projects / deliverable / linux.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Btrfs: read device stats on mount, write modified ones during commit
[deliverable/linux.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <linux/ratelimit.h>
27 #include <linux/kthread.h>
28 #include <asm/div64.h>
29 #include "compat.h"
30 #include "ctree.h"
31 #include "extent_map.h"
32 #include "disk-io.h"
33 #include "transaction.h"
34 #include "print-tree.h"
35 #include "volumes.h"
36 #include "async-thread.h"
37 #include "check-integrity.h"
38
39 static int init_first_rw_device(struct btrfs_trans_handle *trans,
40 struct btrfs_root *root,
41 struct btrfs_device *device);
42 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
43 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
44 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
45
46 static DEFINE_MUTEX(uuid_mutex);
47 static LIST_HEAD(fs_uuids);
48
49 static void lock_chunks(struct btrfs_root *root)
50 {
51 mutex_lock(&root->fs_info->chunk_mutex);
52 }
53
54 static void unlock_chunks(struct btrfs_root *root)
55 {
56 mutex_unlock(&root->fs_info->chunk_mutex);
57 }
58
59 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
60 {
61 struct btrfs_device *device;
62 WARN_ON(fs_devices->opened);
63 while (!list_empty(&fs_devices->devices)) {
64 device = list_entry(fs_devices->devices.next,
65 struct btrfs_device, dev_list);
66 list_del(&device->dev_list);
67 kfree(device->name);
68 kfree(device);
69 }
70 kfree(fs_devices);
71 }
72
73 void btrfs_cleanup_fs_uuids(void)
74 {
75 struct btrfs_fs_devices *fs_devices;
76
77 while (!list_empty(&fs_uuids)) {
78 fs_devices = list_entry(fs_uuids.next,
79 struct btrfs_fs_devices, list);
80 list_del(&fs_devices->list);
81 free_fs_devices(fs_devices);
82 }
83 }
84
85 static noinline struct btrfs_device *__find_device(struct list_head *head,
86 u64 devid, u8 *uuid)
87 {
88 struct btrfs_device *dev;
89
90 list_for_each_entry(dev, head, dev_list) {
91 if (dev->devid == devid &&
92 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
93 return dev;
94 }
95 }
96 return NULL;
97 }
98
99 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
100 {
101 struct btrfs_fs_devices *fs_devices;
102
103 list_for_each_entry(fs_devices, &fs_uuids, list) {
104 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
105 return fs_devices;
106 }
107 return NULL;
108 }
109
110 static void requeue_list(struct btrfs_pending_bios *pending_bios,
111 struct bio *head, struct bio *tail)
112 {
113
114 struct bio *old_head;
115
116 old_head = pending_bios->head;
117 pending_bios->head = head;
118 if (pending_bios->tail)
119 tail->bi_next = old_head;
120 else
121 pending_bios->tail = tail;
122 }
123
124 /*
125 * we try to collect pending bios for a device so we don't get a large
126 * number of procs sending bios down to the same device. This greatly
127 * improves the schedulers ability to collect and merge the bios.
128 *
129 * But, it also turns into a long list of bios to process and that is sure
130 * to eventually make the worker thread block. The solution here is to
131 * make some progress and then put this work struct back at the end of
132 * the list if the block device is congested. This way, multiple devices
133 * can make progress from a single worker thread.
134 */
135 static noinline void run_scheduled_bios(struct btrfs_device *device)
136 {
137 struct bio *pending;
138 struct backing_dev_info *bdi;
139 struct btrfs_fs_info *fs_info;
140 struct btrfs_pending_bios *pending_bios;
141 struct bio *tail;
142 struct bio *cur;
143 int again = 0;
144 unsigned long num_run;
145 unsigned long batch_run = 0;
146 unsigned long limit;
147 unsigned long last_waited = 0;
148 int force_reg = 0;
149 int sync_pending = 0;
150 struct blk_plug plug;
151
152 /*
153 * this function runs all the bios we've collected for
154 * a particular device. We don't want to wander off to
155 * another device without first sending all of these down.
156 * So, setup a plug here and finish it off before we return
157 */
158 blk_start_plug(&plug);
159
160 bdi = blk_get_backing_dev_info(device->bdev);
161 fs_info = device->dev_root->fs_info;
162 limit = btrfs_async_submit_limit(fs_info);
163 limit = limit * 2 / 3;
164
165 loop:
166 spin_lock(&device->io_lock);
167
168 loop_lock:
169 num_run = 0;
170
171 /* take all the bios off the list at once and process them
172 * later on (without the lock held). But, remember the
173 * tail and other pointers so the bios can be properly reinserted
174 * into the list if we hit congestion
175 */
176 if (!force_reg && device->pending_sync_bios.head) {
177 pending_bios = &device->pending_sync_bios;
178 force_reg = 1;
179 } else {
180 pending_bios = &device->pending_bios;
181 force_reg = 0;
182 }
183
184 pending = pending_bios->head;
185 tail = pending_bios->tail;
186 WARN_ON(pending && !tail);
187
188 /*
189 * if pending was null this time around, no bios need processing
190 * at all and we can stop. Otherwise it'll loop back up again
191 * and do an additional check so no bios are missed.
192 *
193 * device->running_pending is used to synchronize with the
194 * schedule_bio code.
195 */
196 if (device->pending_sync_bios.head == NULL &&
197 device->pending_bios.head == NULL) {
198 again = 0;
199 device->running_pending = 0;
200 } else {
201 again = 1;
202 device->running_pending = 1;
203 }
204
205 pending_bios->head = NULL;
206 pending_bios->tail = NULL;
207
208 spin_unlock(&device->io_lock);
209
210 while (pending) {
211
212 rmb();
213 /* we want to work on both lists, but do more bios on the
214 * sync list than the regular list
215 */
216 if ((num_run > 32 &&
217 pending_bios != &device->pending_sync_bios &&
218 device->pending_sync_bios.head) ||
219 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
220 device->pending_bios.head)) {
221 spin_lock(&device->io_lock);
222 requeue_list(pending_bios, pending, tail);
223 goto loop_lock;
224 }
225
226 cur = pending;
227 pending = pending->bi_next;
228 cur->bi_next = NULL;
229 atomic_dec(&fs_info->nr_async_bios);
230
231 if (atomic_read(&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 u64 found_transid = btrfs_super_generation(disk_super);
338 char *name;
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 device->name = kstrdup(path, GFP_NOFS);
373 if (!device->name) {
374 kfree(device);
375 return -ENOMEM;
376 }
377 INIT_LIST_HEAD(&device->dev_alloc_list);
378
379 /* init readahead state */
380 spin_lock_init(&device->reada_lock);
381 device->reada_curr_zone = NULL;
382 atomic_set(&device->reada_in_flight, 0);
383 device->reada_next = 0;
384 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
385 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
386
387 mutex_lock(&fs_devices->device_list_mutex);
388 list_add_rcu(&device->dev_list, &fs_devices->devices);
389 mutex_unlock(&fs_devices->device_list_mutex);
390
391 device->fs_devices = fs_devices;
392 fs_devices->num_devices++;
393 } else if (!device->name || strcmp(device->name, path)) {
394 name = kstrdup(path, GFP_NOFS);
395 if (!name)
396 return -ENOMEM;
397 kfree(device->name);
398 device->name = name;
399 if (device->missing) {
400 fs_devices->missing_devices--;
401 device->missing = 0;
402 }
403 }
404
405 if (found_transid > fs_devices->latest_trans) {
406 fs_devices->latest_devid = devid;
407 fs_devices->latest_trans = found_transid;
408 }
409 *fs_devices_ret = fs_devices;
410 return 0;
411 }
412
413 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
414 {
415 struct btrfs_fs_devices *fs_devices;
416 struct btrfs_device *device;
417 struct btrfs_device *orig_dev;
418
419 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
420 if (!fs_devices)
421 return ERR_PTR(-ENOMEM);
422
423 INIT_LIST_HEAD(&fs_devices->devices);
424 INIT_LIST_HEAD(&fs_devices->alloc_list);
425 INIT_LIST_HEAD(&fs_devices->list);
426 mutex_init(&fs_devices->device_list_mutex);
427 fs_devices->latest_devid = orig->latest_devid;
428 fs_devices->latest_trans = orig->latest_trans;
429 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
430
431 /* We have held the volume lock, it is safe to get the devices. */
432 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
433 device = kzalloc(sizeof(*device), GFP_NOFS);
434 if (!device)
435 goto error;
436
437 device->name = kstrdup(orig_dev->name, GFP_NOFS);
438 if (!device->name) {
439 kfree(device);
440 goto error;
441 }
442
443 device->devid = orig_dev->devid;
444 device->work.func = pending_bios_fn;
445 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
446 spin_lock_init(&device->io_lock);
447 INIT_LIST_HEAD(&device->dev_list);
448 INIT_LIST_HEAD(&device->dev_alloc_list);
449
450 list_add(&device->dev_list, &fs_devices->devices);
451 device->fs_devices = fs_devices;
452 fs_devices->num_devices++;
453 }
454 return fs_devices;
455 error:
456 free_fs_devices(fs_devices);
457 return ERR_PTR(-ENOMEM);
458 }
459
460 void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
461 {
462 struct btrfs_device *device, *next;
463
464 struct block_device *latest_bdev = NULL;
465 u64 latest_devid = 0;
466 u64 latest_transid = 0;
467
468 mutex_lock(&uuid_mutex);
469 again:
470 /* This is the initialized path, it is safe to release the devices. */
471 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
472 if (device->in_fs_metadata) {
473 if (!latest_transid ||
474 device->generation > latest_transid) {
475 latest_devid = device->devid;
476 latest_transid = device->generation;
477 latest_bdev = device->bdev;
478 }
479 continue;
480 }
481
482 if (device->bdev) {
483 blkdev_put(device->bdev, device->mode);
484 device->bdev = NULL;
485 fs_devices->open_devices--;
486 }
487 if (device->writeable) {
488 list_del_init(&device->dev_alloc_list);
489 device->writeable = 0;
490 fs_devices->rw_devices--;
491 }
492 list_del_init(&device->dev_list);
493 fs_devices->num_devices--;
494 kfree(device->name);
495 kfree(device);
496 }
497
498 if (fs_devices->seed) {
499 fs_devices = fs_devices->seed;
500 goto again;
501 }
502
503 fs_devices->latest_bdev = latest_bdev;
504 fs_devices->latest_devid = latest_devid;
505 fs_devices->latest_trans = latest_transid;
506
507 mutex_unlock(&uuid_mutex);
508 }
509
510 static void __free_device(struct work_struct *work)
511 {
512 struct btrfs_device *device;
513
514 device = container_of(work, struct btrfs_device, rcu_work);
515
516 if (device->bdev)
517 blkdev_put(device->bdev, device->mode);
518
519 kfree(device->name);
520 kfree(device);
521 }
522
523 static void free_device(struct rcu_head *head)
524 {
525 struct btrfs_device *device;
526
527 device = container_of(head, struct btrfs_device, rcu);
528
529 INIT_WORK(&device->rcu_work, __free_device);
530 schedule_work(&device->rcu_work);
531 }
532
533 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
534 {
535 struct btrfs_device *device;
536
537 if (--fs_devices->opened > 0)
538 return 0;
539
540 mutex_lock(&fs_devices->device_list_mutex);
541 list_for_each_entry(device, &fs_devices->devices, dev_list) {
542 struct btrfs_device *new_device;
543
544 if (device->bdev)
545 fs_devices->open_devices--;
546
547 if (device->writeable) {
548 list_del_init(&device->dev_alloc_list);
549 fs_devices->rw_devices--;
550 }
551
552 if (device->can_discard)
553 fs_devices->num_can_discard--;
554
555 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
556 BUG_ON(!new_device); /* -ENOMEM */
557 memcpy(new_device, device, sizeof(*new_device));
558 new_device->name = kstrdup(device->name, GFP_NOFS);
559 BUG_ON(device->name && !new_device->name); /* -ENOMEM */
560 new_device->bdev = NULL;
561 new_device->writeable = 0;
562 new_device->in_fs_metadata = 0;
563 new_device->can_discard = 0;
564 list_replace_rcu(&device->dev_list, &new_device->dev_list);
565
566 call_rcu(&device->rcu, free_device);
567 }
568 mutex_unlock(&fs_devices->device_list_mutex);
569
570 WARN_ON(fs_devices->open_devices);
571 WARN_ON(fs_devices->rw_devices);
572 fs_devices->opened = 0;
573 fs_devices->seeding = 0;
574
575 return 0;
576 }
577
578 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
579 {
580 struct btrfs_fs_devices *seed_devices = NULL;
581 int ret;
582
583 mutex_lock(&uuid_mutex);
584 ret = __btrfs_close_devices(fs_devices);
585 if (!fs_devices->opened) {
586 seed_devices = fs_devices->seed;
587 fs_devices->seed = NULL;
588 }
589 mutex_unlock(&uuid_mutex);
590
591 while (seed_devices) {
592 fs_devices = seed_devices;
593 seed_devices = fs_devices->seed;
594 __btrfs_close_devices(fs_devices);
595 free_fs_devices(fs_devices);
596 }
597 return ret;
598 }
599
600 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
601 fmode_t flags, void *holder)
602 {
603 struct request_queue *q;
604 struct block_device *bdev;
605 struct list_head *head = &fs_devices->devices;
606 struct btrfs_device *device;
607 struct block_device *latest_bdev = NULL;
608 struct buffer_head *bh;
609 struct btrfs_super_block *disk_super;
610 u64 latest_devid = 0;
611 u64 latest_transid = 0;
612 u64 devid;
613 int seeding = 1;
614 int ret = 0;
615
616 flags |= FMODE_EXCL;
617
618 list_for_each_entry(device, head, dev_list) {
619 if (device->bdev)
620 continue;
621 if (!device->name)
622 continue;
623
624 bdev = blkdev_get_by_path(device->name, flags, holder);
625 if (IS_ERR(bdev)) {
626 printk(KERN_INFO "open %s failed\n", device->name);
627 goto error;
628 }
629 filemap_write_and_wait(bdev->bd_inode->i_mapping);
630 invalidate_bdev(bdev);
631 set_blocksize(bdev, 4096);
632
633 bh = btrfs_read_dev_super(bdev);
634 if (!bh)
635 goto error_close;
636
637 disk_super = (struct btrfs_super_block *)bh->b_data;
638 devid = btrfs_stack_device_id(&disk_super->dev_item);
639 if (devid != device->devid)
640 goto error_brelse;
641
642 if (memcmp(device->uuid, disk_super->dev_item.uuid,
643 BTRFS_UUID_SIZE))
644 goto error_brelse;
645
646 device->generation = btrfs_super_generation(disk_super);
647 if (!latest_transid || device->generation > latest_transid) {
648 latest_devid = devid;
649 latest_transid = device->generation;
650 latest_bdev = bdev;
651 }
652
653 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
654 device->writeable = 0;
655 } else {
656 device->writeable = !bdev_read_only(bdev);
657 seeding = 0;
658 }
659
660 q = bdev_get_queue(bdev);
661 if (blk_queue_discard(q)) {
662 device->can_discard = 1;
663 fs_devices->num_can_discard++;
664 }
665
666 device->bdev = bdev;
667 device->in_fs_metadata = 0;
668 device->mode = flags;
669
670 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
671 fs_devices->rotating = 1;
672
673 fs_devices->open_devices++;
674 if (device->writeable) {
675 fs_devices->rw_devices++;
676 list_add(&device->dev_alloc_list,
677 &fs_devices->alloc_list);
678 }
679 brelse(bh);
680 continue;
681
682 error_brelse:
683 brelse(bh);
684 error_close:
685 blkdev_put(bdev, flags);
686 error:
687 continue;
688 }
689 if (fs_devices->open_devices == 0) {
690 ret = -EINVAL;
691 goto out;
692 }
693 fs_devices->seeding = seeding;
694 fs_devices->opened = 1;
695 fs_devices->latest_bdev = latest_bdev;
696 fs_devices->latest_devid = latest_devid;
697 fs_devices->latest_trans = latest_transid;
698 fs_devices->total_rw_bytes = 0;
699 out:
700 return ret;
701 }
702
703 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
704 fmode_t flags, void *holder)
705 {
706 int ret;
707
708 mutex_lock(&uuid_mutex);
709 if (fs_devices->opened) {
710 fs_devices->opened++;
711 ret = 0;
712 } else {
713 ret = __btrfs_open_devices(fs_devices, flags, holder);
714 }
715 mutex_unlock(&uuid_mutex);
716 return ret;
717 }
718
719 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
720 struct btrfs_fs_devices **fs_devices_ret)
721 {
722 struct btrfs_super_block *disk_super;
723 struct block_device *bdev;
724 struct buffer_head *bh;
725 int ret;
726 u64 devid;
727 u64 transid;
728
729 flags |= FMODE_EXCL;
730 bdev = blkdev_get_by_path(path, flags, holder);
731
732 if (IS_ERR(bdev)) {
733 ret = PTR_ERR(bdev);
734 goto error;
735 }
736
737 mutex_lock(&uuid_mutex);
738 ret = set_blocksize(bdev, 4096);
739 if (ret)
740 goto error_close;
741 bh = btrfs_read_dev_super(bdev);
742 if (!bh) {
743 ret = -EINVAL;
744 goto error_close;
745 }
746 disk_super = (struct btrfs_super_block *)bh->b_data;
747 devid = btrfs_stack_device_id(&disk_super->dev_item);
748 transid = btrfs_super_generation(disk_super);
749 if (disk_super->label[0])
750 printk(KERN_INFO "device label %s ", disk_super->label);
751 else
752 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
753 printk(KERN_CONT "devid %llu transid %llu %s\n",
754 (unsigned long long)devid, (unsigned long long)transid, path);
755 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
756
757 brelse(bh);
758 error_close:
759 mutex_unlock(&uuid_mutex);
760 blkdev_put(bdev, flags);
761 error:
762 return ret;
763 }
764
765 /* helper to account the used device space in the range */
766 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
767 u64 end, u64 *length)
768 {
769 struct btrfs_key key;
770 struct btrfs_root *root = device->dev_root;
771 struct btrfs_dev_extent *dev_extent;
772 struct btrfs_path *path;
773 u64 extent_end;
774 int ret;
775 int slot;
776 struct extent_buffer *l;
777
778 *length = 0;
779
780 if (start >= device->total_bytes)
781 return 0;
782
783 path = btrfs_alloc_path();
784 if (!path)
785 return -ENOMEM;
786 path->reada = 2;
787
788 key.objectid = device->devid;
789 key.offset = start;
790 key.type = BTRFS_DEV_EXTENT_KEY;
791
792 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
793 if (ret < 0)
794 goto out;
795 if (ret > 0) {
796 ret = btrfs_previous_item(root, path, key.objectid, key.type);
797 if (ret < 0)
798 goto out;
799 }
800
801 while (1) {
802 l = path->nodes[0];
803 slot = path->slots[0];
804 if (slot >= btrfs_header_nritems(l)) {
805 ret = btrfs_next_leaf(root, path);
806 if (ret == 0)
807 continue;
808 if (ret < 0)
809 goto out;
810
811 break;
812 }
813 btrfs_item_key_to_cpu(l, &key, slot);
814
815 if (key.objectid < device->devid)
816 goto next;
817
818 if (key.objectid > device->devid)
819 break;
820
821 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
822 goto next;
823
824 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
825 extent_end = key.offset + btrfs_dev_extent_length(l,
826 dev_extent);
827 if (key.offset <= start && extent_end > end) {
828 *length = end - start + 1;
829 break;
830 } else if (key.offset <= start && extent_end > start)
831 *length += extent_end - start;
832 else if (key.offset > start && extent_end <= end)
833 *length += extent_end - key.offset;
834 else if (key.offset > start && key.offset <= end) {
835 *length += end - key.offset + 1;
836 break;
837 } else if (key.offset > end)
838 break;
839
840 next:
841 path->slots[0]++;
842 }
843 ret = 0;
844 out:
845 btrfs_free_path(path);
846 return ret;
847 }
848
849 /*
850 * find_free_dev_extent - find free space in the specified device
851 * @device: the device which we search the free space in
852 * @num_bytes: the size of the free space that we need
853 * @start: store the start of the free space.
