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Merge branch 'for-3.11' of git://linux-nfs.org/~bfields/linux
[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 <linux/raid/pq.h>
29 #include <asm/div64.h>
30 #include "compat.h"
31 #include "ctree.h"
32 #include "extent_map.h"
33 #include "disk-io.h"
34 #include "transaction.h"
35 #include "print-tree.h"
36 #include "volumes.h"
37 #include "raid56.h"
38 #include "async-thread.h"
39 #include "check-integrity.h"
40 #include "rcu-string.h"
41 #include "math.h"
42 #include "dev-replace.h"
43
44 static int init_first_rw_device(struct btrfs_trans_handle *trans,
45 struct btrfs_root *root,
46 struct btrfs_device *device);
47 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
48 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
49 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
50 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
51
52 static DEFINE_MUTEX(uuid_mutex);
53 static LIST_HEAD(fs_uuids);
54
55 static void lock_chunks(struct btrfs_root *root)
56 {
57 mutex_lock(&root->fs_info->chunk_mutex);
58 }
59
60 static void unlock_chunks(struct btrfs_root *root)
61 {
62 mutex_unlock(&root->fs_info->chunk_mutex);
63 }
64
65 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
66 {
67 struct btrfs_device *device;
68 WARN_ON(fs_devices->opened);
69 while (!list_empty(&fs_devices->devices)) {
70 device = list_entry(fs_devices->devices.next,
71 struct btrfs_device, dev_list);
72 list_del(&device->dev_list);
73 rcu_string_free(device->name);
74 kfree(device);
75 }
76 kfree(fs_devices);
77 }
78
79 static void btrfs_kobject_uevent(struct block_device *bdev,
80 enum kobject_action action)
81 {
82 int ret;
83
84 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
85 if (ret)
86 pr_warn("Sending event '%d' to kobject: '%s' (%p): failed\n",
87 action,
88 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
89 &disk_to_dev(bdev->bd_disk)->kobj);
90 }
91
92 void btrfs_cleanup_fs_uuids(void)
93 {
94 struct btrfs_fs_devices *fs_devices;
95
96 while (!list_empty(&fs_uuids)) {
97 fs_devices = list_entry(fs_uuids.next,
98 struct btrfs_fs_devices, list);
99 list_del(&fs_devices->list);
100 free_fs_devices(fs_devices);
101 }
102 }
103
104 static noinline struct btrfs_device *__find_device(struct list_head *head,
105 u64 devid, u8 *uuid)
106 {
107 struct btrfs_device *dev;
108
109 list_for_each_entry(dev, head, dev_list) {
110 if (dev->devid == devid &&
111 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
112 return dev;
113 }
114 }
115 return NULL;
116 }
117
118 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
119 {
120 struct btrfs_fs_devices *fs_devices;
121
122 list_for_each_entry(fs_devices, &fs_uuids, list) {
123 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
124 return fs_devices;
125 }
126 return NULL;
127 }
128
129 static int
130 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
131 int flush, struct block_device **bdev,
132 struct buffer_head **bh)
133 {
134 int ret;
135
136 *bdev = blkdev_get_by_path(device_path, flags, holder);
137
138 if (IS_ERR(*bdev)) {
139 ret = PTR_ERR(*bdev);
140 printk(KERN_INFO "btrfs: open %s failed\n", device_path);
141 goto error;
142 }
143
144 if (flush)
145 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
146 ret = set_blocksize(*bdev, 4096);
147 if (ret) {
148 blkdev_put(*bdev, flags);
149 goto error;
150 }
151 invalidate_bdev(*bdev);
152 *bh = btrfs_read_dev_super(*bdev);
153 if (!*bh) {
154 ret = -EINVAL;
155 blkdev_put(*bdev, flags);
156 goto error;
157 }
158
159 return 0;
160
161 error:
162 *bdev = NULL;
163 *bh = NULL;
164 return ret;
165 }
166
167 static void requeue_list(struct btrfs_pending_bios *pending_bios,
168 struct bio *head, struct bio *tail)
169 {
170
171 struct bio *old_head;
172
173 old_head = pending_bios->head;
174 pending_bios->head = head;
175 if (pending_bios->tail)
176 tail->bi_next = old_head;
177 else
178 pending_bios->tail = tail;
179 }
180
181 /*
182 * we try to collect pending bios for a device so we don't get a large
183 * number of procs sending bios down to the same device. This greatly
184 * improves the schedulers ability to collect and merge the bios.
185 *
186 * But, it also turns into a long list of bios to process and that is sure
187 * to eventually make the worker thread block. The solution here is to
188 * make some progress and then put this work struct back at the end of
189 * the list if the block device is congested. This way, multiple devices
190 * can make progress from a single worker thread.
191 */
192 static noinline void run_scheduled_bios(struct btrfs_device *device)
193 {
194 struct bio *pending;
195 struct backing_dev_info *bdi;
196 struct btrfs_fs_info *fs_info;
197 struct btrfs_pending_bios *pending_bios;
198 struct bio *tail;
199 struct bio *cur;
200 int again = 0;
201 unsigned long num_run;
202 unsigned long batch_run = 0;
203 unsigned long limit;
204 unsigned long last_waited = 0;
205 int force_reg = 0;
206 int sync_pending = 0;
207 struct blk_plug plug;
208
209 /*
210 * this function runs all the bios we've collected for
211 * a particular device. We don't want to wander off to
212 * another device without first sending all of these down.
213 * So, setup a plug here and finish it off before we return
214 */
215 blk_start_plug(&plug);
216
217 bdi = blk_get_backing_dev_info(device->bdev);
218 fs_info = device->dev_root->fs_info;
219 limit = btrfs_async_submit_limit(fs_info);
220 limit = limit * 2 / 3;
221
222 loop:
223 spin_lock(&device->io_lock);
224
225 loop_lock:
226 num_run = 0;
227
228 /* take all the bios off the list at once and process them
229 * later on (without the lock held). But, remember the
230 * tail and other pointers so the bios can be properly reinserted
231 * into the list if we hit congestion
232 */
233 if (!force_reg && device->pending_sync_bios.head) {
234 pending_bios = &device->pending_sync_bios;
235 force_reg = 1;
236 } else {
237 pending_bios = &device->pending_bios;
238 force_reg = 0;
239 }
240
241 pending = pending_bios->head;
242 tail = pending_bios->tail;
243 WARN_ON(pending && !tail);
244
245 /*
246 * if pending was null this time around, no bios need processing
247 * at all and we can stop. Otherwise it'll loop back up again
248 * and do an additional check so no bios are missed.
249 *
250 * device->running_pending is used to synchronize with the
251 * schedule_bio code.
252 */
253 if (device->pending_sync_bios.head == NULL &&
254 device->pending_bios.head == NULL) {
255 again = 0;
256 device->running_pending = 0;
257 } else {
258 again = 1;
259 device->running_pending = 1;
260 }
261
262 pending_bios->head = NULL;
263 pending_bios->tail = NULL;
264
265 spin_unlock(&device->io_lock);
266
267 while (pending) {
268
269 rmb();
270 /* we want to work on both lists, but do more bios on the
271 * sync list than the regular list
272 */
273 if ((num_run > 32 &&
274 pending_bios != &device->pending_sync_bios &&
275 device->pending_sync_bios.head) ||
276 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
277 device->pending_bios.head)) {
278 spin_lock(&device->io_lock);
279 requeue_list(pending_bios, pending, tail);
280 goto loop_lock;
281 }
282
283 cur = pending;
284 pending = pending->bi_next;
285 cur->bi_next = NULL;
286
287 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
288 waitqueue_active(&fs_info->async_submit_wait))
289 wake_up(&fs_info->async_submit_wait);
290
291 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
292
293 /*
294 * if we're doing the sync list, record that our
295 * plug has some sync requests on it
296 *
297 * If we're doing the regular list and there are
298 * sync requests sitting around, unplug before
299 * we add more
300 */
301 if (pending_bios == &device->pending_sync_bios) {
302 sync_pending = 1;
303 } else if (sync_pending) {
304 blk_finish_plug(&plug);
305 blk_start_plug(&plug);
306 sync_pending = 0;
307 }
308
309 btrfsic_submit_bio(cur->bi_rw, cur);
310 num_run++;
311 batch_run++;
312 if (need_resched())
313 cond_resched();
314
315 /*
316 * we made progress, there is more work to do and the bdi
317 * is now congested. Back off and let other work structs
318 * run instead
319 */
320 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
321 fs_info->fs_devices->open_devices > 1) {
322 struct io_context *ioc;
323
324 ioc = current->io_context;
325
326 /*
327 * the main goal here is that we don't want to
328 * block if we're going to be able to submit
329 * more requests without blocking.
330 *
331 * This code does two great things, it pokes into
332 * the elevator code from a filesystem _and_
333 * it makes assumptions about how batching works.
