dev_stat_inc(dev, index);
4866 btrfs_dev_stat_print_on_error(dev);
4867 }
4868
4869 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
4870 {
4871 if (!dev->dev_stats_valid)
4872 return;
4873 printk_ratelimited_in_rcu(KERN_ERR
4874 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4875 rcu_str_deref(dev->name),
4876 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4877 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4878 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4879 btrfs_dev_stat_read(dev,
4880 BTRFS_DEV_STAT_CORRUPTION_ERRS),
4881 btrfs_dev_stat_read(dev,
4882 BTRFS_DEV_STAT_GENERATION_ERRS));
4883 }
4884
4885 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
4886 {
4887 int i;
4888
4889 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4890 if (btrfs_dev_stat_read(dev, i) != 0)
4891 break;
4892 if (i == BTRFS_DEV_STAT_VALUES_MAX)
4893 return; /* all values == 0, suppress message */
4894
4895 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4896 rcu_str_deref(dev->name),
4897 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4898 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4899 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4900 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
4901 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
4902 }
4903
4904 int btrfs_get_dev_stats(struct btrfs_root *root,
4905 struct btrfs_ioctl_get_dev_stats *stats)
4906 {
4907 struct btrfs_device *dev;
4908 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4909 int i;
4910
4911 mutex_lock(&fs_devices->device_list_mutex);
4912 dev = btrfs_find_device(root, stats->devid, NULL, NULL);
4913 mutex_unlock(&fs_devices->device_list_mutex);
4914
4915 if (!dev) {
4916 printk(KERN_WARNING
4917 "btrfs: get dev_stats failed, device not found\n");
4918 return -ENODEV;
4919 } else if (!dev->dev_stats_valid) {
4920 printk(KERN_WARNING
4921 "btrfs: get dev_stats failed, not yet valid\n");
4922 return -ENODEV;
4923 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
4924 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4925 if (stats->nr_items > i)
4926 stats->values[i] =
4927 btrfs_dev_stat_read_and_reset(dev, i);
4928 else
4929 btrfs_dev_stat_reset(dev, i);
4930 }
4931 } else {
4932 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4933 if (stats->nr_items > i)
4934 stats->values[i] = btrfs_dev_stat_read(dev, i);
4935 }
4936 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
4937 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
4938 return 0;
4939 }
Linux kernel - Deliverables
This page took 0.189714 seconds and 6 git commands to generate.