854 * @len: the size of the free space. that we find, or the size of the max
855 * free space if we don't find suitable free space
856 *
857 * this uses a pretty simple search, the expectation is that it is
858 * called very infrequently and that a given device has a small number
859 * of extents
860 *
861 * @start is used to store the start of the free space if we find. But if we
862 * don't find suitable free space, it will be used to store the start position
863 * of the max free space.
864 *
865 * @len is used to store the size of the free space that we find.
866 * But if we don't find suitable free space, it is used to store the size of
867 * the max free space.
868 */
869 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
870 u64 *start, u64 *len)
871 {
872 struct btrfs_key key;
873 struct btrfs_root *root = device->dev_root;
874 struct btrfs_dev_extent *dev_extent;
875 struct btrfs_path *path;
876 u64 hole_size;
877 u64 max_hole_start;
878 u64 max_hole_size;
879 u64 extent_end;
880 u64 search_start;
881 u64 search_end = device->total_bytes;
882 int ret;
883 int slot;
884 struct extent_buffer *l;
885
886 /* FIXME use last free of some kind */
887
888 /* we don't want to overwrite the superblock on the drive,
889 * so we make sure to start at an offset of at least 1MB
890 */
891 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
892
893 max_hole_start = search_start;
894 max_hole_size = 0;
895 hole_size = 0;
896
897 if (search_start >= search_end) {
898 ret = -ENOSPC;
899 goto error;
900 }
901
902 path = btrfs_alloc_path();
903 if (!path) {
904 ret = -ENOMEM;
905 goto error;
906 }
907 path->reada = 2;
908
909 key.objectid = device->devid;
910 key.offset = search_start;
911 key.type = BTRFS_DEV_EXTENT_KEY;
912
913 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
914 if (ret < 0)
915 goto out;
916 if (ret > 0) {
917 ret = btrfs_previous_item(root, path, key.objectid, key.type);
918 if (ret < 0)
919 goto out;
920 }
921
922 while (1) {
923 l = path->nodes[0];
924 slot = path->slots[0];
925 if (slot >= btrfs_header_nritems(l)) {
926 ret = btrfs_next_leaf(root, path);
927 if (ret == 0)
928 continue;
929 if (ret < 0)
930 goto out;
931
932 break;
933 }
934 btrfs_item_key_to_cpu(l, &key, slot);
935
936 if (key.objectid < device->devid)
937 goto next;
938
939 if (key.objectid > device->devid)
940 break;
941
942 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
943 goto next;
944
945 if (key.offset > search_start) {
946 hole_size = key.offset - search_start;
947
948 if (hole_size > max_hole_size) {
949 max_hole_start = search_start;
950 max_hole_size = hole_size;
951 }
952
953 /*
954 * If this free space is greater than which we need,
955 * it must be the max free space that we have found
956 * until now, so max_hole_start must point to the start
957 * of this free space and the length of this free space
958 * is stored in max_hole_size. Thus, we return
959 * max_hole_start and max_hole_size and go back to the
960 * caller.
961 */
962 if (hole_size >= num_bytes) {
963 ret = 0;
964 goto out;
965 }
966 }
967
968 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
969 extent_end = key.offset + btrfs_dev_extent_length(l,
970 dev_extent);
971 if (extent_end > search_start)
972 search_start = extent_end;
973 next:
974 path->slots[0]++;
975 cond_resched();
976 }
977
978 /*
979 * At this point, search_start should be the end of
980 * allocated dev extents, and when shrinking the device,
981 * search_end may be smaller than search_start.
982 */
983 if (search_end > search_start)
984 hole_size = search_end - search_start;
985
986 if (hole_size > max_hole_size) {
987 max_hole_start = search_start;
988 max_hole_size = hole_size;
989 }
990
991 /* See above. */
992 if (hole_size < num_bytes)
993 ret = -ENOSPC;
994 else
995 ret = 0;
996
997 out:
998 btrfs_free_path(path);
999 error:
1000 *start = max_hole_start;
1001 if (len)
1002 *len = max_hole_size;
1003 return ret;
1004 }
1005
1006 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1007 struct btrfs_device *device,
1008 u64 start)
1009 {
1010 int ret;
1011 struct btrfs_path *path;
1012 struct btrfs_root *root = device->dev_root;
1013 struct btrfs_key key;
1014 struct btrfs_key found_key;
1015 struct extent_buffer *leaf = NULL;
1016 struct btrfs_dev_extent *extent = NULL;
1017
1018 path = btrfs_alloc_path();
1019 if (!path)
1020 return -ENOMEM;
1021
1022 key.objectid = device->devid;
1023 key.offset = start;
1024 key.type = BTRFS_DEV_EXTENT_KEY;
1025 again:
1026 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1027 if (ret > 0) {
1028 ret = btrfs_previous_item(root, path, key.objectid,
1029 BTRFS_DEV_EXTENT_KEY);
1030 if (ret)
1031 goto out;
1032 leaf = path->nodes[0];
1033 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1034 extent = btrfs_item_ptr(leaf, path->slots[0],
1035 struct btrfs_dev_extent);
1036 BUG_ON(found_key.offset > start || found_key.offset +
1037 btrfs_dev_extent_length(leaf, extent) < start);
1038 key = found_key;
1039 btrfs_release_path(path);
1040 goto again;
1041 } else if (ret == 0) {
1042 leaf = path->nodes[0];
1043 extent = btrfs_item_ptr(leaf, path->slots[0],
1044 struct btrfs_dev_extent);
1045 } else {
1046 btrfs_error(root->fs_info, ret, "Slot search failed");
1047 goto out;
1048 }
1049
1050 if (device->bytes_used > 0) {
1051 u64 len = btrfs_dev_extent_length(leaf, extent);
1052 device->bytes_used -= len;
1053 spin_lock(&root->fs_info->free_chunk_lock);
1054 root->fs_info->free_chunk_space += len;
1055 spin_unlock(&root->fs_info->free_chunk_lock);
1056 }
1057 ret = btrfs_del_item(trans, root, path);
1058 if (ret) {
1059 btrfs_error(root->fs_info, ret,
1060 "Failed to remove dev extent item");
1061 }
1062 out:
1063 btrfs_free_path(path);
1064 return ret;
1065 }
1066
1067 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1068 struct btrfs_device *device,
1069 u64 chunk_tree, u64 chunk_objectid,
1070 u64 chunk_offset, u64 start, u64 num_bytes)
1071 {
1072 int ret;
1073 struct btrfs_path *path;
1074 struct btrfs_root *root = device->dev_root;
1075 struct btrfs_dev_extent *extent;
1076 struct extent_buffer *leaf;
1077 struct btrfs_key key;
1078
1079 WARN_ON(!device->in_fs_metadata);
1080 path = btrfs_alloc_path();
1081 if (!path)
1082 return -ENOMEM;
1083
1084 key.objectid = device->devid;
1085 key.offset = start;
1086 key.type = BTRFS_DEV_EXTENT_KEY;
1087 ret = btrfs_insert_empty_item(trans, root, path, &key,
1088 sizeof(*extent));
1089 if (ret)
1090 goto out;
1091
1092 leaf = path->nodes[0];
1093 extent = btrfs_item_ptr(leaf, path->slots[0],
1094 struct btrfs_dev_extent);
1095 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1096 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1097 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1098
1099 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1100 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1101 BTRFS_UUID_SIZE);
1102
1103 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1104 btrfs_mark_buffer_dirty(leaf);
1105 out:
1106 btrfs_free_path(path);
1107 return ret;
1108 }
1109
1110 static noinline int find_next_chunk(struct btrfs_root *root,
1111 u64 objectid, u64 *offset)
1112 {
1113 struct btrfs_path *path;
1114 int ret;
1115 struct btrfs_key key;
1116 struct btrfs_chunk *chunk;
1117 struct btrfs_key found_key;
1118
1119 path = btrfs_alloc_path();
1120 if (!path)
1121 return -ENOMEM;
1122
1123 key.objectid = objectid;
1124 key.offset = (u64)-1;
1125 key.type = BTRFS_CHUNK_ITEM_KEY;
1126
1127 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1128 if (ret < 0)
1129 goto error;
1130
1131 BUG_ON(ret == 0); /* Corruption */
1132
1133 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1134 if (ret) {
1135 *offset = 0;
1136 } else {
1137 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1138 path->slots[0]);
1139 if (found_key.objectid != objectid)
1140 *offset = 0;
1141 else {
1142 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1143 struct btrfs_chunk);
1144 *offset = found_key.offset +
1145 btrfs_chunk_length(path->nodes[0], chunk);
1146 }
1147 }
1148 ret = 0;
1149 error:
1150 btrfs_free_path(path);
1151 return ret;
1152 }
1153
1154 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1155 {
1156 int ret;
1157 struct btrfs_key key;
1158 struct btrfs_key found_key;
1159 struct btrfs_path *path;
1160
1161 root = root->fs_info->chunk_root;
1162
1163 path = btrfs_alloc_path();
1164 if (!path)
1165 return -ENOMEM;
1166
1167 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1168 key.type = BTRFS_DEV_ITEM_KEY;
1169 key.offset = (u64)-1;
1170
1171 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1172 if (ret < 0)
1173 goto error;
1174
1175 BUG_ON(ret == 0); /* Corruption */
1176
1177 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1178 BTRFS_DEV_ITEM_KEY);
1179 if (ret) {
1180 *objectid = 1;
1181 } else {
1182 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1183 path->slots[0]);
1184 *objectid = found_key.offset + 1;
1185 }
1186 ret = 0;
1187 error:
1188 btrfs_free_path(path);
1189 return ret;
1190 }
1191
1192 /*
1193 * the device information is stored in the chunk root
1194 * the btrfs_device struct should be fully filled in
1195 */
1196 int btrfs_add_device(struct btrfs_trans_handle *trans,
1197 struct btrfs_root *root,
1198 struct btrfs_device *device)
1199 {
1200 int ret;
1201 struct btrfs_path *path;
1202 struct btrfs_dev_item *dev_item;
1203 struct extent_buffer *leaf;
1204 struct btrfs_key key;
1205 unsigned long ptr;
1206
1207 root = root->fs_info->chunk_root;
1208
1209 path = btrfs_alloc_path();
1210 if (!path)
1211 return -ENOMEM;
1212
1213 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1214 key.type = BTRFS_DEV_ITEM_KEY;
1215 key.offset = device->devid;
1216
1217 ret = btrfs_insert_empty_item(trans, root, path, &key,
1218 sizeof(*dev_item));
1219 if (ret)
1220 goto out;
1221
1222 leaf = path->nodes[0];
1223 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1224
1225 btrfs_set_device_id(leaf, dev_item, device->devid);
1226 btrfs_set_device_generation(leaf, dev_item, 0);
1227 btrfs_set_device_type(leaf, dev_item, device->type);
1228 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1229 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1230 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1231 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1232 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1233 btrfs_set_device_group(leaf, dev_item, 0);
1234 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1235 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1236 btrfs_set_device_start_offset(leaf, dev_item, 0);
1237
1238 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1239 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1240 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1241 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1242 btrfs_mark_buffer_dirty(leaf);
1243
1244 ret = 0;
1245 out:
1246 btrfs_free_path(path);
1247 return ret;
1248 }
1249
1250 static int btrfs_rm_dev_item(struct btrfs_root *root,
1251 struct btrfs_device *device)
1252 {
1253 int ret;
1254 struct btrfs_path *path;
1255 struct btrfs_key key;
1256 struct btrfs_trans_handle *trans;
1257
1258 root = root->fs_info->chunk_root;
1259
1260 path = btrfs_alloc_path();
1261 if (!path)
1262 return -ENOMEM;
1263
1264 trans = btrfs_start_transaction(root, 0);
1265 if (IS_ERR(trans)) {
1266 btrfs_free_path(path);
1267 return PTR_ERR(trans);
1268 }
1269 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1270 key.type = BTRFS_DEV_ITEM_KEY;
1271 key.offset = device->devid;
1272 lock_chunks(root);
1273
1274 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1275 if (ret < 0)
1276 goto out;
1277
1278 if (ret > 0) {
1279 ret = -ENOENT;
1280 goto out;
1281 }
1282
1283 ret = btrfs_del_item(trans, root, path);
1284 if (ret)
1285 goto out;
1286 out:
1287 btrfs_free_path(path);
1288 unlock_chunks(root);
1289 btrfs_commit_transaction(trans, root);
1290 return ret;
1291 }
1292
1293 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1294 {
1295 struct btrfs_device *device;
1296 struct btrfs_device *next_device;
1297 struct block_device *bdev;
1298 struct buffer_head *bh = NULL;
1299 struct btrfs_super_block *disk_super;
1300 struct btrfs_fs_devices *cur_devices;
1301 u64 all_avail;
1302 u64 devid;
1303 u64 num_devices;
1304 u8 *dev_uuid;
1305 int ret = 0;
1306 bool clear_super = false;
1307
1308 mutex_lock(&uuid_mutex);
1309
1310 all_avail = root->fs_info->avail_data_alloc_bits |
1311 root->fs_info->avail_system_alloc_bits |
1312 root->fs_info->avail_metadata_alloc_bits;
1313
1314 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1315 root->fs_info->fs_devices->num_devices <= 4) {
1316 printk(KERN_ERR "btrfs: unable to go below four devices "
1317 "on raid10\n");
1318 ret = -EINVAL;
1319 goto out;
1320 }
1321
1322 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1323 root->fs_info->fs_devices->num_devices <= 2) {
1324 printk(KERN_ERR "btrfs: unable to go below two "
1325 "devices on raid1\n");
1326 ret = -EINVAL;
1327 goto out;
1328 }
1329
1330 if (strcmp(device_path, "missing") == 0) {
1331 struct list_head *devices;
1332 struct btrfs_device *tmp;
1333
1334 device = NULL;
1335 devices = &root->fs_info->fs_devices->devices;
1336 /*
1337 * It is safe to read the devices since the volume_mutex
1338 * is held.
1339 */
1340 list_for_each_entry(tmp, devices, dev_list) {
1341 if (tmp->in_fs_metadata && !tmp->bdev) {
1342 device = tmp;
1343 break;
1344 }
1345 }
1346 bdev = NULL;
1347 bh = NULL;
1348 disk_super = NULL;
1349 if (!device) {
1350 printk(KERN_ERR "btrfs: no missing devices found to "
1351 "remove\n");
1352 goto out;
1353 }
1354 } else {
1355 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1356 root->fs_info->bdev_holder);
1357 if (IS_ERR(bdev)) {
1358 ret = PTR_ERR(bdev);
1359 goto out;
1360 }
1361
1362 set_blocksize(bdev, 4096);
1363 invalidate_bdev(bdev);
1364 bh = btrfs_read_dev_super(bdev);
1365 if (!bh) {
1366 ret = -EINVAL;
1367 goto error_close;
1368 }
1369 disk_super = (struct btrfs_super_block *)bh->b_data;
1370 devid = btrfs_stack_device_id(&disk_super->dev_item);
1371 dev_uuid = disk_super->dev_item.uuid;
1372 device = btrfs_find_device(root, devid, dev_uuid,
1373 disk_super->fsid);
1374 if (!device) {
1375 ret = -ENOENT;
1376 goto error_brelse;
1377 }
1378 }
1379
1380 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1381 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1382 "device\n");
1383 ret = -EINVAL;
1384 goto error_brelse;
1385 }
1386
1387 if (device->writeable) {
1388 lock_chunks(root);
1389 list_del_init(&device->dev_alloc_list);
1390 unlock_chunks(root);
1391 root->fs_info->fs_devices->rw_devices--;
1392 clear_super = true;
1393 }
1394
1395 ret = btrfs_shrink_device(device, 0);
1396 if (ret)
1397 goto error_undo;
1398
1399 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1400 if (ret)
1401 goto error_undo;
1402
1403 spin_lock(&root->fs_info->free_chunk_lock);
1404 root->fs_info->free_chunk_space = device->total_bytes -
1405 device->bytes_used;
1406 spin_unlock(&root->fs_info->free_chunk_lock);
1407
1408 device->in_fs_metadata = 0;
1409 btrfs_scrub_cancel_dev(root, device);
1410
1411 /*
1412 * the device list mutex makes sure that we don't change
1413 * the device list while someone else is writing out all
1414 * the device supers.