334 */
335 if (ioc && ioc->nr_batch_requests > 0 &&
336 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
337 (last_waited == 0 ||
338 ioc->last_waited == last_waited)) {
339 /*
340 * we want to go through our batch of
341 * requests and stop. So, we copy out
342 * the ioc->last_waited time and test
343 * against it before looping
344 */
345 last_waited = ioc->last_waited;
346 if (need_resched())
347 cond_resched();
348 continue;
349 }
350 spin_lock(&device->io_lock);
351 requeue_list(pending_bios, pending, tail);
352 device->running_pending = 1;
353
354 spin_unlock(&device->io_lock);
355 btrfs_requeue_work(&device->work);
356 goto done;
357 }
358 /* unplug every 64 requests just for good measure */
359 if (batch_run % 64 == 0) {
360 blk_finish_plug(&plug);
361 blk_start_plug(&plug);
362 sync_pending = 0;
363 }
364 }
365
366 cond_resched();
367 if (again)
368 goto loop;
369
370 spin_lock(&device->io_lock);
371 if (device->pending_bios.head || device->pending_sync_bios.head)
372 goto loop_lock;
373 spin_unlock(&device->io_lock);
374
375 done:
376 blk_finish_plug(&plug);
377 }
378
379 static void pending_bios_fn(struct btrfs_work *work)
380 {
381 struct btrfs_device *device;
382
383 device = container_of(work, struct btrfs_device, work);
384 run_scheduled_bios(device);
385 }
386
387 static noinline int device_list_add(const char *path,
388 struct btrfs_super_block *disk_super,
389 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
390 {
391 struct btrfs_device *device;
392 struct btrfs_fs_devices *fs_devices;
393 struct rcu_string *name;
394 u64 found_transid = btrfs_super_generation(disk_super);
395
396 fs_devices = find_fsid(disk_super->fsid);
397 if (!fs_devices) {
398 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
399 if (!fs_devices)
400 return -ENOMEM;
401 INIT_LIST_HEAD(&fs_devices->devices);
402 INIT_LIST_HEAD(&fs_devices->alloc_list);
403 list_add(&fs_devices->list, &fs_uuids);
404 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
405 fs_devices->latest_devid = devid;
406 fs_devices->latest_trans = found_transid;
407 mutex_init(&fs_devices->device_list_mutex);
408 device = NULL;
409 } else {
410 device = __find_device(&fs_devices->devices, devid,
411 disk_super->dev_item.uuid);
412 }
413 if (!device) {
414 if (fs_devices->opened)
415 return -EBUSY;
416
417 device = kzalloc(sizeof(*device), GFP_NOFS);
418 if (!device) {
419 /* we can safely leave the fs_devices entry around */
420 return -ENOMEM;
421 }
422 device->devid = devid;
423 device->dev_stats_valid = 0;
424 device->work.func = pending_bios_fn;
425 memcpy(device->uuid, disk_super->dev_item.uuid,
426 BTRFS_UUID_SIZE);
427 spin_lock_init(&device->io_lock);
428
429 name = rcu_string_strdup(path, GFP_NOFS);
430 if (!name) {
431 kfree(device);
432 return -ENOMEM;
433 }
434 rcu_assign_pointer(device->name, name);
435 INIT_LIST_HEAD(&device->dev_alloc_list);
436
437 /* init readahead state */
438 spin_lock_init(&device->reada_lock);
439 device->reada_curr_zone = NULL;
440 atomic_set(&device->reada_in_flight, 0);
441 device->reada_next = 0;
442 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
443 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
444
445 mutex_lock(&fs_devices->device_list_mutex);
446 list_add_rcu(&device->dev_list, &fs_devices->devices);
447 mutex_unlock(&fs_devices->device_list_mutex);
448
449 device->fs_devices = fs_devices;
450 fs_devices->num_devices++;
451 } else if (!device->name || strcmp(device->name->str, path)) {
452 name = rcu_string_strdup(path, GFP_NOFS);
453 if (!name)
454 return -ENOMEM;
455 rcu_string_free(device->name);
456 rcu_assign_pointer(device->name, name);
457 if (device->missing) {
458 fs_devices->missing_devices--;
459 device->missing = 0;
460 }
461 }
462
463 if (found_transid > fs_devices->latest_trans) {
464 fs_devices->latest_devid = devid;
465 fs_devices->latest_trans = found_transid;
466 }
467 *fs_devices_ret = fs_devices;
468 return 0;
469 }
470
471 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
472 {
473 struct btrfs_fs_devices *fs_devices;
474 struct btrfs_device *device;
475 struct btrfs_device *orig_dev;
476
477 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
478 if (!fs_devices)
479 return ERR_PTR(-ENOMEM);
480
481 INIT_LIST_HEAD(&fs_devices->devices);
482 INIT_LIST_HEAD(&fs_devices->alloc_list);
483 INIT_LIST_HEAD(&fs_devices->list);
484 mutex_init(&fs_devices->device_list_mutex);
485 fs_devices->latest_devid = orig->latest_devid;
486 fs_devices->latest_trans = orig->latest_trans;
487 fs_devices->total_devices = orig->total_devices;
488 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
489
490 /* We have held the volume lock, it is safe to get the devices. */
491 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
492 struct rcu_string *name;
493
494 device = kzalloc(sizeof(*device), GFP_NOFS);
495 if (!device)
496 goto error;
497
498 /*
499 * This is ok to do without rcu read locked because we hold the
500 * uuid mutex so nothing we touch in here is going to disappear.
501 */
502 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
503 if (!name) {
504 kfree(device);
505 goto error;
506 }
507 rcu_assign_pointer(device->name, name);
508
509 device->devid = orig_dev->devid;
510 device->work.func = pending_bios_fn;
511 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
512 spin_lock_init(&device->io_lock);
513 INIT_LIST_HEAD(&device->dev_list);
514 INIT_LIST_HEAD(&device->dev_alloc_list);
515
516 list_add(&device->dev_list, &fs_devices->devices);
517 device->fs_devices = fs_devices;
518 fs_devices->num_devices++;
519 }
520 return fs_devices;
521 error:
522 free_fs_devices(fs_devices);
523 return ERR_PTR(-ENOMEM);
524 }
525
526 void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
527 struct btrfs_fs_devices *fs_devices, int step)
528 {
529 struct btrfs_device *device, *next;
530
531 struct block_device *latest_bdev = NULL;
532 u64 latest_devid = 0;
533 u64 latest_transid = 0;
534
535 mutex_lock(&uuid_mutex);
536 again:
537 /* This is the initialized path, it is safe to release the devices. */
538 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
539 if (device->in_fs_metadata) {
540 if (!device->is_tgtdev_for_dev_replace &&
541 (!latest_transid ||
542 device->generation > latest_transid)) {
543 latest_devid = device->devid;
544 latest_transid = device->generation;
545 latest_bdev = device->bdev;
546 }
547 continue;
548 }
549
550 if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
551 /*
552 * In the first step, keep the device which has
553 * the correct fsid and the devid that is used
554 * for the dev_replace procedure.
555 * In the second step, the dev_replace state is
556 * read from the device tree and it is known
557 * whether the procedure is really active or
558 * not, which means whether this device is
559 * used or whether it should be removed.
560 */
561 if (step == 0 || device->is_tgtdev_for_dev_replace) {
562 continue;
563 }
564 }
565 if (device->bdev) {
566 blkdev_put(device->bdev, device->mode);
567 device->bdev = NULL;
568 fs_devices->open_devices--;
569 }
570 if (device->writeable) {
571 list_del_init(&device->dev_alloc_list);
572 device->writeable = 0;
573 if (!device->is_tgtdev_for_dev_replace)
574 fs_devices->rw_devices--;
575 }
576 list_del_init(&device->dev_list);
577 fs_devices->num_devices--;
578 rcu_string_free(device->name);
579 kfree(device);
580 }
581
582 if (fs_devices->seed) {
583 fs_devices = fs_devices->seed;
584 goto again;
585 }
586
587 fs_devices->latest_bdev = latest_bdev;
588 fs_devices->latest_devid = latest_devid;
589 fs_devices->latest_trans = latest_transid;
590
591 mutex_unlock(&uuid_mutex);
592 }
593
594 static void __free_device(struct work_struct *work)
595 {
596 struct btrfs_device *device;
597
598 device = container_of(work, struct btrfs_device, rcu_work);
599
600 if (device->bdev)
601 blkdev_put(device->bdev, device->mode);
602
603 rcu_string_free(device->name);
604 kfree(device);
605 }
606
607 static void free_device(struct rcu_head *head)
608 {
609 struct btrfs_device *device;
610
611 device = container_of(head, struct btrfs_device, rcu);
612
613 INIT_WORK(&device->rcu_work, __free_device);
614 schedule_work(&device->rcu_work);
615 }
616
617 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
618 {
619 struct btrfs_device *device;
620
621 if (--fs_devices->opened > 0)
622 return 0;
623
624 mutex_lock(&fs_devices->device_list_mutex);
625 list_for_each_entry(device, &fs_devices->devices, dev_list) {
626 struct btrfs_device *new_device;
627 struct rcu_string *name;
628
629 if (device->bdev)
630 fs_devices->open_devices--;
631
632 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
633 list_del_init(&device->dev_alloc_list);
634 fs_devices->rw_devices--;
635 }
636
637 if (device->can_discard)
638 fs_devices->num_can_discard--;
639
640 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
641 BUG_ON(!new_device); /* -ENOMEM */
642 memcpy(new_device, device, sizeof(*new_device));
643
644 /* Safe because we are under uuid_mutex */
645 if (device->name) {
646 name = rcu_string_strdup(device->name->str, GFP_NOFS);
647 BUG_ON(device->name && !name); /* -ENOMEM */
648 rcu_assign_pointer(new_device->name, name);
649 }
650 new_device->bdev = NULL;
651 new_device->writeable = 0;
652 new_device->in_fs_metadata = 0;
653 new_device->can_discard = 0;
654 spin_lock_init(&new_device->io_lock);
655 list_replace_rcu(&device->dev_list, &new_device->dev_list);
656
657 call_rcu(&device->rcu, free_device);
658 }
659 mutex_unlock(&fs_devices->device_list_mutex);
660
661 WARN_ON(fs_devices->open_devices);
662 WARN_ON(fs_devices->rw_devices);
663 fs_devices->opened = 0;
664 fs_devices->seeding = 0;
665
666 return 0;
667 }
668
669 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
670 {
671 struct btrfs_fs_devices *seed_devices = NULL;
672 int ret;
673
674 mutex_lock(&uuid_mutex);
675 ret = __btrfs_close_devices(fs_devices);
676 if (!fs_devices->opened) {
677 seed_devices = fs_devices->seed;
678 fs_devices->seed = NULL;
679 }
680 mutex_unlock(&uuid_mutex);
681
682 while (seed_devices) {
683 fs_devices = seed_devices;
684 seed_devices = fs_devices->seed;
685 __btrfs_close_devices(fs_devices);
686 free_fs_devices(fs_devices);
687 }
688 /*
689 * Wait for rcu kworkers under __btrfs_close_devices
690 * to finish all blkdev_puts so device is really
691 * free when umount is done.