1415 */
1416
1417 cur_devices = device->fs_devices;
1418 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1419 list_del_rcu(&device->dev_list);
1420
1421 device->fs_devices->num_devices--;
1422
1423 if (device->missing)
1424 root->fs_info->fs_devices->missing_devices--;
1425
1426 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1427 struct btrfs_device, dev_list);
1428 if (device->bdev == root->fs_info->sb->s_bdev)
1429 root->fs_info->sb->s_bdev = next_device->bdev;
1430 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1431 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1432
1433 if (device->bdev)
1434 device->fs_devices->open_devices--;
1435
1436 call_rcu(&device->rcu, free_device);
1437 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1438
1439 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1440 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1441
1442 if (cur_devices->open_devices == 0) {
1443 struct btrfs_fs_devices *fs_devices;
1444 fs_devices = root->fs_info->fs_devices;
1445 while (fs_devices) {
1446 if (fs_devices->seed == cur_devices)
1447 break;
1448 fs_devices = fs_devices->seed;
1449 }
1450 fs_devices->seed = cur_devices->seed;
1451 cur_devices->seed = NULL;
1452 lock_chunks(root);
1453 __btrfs_close_devices(cur_devices);
1454 unlock_chunks(root);
1455 free_fs_devices(cur_devices);
1456 }
1457
1458 /*
1459 * at this point, the device is zero sized. We want to
1460 * remove it from the devices list and zero out the old super
1461 */
1462 if (clear_super) {
1463 /* make sure this device isn't detected as part of
1464 * the FS anymore
1465 */
1466 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1467 set_buffer_dirty(bh);
1468 sync_dirty_buffer(bh);
1469 }
1470
1471 ret = 0;
1472
1473 error_brelse:
1474 brelse(bh);
1475 error_close:
1476 if (bdev)
1477 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1478 out:
1479 mutex_unlock(&uuid_mutex);
1480 return ret;
1481 error_undo:
1482 if (device->writeable) {
1483 lock_chunks(root);
1484 list_add(&device->dev_alloc_list,
1485 &root->fs_info->fs_devices->alloc_list);
1486 unlock_chunks(root);
1487 root->fs_info->fs_devices->rw_devices++;
1488 }
1489 goto error_brelse;
1490 }
1491
1492 /*
1493 * does all the dirty work required for changing file system's UUID.
1494 */
1495 static int btrfs_prepare_sprout(struct btrfs_root *root)
1496 {
1497 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1498 struct btrfs_fs_devices *old_devices;
1499 struct btrfs_fs_devices *seed_devices;
1500 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1501 struct btrfs_device *device;
1502 u64 super_flags;
1503
1504 BUG_ON(!mutex_is_locked(&uuid_mutex));
1505 if (!fs_devices->seeding)
1506 return -EINVAL;
1507
1508 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1509 if (!seed_devices)
1510 return -ENOMEM;
1511
1512 old_devices = clone_fs_devices(fs_devices);
1513 if (IS_ERR(old_devices)) {
1514 kfree(seed_devices);
1515 return PTR_ERR(old_devices);
1516 }
1517
1518 list_add(&old_devices->list, &fs_uuids);
1519
1520 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1521 seed_devices->opened = 1;
1522 INIT_LIST_HEAD(&seed_devices->devices);
1523 INIT_LIST_HEAD(&seed_devices->alloc_list);
1524 mutex_init(&seed_devices->device_list_mutex);
1525
1526 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1527 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1528 synchronize_rcu);
1529 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1530
1531 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1532 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1533 device->fs_devices = seed_devices;
1534 }
1535
1536 fs_devices->seeding = 0;
1537 fs_devices->num_devices = 0;
1538 fs_devices->open_devices = 0;
1539 fs_devices->seed = seed_devices;
1540
1541 generate_random_uuid(fs_devices->fsid);
1542 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1543 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1544 super_flags = btrfs_super_flags(disk_super) &
1545 ~BTRFS_SUPER_FLAG_SEEDING;
1546 btrfs_set_super_flags(disk_super, super_flags);
1547
1548 return 0;
1549 }
1550
1551 /*
1552 * strore the expected generation for seed devices in device items.
1553 */
1554 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1555 struct btrfs_root *root)
1556 {
1557 struct btrfs_path *path;
1558 struct extent_buffer *leaf;
1559 struct btrfs_dev_item *dev_item;
1560 struct btrfs_device *device;
1561 struct btrfs_key key;
1562 u8 fs_uuid[BTRFS_UUID_SIZE];
1563 u8 dev_uuid[BTRFS_UUID_SIZE];
1564 u64 devid;
1565 int ret;
1566
1567 path = btrfs_alloc_path();
1568 if (!path)
1569 return -ENOMEM;
1570
1571 root = root->fs_info->chunk_root;
1572 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1573 key.offset = 0;
1574 key.type = BTRFS_DEV_ITEM_KEY;
1575
1576 while (1) {
1577 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1578 if (ret < 0)
1579 goto error;
1580
1581 leaf = path->nodes[0];
1582 next_slot:
1583 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1584 ret = btrfs_next_leaf(root, path);
1585 if (ret > 0)
1586 break;
1587 if (ret < 0)
1588 goto error;
1589 leaf = path->nodes[0];
1590 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1591 btrfs_release_path(path);
1592 continue;
1593 }
1594
1595 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1596 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1597 key.type != BTRFS_DEV_ITEM_KEY)
1598 break;
1599
1600 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1601 struct btrfs_dev_item);
1602 devid = btrfs_device_id(leaf, dev_item);
1603 read_extent_buffer(leaf, dev_uuid,
1604 (unsigned long)btrfs_device_uuid(dev_item),
1605 BTRFS_UUID_SIZE);
1606 read_extent_buffer(leaf, fs_uuid,
1607 (unsigned long)btrfs_device_fsid(dev_item),
1608 BTRFS_UUID_SIZE);
1609 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1610 BUG_ON(!device); /* Logic error */
1611
1612 if (device->fs_devices->seeding) {
1613 btrfs_set_device_generation(leaf, dev_item,
1614 device->generation);
1615 btrfs_mark_buffer_dirty(leaf);
1616 }
1617
1618 path->slots[0]++;
1619 goto next_slot;
1620 }
1621 ret = 0;
1622 error:
1623 btrfs_free_path(path);
1624 return ret;
1625 }
1626
1627 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1628 {
1629 struct request_queue *q;
1630 struct btrfs_trans_handle *trans;
1631 struct btrfs_device *device;
1632 struct block_device *bdev;
1633 struct list_head *devices;
1634 struct super_block *sb = root->fs_info->sb;
1635 u64 total_bytes;
1636 int seeding_dev = 0;
1637 int ret = 0;
1638
1639 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1640 return -EROFS;
1641
1642 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1643 root->fs_info->bdev_holder);
1644 if (IS_ERR(bdev))
1645 return PTR_ERR(bdev);
1646
1647 if (root->fs_info->fs_devices->seeding) {
1648 seeding_dev = 1;
1649 down_write(&sb->s_umount);
1650 mutex_lock(&uuid_mutex);
1651 }
1652
1653 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1654
1655 devices = &root->fs_info->fs_devices->devices;
1656 /*
1657 * we have the volume lock, so we don't need the extra
1658 * device list mutex while reading the list here.
1659 */
1660 list_for_each_entry(device, devices, dev_list) {
1661 if (device->bdev == bdev) {
1662 ret = -EEXIST;
1663 goto error;
1664 }
1665 }
1666
1667 device = kzalloc(sizeof(*device), GFP_NOFS);
1668 if (!device) {
1669 /* we can safely leave the fs_devices entry around */
1670 ret = -ENOMEM;
1671 goto error;
1672 }
1673
1674 device->name = kstrdup(device_path, GFP_NOFS);
1675 if (!device->name) {
1676 kfree(device);
1677 ret = -ENOMEM;
1678 goto error;
1679 }
1680
1681 ret = find_next_devid(root, &device->devid);
1682 if (ret) {
1683 kfree(device->name);
1684 kfree(device);
1685 goto error;
1686 }
1687
1688 trans = btrfs_start_transaction(root, 0);
1689 if (IS_ERR(trans)) {
1690 kfree(device->name);
1691 kfree(device);
1692 ret = PTR_ERR(trans);
1693 goto error;
1694 }
1695
1696 lock_chunks(root);
1697
1698 q = bdev_get_queue(bdev);
1699 if (blk_queue_discard(q))
1700 device->can_discard = 1;
1701 device->writeable = 1;
1702 device->work.func = pending_bios_fn;
1703 generate_random_uuid(device->uuid);
1704 spin_lock_init(&device->io_lock);
1705 device->generation = trans->transid;
1706 device->io_width = root->sectorsize;
1707 device->io_align = root->sectorsize;
1708 device->sector_size = root->sectorsize;
1709 device->total_bytes = i_size_read(bdev->bd_inode);
1710 device->disk_total_bytes = device->total_bytes;
1711 device->dev_root = root->fs_info->dev_root;
1712 device->bdev = bdev;
1713 device->in_fs_metadata = 1;
1714 device->mode = FMODE_EXCL;
1715 set_blocksize(device->bdev, 4096);
1716
1717 if (seeding_dev) {
1718 sb->s_flags &= ~MS_RDONLY;
1719 ret = btrfs_prepare_sprout(root);
1720 BUG_ON(ret); /* -ENOMEM */
1721 }
1722
1723 device->fs_devices = root->fs_info->fs_devices;
1724
1725 /*
1726 * we don't want write_supers to jump in here with our device
1727 * half setup
1728 */
1729 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1730 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1731 list_add(&device->dev_alloc_list,
1732 &root->fs_info->fs_devices->alloc_list);
1733 root->fs_info->fs_devices->num_devices++;
1734 root->fs_info->fs_devices->open_devices++;
1735 root->fs_info->fs_devices->rw_devices++;
1736 if (device->can_discard)
1737 root->fs_info->fs_devices->num_can_discard++;
1738 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1739
1740 spin_lock(&root->fs_info->free_chunk_lock);
1741 root->fs_info->free_chunk_space += device->total_bytes;
1742 spin_unlock(&root->fs_info->free_chunk_lock);
1743
1744 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1745 root->fs_info->fs_devices->rotating = 1;
1746
1747 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1748 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1749 total_bytes + device->total_bytes);
1750
1751 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1752 btrfs_set_super_num_devices(root->fs_info->super_copy,
1753 total_bytes + 1);
1754 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1755
1756 if (seeding_dev) {
1757 ret = init_first_rw_device(trans, root, device);
1758 if (ret)
1759 goto error_trans;
1760 ret = btrfs_finish_sprout(trans, root);
1761 if (ret)
1762 goto error_trans;
1763 } else {
1764 ret = btrfs_add_device(trans, root, device);
1765 if (ret)
1766 goto error_trans;
1767 }
1768
1769 /*
1770 * we've got more storage, clear any full flags on the space
1771 * infos
1772 */
1773 btrfs_clear_space_info_full(root->fs_info);
1774
1775 unlock_chunks(root);
1776 ret = btrfs_commit_transaction(trans, root);
1777
1778 if (seeding_dev) {
1779 mutex_unlock(&uuid_mutex);
1780 up_write(&sb->s_umount);
1781
1782 if (ret) /* transaction commit */
1783 return ret;
1784
1785 ret = btrfs_relocate_sys_chunks(root);
1786 if (ret < 0)
1787 btrfs_error(root->fs_info, ret,
1788 "Failed to relocate sys chunks after "
1789 "device initialization. This can be fixed "
1790 "using the \"btrfs balance\" command.");
1791 }
1792
1793 return ret;
1794
1795 error_trans:
1796 unlock_chunks(root);
1797 btrfs_abort_transaction(trans, root, ret);
1798 btrfs_end_transaction(trans, root);
1799 kfree(device->name);
1800 kfree(device);
1801 error:
1802 blkdev_put(bdev, FMODE_EXCL);
1803 if (seeding_dev) {
1804 mutex_unlock(&uuid_mutex);
1805 up_write(&sb->s_umount);
1806 }
1807 return ret;
1808 }
1809
1810 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1811 struct btrfs_device *device)
1812 {
1813 int ret;
1814 struct btrfs_path *path;
1815 struct btrfs_root *root;
1816 struct btrfs_dev_item *dev_item;
1817 struct extent_buffer *leaf;
1818 struct btrfs_key key;
1819
1820 root = device->dev_root->fs_info->chunk_root;
1821
1822 path = btrfs_alloc_path();
1823 if (!path)
1824 return -ENOMEM;
1825
1826 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1827 key.type = BTRFS_DEV_ITEM_KEY;
1828 key.offset = device->devid;
1829
1830 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1831 if (ret < 0)
1832 goto out;
1833
1834 if (ret > 0) {
1835 ret = -ENOENT;
1836 goto out;
1837 }
1838
1839 leaf = path->nodes[0];
1840 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1841
1842 btrfs_set_device_id(leaf, dev_item, device->devid);
1843 btrfs_set_device_type(leaf, dev_item, device->type);
1844 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1845 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1846 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1847 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1848 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1849 btrfs_mark_buffer_dirty(leaf);
1850
1851 out:
1852 btrfs_free_path(path);
1853 return ret;
1854 }
1855
1856 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1857 struct btrfs_device *device, u64 new_size)
1858 {
1859 struct btrfs_super_block *super_copy =
1860 device->dev_root->fs_info->super_copy;
1861 u64 old_total = btrfs_super_total_bytes(super_copy);
1862 u64 diff = new_size - device->total_bytes;
1863
1864 if (!device->writeable)
1865 return -EACCES;
1866 if (new_size <= device->total_bytes)
1867 return -EINVAL;
1868
1869 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1870 device->fs_devices->total_rw_bytes += diff;
1871
1872 device->total_bytes = new_size;
1873 device->disk_total_bytes = new_size;
1874 btrfs_clear_space_info_full(device->dev_root->fs_info);
1875
1876 return btrfs_update_device(trans, device);
1877 }
1878
1879 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1880 struct btrfs_device *device, u64 new_size)
1881 {
1882 int ret;
1883 lock_chunks(device->dev_root);
1884 ret = __btrfs_grow_device(trans, device, new_size);
1885 unlock_chunks(device->dev_root);
1886 return ret;
1887 }
1888
1889 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1890 struct btrfs_root *root,
1891 u64 chunk_tree, u64 chunk_objectid,
1892 u64 chunk_offset)
1893 {
1894 int ret;
1895 struct btrfs_path *path;
1896 struct btrfs_key key;
1897
1898 root = root->fs_info->chunk_root;
1899 path = btrfs_alloc_path();
1900 if (!path)
1901 return -ENOMEM;
1902
1903 key.objectid = chunk_objectid;
1904 key.offset = chunk_offset;
1905 key.type = BTRFS_CHUNK_ITEM_KEY;
1906
1907 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1908 if (ret < 0)
1909 goto out;
1910 else if (ret > 0) { /* Logic error or corruption */
1911 btrfs_error(root->fs_info, -ENOENT,
1912 "Failed lookup while freeing chunk.");
1913 ret = -ENOENT;
1914 goto out;
1915 }
1916
1917 ret = btrfs_del_item(trans, root, path);
1918 if (ret < 0)
1919 btrfs_error(root->fs_info, ret,
1920 "Failed to delete chunk item.");
1921 out:
1922 btrfs_free_path(path);
1923 return ret;
1924 }
1925
1926 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1927 chunk_offset)
1928 {
1929 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
1930 struct btrfs_disk_key *disk_key;
1931 struct btrfs_chunk *chunk;
1932 u8 *ptr;
1933 int ret = 0;
1934 u32 num_stripes;
1935 u32 array_size;
1936 u32 len = 0;
1937 u32 cur;
1938 struct btrfs_key key;
1939
1940 array_size = btrfs_super_sys_array_size(super_copy);
1941
1942 ptr = super_copy->sys_chunk_array;
1943 cur = 0;
1944
1945 while (cur < array_size) {
1946 disk_key = (struct btrfs_disk_key *)ptr;
1947 btrfs_disk_key_to_cpu(&key, disk_key);
1948
1949 len = sizeof(*disk_key);
1950
1951 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1952 chunk = (struct btrfs_chunk *)(ptr + len);
1953 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1954 len += btrfs_chunk_item_size(num_stripes);
1955 } else {
1956 ret = -EIO;
1957 break;
1958 }
1959 if (key.objectid == chunk_objectid &&
1960 key.offset == chunk_offset) {
1961 memmove(ptr, ptr + len, array_size - (cur + len));
1962 array_size -= len;
1963 btrfs_set_super_sys_array_size(super_copy, array_size);
1964 } else {
1965 ptr += len;
1966 cur += len;
1967 }
1968 }
1969 return ret;
1970 }
1971
1972 static int btrfs_relocate_chunk(struct btrfs_root *root,
1973 u64 chunk_tree, u64 chunk_objectid,
1974 u64 chunk_offset)
1975 {
1976 struct extent_map_tree *em_tree;
1977 struct btrfs_root *extent_root;
1978 struct btrfs_trans_handle *trans;
1979 struct extent_map *em;
1980 struct map_lookup *map;
1981 int ret;
1982 int i;
1983
1984 root = root->fs_info->chunk_root;
1985 extent_root = root->fs_info->extent_root;
1986 em_tree = &root->fs_info->mapping_tree.map_tree;
1987
1988 ret = btrfs_can_relocate(extent_root, chunk_offset);
1989 if (ret)
1990 return -ENOSPC;
1991
1992 /* step one, relocate all the extents inside this chunk */
1993 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1994 if (ret)
1995 return ret;
1996
1997 trans = btrfs_start_transaction(root, 0);
1998 BUG_ON(IS_ERR(trans));
1999
2000 lock_chunks(root);
2001
2002 /*
2003 * step two, delete the device extents and the
2004 * chunk tree entries
2005 */
2006 read_lock(&em_tree->lock);
2007 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2008 read_unlock(&em_tree->lock);
2009
2010 BUG_ON(!em || em->start > chunk_offset ||
2011 em->start + em->len < chunk_offset);
2012 map = (struct map_lookup *)em->bdev;
2013
2014 for (i = 0; i < map->num_stripes; i++) {
2015 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2016 map->stripes[i].physical);
2017 BUG_ON(ret);
2018
2019 if (map->stripes[i].dev) {
2020 ret = btrfs_update_device(trans, map->stripes[i].dev);
2021 BUG_ON(ret);
2022 }
2023 }
2024 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2025 chunk_offset);
2026
2027 BUG_ON(ret);
2028
2029 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2030
2031 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2032 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2033 BUG_ON(ret);
2034 }
2035
2036 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2037 BUG_ON(ret);
2038
2039 write_lock(&em_tree->lock);
2040 remove_extent_mapping(em_tree, em);
2041 write_unlock(&em_tree->lock);
2042
2043 kfree(map);
2044 em->bdev = NULL;
2045
2046 /* once for the tree */
2047 free_extent_map(em);
2048 /* once for us */
2049 free_extent_map(em);
2050
2051 unlock_chunks(root);
2052 btrfs_end_transaction(trans, root);
2053 return 0;
2054 }
2055
2056 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2057 {
2058 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2059 struct btrfs_path *path;
2060 struct extent_buffer *leaf;
2061 struct btrfs_chunk *chunk;
2062 struct btrfs_key key;
2063 struct btrfs_key found_key;
2064 u64 chunk_tree = chunk_root->root_key.objectid;
2065 u64 chunk_type;
2066 bool retried = false;
2067 int failed = 0;
2068 int ret;
2069
2070 path = btrfs_alloc_path();
2071 if (!path)
2072 return -ENOMEM;
2073
2074 again:
2075 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2076 key.offset = (u64)-1;
2077 key.type = BTRFS_CHUNK_ITEM_KEY;
2078
2079 while (1) {
2080 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2081 if (ret < 0)
2082 goto error;
2083 BUG_ON(ret == 0); /* Corruption */
2084
2085 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2086 key.type);
2087 if (ret < 0)
2088 goto error;
2089 if (ret > 0)
2090 break;
2091
2092 leaf = path->nodes[0];
2093 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2094
2095 chunk = btrfs_item_ptr(leaf, path->slots[0],
2096 struct btrfs_chunk);
2097 chunk_type = btrfs_chunk_type(leaf, chunk);
2098 btrfs_release_path(path);
2099
2100 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2101 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2102 found_key.objectid,
2103 found_key.offset);
2104 if (ret == -ENOSPC)
2105 failed++;
2106 else if (ret)
2107 BUG();
2108 }
2109
2110 if (found_key.offset == 0)
2111 break;
2112 key.offset = found_key.offset - 1;
2113 }
2114 ret = 0;
2115 if (failed && !retried) {
2116 failed = 0;
2117 retried = true;
2118 goto again;
2119 } else if (failed && retried) {
2120 WARN_ON(1);
2121 ret = -ENOSPC;
2122 }
2123 error:
2124 btrfs_free_path(path);
2125 return ret;
2126 }
2127
2128 static int insert_balance_item(struct btrfs_root *root,
2129 struct btrfs_balance_control *bctl)
2130 {
2131 struct btrfs_trans_handle *trans;
2132 struct btrfs_balance_item *item;
2133 struct btrfs_disk_balance_args disk_bargs;
2134 struct btrfs_path *path;
2135 struct extent_buffer *leaf;
2136 struct btrfs_key key;
2137 int ret, err;
2138
2139 path = btrfs_alloc_path();
2140 if (!path)
2141 return -ENOMEM;
2142
2143 trans = btrfs_start_transaction(root, 0);
2144 if (IS_ERR(trans)) {
2145 btrfs_free_path(path);
2146 return PTR_ERR(trans);
2147 }
2148
2149 key.objectid = BTRFS_BALANCE_OBJECTID;
2150 key.type = BTRFS_BALANCE_ITEM_KEY;
2151 key.offset = 0;
2152
2153 ret = btrfs_insert_empty_item(trans, root, path, &key,
2154 sizeof(*item));
2155 if (ret)
2156 goto out;
2157
2158 leaf = path->nodes[0];
2159 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2160
2161 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2162
2163 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2164 btrfs_set_balance_data(leaf, item, &disk_bargs);
2165 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2166 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2167 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2168 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2169
2170 btrfs_set_balance_flags(leaf, item, bctl->flags);
2171
2172 btrfs_mark_buffer_dirty(leaf);
2173 out:
2174 btrfs_free_path(path);
2175 err = btrfs_commit_transaction(trans, root);
2176 if (err && !ret)
2177 ret = err;
2178 return ret;
2179 }
2180
2181 static int del_balance_item(struct btrfs_root *root)
2182 {
2183 struct btrfs_trans_handle *trans;
2184 struct btrfs_path *path;
2185 struct btrfs_key key;
2186 int ret, err;
2187
2188 path = btrfs_alloc_path();
2189 if (!path)
2190 return -ENOMEM;
2191
2192 trans = btrfs_start_transaction(root, 0);
2193 if (IS_ERR(trans)) {
2194 btrfs_free_path(path);
2195 return PTR_ERR(trans);
2196 }
2197
2198 key.objectid = BTRFS_BALANCE_OBJECTID;
2199 key.type = BTRFS_BALANCE_ITEM_KEY;
2200 key.offset = 0;
2201
2202 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2203 if (ret < 0)
2204 goto out;
2205 if (ret > 0) {
2206 ret = -ENOENT;
2207 goto out;
2208 }
2209
2210 ret = btrfs_del_item(trans, root, path);
2211 out:
2212 btrfs_free_path(path);
2213 err = btrfs_commit_transaction(trans, root);
2214 if (err && !ret)
2215 ret = err;
2216 return ret;
2217 }
2218
2219 /*
2220 * This is a heuristic used to reduce the number of chunks balanced on
2221 * resume after balance was interrupted.
2222 */
2223 static void update_balance_args(struct btrfs_balance_control *bctl)
2224 {
2225 /*
2226 * Turn on soft mode for chunk types that were being converted.
2227 */
2228 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2229 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2230 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2231 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2232 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2233 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2234
2235 /*
2236 * Turn on usage filter if is not already used. The idea is
2237 * that chunks that we have already balanced should be
2238 * reasonably full. Don't do it for chunks that are being
2239 * converted - that will keep us from relocating unconverted
2240 * (albeit full) chunks.
2241 */
2242 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2243 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2244 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2245 bctl->data.usage = 90;
2246 }
2247 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2248 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2249 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2250 bctl->sys.usage = 90;
2251 }
2252 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2253 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2254 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2255 bctl->meta.usage = 90;
2256 }
2257 }
2258
2259 /*
2260 * Should be called with both balance and volume mutexes held to
2261 * serialize other volume operations (add_dev/rm_dev/resize) with
2262 * restriper. Same goes for unset_balance_control.
2263 */
2264 static void set_balance_control(struct btrfs_balance_control *bctl)
2265 {
2266 struct btrfs_fs_info *fs_info = bctl->fs_info;
2267
2268 BUG_ON(fs_info->balance_ctl);
2269
2270 spin_lock(&fs_info->balance_lock);
2271 fs_info->balance_ctl = bctl;
2272 spin_unlock(&fs_info->balance_lock);
2273 }
2274
2275 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2276 {
2277 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2278
2279 BUG_ON(!fs_info->balance_ctl);
2280
2281 spin_lock(&fs_info->balance_lock);
2282 fs_info->balance_ctl = NULL;
2283 spin_unlock(&fs_info->balance_lock);
2284
2285 kfree(bctl);
2286 }
2287
2288 /*
2289 * Balance filters. Return 1 if chunk should be filtered out
2290 * (should not be balanced).
2291 */
2292 static int chunk_profiles_filter(u64 chunk_type,
2293 struct btrfs_balance_args *bargs)
2294 {
2295 chunk_type = chunk_to_extended(chunk_type) &
2296 BTRFS_EXTENDED_PROFILE_MASK;
2297
2298 if (bargs->profiles & chunk_type)
2299 return 0;
2300
2301 return 1;
2302 }
2303
2304 static u64 div_factor_fine(u64 num, int factor)
2305 {
2306 if (factor <= 0)
2307 return 0;
2308 if (factor >= 100)
2309 return num;
2310
2311 num *= factor;
2312 do_div(num, 100);
2313 return num;
2314 }
2315
2316 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2317 struct btrfs_balance_args *bargs)
2318 {
2319 struct btrfs_block_group_cache *cache;
2320 u64 chunk_used, user_thresh;
2321 int ret = 1;
2322
2323 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2324 chunk_used = btrfs_block_group_used(&cache->item);
2325
2326 user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
2327 if (chunk_used < user_thresh)
2328 ret = 0;
2329
2330 btrfs_put_block_group(cache);
2331 return ret;
2332 }
2333
2334 static int chunk_devid_filter(struct extent_buffer *leaf,
2335 struct btrfs_chunk *chunk,
2336 struct btrfs_balance_args *bargs)
2337 {
2338 struct btrfs_stripe *stripe;
2339 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2340 int i;
2341
2342 for (i = 0; i < num_stripes; i++) {
2343 stripe = btrfs_stripe_nr(chunk, i);
2344 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2345 return 0;
2346 }
2347
2348 return 1;
2349 }
2350
2351 /* [pstart, pend) */
2352 static int chunk_drange_filter(struct extent_buffer *leaf,
2353 struct btrfs_chunk *chunk,
2354 u64 chunk_offset,
2355 struct btrfs_balance_args *bargs)
2356 {
2357 struct btrfs_stripe *stripe;
2358 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2359 u64 stripe_offset;
2360 u64 stripe_length;
2361 int factor;
2362 int i;
2363
2364 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2365 return 0;
2366
2367 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2368 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2369 factor = 2;
2370 else
2371 factor = 1;
2372 factor = num_stripes / factor;
2373
2374 for (i = 0; i < num_stripes; i++) {
2375 stripe = btrfs_stripe_nr(chunk, i);
2376 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2377 continue;
2378
2379 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2380 stripe_length = btrfs_chunk_length(leaf, chunk);
2381 do_div(stripe_length, factor);
2382
2383 if (stripe_offset < bargs->pend &&
2384 stripe_offset + stripe_length > bargs->pstart)
2385 return 0;
2386 }
2387
2388 return 1;
2389 }
2390
2391 /* [vstart, vend) */
2392 static int chunk_vrange_filter(struct extent_buffer *leaf,
2393 struct btrfs_chunk *chunk,
2394 u64 chunk_offset,
2395 struct btrfs_balance_args *bargs)
2396 {
2397 if (chunk_offset < bargs->vend &&
2398 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2399 /* at least part of the chunk is inside this vrange */
2400 return 0;
2401
2402 return 1;
2403 }
2404
2405 static int chunk_soft_convert_filter(u64 chunk_type,
2406 struct btrfs_balance_args *bargs)
2407 {
2408 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2409 return 0;
2410
2411 chunk_type = chunk_to_extended(chunk_type) &
2412 BTRFS_EXTENDED_PROFILE_MASK;
2413
2414 if (bargs->target == chunk_type)
2415 return 1;
2416
2417 return 0;
2418 }
2419
2420 static int should_balance_chunk(struct btrfs_root *root,
2421 struct extent_buffer *leaf,
2422 struct btrfs_chunk *chunk, u64 chunk_offset)
2423 {
2424 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2425 struct btrfs_balance_args *bargs = NULL;
2426 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2427
2428 /* type filter */
2429 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2430 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2431 return 0;
2432 }
2433
2434 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2435 bargs = &bctl->data;
2436 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2437 bargs = &bctl->sys;
2438 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2439 bargs = &bctl->meta;
2440
2441 /* profiles filter */
2442 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2443 chunk_profiles_filter(chunk_type, bargs)) {
2444 return 0;
2445 }
2446
2447 /* usage filter */
2448 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2449 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2450 return 0;
2451 }
2452
2453 /* devid filter */
2454 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2455 chunk_devid_filter(leaf, chunk, bargs)) {
2456 return 0;
2457 }
2458
2459 /* drange filter, makes sense only with devid filter */
2460 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2461 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2462 return 0;
2463 }
2464
2465 /* vrange filter */
2466 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2467 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2468 return 0;
2469 }
2470
2471 /* soft profile changing mode */
2472 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2473 chunk_soft_convert_filter(chunk_type, bargs)) {
2474 return 0;
2475 }
2476
2477 return 1;
2478 }
2479
2480 static u64 div_factor(u64 num, int factor)
2481 {
2482 if (factor == 10)
2483 return num;
2484 num *= factor;
2485 do_div(num, 10);
2486 return num;
2487 }
2488
2489 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2490 {
2491 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2492 struct btrfs_root *chunk_root = fs_info->chunk_root;
2493 struct btrfs_root *dev_root = fs_info->dev_root;
2494 struct list_head *devices;
2495 struct btrfs_device *device;
2496 u64 old_size;
2497 u64 size_to_free;
2498 struct btrfs_chunk *chunk;
2499 struct btrfs_path *path;
2500 struct btrfs_key key;
2501 struct btrfs_key found_key;
2502 struct btrfs_trans_handle *trans;
2503 struct extent_buffer *leaf;
2504 int slot;
2505 int ret;
2506 int enospc_errors = 0;
2507 bool counting = true;
2508
2509 /* step one make some room on all the devices */
2510 devices = &fs_info->fs_devices->devices;
2511 list_for_each_entry(device, devices, dev_list) {
2512 old_size = device->total_bytes;
2513 size_to_free = div_factor(old_size, 1);
2514 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2515 if (!device->writeable ||
2516 device->total_bytes - device->bytes_used > size_to_free)
2517 continue;
2518
2519 ret = btrfs_shrink_device(device, old_size - size_to_free);
2520 if (ret == -ENOSPC)
2521 break;
2522 BUG_ON(ret);
2523
2524 trans = btrfs_start_transaction(dev_root, 0);
2525 BUG_ON(IS_ERR(trans));
2526
2527 ret = btrfs_grow_device(trans, device, old_size);
2528 BUG_ON(ret);
2529
2530 btrfs_end_transaction(trans, dev_root);
2531 }
2532
2533 /* step two, relocate all the chunks */
2534 path = btrfs_alloc_path();
2535 if (!path) {
2536 ret = -ENOMEM;
2537 goto error;
2538 }
2539
2540 /* zero out stat counters */
2541 spin_lock(&fs_info->balance_lock);
2542 memset(&bctl->stat, 0, sizeof(bctl->stat));
2543 spin_unlock(&fs_info->balance_lock);
2544 again:
2545 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2546 key.offset = (u64)-1;
2547 key.type = BTRFS_CHUNK_ITEM_KEY;
2548
2549 while (1) {
2550 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2551 atomic_read(&fs_info->balance_cancel_req)) {
2552 ret = -ECANCELED;
2553 goto error;
2554 }
2555
2556 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2557 if (ret < 0)
2558 goto error;
2559
2560 /*
2561 * this shouldn't happen, it means the last relocate
2562 * failed
2563 */
2564 if (ret == 0)
2565 BUG(); /* FIXME break ? */
2566
2567 ret = btrfs_previous_item(chunk_root, path, 0,
2568 BTRFS_CHUNK_ITEM_KEY);
2569 if (ret) {
2570 ret = 0;
2571 break;
2572 }
2573
2574 leaf = path->nodes[0];
2575 slot = path->slots[0];
2576 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2577
2578 if (found_key.objectid != key.objectid)
2579 break;
2580
2581 /* chunk zero is special */
2582 if (found_key.offset == 0)
2583 break;
2584
2585 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2586
2587 if (!counting) {
2588 spin_lock(&fs_info->balance_lock);
2589 bctl->stat.considered++;
2590 spin_unlock(&fs_info->balance_lock);
2591 }
2592
2593 ret = should_balance_chunk(chunk_root, leaf, chunk,
2594 found_key.offset);
2595 btrfs_release_path(path);
2596 if (!ret)
2597 goto loop;
2598
2599 if (counting) {
2600 spin_lock(&fs_info->balance_lock);
2601 bctl->stat.expected++;
2602 spin_unlock(&fs_info->balance_lock);
2603 goto loop;
2604 }
2605
2606 ret = btrfs_relocate_chunk(chunk_root,
2607 chunk_root->root_key.objectid,
2608 found_key.objectid,
2609 found_key.offset);
2610 if (ret && ret != -ENOSPC)
2611 goto error;
2612 if (ret == -ENOSPC) {
2613 enospc_errors++;
2614 } else {
2615 spin_lock(&fs_info->balance_lock);
2616 bctl->stat.completed++;
2617 spin_unlock(&fs_info->balance_lock);
2618 }
2619 loop:
2620 key.offset = found_key.offset - 1;
2621 }
2622
2623 if (counting) {
2624 btrfs_release_path(path);
2625 counting = false;
2626 goto again;
2627 }
2628 error:
2629 btrfs_free_path(path);
2630 if (enospc_errors) {
2631 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2632 enospc_errors);
2633 if (!ret)
2634 ret = -ENOSPC;
2635 }
2636
2637 return ret;
2638 }
2639
2640 /**
2641 * alloc_profile_is_valid - see if a given profile is valid and reduced
2642 * @flags: profile to validate
2643 * @extended: if true @flags is treated as an extended profile
2644 */
2645 static int alloc_profile_is_valid(u64 flags, int extended)
2646 {
2647 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
2648 BTRFS_BLOCK_GROUP_PROFILE_MASK);
2649
2650 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
2651
2652 /* 1) check that all other bits are zeroed */
2653 if (flags & ~mask)
2654 return 0;
2655
2656 /* 2) see if profile is reduced */
2657 if (flags == 0)
2658 return !extended; /* "0" is valid for usual profiles */
2659
2660 /* true if exactly one bit set */
2661 return (flags & (flags - 1)) == 0;
2662 }
2663
2664 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2665 {
2666 /* cancel requested || normal exit path */
2667 return atomic_read(&fs_info->balance_cancel_req) ||
2668 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2669 atomic_read(&fs_info->balance_cancel_req) == 0);
2670 }
2671
2672 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2673 {
2674 int ret;
2675
2676 unset_balance_control(fs_info);
2677 ret = del_balance_item(fs_info->tree_root);
2678 BUG_ON(ret);
2679 }
2680
2681 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2682 struct btrfs_ioctl_balance_args *bargs);
2683
2684 /*
2685 * Should be called with both balance and volume mutexes held
2686 */
2687 int btrfs_balance(struct btrfs_balance_control *bctl,
2688 struct btrfs_ioctl_balance_args *bargs)
2689 {
2690 struct btrfs_fs_info *fs_info = bctl->fs_info;
2691 u64 allowed;
2692 int mixed = 0;
2693 int ret;
2694
2695 if (btrfs_fs_closing(fs_info) ||
2696 atomic_read(&fs_info->balance_pause_req) ||
2697 atomic_read(&fs_info->balance_cancel_req)) {
2698 ret = -EINVAL;
2699 goto out;
2700 }
2701
2702 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2703 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
2704 mixed = 1;
2705
2706 /*
2707 * In case of mixed groups both data and meta should be picked,
2708 * and identical options should be given for both of them.