692 */
693 rcu_barrier();
694 return ret;
695 }
696
697 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
698 fmode_t flags, void *holder)
699 {
700 struct request_queue *q;
701 struct block_device *bdev;
702 struct list_head *head = &fs_devices->devices;
703 struct btrfs_device *device;
704 struct block_device *latest_bdev = NULL;
705 struct buffer_head *bh;
706 struct btrfs_super_block *disk_super;
707 u64 latest_devid = 0;
708 u64 latest_transid = 0;
709 u64 devid;
710 int seeding = 1;
711 int ret = 0;
712
713 flags |= FMODE_EXCL;
714
715 list_for_each_entry(device, head, dev_list) {
716 if (device->bdev)
717 continue;
718 if (!device->name)
719 continue;
720
721 /* Just open everything we can; ignore failures here */
722 if (btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
723 &bdev, &bh))
724 continue;
725
726 disk_super = (struct btrfs_super_block *)bh->b_data;
727 devid = btrfs_stack_device_id(&disk_super->dev_item);
728 if (devid != device->devid)
729 goto error_brelse;
730
731 if (memcmp(device->uuid, disk_super->dev_item.uuid,
732 BTRFS_UUID_SIZE))
733 goto error_brelse;
734
735 device->generation = btrfs_super_generation(disk_super);
736 if (!latest_transid || device->generation > latest_transid) {
737 latest_devid = devid;
738 latest_transid = device->generation;
739 latest_bdev = bdev;
740 }
741
742 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
743 device->writeable = 0;
744 } else {
745 device->writeable = !bdev_read_only(bdev);
746 seeding = 0;
747 }
748
749 q = bdev_get_queue(bdev);
750 if (blk_queue_discard(q)) {
751 device->can_discard = 1;
752 fs_devices->num_can_discard++;
753 }
754
755 device->bdev = bdev;
756 device->in_fs_metadata = 0;
757 device->mode = flags;
758
759 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
760 fs_devices->rotating = 1;
761
762 fs_devices->open_devices++;
763 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
764 fs_devices->rw_devices++;
765 list_add(&device->dev_alloc_list,
766 &fs_devices->alloc_list);
767 }
768 brelse(bh);
769 continue;
770
771 error_brelse:
772 brelse(bh);
773 blkdev_put(bdev, flags);
774 continue;
775 }
776 if (fs_devices->open_devices == 0) {
777 ret = -EINVAL;
778 goto out;
779 }
780 fs_devices->seeding = seeding;
781 fs_devices->opened = 1;
782 fs_devices->latest_bdev = latest_bdev;
783 fs_devices->latest_devid = latest_devid;
784 fs_devices->latest_trans = latest_transid;
785 fs_devices->total_rw_bytes = 0;
786 out:
787 return ret;
788 }
789
790 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
791 fmode_t flags, void *holder)
792 {
793 int ret;
794
795 mutex_lock(&uuid_mutex);
796 if (fs_devices->opened) {
797 fs_devices->opened++;
798 ret = 0;
799 } else {
800 ret = __btrfs_open_devices(fs_devices, flags, holder);
801 }
802 mutex_unlock(&uuid_mutex);
803 return ret;
804 }
805
806 /*
807 * Look for a btrfs signature on a device. This may be called out of the mount path
808 * and we are not allowed to call set_blocksize during the scan. The superblock
809 * is read via pagecache
810 */
811 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
812 struct btrfs_fs_devices **fs_devices_ret)
813 {
814 struct btrfs_super_block *disk_super;
815 struct block_device *bdev;
816 struct page *page;
817 void *p;
818 int ret = -EINVAL;
819 u64 devid;
820 u64 transid;
821 u64 total_devices;
822 u64 bytenr;
823 pgoff_t index;
824
825 /*
826 * we would like to check all the supers, but that would make
827 * a btrfs mount succeed after a mkfs from a different FS.
828 * So, we need to add a special mount option to scan for
829 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
830 */
831 bytenr = btrfs_sb_offset(0);
832 flags |= FMODE_EXCL;
833 mutex_lock(&uuid_mutex);
834
835 bdev = blkdev_get_by_path(path, flags, holder);
836
837 if (IS_ERR(bdev)) {
838 ret = PTR_ERR(bdev);
839 goto error;
840 }
841
842 /* make sure our super fits in the device */
843 if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
844 goto error_bdev_put;
845
846 /* make sure our super fits in the page */
847 if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
848 goto error_bdev_put;
849
850 /* make sure our super doesn't straddle pages on disk */
851 index = bytenr >> PAGE_CACHE_SHIFT;
852 if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
853 goto error_bdev_put;
854
855 /* pull in the page with our super */
856 page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
857 index, GFP_NOFS);
858
859 if (IS_ERR_OR_NULL(page))
860 goto error_bdev_put;
861
862 p = kmap(page);
863
864 /* align our pointer to the offset of the super block */
865 disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
866
867 if (btrfs_super_bytenr(disk_super) != bytenr ||
868 disk_super->magic != cpu_to_le64(BTRFS_MAGIC))
869 goto error_unmap;
870
871 devid = btrfs_stack_device_id(&disk_super->dev_item);
872 transid = btrfs_super_generation(disk_super);
873 total_devices = btrfs_super_num_devices(disk_super);
874
875 if (disk_super->label[0]) {
876 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
877 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
878 printk(KERN_INFO "device label %s ", disk_super->label);
879 } else {
880 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
881 }
882
883 printk(KERN_CONT "devid %llu transid %llu %s\n",
884 (unsigned long long)devid, (unsigned long long)transid, path);
885
886 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
887 if (!ret && fs_devices_ret)
888 (*fs_devices_ret)->total_devices = total_devices;
889
890 error_unmap:
891 kunmap(page);
892 page_cache_release(page);
893
894 error_bdev_put:
895 blkdev_put(bdev, flags);
896 error:
897 mutex_unlock(&uuid_mutex);
898 return ret;
899 }
900
901 /* helper to account the used device space in the range */
902 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
903 u64 end, u64 *length)
904 {
905 struct btrfs_key key;
906 struct btrfs_root *root = device->dev_root;
907 struct btrfs_dev_extent *dev_extent;
908 struct btrfs_path *path;
909 u64 extent_end;
910 int ret;
911 int slot;
912 struct extent_buffer *l;
913
914 *length = 0;
915
916 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
917 return 0;
918
919 path = btrfs_alloc_path();
920 if (!path)
921 return -ENOMEM;
922 path->reada = 2;
923
924 key.objectid = device->devid;
925 key.offset = start;
926 key.type = BTRFS_DEV_EXTENT_KEY;
927
928 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
929 if (ret < 0)
930 goto out;
931 if (ret > 0) {
932 ret = btrfs_previous_item(root, path, key.objectid, key.type);
933 if (ret < 0)
934 goto out;
935 }
936
937 while (1) {
938 l = path->nodes[0];
939 slot = path->slots[0];
940 if (slot >= btrfs_header_nritems(l)) {
941 ret = btrfs_next_leaf(root, path);
942 if (ret == 0)
943 continue;
944 if (ret < 0)
945 goto out;
946
947 break;
948 }
949 btrfs_item_key_to_cpu(l, &key, slot);
950
951 if (key.objectid < device->devid)
952 goto next;
953
954 if (key.objectid > device->devid)
955 break;
956
957 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
958 goto next;
959
960 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
961 extent_end = key.offset + btrfs_dev_extent_length(l,
962 dev_extent);
963 if (key.offset <= start && extent_end > end) {
964 *length = end - start + 1;
965 break;
966 } else if (key.offset <= start && extent_end > start)
967 *length += extent_end - start;
968 else if (key.offset > start && extent_end <= end)
969 *length += extent_end - key.offset;
970 else if (key.offset > start && key.offset <= end) {
971 *length += end - key.offset + 1;
972 break;
973 } else if (key.offset > end)
974 break;
975
976 next:
977 path->slots[0]++;
978 }
979 ret = 0;
980 out:
981 btrfs_free_path(path);
982 return ret;
983 }
984
985 static int contains_pending_extent(struct btrfs_trans_handle *trans,
986 struct btrfs_device *device,
987 u64 *start, u64 len)
988 {
989 struct extent_map *em;
990 int ret = 0;
991
992 list_for_each_entry(em, &trans->transaction->pending_chunks, list) {
993 struct map_lookup *map;
994 int i;
995
996 map = (struct map_lookup *)em->bdev;
997 for (i = 0; i < map->num_stripes; i++) {
998 if (map->stripes[i].dev != device)
999 continue;
1000 if (map->stripes[i].physical >= *start + len ||
1001 map->stripes[i].physical + em->orig_block_len <=
1002 *start)
1003 continue;
1004 *start = map->stripes[i].physical +
1005 em->orig_block_len;
1006 ret = 1;
1007 }
1008 }
1009
1010 return ret;
1011 }
1012
1013
1014 /*
1015 * find_free_dev_extent - find free space in the specified device
1016 * @device: the device which we search the free space in
1017 * @num_bytes: the size of the free space that we need
1018 * @start: store the start of the free space.
1019 * @len: the size of the free space. that we find, or the size of the max
1020 * free space if we don't find suitable free space
1021 *
1022 * this uses a pretty simple search, the expectation is that it is
1023 * called very infrequently and that a given device has a small number
1024 * of extents
1025 *
1026 * @start is used to store the start of the free space if we find. But if we
1027 * don't find suitable free space, it will be used to store the start position
1028 * of the max free space.
1029 *
1030 * @len is used to store the size of the free space that we find.
1031 * But if we don't find suitable free space, it is used to store the size of
1032 * the max free space.
1033 */
1034 int find_free_dev_extent(struct btrfs_trans_handle *trans,
1035 struct btrfs_device *device, u64 num_bytes,
1036 u64 *start, u64 *len)
1037 {
1038 struct btrfs_key key;
1039 struct btrfs_root *root = device->dev_root;
1040 struct btrfs_dev_extent *dev_extent;
1041 struct btrfs_path *path;
1042 u64 hole_size;
1043 u64 max_hole_start;
1044 u64 max_hole_size;
1045 u64 extent_end;
1046 u64 search_start;
1047 u64 search_end = device->total_bytes;
1048 int ret;
1049 int slot;
1050 struct extent_buffer *l;
1051
1052 /* FIXME use last free of some kind */
1053
1054 /* we don't want to overwrite the superblock on the drive,
1055 * so we make sure to start at an offset of at least 1MB
1056 */
1057 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1058
1059 path = btrfs_alloc_path();
1060 if (!path)
1061 return -ENOMEM;
1062 again:
1063 max_hole_start = search_start;
1064 max_hole_size = 0;
1065 hole_size = 0;
1066
1067 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1068 ret = -ENOSPC;
1069 goto out;
1070 }
1071
1072 path->reada = 2;
1073 path->search_commit_root = 1;
1074 path->skip_locking = 1;
1075
1076 key.objectid = device->devid;
1077 key.offset = search_start;
1078 key.type = BTRFS_DEV_EXTENT_KEY;
1079
1080 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1081 if (ret < 0)
1082 goto out;
1083 if (ret > 0) {
1084 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1085 if (ret < 0)
1086 goto out;
1087 }
1088
1089 while (1) {
1090 l = path->nodes[0];
1091 slot = path->slots[0];
1092 if (slot >= btrfs_header_nritems(l)) {
1093 ret = btrfs_next_leaf(root, path);
1094 if (ret == 0)
1095 continue;
1096 if (ret < 0)
1097 goto out;
1098
1099 break;
1100 }
1101 btrfs_item_key_to_cpu(l, &key, slot);
1102
1103 if (key.objectid < device->devid)
1104 goto next;
1105
1106 if (key.objectid > device->devid)
1107 break;
1108
1109 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1110 goto next;
1111
1112 if (key.offset > search_start) {
1113 hole_size = key.offset - search_start;
1114
1115 /*
1116 * Have to check before we set max_hole_start, otherwise
1117 * we could end up sending back this offset anyway.