2709 */
2710 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
2711 if (mixed && (bctl->flags & allowed)) {
2712 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
2713 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
2714 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
2715 printk(KERN_ERR "btrfs: with mixed groups data and "
2716 "metadata balance options must be the same\n");
2717 ret = -EINVAL;
2718 goto out;
2719 }
2720 }
2721
2722 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
2723 if (fs_info->fs_devices->num_devices == 1)
2724 allowed |= BTRFS_BLOCK_GROUP_DUP;
2725 else if (fs_info->fs_devices->num_devices < 4)
2726 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
2727 else
2728 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
2729 BTRFS_BLOCK_GROUP_RAID10);
2730
2731 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2732 (!alloc_profile_is_valid(bctl->data.target, 1) ||
2733 (bctl->data.target & ~allowed))) {
2734 printk(KERN_ERR "btrfs: unable to start balance with target "
2735 "data profile %llu\n",
2736 (unsigned long long)bctl->data.target);
2737 ret = -EINVAL;
2738 goto out;
2739 }
2740 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2741 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
2742 (bctl->meta.target & ~allowed))) {
2743 printk(KERN_ERR "btrfs: unable to start balance with target "
2744 "metadata profile %llu\n",
2745 (unsigned long long)bctl->meta.target);
2746 ret = -EINVAL;
2747 goto out;
2748 }
2749 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2750 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
2751 (bctl->sys.target & ~allowed))) {
2752 printk(KERN_ERR "btrfs: unable to start balance with target "
2753 "system profile %llu\n",
2754 (unsigned long long)bctl->sys.target);
2755 ret = -EINVAL;
2756 goto out;
2757 }
2758
2759 /* allow dup'ed data chunks only in mixed mode */
2760 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2761 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
2762 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
2763 ret = -EINVAL;
2764 goto out;
2765 }
2766
2767 /* allow to reduce meta or sys integrity only if force set */
2768 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
2769 BTRFS_BLOCK_GROUP_RAID10;
2770 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2771 (fs_info->avail_system_alloc_bits & allowed) &&
2772 !(bctl->sys.target & allowed)) ||
2773 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
2774 (fs_info->avail_metadata_alloc_bits & allowed) &&
2775 !(bctl->meta.target & allowed))) {
2776 if (bctl->flags & BTRFS_BALANCE_FORCE) {
2777 printk(KERN_INFO "btrfs: force reducing metadata "
2778 "integrity\n");
2779 } else {
2780 printk(KERN_ERR "btrfs: balance will reduce metadata "
2781 "integrity, use force if you want this\n");
2782 ret = -EINVAL;
2783 goto out;
2784 }
2785 }
2786
2787 ret = insert_balance_item(fs_info->tree_root, bctl);
2788 if (ret && ret != -EEXIST)
2789 goto out;
2790
2791 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
2792 BUG_ON(ret == -EEXIST);
2793 set_balance_control(bctl);
2794 } else {
2795 BUG_ON(ret != -EEXIST);
2796 spin_lock(&fs_info->balance_lock);
2797 update_balance_args(bctl);
2798 spin_unlock(&fs_info->balance_lock);
2799 }
2800
2801 atomic_inc(&fs_info->balance_running);
2802 mutex_unlock(&fs_info->balance_mutex);
2803
2804 ret = __btrfs_balance(fs_info);
2805
2806 mutex_lock(&fs_info->balance_mutex);
2807 atomic_dec(&fs_info->balance_running);
2808
2809 if (bargs) {
2810 memset(bargs, 0, sizeof(*bargs));
2811 update_ioctl_balance_args(fs_info, 0, bargs);
2812 }
2813
2814 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
2815 balance_need_close(fs_info)) {
2816 __cancel_balance(fs_info);
2817 }
2818
2819 wake_up(&fs_info->balance_wait_q);
2820
2821 return ret;
2822 out:
2823 if (bctl->flags & BTRFS_BALANCE_RESUME)
2824 __cancel_balance(fs_info);
2825 else
2826 kfree(bctl);
2827 return ret;
2828 }
2829
2830 static int balance_kthread(void *data)
2831 {
2832 struct btrfs_balance_control *bctl =
2833 (struct btrfs_balance_control *)data;
2834 struct btrfs_fs_info *fs_info = bctl->fs_info;
2835 int ret = 0;
2836
2837 mutex_lock(&fs_info->volume_mutex);
2838 mutex_lock(&fs_info->balance_mutex);
2839
2840 set_balance_control(bctl);
2841
2842 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
2843 printk(KERN_INFO "btrfs: force skipping balance\n");
2844 } else {
2845 printk(KERN_INFO "btrfs: continuing balance\n");
2846 ret = btrfs_balance(bctl, NULL);
2847 }
2848
2849 mutex_unlock(&fs_info->balance_mutex);
2850 mutex_unlock(&fs_info->volume_mutex);
2851 return ret;
2852 }
2853
2854 int btrfs_recover_balance(struct btrfs_root *tree_root)
2855 {
2856 struct task_struct *tsk;
2857 struct btrfs_balance_control *bctl;
2858 struct btrfs_balance_item *item;
2859 struct btrfs_disk_balance_args disk_bargs;
2860 struct btrfs_path *path;
2861 struct extent_buffer *leaf;
2862 struct btrfs_key key;
2863 int ret;
2864
2865 path = btrfs_alloc_path();
2866 if (!path)
2867 return -ENOMEM;
2868
2869 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
2870 if (!bctl) {
2871 ret = -ENOMEM;
2872 goto out;
2873 }
2874
2875 key.objectid = BTRFS_BALANCE_OBJECTID;
2876 key.type = BTRFS_BALANCE_ITEM_KEY;
2877 key.offset = 0;
2878
2879 ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
2880 if (ret < 0)
2881 goto out_bctl;
2882 if (ret > 0) { /* ret = -ENOENT; */
2883 ret = 0;
2884 goto out_bctl;
2885 }
2886
2887 leaf = path->nodes[0];
2888 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2889
2890 bctl->fs_info = tree_root->fs_info;
2891 bctl->flags = btrfs_balance_flags(leaf, item) | BTRFS_BALANCE_RESUME;
2892
2893 btrfs_balance_data(leaf, item, &disk_bargs);
2894 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
2895 btrfs_balance_meta(leaf, item, &disk_bargs);
2896 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
2897 btrfs_balance_sys(leaf, item, &disk_bargs);
2898 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
2899
2900 tsk = kthread_run(balance_kthread, bctl, "btrfs-balance");
2901 if (IS_ERR(tsk))
2902 ret = PTR_ERR(tsk);
2903 else
2904 goto out;
2905
2906 out_bctl:
2907 kfree(bctl);
2908 out:
2909 btrfs_free_path(path);
2910 return ret;
2911 }
2912
2913 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
2914 {
2915 int ret = 0;
2916
2917 mutex_lock(&fs_info->balance_mutex);
2918 if (!fs_info->balance_ctl) {
2919 mutex_unlock(&fs_info->balance_mutex);
2920 return -ENOTCONN;
2921 }
2922
2923 if (atomic_read(&fs_info->balance_running)) {
2924 atomic_inc(&fs_info->balance_pause_req);
2925 mutex_unlock(&fs_info->balance_mutex);
2926
2927 wait_event(fs_info->balance_wait_q,
2928 atomic_read(&fs_info->balance_running) == 0);
2929
2930 mutex_lock(&fs_info->balance_mutex);
2931 /* we are good with balance_ctl ripped off from under us */
2932 BUG_ON(atomic_read(&fs_info->balance_running));
2933 atomic_dec(&fs_info->balance_pause_req);
2934 } else {
2935 ret = -ENOTCONN;
2936 }
2937
2938 mutex_unlock(&fs_info->balance_mutex);
2939 return ret;
2940 }
2941
2942 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
2943 {
2944 mutex_lock(&fs_info->balance_mutex);
2945 if (!fs_info->balance_ctl) {
2946 mutex_unlock(&fs_info->balance_mutex);
2947 return -ENOTCONN;
2948 }
2949
2950 atomic_inc(&fs_info->balance_cancel_req);
2951 /*
2952 * if we are running just wait and return, balance item is
2953 * deleted in btrfs_balance in this case
2954 */
2955 if (atomic_read(&fs_info->balance_running)) {
2956 mutex_unlock(&fs_info->balance_mutex);
2957 wait_event(fs_info->balance_wait_q,
2958 atomic_read(&fs_info->balance_running) == 0);
2959 mutex_lock(&fs_info->balance_mutex);
2960 } else {
2961 /* __cancel_balance needs volume_mutex */
2962 mutex_unlock(&fs_info->balance_mutex);
2963 mutex_lock(&fs_info->volume_mutex);
2964 mutex_lock(&fs_info->balance_mutex);
2965
2966 if (fs_info->balance_ctl)
2967 __cancel_balance(fs_info);
2968
2969 mutex_unlock(&fs_info->volume_mutex);
2970 }
2971
2972 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
2973 atomic_dec(&fs_info->balance_cancel_req);
2974 mutex_unlock(&fs_info->balance_mutex);
2975 return 0;
2976 }
2977
2978 /*
2979 * shrinking a device means finding all of the device extents past
2980 * the new size, and then following the back refs to the chunks.
2981 * The chunk relocation code actually frees the device extent
2982 */
2983 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2984 {
2985 struct btrfs_trans_handle *trans;
2986 struct btrfs_root *root = device->dev_root;
2987 struct btrfs_dev_extent *dev_extent = NULL;
2988 struct btrfs_path *path;
2989 u64 length;
2990 u64 chunk_tree;
2991 u64 chunk_objectid;
2992 u64 chunk_offset;
2993 int ret;
2994 int slot;
2995 int failed = 0;
2996 bool retried = false;
2997 struct extent_buffer *l;
2998 struct btrfs_key key;
2999 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3000 u64 old_total = btrfs_super_total_bytes(super_copy);
3001 u64 old_size = device->total_bytes;
3002 u64 diff = device->total_bytes - new_size;
3003
3004 if (new_size >= device->total_bytes)
3005 return -EINVAL;
3006
3007 path = btrfs_alloc_path();
3008 if (!path)
3009 return -ENOMEM;
3010
3011 path->reada = 2;
3012
3013 lock_chunks(root);
3014
3015 device->total_bytes = new_size;
3016 if (device->writeable) {
3017 device->fs_devices->total_rw_bytes -= diff;
3018 spin_lock(&root->fs_info->free_chunk_lock);
3019 root->fs_info->free_chunk_space -= diff;
3020 spin_unlock(&root->fs_info->free_chunk_lock);
3021 }
3022 unlock_chunks(root);
3023
3024 again:
3025 key.objectid = device->devid;
3026 key.offset = (u64)-1;
3027 key.type = BTRFS_DEV_EXTENT_KEY;
3028
3029 do {
3030 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3031 if (ret < 0)
3032 goto done;
3033
3034 ret = btrfs_previous_item(root, path, 0, key.type);
3035 if (ret < 0)
3036 goto done;
3037 if (ret) {
3038 ret = 0;
3039 btrfs_release_path(path);
3040 break;
3041 }
3042
3043 l = path->nodes[0];
3044 slot = path->slots[0];
3045 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3046
3047 if (key.objectid != device->devid) {
3048 btrfs_release_path(path);
3049 break;
3050 }
3051
3052 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3053 length = btrfs_dev_extent_length(l, dev_extent);
3054
3055 if (key.offset + length <= new_size) {
3056 btrfs_release_path(path);
3057 break;
3058 }
3059
3060 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3061 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3062 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3063 btrfs_release_path(path);
3064
3065 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3066 chunk_offset);
3067 if (ret && ret != -ENOSPC)
3068 goto done;
3069 if (ret == -ENOSPC)
3070 failed++;
3071 } while (key.offset-- > 0);
3072
3073 if (failed && !retried) {
3074 failed = 0;
3075 retried = true;
3076 goto again;
3077 } else if (failed && retried) {
3078 ret = -ENOSPC;
3079 lock_chunks(root);
3080
3081 device->total_bytes = old_size;
3082 if (device->writeable)
3083 device->fs_devices->total_rw_bytes += diff;
3084 spin_lock(&root->fs_info->free_chunk_lock);
3085 root->fs_info->free_chunk_space += diff;
3086 spin_unlock(&root->fs_info->free_chunk_lock);
3087 unlock_chunks(root);
3088 goto done;
3089 }
3090
3091 /* Shrinking succeeded, else we would be at "done". */
3092 trans = btrfs_start_transaction(root, 0);
3093 if (IS_ERR(trans)) {
3094 ret = PTR_ERR(trans);
3095 goto done;
3096 }
3097
3098 lock_chunks(root);
3099
3100 device->disk_total_bytes = new_size;
3101 /* Now btrfs_update_device() will change the on-disk size. */
3102 ret = btrfs_update_device(trans, device);
3103 if (ret) {
3104 unlock_chunks(root);
3105 btrfs_end_transaction(trans, root);
3106 goto done;
3107 }
3108 WARN_ON(diff > old_total);
3109 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3110 unlock_chunks(root);
3111 btrfs_end_transaction(trans, root);
3112 done:
3113 btrfs_free_path(path);
3114 return ret;
3115 }
3116
3117 static int btrfs_add_system_chunk(struct btrfs_root *root,
3118 struct btrfs_key *key,
3119 struct btrfs_chunk *chunk, int item_size)
3120 {
3121 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3122 struct btrfs_disk_key disk_key;
3123 u32 array_size;
3124 u8 *ptr;
3125
3126 array_size = btrfs_super_sys_array_size(super_copy);
3127 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3128 return -EFBIG;
3129
3130 ptr = super_copy->sys_chunk_array + array_size;
3131 btrfs_cpu_key_to_disk(&disk_key, key);
3132 memcpy(ptr, &disk_key, sizeof(disk_key));
3133 ptr += sizeof(disk_key);
3134 memcpy(ptr, chunk, item_size);
3135 item_size += sizeof(disk_key);
3136 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3137 return 0;
3138 }
3139
3140 /*
3141 * sort the devices in descending order by max_avail, total_avail
3142 */
3143 static int btrfs_cmp_device_info(const void *a, const void *b)
3144 {
3145 const struct btrfs_device_info *di_a = a;
3146 const struct btrfs_device_info *di_b = b;
3147
3148 if (di_a->max_avail > di_b->max_avail)
3149 return -1;
3150 if (di_a->max_avail < di_b->max_avail)
3151 return 1;
3152 if (di_a->total_avail > di_b->total_avail)
3153 return -1;
3154 if (di_a->total_avail < di_b->total_avail)
3155 return 1;
3156 return 0;
3157 }
3158
3159 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3160 struct btrfs_root *extent_root,
3161 struct map_lookup **map_ret,
3162 u64 *num_bytes_out, u64 *stripe_size_out,
3163 u64 start, u64 type)
3164 {
3165 struct btrfs_fs_info *info = extent_root->fs_info;
3166 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3167 struct list_head *cur;
3168 struct map_lookup *map = NULL;
3169 struct extent_map_tree *em_tree;
3170 struct extent_map *em;
3171 struct btrfs_device_info *devices_info = NULL;
3172 u64 total_avail;
3173 int num_stripes; /* total number of stripes to allocate */
3174 int sub_stripes; /* sub_stripes info for map */
3175 int dev_stripes; /* stripes per dev */
3176 int devs_max; /* max devs to use */
3177 int devs_min; /* min devs needed */
3178 int devs_increment; /* ndevs has to be a multiple of this */
3179 int ncopies; /* how many copies to data has */
3180 int ret;
3181 u64 max_stripe_size;
3182 u64 max_chunk_size;
3183 u64 stripe_size;
3184 u64 num_bytes;
3185 int ndevs;
3186 int i;
3187 int j;
3188
3189 BUG_ON(!alloc_profile_is_valid(type, 0));
3190
3191 if (list_empty(&fs_devices->alloc_list))
3192 return -ENOSPC;
3193
3194 sub_stripes = 1;
3195 dev_stripes = 1;
3196 devs_increment = 1;
3197 ncopies = 1;
3198 devs_max = 0; /* 0 == as many as possible */
3199 devs_min = 1;
3200
3201 /*
3202 * define the properties of each RAID type.
3203 * FIXME: move this to a global table and use it in all RAID
3204 * calculation code
3205 */
3206 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
3207 dev_stripes = 2;
3208 ncopies = 2;
3209 devs_max = 1;
3210 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
3211 devs_min = 2;
3212 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
3213 devs_increment = 2;
3214 ncopies = 2;
3215 devs_max = 2;
3216 devs_min = 2;
3217 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
3218 sub_stripes = 2;
3219 devs_increment = 2;
3220 ncopies = 2;
3221 devs_min = 4;
3222 } else {
3223 devs_max = 1;
3224 }
3225
3226 if (type & BTRFS_BLOCK_GROUP_DATA) {
3227 max_stripe_size = 1024 * 1024 * 1024;
3228 max_chunk_size = 10 * max_stripe_size;
3229 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3230 /* for larger filesystems, use larger metadata chunks */
3231 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3232 max_stripe_size = 1024 * 1024 * 1024;
3233 else
3234 max_stripe_size = 256 * 1024 * 1024;
3235 max_chunk_size = max_stripe_size;
3236 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3237 max_stripe_size = 32 * 1024 * 1024;
3238 max_chunk_size = 2 * max_stripe_size;
3239 } else {
3240 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3241 type);
3242 BUG_ON(1);
3243 }
3244
3245 /* we don't want a chunk larger than 10% of writeable space */
3246 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3247 max_chunk_size);
3248
3249 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3250 GFP_NOFS);
3251 if (!devices_info)
3252 return -ENOMEM;
3253
3254 cur = fs_devices->alloc_list.next;
3255
3256 /*
3257 * in the first pass through the devices list, we gather information
3258 * about the available holes on each device.
3259 */
3260 ndevs = 0;
3261 while (cur != &fs_devices->alloc_list) {
3262 struct btrfs_device *device;
3263 u64 max_avail;
3264 u64 dev_offset;
3265
3266 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3267
3268 cur = cur->next;
3269
3270 if (!device->writeable) {
3271 printk(KERN_ERR
3272 "btrfs: read-only device in alloc_list\n");
3273 WARN_ON(1);
3274 continue;
3275 }
3276
3277 if (!device->in_fs_metadata)
3278 continue;
3279
3280 if (device->total_bytes > device->bytes_used)
3281 total_avail = device->total_bytes - device->bytes_used;
3282 else
3283 total_avail = 0;
3284
3285 /* If there is no space on this device, skip it. */
3286 if (total_avail == 0)
3287 continue;
3288
3289 ret = find_free_dev_extent(device,
3290 max_stripe_size * dev_stripes,
3291 &dev_offset, &max_avail);
3292 if (ret && ret != -ENOSPC)
3293 goto error;
3294
3295 if (ret == 0)
3296 max_avail = max_stripe_size * dev_stripes;
3297
3298 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3299 continue;
3300
3301 devices_info[ndevs].dev_offset = dev_offset;
3302 devices_info[ndevs].max_avail = max_avail;
3303 devices_info[ndevs].total_avail = total_avail;
3304 devices_info[ndevs].dev = device;
3305 ++ndevs;
3306 }
3307
3308 /*
3309 * now sort the devices by hole size / available space
3310 */
3311 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3312 btrfs_cmp_device_info, NULL);
3313
3314 /* round down to number of usable stripes */
3315 ndevs -= ndevs % devs_increment;
3316
3317 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3318 ret = -ENOSPC;
3319 goto error;
3320 }
3321
3322 if (devs_max && ndevs > devs_max)
3323 ndevs = devs_max;
3324 /*
3325 * the primary goal is to maximize the number of stripes, so use as many
3326 * devices as possible, even if the stripes are not maximum sized.
3327 */
3328 stripe_size = devices_info[ndevs-1].max_avail;
3329 num_stripes = ndevs * dev_stripes;
3330
3331 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3332 stripe_size = max_chunk_size * ncopies;
3333 do_div(stripe_size, ndevs);
3334 }
3335
3336 do_div(stripe_size, dev_stripes);
3337
3338 /* align to BTRFS_STRIPE_LEN */
3339 do_div(stripe_size, BTRFS_STRIPE_LEN);
3340 stripe_size *= BTRFS_STRIPE_LEN;
3341
3342 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3343 if (!map) {
3344 ret = -ENOMEM;
3345 goto error;
3346 }
3347 map->num_stripes = num_stripes;
3348
3349 for (i = 0; i < ndevs; ++i) {
3350 for (j = 0; j < dev_stripes; ++j) {
3351 int s = i * dev_stripes + j;
3352 map->stripes[s].dev = devices_info[i].dev;
3353 map->stripes[s].physical = devices_info[i].dev_offset +
3354 j * stripe_size;
3355 }
3356 }
3357 map->sector_size = extent_root->sectorsize;
3358 map->stripe_len = BTRFS_STRIPE_LEN;
3359 map->io_align = BTRFS_STRIPE_LEN;
3360 map->io_width = BTRFS_STRIPE_LEN;
3361 map->type = type;
3362 map->sub_stripes = sub_stripes;
3363
3364 *map_ret = map;
3365 num_bytes = stripe_size * (num_stripes / ncopies);
3366
3367 *stripe_size_out = stripe_size;
3368 *num_bytes_out = num_bytes;
3369
3370 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3371
3372 em = alloc_extent_map();
3373 if (!em) {
3374 ret = -ENOMEM;
3375 goto error;
3376 }
3377 em->bdev = (struct block_device *)map;
3378 em->start = start;
3379 em->len = num_bytes;
3380 em->block_start = 0;
3381 em->block_len = em->len;
3382
3383 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3384 write_lock(&em_tree->lock);
3385 ret = add_extent_mapping(em_tree, em);
3386 write_unlock(&em_tree->lock);
3387 free_extent_map(em);
3388 if (ret)
3389 goto error;
3390
3391 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3392 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3393 start, num_bytes);
3394 if (ret)
3395 goto error;
3396
3397 for (i = 0; i < map->num_stripes; ++i) {
3398 struct btrfs_device *device;
3399 u64 dev_offset;
3400
3401 device = map->stripes[i].dev;
3402 dev_offset = map->stripes[i].physical;
3403
3404 ret = btrfs_alloc_dev_extent(trans, device,
3405 info->chunk_root->root_key.objectid,
3406 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3407 start, dev_offset, stripe_size);
3408 if (ret) {
3409 btrfs_abort_transaction(trans, extent_root, ret);
3410 goto error;
3411 }
3412 }
3413
3414 kfree(devices_info);
3415 return 0;
3416
3417 error:
3418 kfree(map);
3419 kfree(devices_info);
3420 return ret;
3421 }
3422
3423 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3424 struct btrfs_root *extent_root,
3425 struct map_lookup *map, u64 chunk_offset,
3426 u64 chunk_size, u64 stripe_size)
3427 {
3428 u64 dev_offset;
3429 struct btrfs_key key;
3430 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3431 struct btrfs_device *device;
3432 struct btrfs_chunk *chunk;
3433 struct btrfs_stripe *stripe;
3434 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3435 int index = 0;
3436 int ret;
3437
3438 chunk = kzalloc(item_size, GFP_NOFS);
3439 if (!chunk)
3440 return -ENOMEM;
3441
3442 index = 0;
3443 while (index < map->num_stripes) {
3444 device = map->stripes[index].dev;
3445 device->bytes_used += stripe_size;
3446 ret = btrfs_update_device(trans, device);
3447 if (ret)
3448 goto out_free;
3449 index++;
3450 }
3451
3452 spin_lock(&extent_root->fs_info->free_chunk_lock);
3453 extent_root->fs_info->free_chunk_space -= (stripe_size *
3454 map->num_stripes);
3455 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3456
3457 index = 0;
3458 stripe = &chunk->stripe;
3459 while (index < map->num_stripes) {
3460 device = map->stripes[index].dev;
3461 dev_offset = map->stripes[index].physical;
3462
3463 btrfs_set_stack_stripe_devid(stripe, device->devid);
3464 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3465 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3466 stripe++;
3467 index++;
3468 }
3469
3470 btrfs_set_stack_chunk_length(chunk, chunk_size);
3471 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3472 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3473 btrfs_set_stack_chunk_type(chunk, map->type);
3474 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3475 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3476 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3477 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3478 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3479
3480 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3481 key.type = BTRFS_CHUNK_ITEM_KEY;
3482 key.offset = chunk_offset;
3483
3484 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3485
3486 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3487 /*
3488 * TODO: Cleanup of inserted chunk root in case of
3489 * failure.
3490 */
3491 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3492 item_size);
3493 }
3494
3495 out_free:
3496 kfree(chunk);
3497 return ret;
3498 }
3499
3500 /*
3501 * Chunk allocation falls into two parts. The first part does works
3502 * that make the new allocated chunk useable, but not do any operation
3503 * that modifies the chunk tree. The second part does the works that
3504 * require modifying the chunk tree. This division is important for the
3505 * bootstrap process of adding storage to a seed btrfs.
3506 */
3507 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3508 struct btrfs_root *extent_root, u64 type)
3509 {
3510 u64 chunk_offset;
3511 u64 chunk_size;
3512 u64 stripe_size;
3513 struct map_lookup *map;
3514 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3515 int ret;
3516
3517 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3518 &chunk_offset);
3519 if (ret)
3520 return ret;
3521
3522 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3523 &stripe_size, chunk_offset, type);
3524 if (ret)
3525 return ret;
3526
3527 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3528 chunk_size, stripe_size);
3529 if (ret)
3530 return ret;
3531 return 0;
3532 }
3533
3534 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3535 struct btrfs_root *root,
3536 struct btrfs_device *device)
3537 {
3538 u64 chunk_offset;
3539 u64 sys_chunk_offset;
3540 u64 chunk_size;
3541 u64 sys_chunk_size;
3542 u64 stripe_size;
3543 u64 sys_stripe_size;
3544 u64 alloc_profile;
3545 struct map_lookup *map;
3546 struct map_lookup *sys_map;
3547 struct btrfs_fs_info *fs_info = root->fs_info;
3548 struct btrfs_root *extent_root = fs_info->extent_root;
3549 int ret;
3550
3551 ret = find_next_chunk(fs_info->chunk_root,
3552 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3553 if (ret)
3554 return ret;
3555
3556 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3557 fs_info->avail_metadata_alloc_bits;
3558 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3559
3560 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3561 &stripe_size, chunk_offset, alloc_profile);
3562 if (ret)
3563 return ret;
3564
3565 sys_chunk_offset = chunk_offset + chunk_size;
3566
3567 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3568 fs_info->avail_system_alloc_bits;
3569 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3570
3571 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3572 &sys_chunk_size, &sys_stripe_size,
3573 sys_chunk_offset, alloc_profile);
3574 if (ret)
3575 goto abort;
3576
3577 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3578 if (ret)
3579 goto abort;
3580
3581 /*
3582 * Modifying chunk tree needs allocating new blocks from both
3583 * system block group and metadata block group. So we only can
3584 * do operations require modifying the chunk tree after both
3585 * block groups were created.
3586 */
3587 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3588 chunk_size, stripe_size);
3589 if (ret)
3590 goto abort;
3591
3592 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3593 sys_chunk_offset, sys_chunk_size,
3594 sys_stripe_size);
3595 if (ret)
3596 goto abort;
3597
3598 return 0;
3599
3600 abort:
3601 btrfs_abort_transaction(trans, root, ret);
3602 return ret;
3603 }
3604
3605 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3606 {
3607 struct extent_map *em;
3608 struct map_lookup *map;
3609 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3610 int readonly = 0;
3611 int i;
3612
3613 read_lock(&map_tree->map_tree.lock);
3614 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3615 read_unlock(&map_tree->map_tree.lock);
3616 if (!em)
3617 return 1;
3618
3619 if (btrfs_test_opt(root, DEGRADED)) {
3620 free_extent_map(em);
3621 return 0;
3622 }
3623
3624 map = (struct map_lookup *)em->bdev;
3625 for (i = 0; i < map->num_stripes; i++) {
3626 if (!map->stripes[i].dev->writeable) {
3627 readonly = 1;
3628 break;
3629 }
3630 }
3631 free_extent_map(em);
3632 return readonly;
3633 }
3634
3635 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3636 {
3637 extent_map_tree_init(&tree->map_tree);
3638 }
3639
3640 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3641 {
3642 struct extent_map *em;
3643
3644 while (1) {
3645 write_lock(&tree->map_tree.lock);
3646 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3647 if (em)
3648 remove_extent_mapping(&tree->map_tree, em);
3649 write_unlock(&tree->map_tree.lock);
3650 if (!em)
3651 break;
3652 kfree(em->bdev);
3653 /* once for us */
3654 free_extent_map(em);
3655 /* once for the tree */
3656 free_extent_map(em);
3657 }
3658 }
3659
3660 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
3661 {
3662 struct extent_map *em;
3663 struct map_lookup *map;
3664 struct extent_map_tree *em_tree = &map_tree->map_tree;
3665 int ret;
3666
3667 read_lock(&em_tree->lock);
3668 em = lookup_extent_mapping(em_tree, logical, len);
3669 read_unlock(&em_tree->lock);
3670 BUG_ON(!em);
3671
3672 BUG_ON(em->start > logical || em->start + em->len < logical);
3673 map = (struct map_lookup *)em->bdev;
3674 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
3675 ret = map->num_stripes;
3676 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3677 ret = map->sub_stripes;
3678 else
3679 ret = 1;
3680 free_extent_map(em);
3681 return ret;
3682 }
3683
3684 static int find_live_mirror(struct map_lookup *map, int first, int num,
3685 int optimal)
3686 {
3687 int i;
3688 if (map->stripes[optimal].dev->bdev)
3689 return optimal;
3690 for (i = first; i < first + num; i++) {
3691 if (map->stripes[i].dev->bdev)
3692 return i;
3693 }
3694 /* we couldn't find one that doesn't fail. Just return something
3695 * and the io error handling code will clean up eventually
3696 */
3697 return optimal;
3698 }
3699
3700 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3701 u64 logical, u64 *length,
3702 struct btrfs_bio **bbio_ret,
3703 int mirror_num)
3704 {
3705 struct extent_map *em;
3706 struct map_lookup *map;
3707 struct extent_map_tree *em_tree = &map_tree->map_tree;
3708 u64 offset;
3709 u64 stripe_offset;
3710 u64 stripe_end_offset;
3711 u64 stripe_nr;
3712 u64 stripe_nr_orig;
3713 u64 stripe_nr_end;
3714 int stripe_index;
3715 int i;
3716 int ret = 0;
3717 int num_stripes;
3718 int max_errors = 0;
3719 struct btrfs_bio *bbio = NULL;
3720
3721 read_lock(&em_tree->lock);
3722 em = lookup_extent_mapping(em_tree, logical, *length);
3723 read_unlock(&em_tree->lock);
3724
3725 if (!em) {
3726 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
3727 (unsigned long long)logical,
3728 (unsigned long long)*length);
3729 BUG();
3730 }
3731
3732 BUG_ON(em->start > logical || em->start + em->len < logical);
3733 map = (struct map_lookup *)em->bdev;
3734 offset = logical - em->start;
3735
3736 if (mirror_num > map->num_stripes)
3737 mirror_num = 0;
3738
3739 stripe_nr = offset;
3740 /*
3741 * stripe_nr counts the total number of stripes we have to stride
3742 * to get to this block
3743 */
3744 do_div(stripe_nr, map->stripe_len);
3745
3746 stripe_offset = stripe_nr * map->stripe_len;
3747 BUG_ON(offset < stripe_offset);
3748
3749 /* stripe_offset is the offset of this block in its stripe*/
3750 stripe_offset = offset - stripe_offset;
3751
3752 if (rw & REQ_DISCARD)
3753 *length = min_t(u64, em->len - offset, *length);
3754 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
3755 /* we limit the length of each bio to what fits in a stripe */
3756 *length = min_t(u64, em->len - offset,
3757 map->stripe_len - stripe_offset);
3758 } else {
3759 *length = em->len - offset;
3760 }
3761
3762 if (!bbio_ret)
3763 goto out;
3764
3765 num_stripes = 1;
3766 stripe_index = 0;
3767 stripe_nr_orig = stripe_nr;
3768 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
3769 (~(map->stripe_len - 1));
3770 do_div(stripe_nr_end, map->stripe_len);
3771 stripe_end_offset = stripe_nr_end * map->stripe_len -
3772 (offset + *length);
3773 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3774 if (rw & REQ_DISCARD)
3775 num_stripes = min_t(u64, map->num_stripes,
3776 stripe_nr_end - stripe_nr_orig);
3777 stripe_index = do_div(stripe_nr, map->num_stripes);
3778 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
3779 if (rw & (REQ_WRITE | REQ_DISCARD))
3780 num_stripes = map->num_stripes;
3781 else if (mirror_num)
3782 stripe_index = mirror_num - 1;
3783 else {
3784 stripe_index = find_live_mirror(map, 0,
3785 map->num_stripes,
3786 current->pid % map->num_stripes);
3787 mirror_num = stripe_index + 1;
3788 }
3789
3790 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
3791 if (rw & (REQ_WRITE | REQ_DISCARD)) {
3792 num_stripes = map->num_stripes;
3793 } else if (mirror_num) {
3794 stripe_index = mirror_num - 1;
3795 } else {
3796 mirror_num = 1;
3797 }
3798
3799 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3800 int factor = map->num_stripes / map->sub_stripes;
3801
3802 stripe_index = do_div(stripe_nr, factor);
3803 stripe_index *= map->sub_stripes;
3804
3805 if (rw & REQ_WRITE)
3806 num_stripes = map->sub_stripes;
3807 else if (rw & REQ_DISCARD)
3808 num_stripes = min_t(u64, map->sub_stripes *
3809 (stripe_nr_end - stripe_nr_orig),
3810 map->num_stripes);
3811 else if (mirror_num)
3812 stripe_index += mirror_num - 1;
3813 else {
3814 int old_stripe_index = stripe_index;
3815 stripe_index = find_live_mirror(map, stripe_index,
3816 map->sub_stripes, stripe_index +
3817 current->pid % map->sub_stripes);
3818 mirror_num = stripe_index - old_stripe_index + 1;
3819 }
3820 } else {
3821 /*
3822 * after this do_div call, stripe_nr is the number of stripes
3823 * on this device we have to walk to find the data, and
3824 * stripe_index is the number of our device in the stripe array
3825 */
3826 stripe_index = do_div(stripe_nr, map->num_stripes);
3827 mirror_num = stripe_index + 1;
3828 }