1118 */
1119 if (contains_pending_extent(trans, device,
1120 &search_start,
1121 hole_size))
1122 hole_size = 0;
1123
1124 if (hole_size > max_hole_size) {
1125 max_hole_start = search_start;
1126 max_hole_size = hole_size;
1127 }
1128
1129 /*
1130 * If this free space is greater than which we need,
1131 * it must be the max free space that we have found
1132 * until now, so max_hole_start must point to the start
1133 * of this free space and the length of this free space
1134 * is stored in max_hole_size. Thus, we return
1135 * max_hole_start and max_hole_size and go back to the
1136 * caller.
1137 */
1138 if (hole_size >= num_bytes) {
1139 ret = 0;
1140 goto out;
1141 }
1142 }
1143
1144 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1145 extent_end = key.offset + btrfs_dev_extent_length(l,
1146 dev_extent);
1147 if (extent_end > search_start)
1148 search_start = extent_end;
1149 next:
1150 path->slots[0]++;
1151 cond_resched();
1152 }
1153
1154 /*
1155 * At this point, search_start should be the end of
1156 * allocated dev extents, and when shrinking the device,
1157 * search_end may be smaller than search_start.
1158 */
1159 if (search_end > search_start)
1160 hole_size = search_end - search_start;
1161
1162 if (hole_size > max_hole_size) {
1163 max_hole_start = search_start;
1164 max_hole_size = hole_size;
1165 }
1166
1167 if (contains_pending_extent(trans, device, &search_start, hole_size)) {
1168 btrfs_release_path(path);
1169 goto again;
1170 }
1171
1172 /* See above. */
1173 if (hole_size < num_bytes)
1174 ret = -ENOSPC;
1175 else
1176 ret = 0;
1177
1178 out:
1179 btrfs_free_path(path);
1180 *start = max_hole_start;
1181 if (len)
1182 *len = max_hole_size;
1183 return ret;
1184 }
1185
1186 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1187 struct btrfs_device *device,
1188 u64 start)
1189 {
1190 int ret;
1191 struct btrfs_path *path;
1192 struct btrfs_root *root = device->dev_root;
1193 struct btrfs_key key;
1194 struct btrfs_key found_key;
1195 struct extent_buffer *leaf = NULL;
1196 struct btrfs_dev_extent *extent = NULL;
1197
1198 path = btrfs_alloc_path();
1199 if (!path)
1200 return -ENOMEM;
1201
1202 key.objectid = device->devid;
1203 key.offset = start;
1204 key.type = BTRFS_DEV_EXTENT_KEY;
1205 again:
1206 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1207 if (ret > 0) {
1208 ret = btrfs_previous_item(root, path, key.objectid,
1209 BTRFS_DEV_EXTENT_KEY);
1210 if (ret)
1211 goto out;
1212 leaf = path->nodes[0];
1213 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1214 extent = btrfs_item_ptr(leaf, path->slots[0],
1215 struct btrfs_dev_extent);
1216 BUG_ON(found_key.offset > start || found_key.offset +
1217 btrfs_dev_extent_length(leaf, extent) < start);
1218 key = found_key;
1219 btrfs_release_path(path);
1220 goto again;
1221 } else if (ret == 0) {
1222 leaf = path->nodes[0];
1223 extent = btrfs_item_ptr(leaf, path->slots[0],
1224 struct btrfs_dev_extent);
1225 } else {
1226 btrfs_error(root->fs_info, ret, "Slot search failed");
1227 goto out;
1228 }
1229
1230 if (device->bytes_used > 0) {
1231 u64 len = btrfs_dev_extent_length(leaf, extent);
1232 device->bytes_used -= len;
1233 spin_lock(&root->fs_info->free_chunk_lock);
1234 root->fs_info->free_chunk_space += len;
1235 spin_unlock(&root->fs_info->free_chunk_lock);
1236 }
1237 ret = btrfs_del_item(trans, root, path);
1238 if (ret) {
1239 btrfs_error(root->fs_info, ret,
1240 "Failed to remove dev extent item");
1241 }
1242 out:
1243 btrfs_free_path(path);
1244 return ret;
1245 }
1246
1247 static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1248 struct btrfs_device *device,
1249 u64 chunk_tree, u64 chunk_objectid,
1250 u64 chunk_offset, u64 start, u64 num_bytes)
1251 {
1252 int ret;
1253 struct btrfs_path *path;
1254 struct btrfs_root *root = device->dev_root;
1255 struct btrfs_dev_extent *extent;
1256 struct extent_buffer *leaf;
1257 struct btrfs_key key;
1258
1259 WARN_ON(!device->in_fs_metadata);
1260 WARN_ON(device->is_tgtdev_for_dev_replace);
1261 path = btrfs_alloc_path();
1262 if (!path)
1263 return -ENOMEM;
1264
1265 key.objectid = device->devid;
1266 key.offset = start;
1267 key.type = BTRFS_DEV_EXTENT_KEY;
1268 ret = btrfs_insert_empty_item(trans, root, path, &key,
1269 sizeof(*extent));
1270 if (ret)
1271 goto out;
1272
1273 leaf = path->nodes[0];
1274 extent = btrfs_item_ptr(leaf, path->slots[0],
1275 struct btrfs_dev_extent);
1276 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1277 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1278 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1279
1280 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1281 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1282 BTRFS_UUID_SIZE);
1283
1284 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1285 btrfs_mark_buffer_dirty(leaf);
1286 out:
1287 btrfs_free_path(path);
1288 return ret;
1289 }
1290
1291 static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
1292 {
1293 struct extent_map_tree *em_tree;
1294 struct extent_map *em;
1295 struct rb_node *n;
1296 u64 ret = 0;
1297
1298 em_tree = &fs_info->mapping_tree.map_tree;
1299 read_lock(&em_tree->lock);
1300 n = rb_last(&em_tree->map);
1301 if (n) {
1302 em = rb_entry(n, struct extent_map, rb_node);
1303 ret = em->start + em->len;
1304 }
1305 read_unlock(&em_tree->lock);
1306
1307 return ret;
1308 }
1309
1310 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1311 {
1312 int ret;
1313 struct btrfs_key key;
1314 struct btrfs_key found_key;
1315 struct btrfs_path *path;
1316
1317 root = root->fs_info->chunk_root;
1318
1319 path = btrfs_alloc_path();
1320 if (!path)
1321 return -ENOMEM;
1322
1323 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1324 key.type = BTRFS_DEV_ITEM_KEY;
1325 key.offset = (u64)-1;
1326
1327 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1328 if (ret < 0)
1329 goto error;
1330
1331 BUG_ON(ret == 0); /* Corruption */
1332
1333 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1334 BTRFS_DEV_ITEM_KEY);
1335 if (ret) {
1336 *objectid = 1;
1337 } else {
1338 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1339 path->slots[0]);
1340 *objectid = found_key.offset + 1;
1341 }
1342 ret = 0;
1343 error:
1344 btrfs_free_path(path);
1345 return ret;
1346 }
1347
1348 /*
1349 * the device information is stored in the chunk root
1350 * the btrfs_device struct should be fully filled in
1351 */
1352 static int btrfs_add_device(struct btrfs_trans_handle *trans,
1353 struct btrfs_root *root,
1354 struct btrfs_device *device)
1355 {
1356 int ret;
1357 struct btrfs_path *path;
1358 struct btrfs_dev_item *dev_item;
1359 struct extent_buffer *leaf;
1360 struct btrfs_key key;
1361 unsigned long ptr;
1362
1363 root = root->fs_info->chunk_root;
1364
1365 path = btrfs_alloc_path();
1366 if (!path)
1367 return -ENOMEM;
1368
1369 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1370 key.type = BTRFS_DEV_ITEM_KEY;
1371 key.offset = device->devid;
1372
1373 ret = btrfs_insert_empty_item(trans, root, path, &key,
1374 sizeof(*dev_item));
1375 if (ret)
1376 goto out;
1377
1378 leaf = path->nodes[0];
1379 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1380
1381 btrfs_set_device_id(leaf, dev_item, device->devid);
1382 btrfs_set_device_generation(leaf, dev_item, 0);
1383 btrfs_set_device_type(leaf, dev_item, device->type);
1384 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1385 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1386 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1387 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1388 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1389 btrfs_set_device_group(leaf, dev_item, 0);
1390 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1391 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1392 btrfs_set_device_start_offset(leaf, dev_item, 0);
1393
1394 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1395 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1396 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1397 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1398 btrfs_mark_buffer_dirty(leaf);
1399
1400 ret = 0;
1401 out:
1402 btrfs_free_path(path);
1403 return ret;
1404 }
1405
1406 static int btrfs_rm_dev_item(struct btrfs_root *root,
1407 struct btrfs_device *device)
1408 {
1409 int ret;
1410 struct btrfs_path *path;
1411 struct btrfs_key key;
1412 struct btrfs_trans_handle *trans;
1413
1414 root = root->fs_info->chunk_root;
1415
1416 path = btrfs_alloc_path();
1417 if (!path)
1418 return -ENOMEM;
1419
1420 trans = btrfs_start_transaction(root, 0);
1421 if (IS_ERR(trans)) {
1422 btrfs_free_path(path);
1423 return PTR_ERR(trans);
1424 }
1425 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1426 key.type = BTRFS_DEV_ITEM_KEY;
1427 key.offset = device->devid;
1428 lock_chunks(root);
1429
1430 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1431 if (ret < 0)
1432 goto out;
1433
1434 if (ret > 0) {
1435 ret = -ENOENT;
1436 goto out;
1437 }
1438
1439 ret = btrfs_del_item(trans, root, path);
1440 if (ret)
1441 goto out;
1442 out:
1443 btrfs_free_path(path);
1444 unlock_chunks(root);
1445 btrfs_commit_transaction(trans, root);
1446 return ret;
1447 }
1448
1449 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1450 {
1451 struct btrfs_device *device;
1452 struct btrfs_device *next_device;
1453 struct block_device *bdev;
1454 struct buffer_head *bh = NULL;
1455 struct btrfs_super_block *disk_super;
1456 struct btrfs_fs_devices *cur_devices;
1457 u64 all_avail;
1458 u64 devid;
1459 u64 num_devices;
1460 u8 *dev_uuid;
1461 unsigned seq;
1462 int ret = 0;
1463 bool clear_super = false;
1464
1465 mutex_lock(&uuid_mutex);
1466
1467 do {
1468 seq = read_seqbegin(&root->fs_info->profiles_lock);
1469
1470 all_avail = root->fs_info->avail_data_alloc_bits |
1471 root->fs_info->avail_system_alloc_bits |
1472 root->fs_info->avail_metadata_alloc_bits;
1473 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
1474
1475 num_devices = root->fs_info->fs_devices->num_devices;
1476 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1477 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1478 WARN_ON(num_devices < 1);
1479 num_devices--;
1480 }
1481 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1482
1483 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1484 ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
1485 goto out;
1486 }
1487
1488 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1489 ret = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
1490 goto out;
1491 }
1492
1493 if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1494 root->fs_info->fs_devices->rw_devices <= 2) {
1495 ret = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
1496 goto out;
1497 }
1498 if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1499 root->fs_info->fs_devices->rw_devices <= 3) {
1500 ret = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
1501 goto out;
1502 }
1503
1504 if (strcmp(device_path, "missing") == 0) {
1505 struct list_head *devices;
1506 struct btrfs_device *tmp;
1507
1508 device = NULL;
1509 devices = &root->fs_info->fs_devices->devices;
1510 /*
1511 * It is safe to read the devices since the volume_mutex
1512 * is held.
1513 */
1514 list_for_each_entry(tmp, devices, dev_list) {
1515 if (tmp->in_fs_metadata &&
1516 !tmp->is_tgtdev_for_dev_replace &&
1517 !tmp->bdev) {
1518 device = tmp;
1519 break;
1520 }
1521 }
1522 bdev = NULL;
1523 bh = NULL;
1524 disk_super = NULL;
1525 if (!device) {
1526 ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
1527 goto out;
1528 }
1529 } else {
1530 ret = btrfs_get_bdev_and_sb(device_path,
1531 FMODE_WRITE | FMODE_EXCL,
1532 root->fs_info->bdev_holder, 0,
1533 &bdev, &bh);
1534 if (ret)
1535 goto out;
1536 disk_super = (struct btrfs_super_block *)bh->b_data;
1537 devid = btrfs_stack_device_id(&disk_super->dev_item);
1538 dev_uuid = disk_super->dev_item.uuid;
1539 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1540 disk_super->fsid);
1541 if (!device) {
1542 ret = -ENOENT;
1543 goto error_brelse;
1544 }
1545 }
1546
1547 if (device->is_tgtdev_for_dev_replace) {
1548 ret = BTRFS_ERROR_DEV_TGT_REPLACE;
1549 goto error_brelse;
1550 }
1551
1552 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1553 ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
1554 goto error_brelse;
1555 }
1556
1557 if (device->writeable) {
1558 lock_chunks(root);
1559 list_del_init(&device->dev_alloc_list);
1560 unlock_chunks(root);
1561 root->fs_info->fs_devices->rw_devices--;
1562 clear_super = true;
1563 }
1564
1565 ret = btrfs_shrink_device(device, 0);
1566 if (ret)
1567 goto error_undo;
1568
1569 /*
1570 * TODO: the superblock still includes this device in its num_devices
1571 * counter although write_all_supers() is not locked out. This
1572 * could give a filesystem state which requires a degraded mount.
1573 */
1574 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1575 if (ret)
1576 goto error_undo;
1577
1578 spin_lock(&root->fs_info->free_chunk_lock);
1579 root->fs_info->free_chunk_space = device->total_bytes -
1580 device->bytes_used;
1581 spin_unlock(&root->fs_info->free_chunk_lock);
1582
1583 device->in_fs_metadata = 0;
1584 btrfs_scrub_cancel_dev(root->fs_info, device);
1585
1586 /*
1587 * the device list mutex makes sure that we don't change
1588 * the device list while someone else is writing out all
1589 * the device supers.
1590 */
1591
1592 cur_devices = device->fs_devices;
1593 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1594 list_del_rcu(&device->dev_list);
1595
1596 device->fs_devices->num_devices--;
1597 device->fs_devices->total_devices--;
1598
1599 if (device->missing)
1600 root->fs_info->fs_devices->missing_devices--;
1601
1602 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1603 struct btrfs_device, dev_list);
1604 if (device->bdev == root->fs_info->sb->s_bdev)
1605 root->fs_info->sb->s_bdev = next_device->bdev;
1606 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1607 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1608
1609 if (device->bdev)
1610 device->fs_devices->open_devices--;
1611
1612 call_rcu(&device->rcu, free_device);
1613 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1614
1615 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1616 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1617
1618 if (cur_devices->open_devices == 0) {
1619 struct btrfs_fs_devices *fs_devices;
1620 fs_devices = root->fs_info->fs_devices;
1621 while (fs_devices) {
1622 if (fs_devices->seed == cur_devices)
1623 break;
1624 fs_devices = fs_devices->seed;
1625 }
1626 fs_devices->seed = cur_devices->seed;
1627 cur_devices->seed = NULL;
1628 lock_chunks(root);
1629 __btrfs_close_devices(cur_devices);
1630 unlock_chunks(root);
1631 free_fs_devices(cur_devices);
1632 }
1633
1634 root->fs_info->num_tolerated_disk_barrier_failures =
1635 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1636
1637 /*
1638 * at this point, the device is zero sized. We want to
1639 * remove it from the devices list and zero out the old super
1640 */
1641 if (clear_super && disk_super) {
1642 /* make sure this device isn't detected as part of
1643 * the FS anymore
1644 */
1645 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1646 set_buffer_dirty(bh);
1647 sync_dirty_buffer(bh);
1648 }
1649
1650 ret = 0;
1651
1652 /* Notify udev that device has changed */
1653 if (bdev)
1654 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1655
1656 error_brelse:
1657 brelse(bh);
1658 if (bdev)
1659 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1660 out:
1661 mutex_unlock(&uuid_mutex);
1662 return ret;
1663 error_undo:
1664 if (device->writeable) {
1665 lock_chunks(root);
1666 list_add(&device->dev_alloc_list,
1667 &root->fs_info->fs_devices->alloc_list);
1668 unlock_chunks(root);
1669 root->fs_info->fs_devices->rw_devices++;
1670 }
1671 goto error_brelse;
1672 }
1673
1674 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1675 struct btrfs_device *srcdev)
1676 {
1677 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1678 list_del_rcu(&srcdev->dev_list);
1679 list_del_rcu(&srcdev->dev_alloc_list);
1680 fs_info->fs_devices->num_devices--;
1681 if (srcdev->missing) {
1682 fs_info->fs_devices->missing_devices--;
1683 fs_info->fs_devices->rw_devices++;
1684 }
1685 if (srcdev->can_discard)
1686 fs_info->fs_devices->num_can_discard--;
1687 if (srcdev->bdev)
1688 fs_info->fs_devices->open_devices--;
1689
1690 call_rcu(&srcdev->rcu, free_device);
1691 }
1692
1693 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1694 struct btrfs_device *tgtdev)
1695 {
1696 struct btrfs_device *next_device;
1697
1698 WARN_ON(!tgtdev);
1699 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1700 if (tgtdev->bdev) {
1701 btrfs_scratch_superblock(tgtdev);
1702 fs_info->fs_devices->open_devices--;
1703 }
1704 fs_info->fs_devices->num_devices--;
1705 if (tgtdev->can_discard)
1706 fs_info->fs_devices->num_can_discard++;
1707
1708 next_device = list_entry(fs_info->fs_devices->devices.next,
1709 struct btrfs_device, dev_list);
1710 if (tgtdev->bdev == fs_info->sb->s_bdev)
1711 fs_info->sb->s_bdev = next_device->bdev;
1712 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1713 fs_info->fs_devices->latest_bdev = next_device->bdev;
1714 list_del_rcu(&tgtdev->dev_list);
1715
1716 call_rcu(&tgtdev->rcu, free_device);
1717
1718 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1719 }
1720
1721 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1722 struct btrfs_device **device)
1723 {
1724 int ret = 0;
1725 struct btrfs_super_block *disk_super;
1726 u64 devid;
1727 u8 *dev_uuid;
1728 struct block_device *bdev;
1729 struct buffer_head *bh;
1730
1731 *device = NULL;
1732 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1733 root->fs_info->bdev_holder, 0, &bdev, &bh);
1734 if (ret)
1735 return ret;
1736 disk_super = (struct btrfs_super_block *)bh->b_data;
1737 devid = btrfs_stack_device_id(&disk_super->dev_item);
1738 dev_uuid = disk_super->dev_item.uuid;
1739 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1740 disk_super->fsid);
1741 brelse(bh);
1742 if (!*device)
1743 ret = -ENOENT;
1744 blkdev_put(bdev, FMODE_READ);
1745 return ret;
1746 }
1747
1748 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1749 char *device_path,
1750 struct btrfs_device **device)
1751 {
1752 *device = NULL;
1753 if (strcmp(device_path, "missing") == 0) {
1754 struct list_head *devices;
1755 struct btrfs_device *tmp;
1756
1757 devices = &root->fs_info->fs_devices->devices;
1758 /*
1759 * It is safe to read the devices since the volume_mutex
1760 * is held by the caller.
1761 */
1762 list_for_each_entry(tmp, devices, dev_list) {
1763 if (tmp->in_fs_metadata && !tmp->bdev) {
1764 *device = tmp;
1765 break;
1766 }
1767 }
1768
1769 if (!*device) {
1770 pr_err("btrfs: no missing device found\n");
1771 return -ENOENT;
1772 }
1773
1774 return 0;
1775 } else {
1776 return btrfs_find_device_by_path(root, device_path, device);
1777 }
1778 }
1779
1780 /*
1781 * does all the dirty work required for changing file system's UUID.