3829 BUG_ON(stripe_index >= map->num_stripes);
3830
3831 bbio = kzalloc(btrfs_bio_size(num_stripes), GFP_NOFS);
3832 if (!bbio) {
3833 ret = -ENOMEM;
3834 goto out;
3835 }
3836 atomic_set(&bbio->error, 0);
3837
3838 if (rw & REQ_DISCARD) {
3839 int factor = 0;
3840 int sub_stripes = 0;
3841 u64 stripes_per_dev = 0;
3842 u32 remaining_stripes = 0;
3843 u32 last_stripe = 0;
3844
3845 if (map->type &
3846 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
3847 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3848 sub_stripes = 1;
3849 else
3850 sub_stripes = map->sub_stripes;
3851
3852 factor = map->num_stripes / sub_stripes;
3853 stripes_per_dev = div_u64_rem(stripe_nr_end -
3854 stripe_nr_orig,
3855 factor,
3856 &remaining_stripes);
3857 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
3858 last_stripe *= sub_stripes;
3859 }
3860
3861 for (i = 0; i < num_stripes; i++) {
3862 bbio->stripes[i].physical =
3863 map->stripes[stripe_index].physical +
3864 stripe_offset + stripe_nr * map->stripe_len;
3865 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
3866
3867 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
3868 BTRFS_BLOCK_GROUP_RAID10)) {
3869 bbio->stripes[i].length = stripes_per_dev *
3870 map->stripe_len;
3871
3872 if (i / sub_stripes < remaining_stripes)
3873 bbio->stripes[i].length +=
3874 map->stripe_len;
3875
3876 /*
3877 * Special for the first stripe and
3878 * the last stripe:
3879 *
3880 * |-------|...|-------|
3881 * |----------|
3882 * off end_off
3883 */
3884 if (i < sub_stripes)
3885 bbio->stripes[i].length -=
3886 stripe_offset;
3887
3888 if (stripe_index >= last_stripe &&
3889 stripe_index <= (last_stripe +
3890 sub_stripes - 1))
3891 bbio->stripes[i].length -=
3892 stripe_end_offset;
3893
3894 if (i == sub_stripes - 1)
3895 stripe_offset = 0;
3896 } else
3897 bbio->stripes[i].length = *length;
3898
3899 stripe_index++;
3900 if (stripe_index == map->num_stripes) {
3901 /* This could only happen for RAID0/10 */
3902 stripe_index = 0;
3903 stripe_nr++;
3904 }
3905 }
3906 } else {
3907 for (i = 0; i < num_stripes; i++) {
3908 bbio->stripes[i].physical =
3909 map->stripes[stripe_index].physical +
3910 stripe_offset +
3911 stripe_nr * map->stripe_len;
3912 bbio->stripes[i].dev =
3913 map->stripes[stripe_index].dev;
3914 stripe_index++;
3915 }
3916 }
3917
3918 if (rw & REQ_WRITE) {
3919 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
3920 BTRFS_BLOCK_GROUP_RAID10 |
3921 BTRFS_BLOCK_GROUP_DUP)) {
3922 max_errors = 1;
3923 }
3924 }
3925
3926 *bbio_ret = bbio;
3927 bbio->num_stripes = num_stripes;
3928 bbio->max_errors = max_errors;
3929 bbio->mirror_num = mirror_num;
3930 out:
3931 free_extent_map(em);
3932 return ret;
3933 }
3934
3935 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3936 u64 logical, u64 *length,
3937 struct btrfs_bio **bbio_ret, int mirror_num)
3938 {
3939 return __btrfs_map_block(map_tree, rw, logical, length, bbio_ret,
3940 mirror_num);
3941 }
3942
3943 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3944 u64 chunk_start, u64 physical, u64 devid,
3945 u64 **logical, int *naddrs, int *stripe_len)
3946 {
3947 struct extent_map_tree *em_tree = &map_tree->map_tree;
3948 struct extent_map *em;
3949 struct map_lookup *map;
3950 u64 *buf;
3951 u64 bytenr;
3952 u64 length;
3953 u64 stripe_nr;
3954 int i, j, nr = 0;
3955
3956 read_lock(&em_tree->lock);
3957 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3958 read_unlock(&em_tree->lock);
3959
3960 BUG_ON(!em || em->start != chunk_start);
3961 map = (struct map_lookup *)em->bdev;
3962
3963 length = em->len;
3964 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3965 do_div(length, map->num_stripes / map->sub_stripes);
3966 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3967 do_div(length, map->num_stripes);
3968
3969 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3970 BUG_ON(!buf); /* -ENOMEM */
3971
3972 for (i = 0; i < map->num_stripes; i++) {
3973 if (devid && map->stripes[i].dev->devid != devid)
3974 continue;
3975 if (map->stripes[i].physical > physical ||
3976 map->stripes[i].physical + length <= physical)
3977 continue;
3978
3979 stripe_nr = physical - map->stripes[i].physical;
3980 do_div(stripe_nr, map->stripe_len);
3981
3982 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3983 stripe_nr = stripe_nr * map->num_stripes + i;
3984 do_div(stripe_nr, map->sub_stripes);
3985 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3986 stripe_nr = stripe_nr * map->num_stripes + i;
3987 }
3988 bytenr = chunk_start + stripe_nr * map->stripe_len;
3989 WARN_ON(nr >= map->num_stripes);
3990 for (j = 0; j < nr; j++) {
3991 if (buf[j] == bytenr)
3992 break;
3993 }
3994 if (j == nr) {
3995 WARN_ON(nr >= map->num_stripes);
3996 buf[nr++] = bytenr;
3997 }
3998 }
3999
4000 *logical = buf;
4001 *naddrs = nr;
4002 *stripe_len = map->stripe_len;
4003
4004 free_extent_map(em);
4005 return 0;
4006 }
4007
4008 static void *merge_stripe_index_into_bio_private(void *bi_private,
4009 unsigned int stripe_index)
4010 {
4011 /*
4012 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4013 * at most 1.
4014 * The alternative solution (instead of stealing bits from the
4015 * pointer) would be to allocate an intermediate structure
4016 * that contains the old private pointer plus the stripe_index.
4017 */
4018 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4019 BUG_ON(stripe_index > 3);
4020 return (void *)(((uintptr_t)bi_private) | stripe_index);
4021 }
4022
4023 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4024 {
4025 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4026 }
4027
4028 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4029 {
4030 return (unsigned int)((uintptr_t)bi_private) & 3;
4031 }
4032
4033 static void btrfs_end_bio(struct bio *bio, int err)
4034 {
4035 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4036 int is_orig_bio = 0;
4037
4038 if (err) {
4039 atomic_inc(&bbio->error);
4040 if (err == -EIO || err == -EREMOTEIO) {
4041 unsigned int stripe_index =
4042 extract_stripe_index_from_bio_private(
4043 bio->bi_private);
4044 struct btrfs_device *dev;
4045
4046 BUG_ON(stripe_index >= bbio->num_stripes);
4047 dev = bbio->stripes[stripe_index].dev;
4048 if (bio->bi_rw & WRITE)
4049 btrfs_dev_stat_inc(dev,
4050 BTRFS_DEV_STAT_WRITE_ERRS);
4051 else
4052 btrfs_dev_stat_inc(dev,
4053 BTRFS_DEV_STAT_READ_ERRS);
4054 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4055 btrfs_dev_stat_inc(dev,
4056 BTRFS_DEV_STAT_FLUSH_ERRS);
4057 btrfs_dev_stat_print_on_error(dev);
4058 }
4059 }
4060
4061 if (bio == bbio->orig_bio)
4062 is_orig_bio = 1;
4063
4064 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4065 if (!is_orig_bio) {
4066 bio_put(bio);
4067 bio = bbio->orig_bio;
4068 }
4069 bio->bi_private = bbio->private;
4070 bio->bi_end_io = bbio->end_io;
4071 bio->bi_bdev = (struct block_device *)
4072 (unsigned long)bbio->mirror_num;
4073 /* only send an error to the higher layers if it is
4074 * beyond the tolerance of the multi-bio
4075 */
4076 if (atomic_read(&bbio->error) > bbio->max_errors) {
4077 err = -EIO;
4078 } else {
4079 /*
4080 * this bio is actually up to date, we didn't
4081 * go over the max number of errors
4082 */
4083 set_bit(BIO_UPTODATE, &bio->bi_flags);
4084 err = 0;
4085 }
4086 kfree(bbio);
4087
4088 bio_endio(bio, err);
4089 } else if (!is_orig_bio) {
4090 bio_put(bio);
4091 }
4092 }
4093
4094 struct async_sched {
4095 struct bio *bio;
4096 int rw;
4097 struct btrfs_fs_info *info;
4098 struct btrfs_work work;
4099 };
4100
4101 /*
4102 * see run_scheduled_bios for a description of why bios are collected for
4103 * async submit.
4104 *
4105 * This will add one bio to the pending list for a device and make sure
4106 * the work struct is scheduled.
4107 */
4108 static noinline void schedule_bio(struct btrfs_root *root,
4109 struct btrfs_device *device,
4110 int rw, struct bio *bio)
4111 {
4112 int should_queue = 1;
4113 struct btrfs_pending_bios *pending_bios;
4114
4115 /* don't bother with additional async steps for reads, right now */
4116 if (!(rw & REQ_WRITE)) {
4117 bio_get(bio);
4118 btrfsic_submit_bio(rw, bio);
4119 bio_put(bio);
4120 return;
4121 }
4122
4123 /*
4124 * nr_async_bios allows us to reliably return congestion to the
4125 * higher layers. Otherwise, the async bio makes it appear we have
4126 * made progress against dirty pages when we've really just put it
4127 * on a queue for later
4128 */
4129 atomic_inc(&root->fs_info->nr_async_bios);
4130 WARN_ON(bio->bi_next);
4131 bio->bi_next = NULL;
4132 bio->bi_rw |= rw;
4133
4134 spin_lock(&device->io_lock);
4135 if (bio->bi_rw & REQ_SYNC)
4136 pending_bios = &device->pending_sync_bios;
4137 else
4138 pending_bios = &device->pending_bios;
4139
4140 if (pending_bios->tail)
4141 pending_bios->tail->bi_next = bio;
4142
4143 pending_bios->tail = bio;
4144 if (!pending_bios->head)
4145 pending_bios->head = bio;
4146 if (device->running_pending)
4147 should_queue = 0;
4148
4149 spin_unlock(&device->io_lock);
4150
4151 if (should_queue)
4152 btrfs_queue_worker(&root->fs_info->submit_workers,
4153 &device->work);
4154 }
4155
4156 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4157 int mirror_num, int async_submit)
4158 {
4159 struct btrfs_mapping_tree *map_tree;
4160 struct btrfs_device *dev;
4161 struct bio *first_bio = bio;
4162 u64 logical = (u64)bio->bi_sector << 9;
4163 u64 length = 0;
4164 u64 map_length;
4165 int ret;
4166 int dev_nr = 0;
4167 int total_devs = 1;
4168 struct btrfs_bio *bbio = NULL;
4169
4170 length = bio->bi_size;
4171 map_tree = &root->fs_info->mapping_tree;
4172 map_length = length;
4173
4174 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &bbio,
4175 mirror_num);
4176 if (ret) /* -ENOMEM */
4177 return ret;
4178
4179 total_devs = bbio->num_stripes;
4180 if (map_length < length) {
4181 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
4182 "len %llu\n", (unsigned long long)logical,
4183 (unsigned long long)length,
4184 (unsigned long long)map_length);
4185 BUG();
4186 }
4187
4188 bbio->orig_bio = first_bio;
4189 bbio->private = first_bio->bi_private;
4190 bbio->end_io = first_bio->bi_end_io;
4191 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4192
4193 while (dev_nr < total_devs) {
4194 if (dev_nr < total_devs - 1) {
4195 bio = bio_clone(first_bio, GFP_NOFS);
4196 BUG_ON(!bio); /* -ENOMEM */
4197 } else {
4198 bio = first_bio;
4199 }
4200 bio->bi_private = bbio;
4201 bio->bi_private = merge_stripe_index_into_bio_private(
4202 bio->bi_private, (unsigned int)dev_nr);
4203 bio->bi_end_io = btrfs_end_bio;
4204 bio->bi_sector = bbio->stripes[dev_nr].physical >> 9;
4205 dev = bbio->stripes[dev_nr].dev;
4206 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
4207 pr_debug("btrfs_map_bio: rw %d, secor=%llu, dev=%lu "
4208 "(%s id %llu), size=%u\n", rw,
4209 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4210 dev->name, dev->devid, bio->bi_size);
4211 bio->bi_bdev = dev->bdev;
4212 if (async_submit)
4213 schedule_bio(root, dev, rw, bio);
4214 else
4215 btrfsic_submit_bio(rw, bio);
4216 } else {
4217 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
4218 bio->bi_sector = logical >> 9;
4219 bio_endio(bio, -EIO);
4220 }
4221 dev_nr++;
4222 }
4223 return 0;
4224 }
4225
4226 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
4227 u8 *uuid, u8 *fsid)
4228 {
4229 struct btrfs_device *device;
4230 struct btrfs_fs_devices *cur_devices;
4231
4232 cur_devices = root->fs_info->fs_devices;
4233 while (cur_devices) {
4234 if (!fsid ||
4235 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4236 device = __find_device(&cur_devices->devices,
4237 devid, uuid);
4238 if (device)
4239 return device;
4240 }
4241 cur_devices = cur_devices->seed;
4242 }
4243 return NULL;
4244 }
4245
4246 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4247 u64 devid, u8 *dev_uuid)
4248 {
4249 struct btrfs_device *device;
4250 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4251
4252 device = kzalloc(sizeof(*device), GFP_NOFS);
4253 if (!device)
4254 return NULL;
4255 list_add(&device->dev_list,
4256 &fs_devices->devices);
4257 device->dev_root = root->fs_info->dev_root;
4258 device->devid = devid;
4259 device->work.func = pending_bios_fn;
4260 device->fs_devices = fs_devices;
4261 device->missing = 1;
4262 fs_devices->num_devices++;
4263 fs_devices->missing_devices++;
4264 spin_lock_init(&device->io_lock);
4265 INIT_LIST_HEAD(&device->dev_alloc_list);
4266 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4267 return device;
4268 }
4269
4270 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4271 struct extent_buffer *leaf,
4272 struct btrfs_chunk *chunk)
4273 {
4274 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4275 struct map_lookup *map;
4276 struct extent_map *em;
4277 u64 logical;
4278 u64 length;
4279 u64 devid;
4280 u8 uuid[BTRFS_UUID_SIZE];
4281 int num_stripes;
4282 int ret;
4283 int i;
4284
4285 logical = key->offset;
4286 length = btrfs_chunk_length(leaf, chunk);
4287
4288 read_lock(&map_tree->map_tree.lock);
4289 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4290 read_unlock(&map_tree->map_tree.lock);
4291
4292 /* already mapped? */
4293 if (em && em->start <= logical && em->start + em->len > logical) {
4294 free_extent_map(em);
4295 return 0;
4296 } else if (em) {
4297 free_extent_map(em);
4298 }
4299
4300 em = alloc_extent_map();
4301 if (!em)
4302 return -ENOMEM;
4303 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4304 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4305 if (!map) {
4306 free_extent_map(em);
4307 return -ENOMEM;
4308 }
4309
4310 em->bdev = (struct block_device *)map;
4311 em->start = logical;
4312 em->len = length;
4313 em->block_start = 0;
4314 em->block_len = em->len;
4315
4316 map->num_stripes = num_stripes;
4317 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4318 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4319 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4320 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4321 map->type = btrfs_chunk_type(leaf, chunk);
4322 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4323 for (i = 0; i < num_stripes; i++) {
4324 map->stripes[i].physical =
4325 btrfs_stripe_offset_nr(leaf, chunk, i);
4326 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4327 read_extent_buffer(leaf, uuid, (unsigned long)
4328 btrfs_stripe_dev_uuid_nr(chunk, i),
4329 BTRFS_UUID_SIZE);
4330 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
4331 NULL);
4332 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
4333 kfree(map);
4334 free_extent_map(em);
4335 return -EIO;
4336 }
4337 if (!map->stripes[i].dev) {
4338 map->stripes[i].dev =
4339 add_missing_dev(root, devid, uuid);
4340 if (!map->stripes[i].dev) {
4341 kfree(map);
4342 free_extent_map(em);
4343 return -EIO;
4344 }
4345 }
4346 map->stripes[i].dev->in_fs_metadata = 1;
4347 }
4348
4349 write_lock(&map_tree->map_tree.lock);
4350 ret = add_extent_mapping(&map_tree->map_tree, em);
4351 write_unlock(&map_tree->map_tree.lock);
4352 BUG_ON(ret); /* Tree corruption */
4353 free_extent_map(em);
4354
4355 return 0;
4356 }
4357
4358 static void fill_device_from_item(struct extent_buffer *leaf,
4359 struct btrfs_dev_item *dev_item,
4360 struct btrfs_device *device)
4361 {
4362 unsigned long ptr;
4363
4364 device->devid = btrfs_device_id(leaf, dev_item);
4365 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
4366 device->total_bytes = device->disk_total_bytes;
4367 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
4368 device->type = btrfs_device_type(leaf, dev_item);
4369 device->io_align = btrfs_device_io_align(leaf, dev_item);
4370 device->io_width = btrfs_device_io_width(leaf, dev_item);
4371 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
4372
4373 ptr = (unsigned long)btrfs_device_uuid(dev_item);
4374 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
4375 }
4376
4377 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
4378 {
4379 struct btrfs_fs_devices *fs_devices;
4380 int ret;
4381
4382 BUG_ON(!mutex_is_locked(&uuid_mutex));
4383
4384 fs_devices = root->fs_info->fs_devices->seed;
4385 while (fs_devices) {
4386 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4387 ret = 0;
4388 goto out;
4389 }
4390 fs_devices = fs_devices->seed;
4391 }
4392
4393 fs_devices = find_fsid(fsid);
4394 if (!fs_devices) {
4395 ret = -ENOENT;
4396 goto out;
4397 }
4398
4399 fs_devices = clone_fs_devices(fs_devices);
4400 if (IS_ERR(fs_devices)) {
4401 ret = PTR_ERR(fs_devices);
4402 goto out;
4403 }
4404
4405 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
4406 root->fs_info->bdev_holder);
4407 if (ret) {
4408 free_fs_devices(fs_devices);
4409 goto out;
4410 }
4411
4412 if (!fs_devices->seeding) {
4413 __btrfs_close_devices(fs_devices);
4414 free_fs_devices(fs_devices);
4415 ret = -EINVAL;
4416 goto out;
4417 }
4418
4419 fs_devices->seed = root->fs_info->fs_devices->seed;
4420 root->fs_info->fs_devices->seed = fs_devices;
4421 out:
4422 return ret;
4423 }
4424
4425 static int read_one_dev(struct btrfs_root *root,
4426 struct extent_buffer *leaf,
4427 struct btrfs_dev_item *dev_item)
4428 {
4429 struct btrfs_device *device;
4430 u64 devid;
4431 int ret;
4432 u8 fs_uuid[BTRFS_UUID_SIZE];
4433 u8 dev_uuid[BTRFS_UUID_SIZE];
4434
4435 devid = btrfs_device_id(leaf, dev_item);
4436 read_extent_buffer(leaf, dev_uuid,
4437 (unsigned long)btrfs_device_uuid(dev_item),
4438 BTRFS_UUID_SIZE);
4439 read_extent_buffer(leaf, fs_uuid,
4440 (unsigned long)btrfs_device_fsid(dev_item),
4441 BTRFS_UUID_SIZE);
4442
4443 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
4444 ret = open_seed_devices(root, fs_uuid);
4445 if (ret && !btrfs_test_opt(root, DEGRADED))
4446 return ret;
4447 }
4448
4449 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
4450 if (!device || !device->bdev) {
4451 if (!btrfs_test_opt(root, DEGRADED))
4452 return -EIO;
4453
4454 if (!device) {
4455 printk(KERN_WARNING "warning devid %llu missing\n",
4456 (unsigned long long)devid);
4457 device = add_missing_dev(root, devid, dev_uuid);
4458 if (!device)
4459 return -ENOMEM;
4460 } else if (!device->missing) {
4461 /*
4462 * this happens when a device that was properly setup
4463 * in the device info lists suddenly goes bad.