1782 */
1783 static int btrfs_prepare_sprout(struct btrfs_root *root)
1784 {
1785 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1786 struct btrfs_fs_devices *old_devices;
1787 struct btrfs_fs_devices *seed_devices;
1788 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1789 struct btrfs_device *device;
1790 u64 super_flags;
1791
1792 BUG_ON(!mutex_is_locked(&uuid_mutex));
1793 if (!fs_devices->seeding)
1794 return -EINVAL;
1795
1796 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1797 if (!seed_devices)
1798 return -ENOMEM;
1799
1800 old_devices = clone_fs_devices(fs_devices);
1801 if (IS_ERR(old_devices)) {
1802 kfree(seed_devices);
1803 return PTR_ERR(old_devices);
1804 }
1805
1806 list_add(&old_devices->list, &fs_uuids);
1807
1808 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1809 seed_devices->opened = 1;
1810 INIT_LIST_HEAD(&seed_devices->devices);
1811 INIT_LIST_HEAD(&seed_devices->alloc_list);
1812 mutex_init(&seed_devices->device_list_mutex);
1813
1814 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1815 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1816 synchronize_rcu);
1817 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1818
1819 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1820 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1821 device->fs_devices = seed_devices;
1822 }
1823
1824 fs_devices->seeding = 0;
1825 fs_devices->num_devices = 0;
1826 fs_devices->open_devices = 0;
1827 fs_devices->total_devices = 0;
1828 fs_devices->seed = seed_devices;
1829
1830 generate_random_uuid(fs_devices->fsid);
1831 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1832 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1833 super_flags = btrfs_super_flags(disk_super) &
1834 ~BTRFS_SUPER_FLAG_SEEDING;
1835 btrfs_set_super_flags(disk_super, super_flags);
1836
1837 return 0;
1838 }
1839
1840 /*
1841 * strore the expected generation for seed devices in device items.
1842 */
1843 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1844 struct btrfs_root *root)
1845 {
1846 struct btrfs_path *path;
1847 struct extent_buffer *leaf;
1848 struct btrfs_dev_item *dev_item;
1849 struct btrfs_device *device;
1850 struct btrfs_key key;
1851 u8 fs_uuid[BTRFS_UUID_SIZE];
1852 u8 dev_uuid[BTRFS_UUID_SIZE];
1853 u64 devid;
1854 int ret;
1855
1856 path = btrfs_alloc_path();
1857 if (!path)
1858 return -ENOMEM;
1859
1860 root = root->fs_info->chunk_root;
1861 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1862 key.offset = 0;
1863 key.type = BTRFS_DEV_ITEM_KEY;
1864
1865 while (1) {
1866 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1867 if (ret < 0)
1868 goto error;
1869
1870 leaf = path->nodes[0];
1871 next_slot:
1872 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1873 ret = btrfs_next_leaf(root, path);
1874 if (ret > 0)
1875 break;
1876 if (ret < 0)
1877 goto error;
1878 leaf = path->nodes[0];
1879 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1880 btrfs_release_path(path);
1881 continue;
1882 }
1883
1884 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1885 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1886 key.type != BTRFS_DEV_ITEM_KEY)
1887 break;
1888
1889 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1890 struct btrfs_dev_item);
1891 devid = btrfs_device_id(leaf, dev_item);
1892 read_extent_buffer(leaf, dev_uuid,
1893 (unsigned long)btrfs_device_uuid(dev_item),
1894 BTRFS_UUID_SIZE);
1895 read_extent_buffer(leaf, fs_uuid,
1896 (unsigned long)btrfs_device_fsid(dev_item),
1897 BTRFS_UUID_SIZE);
1898 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1899 fs_uuid);
1900 BUG_ON(!device); /* Logic error */
1901
1902 if (device->fs_devices->seeding) {
1903 btrfs_set_device_generation(leaf, dev_item,
1904 device->generation);
1905 btrfs_mark_buffer_dirty(leaf);
1906 }
1907
1908 path->slots[0]++;
1909 goto next_slot;
1910 }
1911 ret = 0;
1912 error:
1913 btrfs_free_path(path);
1914 return ret;
1915 }
1916
1917 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1918 {
1919 struct request_queue *q;
1920 struct btrfs_trans_handle *trans;
1921 struct btrfs_device *device;
1922 struct block_device *bdev;
1923 struct list_head *devices;
1924 struct super_block *sb = root->fs_info->sb;
1925 struct rcu_string *name;
1926 u64 total_bytes;
1927 int seeding_dev = 0;
1928 int ret = 0;
1929
1930 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1931 return -EROFS;
1932
1933 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1934 root->fs_info->bdev_holder);
1935 if (IS_ERR(bdev))
1936 return PTR_ERR(bdev);
1937
1938 if (root->fs_info->fs_devices->seeding) {
1939 seeding_dev = 1;
1940 down_write(&sb->s_umount);
1941 mutex_lock(&uuid_mutex);
1942 }
1943
1944 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1945
1946 devices = &root->fs_info->fs_devices->devices;
1947
1948 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1949 list_for_each_entry(device, devices, dev_list) {
1950 if (device->bdev == bdev) {
1951 ret = -EEXIST;
1952 mutex_unlock(
1953 &root->fs_info->fs_devices->device_list_mutex);
1954 goto error;
1955 }
1956 }
1957 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1958
1959 device = kzalloc(sizeof(*device), GFP_NOFS);
1960 if (!device) {
1961 /* we can safely leave the fs_devices entry around */
1962 ret = -ENOMEM;
1963 goto error;
1964 }
1965
1966 name = rcu_string_strdup(device_path, GFP_NOFS);
1967 if (!name) {
1968 kfree(device);
1969 ret = -ENOMEM;
1970 goto error;
1971 }
1972 rcu_assign_pointer(device->name, name);
1973
1974 ret = find_next_devid(root, &device->devid);
1975 if (ret) {
1976 rcu_string_free(device->name);
1977 kfree(device);
1978 goto error;
1979 }
1980
1981 trans = btrfs_start_transaction(root, 0);
1982 if (IS_ERR(trans)) {
1983 rcu_string_free(device->name);
1984 kfree(device);
1985 ret = PTR_ERR(trans);
1986 goto error;
1987 }
1988
1989 lock_chunks(root);
1990
1991 q = bdev_get_queue(bdev);
1992 if (blk_queue_discard(q))
1993 device->can_discard = 1;
1994 device->writeable = 1;
1995 device->work.func = pending_bios_fn;
1996 generate_random_uuid(device->uuid);
1997 spin_lock_init(&device->io_lock);
1998 device->generation = trans->transid;
1999 device->io_width = root->sectorsize;
2000 device->io_align = root->sectorsize;
2001 device->sector_size = root->sectorsize;
2002 device->total_bytes = i_size_read(bdev->bd_inode);
2003 device->disk_total_bytes = device->total_bytes;
2004 device->dev_root = root->fs_info->dev_root;
2005 device->bdev = bdev;
2006 device->in_fs_metadata = 1;
2007 device->is_tgtdev_for_dev_replace = 0;
2008 device->mode = FMODE_EXCL;
2009 set_blocksize(device->bdev, 4096);
2010
2011 if (seeding_dev) {
2012 sb->s_flags &= ~MS_RDONLY;
2013 ret = btrfs_prepare_sprout(root);
2014 BUG_ON(ret); /* -ENOMEM */
2015 }
2016
2017 device->fs_devices = root->fs_info->fs_devices;
2018
2019 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2020 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2021 list_add(&device->dev_alloc_list,
2022 &root->fs_info->fs_devices->alloc_list);
2023 root->fs_info->fs_devices->num_devices++;
2024 root->fs_info->fs_devices->open_devices++;
2025 root->fs_info->fs_devices->rw_devices++;
2026 root->fs_info->fs_devices->total_devices++;
2027 if (device->can_discard)
2028 root->fs_info->fs_devices->num_can_discard++;
2029 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2030
2031 spin_lock(&root->fs_info->free_chunk_lock);
2032 root->fs_info->free_chunk_space += device->total_bytes;
2033 spin_unlock(&root->fs_info->free_chunk_lock);
2034
2035 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2036 root->fs_info->fs_devices->rotating = 1;
2037
2038 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2039 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2040 total_bytes + device->total_bytes);
2041
2042 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2043 btrfs_set_super_num_devices(root->fs_info->super_copy,
2044 total_bytes + 1);
2045 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2046
2047 if (seeding_dev) {
2048 ret = init_first_rw_device(trans, root, device);
2049 if (ret) {
2050 btrfs_abort_transaction(trans, root, ret);
2051 goto error_trans;
2052 }
2053 ret = btrfs_finish_sprout(trans, root);
2054 if (ret) {
2055 btrfs_abort_transaction(trans, root, ret);
2056 goto error_trans;
2057 }
2058 } else {
2059 ret = btrfs_add_device(trans, root, device);
2060 if (ret) {
2061 btrfs_abort_transaction(trans, root, ret);
2062 goto error_trans;
2063 }
2064 }
2065
2066 /*
2067 * we've got more storage, clear any full flags on the space
2068 * infos
2069 */
2070 btrfs_clear_space_info_full(root->fs_info);
2071
2072 unlock_chunks(root);
2073 root->fs_info->num_tolerated_disk_barrier_failures =
2074 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2075 ret = btrfs_commit_transaction(trans, root);
2076
2077 if (seeding_dev) {
2078 mutex_unlock(&uuid_mutex);
2079 up_write(&sb->s_umount);
2080
2081 if (ret) /* transaction commit */
2082 return ret;
2083
2084 ret = btrfs_relocate_sys_chunks(root);
2085 if (ret < 0)
2086 btrfs_error(root->fs_info, ret,
2087 "Failed to relocate sys chunks after "
2088 "device initialization. This can be fixed "
2089 "using the \"btrfs balance\" command.");
2090 trans = btrfs_attach_transaction(root);
2091 if (IS_ERR(trans)) {
2092 if (PTR_ERR(trans) == -ENOENT)
2093 return 0;
2094 return PTR_ERR(trans);
2095 }
2096 ret = btrfs_commit_transaction(trans, root);
2097 }
2098
2099 return ret;
2100
2101 error_trans:
2102 unlock_chunks(root);
2103 btrfs_end_transaction(trans, root);
2104 rcu_string_free(device->name);
2105 kfree(device);
2106 error:
2107 blkdev_put(bdev, FMODE_EXCL);
2108 if (seeding_dev) {
2109 mutex_unlock(&uuid_mutex);
2110 up_write(&sb->s_umount);
2111 }
2112 return ret;
2113 }
2114
2115 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2116 struct btrfs_device **device_out)
2117 {
2118 struct request_queue *q;
2119 struct btrfs_device *device;
2120 struct block_device *bdev;
2121 struct btrfs_fs_info *fs_info = root->fs_info;
2122 struct list_head *devices;
2123 struct rcu_string *name;
2124 int ret = 0;
2125
2126 *device_out = NULL;
2127 if (fs_info->fs_devices->seeding)
2128 return -EINVAL;
2129
2130 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2131 fs_info->bdev_holder);