4464 * device->bdev is NULL, and so we have to set
4465 * device->missing to one here
4466 */
4467 root->fs_info->fs_devices->missing_devices++;
4468 device->missing = 1;
4469 }
4470 }
4471
4472 if (device->fs_devices != root->fs_info->fs_devices) {
4473 BUG_ON(device->writeable);
4474 if (device->generation !=
4475 btrfs_device_generation(leaf, dev_item))
4476 return -EINVAL;
4477 }
4478
4479 fill_device_from_item(leaf, dev_item, device);
4480 device->dev_root = root->fs_info->dev_root;
4481 device->in_fs_metadata = 1;
4482 if (device->writeable) {
4483 device->fs_devices->total_rw_bytes += device->total_bytes;
4484 spin_lock(&root->fs_info->free_chunk_lock);
4485 root->fs_info->free_chunk_space += device->total_bytes -
4486 device->bytes_used;
4487 spin_unlock(&root->fs_info->free_chunk_lock);
4488 }
4489 ret = 0;
4490 return ret;
4491 }
4492
4493 int btrfs_read_sys_array(struct btrfs_root *root)
4494 {
4495 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4496 struct extent_buffer *sb;
4497 struct btrfs_disk_key *disk_key;
4498 struct btrfs_chunk *chunk;
4499 u8 *ptr;
4500 unsigned long sb_ptr;
4501 int ret = 0;
4502 u32 num_stripes;
4503 u32 array_size;
4504 u32 len = 0;
4505 u32 cur;
4506 struct btrfs_key key;
4507
4508 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
4509 BTRFS_SUPER_INFO_SIZE);
4510 if (!sb)
4511 return -ENOMEM;
4512 btrfs_set_buffer_uptodate(sb);
4513 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
4514 /*
4515 * The sb extent buffer is artifical and just used to read the system array.
4516 * btrfs_set_buffer_uptodate() call does not properly mark all it's
4517 * pages up-to-date when the page is larger: extent does not cover the
4518 * whole page and consequently check_page_uptodate does not find all
4519 * the page's extents up-to-date (the hole beyond sb),
4520 * write_extent_buffer then triggers a WARN_ON.
4521 *
4522 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
4523 * but sb spans only this function. Add an explicit SetPageUptodate call
4524 * to silence the warning eg. on PowerPC 64.
4525 */
4526 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
4527 SetPageUptodate(sb->pages[0]);
4528
4529 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
4530 array_size = btrfs_super_sys_array_size(super_copy);
4531
4532 ptr = super_copy->sys_chunk_array;
4533 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
4534 cur = 0;
4535
4536 while (cur < array_size) {
4537 disk_key = (struct btrfs_disk_key *)ptr;
4538 btrfs_disk_key_to_cpu(&key, disk_key);
4539
4540 len = sizeof(*disk_key); ptr += len;
4541 sb_ptr += len;
4542 cur += len;
4543
4544 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
4545 chunk = (struct btrfs_chunk *)sb_ptr;
4546 ret = read_one_chunk(root, &key, sb, chunk);
4547 if (ret)
4548 break;
4549 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
4550 len = btrfs_chunk_item_size(num_stripes);
4551 } else {
4552 ret = -EIO;
4553 break;
4554 }
4555 ptr += len;
4556 sb_ptr += len;
4557 cur += len;
4558 }
4559 free_extent_buffer(sb);
4560 return ret;
4561 }
4562
4563 struct btrfs_device *btrfs_find_device_for_logical(struct btrfs_root *root,
4564 u64 logical, int mirror_num)
4565 {
4566 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4567 int ret;
4568 u64 map_length = 0;
4569 struct btrfs_bio *bbio = NULL;
4570 struct btrfs_device *device;
4571
4572 BUG_ON(mirror_num == 0);
4573 ret = btrfs_map_block(map_tree, WRITE, logical, &map_length, &bbio,
4574 mirror_num);
4575 if (ret) {
4576 BUG_ON(bbio != NULL);
4577 return NULL;
4578 }
4579 BUG_ON(mirror_num != bbio->mirror_num);
4580 device = bbio->stripes[mirror_num - 1].dev;
4581 kfree(bbio);
4582 return device;
4583 }
4584
4585 int btrfs_read_chunk_tree(struct btrfs_root *root)
4586 {
4587 struct btrfs_path *path;
4588 struct extent_buffer *leaf;
4589 struct btrfs_key key;
4590 struct btrfs_key found_key;
4591 int ret;
4592 int slot;
4593
4594 root = root->fs_info->chunk_root;
4595
4596 path = btrfs_alloc_path();
4597 if (!path)
4598 return -ENOMEM;
4599
4600 mutex_lock(&uuid_mutex);
4601 lock_chunks(root);
4602
4603 /* first we search for all of the device items, and then we
4604 * read in all of the chunk items. This way we can create chunk
4605 * mappings that reference all of the devices that are afound
4606 */
4607 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
4608 key.offset = 0;
4609 key.type = 0;
4610 again:
4611 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4612 if (ret < 0)
4613 goto error;
4614 while (1) {
4615 leaf = path->nodes[0];
4616 slot = path->slots[0];
4617 if (slot >= btrfs_header_nritems(leaf)) {
4618 ret = btrfs_next_leaf(root, path);
4619 if (ret == 0)
4620 continue;
4621 if (ret < 0)
4622 goto error;
4623 break;
4624 }
4625 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4626 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4627 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
4628 break;
4629 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
4630 struct btrfs_dev_item *dev_item;
4631 dev_item = btrfs_item_ptr(leaf, slot,
4632 struct btrfs_dev_item);
4633 ret = read_one_dev(root, leaf, dev_item);
4634 if (ret)
4635 goto error;
4636 }
4637 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
4638 struct btrfs_chunk *chunk;
4639 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
4640 ret = read_one_chunk(root, &found_key, leaf, chunk);
4641 if (ret)
4642 goto error;
4643 }
4644 path->slots[0]++;
4645 }
4646 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
4647 key.objectid = 0;
4648 btrfs_release_path(path);
4649 goto again;
4650 }
4651 ret = 0;
4652 error:
4653 unlock_chunks(root);
4654 mutex_unlock(&uuid_mutex);
4655
4656 btrfs_free_path(path);
4657 return ret;
4658 }
4659
4660 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
4661 {
4662 int i;
4663
4664 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4665 btrfs_dev_stat_reset(dev, i);
4666 }
4667
4668 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
4669 {
4670 struct btrfs_key key;
4671 struct btrfs_key found_key;
4672 struct btrfs_root *dev_root = fs_info->dev_root;
4673 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4674 struct extent_buffer *eb;
4675 int slot;
4676 int ret = 0;
4677 struct btrfs_device *device;
4678 struct btrfs_path *path = NULL;
4679 int i;
4680
4681 path = btrfs_alloc_path();
4682 if (!path) {
4683 ret = -ENOMEM;
4684 goto out;
4685 }
4686
4687 mutex_lock(&fs_devices->device_list_mutex);
4688 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4689 int item_size;
4690 struct btrfs_dev_stats_item *ptr;
4691
4692 key.objectid = 0;
4693 key.type = BTRFS_DEV_STATS_KEY;
4694 key.offset = device->devid;
4695 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
4696 if (ret) {
4697 printk(KERN_WARNING "btrfs: no dev_stats entry found for device %s (devid %llu) (OK on first mount after mkfs)\n",
4698 device->name, (unsigned long long)device->devid);
4699 __btrfs_reset_dev_stats(device);
4700 device->dev_stats_valid = 1;
4701 btrfs_release_path(path);
4702 continue;
4703 }
4704 slot = path->slots[0];
4705 eb = path->nodes[0];
4706 btrfs_item_key_to_cpu(eb, &found_key, slot);
4707 item_size = btrfs_item_size_nr(eb, slot);
4708
4709 ptr = btrfs_item_ptr(eb, slot,
4710 struct btrfs_dev_stats_item);
4711
4712 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4713 if (item_size >= (1 + i) * sizeof(__le64))
4714 btrfs_dev_stat_set(device, i,
4715 btrfs_dev_stats_value(eb, ptr, i));
4716 else
4717 btrfs_dev_stat_reset(device, i);
4718 }
4719
4720 device->dev_stats_valid = 1;
4721 btrfs_dev_stat_print_on_load(device);
4722 btrfs_release_path(path);
4723 }
4724 mutex_unlock(&fs_devices->device_list_mutex);
4725
4726 out:
4727 btrfs_free_path(path);
4728 return ret < 0 ? ret : 0;
4729 }
4730
4731 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
4732 struct btrfs_root *dev_root,
4733 struct btrfs_device *device)
4734 {
4735 struct btrfs_path *path;
4736 struct btrfs_key key;
4737 struct extent_buffer *eb;
4738 struct btrfs_dev_stats_item *ptr;
4739 int ret;
4740 int i;
4741
4742 key.objectid = 0;
4743 key.type = BTRFS_DEV_STATS_KEY;
4744 key.offset = device->devid;
4745
4746 path = btrfs_alloc_path();
4747 BUG_ON(!path);
4748 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
4749 if (ret < 0) {
4750 printk(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
4751 ret, device->name);
4752 goto out;
4753 }
4754
4755 if (ret == 0 &&
4756 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
4757 /* need to delete old one and insert a new one */
4758 ret = btrfs_del_item(trans, dev_root, path);
4759 if (ret != 0) {
4760 printk(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
4761 device->name, ret);
4762 goto out;
4763 }
4764 ret = 1;
4765 }
4766
4767 if (ret == 1) {
4768 /* need to insert a new item */
4769 btrfs_release_path(path);
4770 ret = btrfs_insert_empty_item(trans, dev_root, path,
4771 &key, sizeof(*ptr));
4772 if (ret < 0) {
4773 printk(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
4774 device->name, ret);
4775 goto out;
4776 }
4777 }
4778
4779 eb = path->nodes[0];
4780 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
4781 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4782 btrfs_set_dev_stats_value(eb, ptr, i,
4783 btrfs_dev_stat_read(device, i));
4784 btrfs_mark_buffer_dirty(eb);
4785
4786 out:
4787 btrfs_free_path(path);
4788 return ret;
4789 }
4790
4791 /*
4792 * called from commit_transaction. Writes all changed device stats to disk.
4793 */
4794 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
4795 struct btrfs_fs_info *fs_info)
4796 {
4797 struct btrfs_root *dev_root = fs_info->dev_root;
4798 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
4799 struct btrfs_device *device;
4800 int ret = 0;
4801
4802 mutex_lock(&fs_devices->device_list_mutex);
4803 list_for_each_entry(device, &fs_devices->devices, dev_list) {
4804 if (!device->dev_stats_valid || !device->dev_stats_dirty)
4805 continue;
4806
4807 ret = update_dev_stat_item(trans, dev_root, device);
4808 if (!ret)
4809 device->dev_stats_dirty = 0;
4810 }
4811 mutex_unlock(&fs_devices->device_list_mutex);
4812
4813 return ret;
4814 }
4815
4816 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
4817 {
4818 btrfs_dev_stat_inc(dev, index);
4819 btrfs_dev_stat_print_on_error(dev);
4820 }
4821
4822 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
4823 {
4824 if (!dev->dev_stats_valid)
4825 return;
4826 printk_ratelimited(KERN_ERR
4827 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4828 dev->name,
4829 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4830 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4831 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4832 btrfs_dev_stat_read(dev,
4833 BTRFS_DEV_STAT_CORRUPTION_ERRS),
4834 btrfs_dev_stat_read(dev,
4835 BTRFS_DEV_STAT_GENERATION_ERRS));
4836 }
4837
4838 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
4839 {
4840 printk(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
4841 dev->name,
4842 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
4843 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
4844 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
4845 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
4846 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
4847 }
4848
4849 int btrfs_get_dev_stats(struct btrfs_root *root,
4850 struct btrfs_ioctl_get_dev_stats *stats,
4851 int reset_after_read)
4852 {
4853 struct btrfs_device *dev;
4854 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4855 int i;
4856
4857 mutex_lock(&fs_devices->device_list_mutex);
4858 dev = btrfs_find_device(root, stats->devid, NULL, NULL);
4859 mutex_unlock(&fs_devices->device_list_mutex);
4860
4861 if (!dev) {
4862 printk(KERN_WARNING
4863 "btrfs: get dev_stats failed, device not found\n");
4864 return -ENODEV;
4865 } else if (!dev->dev_stats_valid) {
4866 printk(KERN_WARNING
4867 "btrfs: get dev_stats failed, not yet valid\n");
4868 return -ENODEV;
4869 } else if (reset_after_read) {
4870 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
4871 if (stats->nr_items > i)
4872 stats->values[i] =
4873 btrfs_dev_stat_read_and_reset(dev, i);
4874 else
4875 btrfs_dev_stat_reset(dev, i);
4876 }
4877 } else {
4878 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
4879 if (stats->nr_items > i)
4880 stats->values[i] = btrfs_dev_stat_read(dev, i);
4881 }
4882 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
4883 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
4884 return 0;
4885 }
Linux kernel - Deliverables
This page took 0.136747 seconds and 5 git commands to generate.