2132 if (IS_ERR(bdev))
2133 return PTR_ERR(bdev);
2134
2135 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2136
2137 devices = &fs_info->fs_devices->devices;
2138 list_for_each_entry(device, devices, dev_list) {
2139 if (device->bdev == bdev) {
2140 ret = -EEXIST;
2141 goto error;
2142 }
2143 }
2144
2145 device = kzalloc(sizeof(*device), GFP_NOFS);
2146 if (!device) {
2147 ret = -ENOMEM;
2148 goto error;
2149 }
2150
2151 name = rcu_string_strdup(device_path, GFP_NOFS);
2152 if (!name) {
2153 kfree(device);
2154 ret = -ENOMEM;
2155 goto error;
2156 }
2157 rcu_assign_pointer(device->name, name);
2158
2159 q = bdev_get_queue(bdev);
2160 if (blk_queue_discard(q))
2161 device->can_discard = 1;
2162 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2163 device->writeable = 1;
2164 device->work.func = pending_bios_fn;
2165 generate_random_uuid(device->uuid);
2166 device->devid = BTRFS_DEV_REPLACE_DEVID;
2167 spin_lock_init(&device->io_lock);
2168 device->generation = 0;
2169 device->io_width = root->sectorsize;
2170 device->io_align = root->sectorsize;
2171 device->sector_size = root->sectorsize;
2172 device->total_bytes = i_size_read(bdev->bd_inode);
2173 device->disk_total_bytes = device->total_bytes;
2174 device->dev_root = fs_info->dev_root;
2175 device->bdev = bdev;
2176 device->in_fs_metadata = 1;
2177 device->is_tgtdev_for_dev_replace = 1;
2178 device->mode = FMODE_EXCL;
2179 set_blocksize(device->bdev, 4096);
2180 device->fs_devices = fs_info->fs_devices;
2181 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2182 fs_info->fs_devices->num_devices++;
2183 fs_info->fs_devices->open_devices++;
2184 if (device->can_discard)
2185 fs_info->fs_devices->num_can_discard++;
2186 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2187
2188 *device_out = device;
2189 return ret;
2190
2191 error:
2192 blkdev_put(bdev, FMODE_EXCL);
2193 return ret;
2194 }
2195
2196 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2197 struct btrfs_device *tgtdev)
2198 {
2199 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2200 tgtdev->io_width = fs_info->dev_root->sectorsize;
2201 tgtdev->io_align = fs_info->dev_root->sectorsize;
2202 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2203 tgtdev->dev_root = fs_info->dev_root;
2204 tgtdev->in_fs_metadata = 1;
2205 }
2206
2207 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2208 struct btrfs_device *device)
2209 {
2210 int ret;
2211 struct btrfs_path *path;
2212 struct btrfs_root *root;
2213 struct btrfs_dev_item *dev_item;
2214 struct extent_buffer *leaf;
2215 struct btrfs_key key;
2216
2217 root = device->dev_root->fs_info->chunk_root;
2218
2219 path = btrfs_alloc_path();
2220 if (!path)
2221 return -ENOMEM;
2222
2223 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2224 key.type = BTRFS_DEV_ITEM_KEY;
2225 key.offset = device->devid;
2226
2227 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2228 if (ret < 0)
2229 goto out;
2230
2231 if (ret > 0) {
2232 ret = -ENOENT;
2233 goto out;
2234 }
2235
2236 leaf = path->nodes[0];
2237 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2238
2239 btrfs_set_device_id(leaf, dev_item, device->devid);
2240 btrfs_set_device_type(leaf, dev_item, device->type);
2241 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2242 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2243 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2244 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2245 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2246 btrfs_mark_buffer_dirty(leaf);
2247
2248 out:
2249 btrfs_free_path(path);
2250 return ret;
2251 }
2252
2253 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2254 struct btrfs_device *device, u64 new_size)
2255 {
2256 struct btrfs_super_block *super_copy =
2257 device->dev_root->fs_info->super_copy;
2258 u64 old_total = btrfs_super_total_bytes(super_copy);
2259 u64 diff = new_size - device->total_bytes;
2260
2261 if (!device->writeable)
2262 return -EACCES;
2263 if (new_size <= device->total_bytes ||
2264 device->is_tgtdev_for_dev_replace)
2265 return -EINVAL;
2266
2267 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2268 device->fs_devices->total_rw_bytes += diff;
2269
2270 device->total_bytes = new_size;
2271 device->disk_total_bytes = new_size;
2272 btrfs_clear_space_info_full(device->dev_root->fs_info);
2273
2274 return btrfs_update_device(trans, device);
2275 }
2276
2277 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2278 struct btrfs_device *device, u64 new_size)
2279 {
2280 int ret;
2281 lock_chunks(device->dev_root);
2282 ret = __btrfs_grow_device(trans, device, new_size);
2283 unlock_chunks(device->dev_root);
2284 return ret;
2285 }
2286
2287 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2288 struct btrfs_root *root,
2289 u64 chunk_tree, u64 chunk_objectid,
2290 u64 chunk_offset)
2291 {
2292 int ret;
2293 struct btrfs_path *path;
2294 struct btrfs_key key;
2295
2296 root = root->fs_info->chunk_root;
2297 path = btrfs_alloc_path();
2298 if (!path)
2299 return -ENOMEM;
2300
2301 key.objectid = chunk_objectid;
2302 key.offset = chunk_offset;
2303 key.type = BTRFS_CHUNK_ITEM_KEY;
2304
2305 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2306 if (ret < 0)
2307 goto out;
2308 else if (ret > 0) { /* Logic error or corruption */
2309 btrfs_error(root->fs_info, -ENOENT,
2310 "Failed lookup while freeing chunk.");
2311 ret = -ENOENT;
2312 goto out;
2313 }
2314
2315 ret = btrfs_del_item(trans, root, path);
2316 if (ret < 0)
2317 btrfs_error(root->fs_info, ret,
2318 "Failed to delete chunk item.");
2319 out:
2320 btrfs_free_path(path);
2321 return ret;
2322 }
2323
2324 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2325 chunk_offset)
2326 {
2327 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2328 struct btrfs_disk_key *disk_key;
2329 struct btrfs_chunk *chunk;
2330 u8 *ptr;
2331 int ret = 0;
2332 u32 num_stripes;
2333 u32 array_size;
2334 u32 len = 0;
2335 u32 cur;
2336 struct btrfs_key key;
2337
2338 array_size = btrfs_super_sys_array_size(super_copy);
2339
2340 ptr = super_copy->sys_chunk_array;
2341 cur = 0;
2342
2343 while (cur < array_size) {
2344 disk_key = (struct btrfs_disk_key *)ptr;
2345 btrfs_disk_key_to_cpu(&key, disk_key);
2346
2347 len = sizeof(*disk_key);
2348
2349 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2350 chunk = (struct btrfs_chunk *)(ptr + len);
2351 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2352 len += btrfs_chunk_item_size(num_stripes);
2353 } else {
2354 ret = -EIO;
2355 break;
2356 }
2357 if (key.objectid == chunk_objectid &&
2358 key.offset == chunk_offset) {
2359 memmove(ptr, ptr + len, array_size - (cur + len));
2360 array_size -= len;
2361 btrfs_set_super_sys_array_size(super_copy, array_size);
2362 } else {
2363 ptr += len;
2364 cur += len;
2365 }
2366 }
2367 return ret;
2368 }
2369
2370 static int btrfs_relocate_chunk(struct btrfs_root *root,
2371 u64 chunk_tree, u64 chunk_objectid,
2372 u64 chunk_offset)
2373 {
2374 struct extent_map_tree *em_tree;
2375 struct btrfs_root *extent_root;
2376 struct btrfs_trans_handle *trans;
2377 struct extent_map *em;
2378 struct map_lookup *map;
2379 int ret;
2380 int i;
2381
2382 root = root->fs_info->chunk_root;
2383 extent_root = root->fs_info->extent_root;
2384 em_tree = &root->fs_info->mapping_tree.map_tree;
2385
2386 ret = btrfs_can_relocate(extent_root, chunk_offset);
2387 if (ret)
2388 return -ENOSPC;
2389
2390 /* step one, relocate all the extents inside this chunk */
2391 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2392 if (ret)
2393 return ret;
2394
2395 trans = btrfs_start_transaction(root, 0);
2396 if (IS_ERR(trans)) {
2397 ret = PTR_ERR(trans);
2398 btrfs_std_error(root->fs_info, ret);
2399 return ret;
2400 }
2401
2402 lock_chunks(root);
2403
2404 /*
2405 * step two, delete the device extents and the
2406 * chunk tree entries
2407 */
2408 read_lock(&em_tree->lock);
2409 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2410 read_unlock(&em_tree->lock);
2411
2412 BUG_ON(!em || em->start > chunk_offset ||
2413 em->start + em->len < chunk_offset);
2414 map = (struct map_lookup *)em->bdev;
2415
2416 for (i = 0; i < map->num_stripes; i++) {
2417 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2418 map->stripes[i].physical);
2419 BUG_ON(ret);
2420
2421 if (map->stripes[i].dev) {
2422 ret = btrfs_update_device(trans, map->stripes[i].dev);
2423 BUG_ON(ret);
2424 }
2425 }
2426 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2427 chunk_offset);
2428
2429 BUG_ON(ret);
2430
2431 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2432
2433 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2434 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2435 BUG_ON(ret);
2436 }
2437
2438 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2439 BUG_ON(ret);
2440
2441 write_lock(&em_tree->lock);
2442 remove_extent_mapping(em_tree, em);
2443 write_unlock(&em_tree->lock);
2444
2445 kfree(map);
2446 em->bdev = NULL;
2447
2448 /* once for the tree */
2449 free_extent_map(em);
2450 /* once for us */
2451 free_extent_map(em);
2452
2453 unlock_chunks(root);
2454 btrfs_end_transaction(trans, root);
2455 return 0;
2456 }
2457
2458 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2459 {
2460 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2461 struct btrfs_path *path;
2462 struct extent_buffer *leaf;
2463 struct btrfs_chunk *chunk;
2464 struct btrfs_key key;
2465 struct btrfs_key found_key;
2466 u64 chunk_tree = chunk_root->root_key.objectid;
2467 u64 chunk_type;
2468 bool retried = false;
2469 int failed = 0;
2470 int ret;
2471
2472 path = btrfs_alloc_path();
2473 if (!path)
2474 return -ENOMEM;
2475
2476 again:
2477 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2478 key.offset = (u64)-1;
2479 key.type = BTRFS_CHUNK_ITEM_KEY;
2480
2481 while (1) {
2482 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2483 if (ret < 0)
2484 goto error;
2485 BUG_ON(ret == 0); /* Corruption */
2486
2487 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2488 key.type);
2489 if (ret < 0)
2490 goto error;
2491 if (ret > 0)
2492 break;
2493
2494 leaf = path->nodes[0];
2495 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2496
2497 chunk = btrfs_item_ptr(leaf, path->slots[0],
2498 struct btrfs_chunk);
2499 chunk_type = btrfs_chunk_type(leaf, chunk);
2500 btrfs_release_path(path);
2501
2502 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2503 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2504 found_key.objectid,
2505 found_key.offset);
2506 if (ret == -ENOSPC)
2507 failed++;
2508 else if (ret)
2509 BUG();
2510 }
2511
2512 if (found_key.offset == 0)
2513 break;
2514 key.offset = found_key.offset - 1;
2515 }
2516 ret = 0;
2517 if (failed && !retried) {
2518 failed = 0;
2519 retried = true;
2520 goto again;
2521 } else if (failed && retried) {
2522 WARN_ON(1);
2523 ret = -ENOSPC;
2524 }
2525 error:
2526 btrfs_free_path(path);
2527 return ret;
2528 }
2529
2530 static int insert_balance_item(struct btrfs_root *root,
2531 struct btrfs_balance_control *bctl)
2532 {
2533 struct btrfs_trans_handle *trans;
2534 struct btrfs_balance_item *item;
2535 struct btrfs_disk_balance_args disk_bargs;
2536 struct btrfs_path *path;
2537 struct extent_buffer *leaf;
2538 struct btrfs_key key;
2539 int ret, err;
2540
2541 path = btrfs_alloc_path();
2542 if (!path)
2543 return -ENOMEM;
2544
2545 trans = btrfs_start_transaction(root, 0);
2546 if (IS_ERR(trans)) {
2547 btrfs_free_path(path);
2548 return PTR_ERR(trans);
2549 }
2550
2551 key.objectid = BTRFS_BALANCE_OBJECTID;
2552 key.type = BTRFS_BALANCE_ITEM_KEY;
2553 key.offset = 0;
2554
2555 ret = btrfs_insert_empty_item(trans, root, path, &key,
2556 sizeof(*item));
2557 if (ret)
2558 goto out;
2559
2560 leaf = path->nodes[0];
2561 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2562
2563 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2564
2565 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2566 btrfs_set_balance_data(leaf, item, &disk_bargs);
2567 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2568 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2569 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2570 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2571
2572 btrfs_set_balance_flags(leaf, item, bctl->flags);
2573
2574 btrfs_mark_buffer_dirty(leaf);
2575 out:
2576 btrfs_free_path(path);
2577 err = btrfs_commit_transaction(trans, root);
2578 if (err && !ret)
2579 ret = err;
2580 return ret;
2581 }
2582
2583 static int del_balance_item(struct btrfs_root *root)
2584 {
2585 struct btrfs_trans_handle *trans;
2586 struct btrfs_path *path;
2587 struct btrfs_key key;
2588 int ret, err;
2589
2590 path = btrfs_alloc_path();
2591 if (!path)
2592 return -ENOMEM;
2593
2594 trans = btrfs_start_transaction(root, 0);
2595 if (IS_ERR(trans)) {
2596 btrfs_free_path(path);
2597 return PTR_ERR(trans);
2598 }
2599
2600 key.objectid = BTRFS_BALANCE_OBJECTID;
2601 key.type = BTRFS_BALANCE_ITEM_KEY;
2602 key.offset = 0;
2603
2604 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2605 if (ret < 0)
2606 goto out;
2607 if (ret > 0) {
2608 ret = -ENOENT;
2609 goto out;
2610 }
2611
2612 ret = btrfs_del_item(trans, root, path);
2613 out:
2614 btrfs_free_path(path);
2615 err = btrfs_commit_transaction(trans, root);
2616 if (err && !ret)
2617 ret = err;
2618 return ret;
2619 }
2620
2621 /*
2622 * This is a heuristic used to reduce the number of chunks balanced on
2623 * resume after balance was interrupted.
2624 */
2625 static void update_balance_args(struct btrfs_balance_control *bctl)
2626 {
2627 /*
2628 * Turn on soft mode for chunk types that were being converted.
2629 */
2630 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2631 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2632 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2633 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2634 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2635 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2636
2637 /*
2638 * Turn on usage filter if is not already used. The idea is
2639 * that chunks that we have already balanced should be
2640 * reasonably full. Don't do it for chunks that are being
2641 * converted - that will keep us from relocating unconverted
2642 * (albeit full) chunks.
2643 */
2644 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2645 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2646 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2647 bctl->data.usage = 90;
2648 }
2649 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2650 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2651 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2652 bctl->sys.usage = 90;
2653 }
2654 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2655 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2656 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2657 bctl->meta.usage = 90;
2658 }
2659 }
2660
2661 /*
2662 * Should be called with both balance and volume mutexes held to
2663 * serialize other volume operations (add_dev/rm_dev/resize) with
2664 * restriper. Same goes for unset_balance_control.
2665 */
2666 static void set_balance_control(struct btrfs_balance_control *bctl)
2667 {
2668 struct btrfs_fs_info *fs_info = bctl->fs_info;
2669
2670 BUG_ON(fs_info->balance_ctl);
2671
2672 spin_lock(&fs_info->balance_lock);
2673 fs_info->balance_ctl = bctl;
2674 spin_unlock(&fs_info->balance_lock);
2675 }
2676
2677 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2678 {
2679 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2680
2681 BUG_ON(!fs_info->balance_ctl);
2682
2683 spin_lock(&fs_info->balance_lock);
2684 fs_info->balance_ctl = NULL;
2685 spin_unlock(&fs_info->balance_lock);
2686
2687 kfree(bctl);
2688 }
2689
2690 /*
2691 * Balance filters. Return 1 if chunk should be filtered out
2692 * (should not be balanced).
2693 */
2694 static int chunk_profiles_filter(u64 chunk_type,
2695 struct btrfs_balance_args *bargs)
2696 {
2697 chunk_type = chunk_to_extended(chunk_type) &
2698 BTRFS_EXTENDED_PROFILE_MASK;
2699
2700 if (bargs->profiles & chunk_type)
2701 return 0;
2702
2703 return 1;
2704 }
2705
2706 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2707 struct btrfs_balance_args *bargs)
2708 {
2709 struct btrfs_block_group_cache *cache;
2710 u64 chunk_used, user_thresh;
2711 int ret = 1;
2712
2713 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2714 chunk_used = btrfs_block_group_used(&cache->item);
2715
2716 if (bargs->usage == 0)
2717 user_thresh = 1;
2718 else if (bargs->usage > 100)
2719 user_thresh = cache->key.offset;
2720 else
2721 user_thresh = div_factor_fine(cache->key.offset,
2722 bargs->usage);
2723
2724 if (chunk_used < user_thresh)
2725 ret = 0;
2726
2727 btrfs_put_block_group(cache);
2728 return ret;
2729 }
2730
2731 static int chunk_devid_filter(struct extent_buffer *leaf,
2732 struct btrfs_chunk *chunk,
2733 struct btrfs_balance_args *bargs)
2734 {
2735 struct btrfs_stripe *stripe;
2736 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2737 int i;
2738
2739 for (i = 0; i < num_stripes; i++) {
2740 stripe = btrfs_stripe_nr(chunk, i);
2741 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2742 return 0;
2743 }
2744
2745 return 1;
2746 }
2747
2748 /* [pstart, pend) */
2749 static int chunk_drange_filter(struct extent_buffer *leaf,
2750 struct btrfs_chunk *chunk,
2751 u64 chunk_offset,
2752 struct btrfs_balance_args *bargs)
2753 {
2754 struct btrfs_stripe *stripe;
2755 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2756 u64 stripe_offset;
2757 u64 stripe_length;
2758 int factor;
2759 int i;
2760
2761 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2762 return 0;
2763
2764 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2765 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2766 factor = num_stripes / 2;
2767 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2768 factor = num_stripes - 1;
2769 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2770 factor = num_stripes - 2;
2771 } else {
2772 factor = num_stripes;
2773 }
2774
2775 for (i = 0; i < num_stripes; i++) {
2776 stripe = btrfs_stripe_nr(chunk, i);
2777 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2778 continue;
2779
2780 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2781 stripe_length = btrfs_chunk_length(leaf, chunk);
2782 do_div(stripe_length, factor);
2783
2784 if (stripe_offset < bargs->pend &&
2785 stripe_offset + stripe_length > bargs->pstart)
2786 return 0;
2787 }
2788
2789 return 1;
2790 }
2791
2792 /* [vstart, vend) */
2793 static int chunk_vrange_filter(struct extent_buffer *leaf,
2794 struct btrfs_chunk *chunk,
2795 u64 chunk_offset,
2796 struct btrfs_balance_args *bargs)
2797 {
2798 if (chunk_offset < bargs->vend &&
2799 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2800 /* at least part of the chunk is inside this vrange */
2801 return 0;
2802
2803 return 1;
2804 }
2805
2806 static int chunk_soft_convert_filter(u64 chunk_type,
2807 struct btrfs_balance_args *bargs)
2808 {
2809 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2810 return 0;
2811
2812 chunk_type = chunk_to_extended(chunk_type) &
2813 BTRFS_EXTENDED_PROFILE_MASK;
2814
2815 if (bargs->target == chunk_type)
2816 return 1;
2817
2818 return 0;
2819 }
2820
2821 static int should_balance_chunk(struct btrfs_root *root,
2822 struct extent_buffer *leaf,
2823 struct btrfs_chunk *chunk, u64 chunk_offset)
2824 {
2825 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2826 struct btrfs_balance_args *bargs = NULL;
2827 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2828
2829 /* type filter */
2830 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2831 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2832 return 0;
2833 }
2834
2835 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2836 bargs = &bctl->data;
2837 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2838 bargs = &bctl->sys;
2839 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2840 bargs = &bctl->meta;
2841
2842 /* profiles filter */
2843 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2844 chunk_profiles_filter(chunk_type, bargs)) {
2845 return 0;
2846 }
2847
2848 /* usage filter */
2849 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2850 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2851 return 0;
2852 }
2853
2854 /* devid filter */
2855 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2856 chunk_devid_filter(leaf, chunk, bargs)) {
2857 return 0;
2858 }
2859
2860 /* drange filter, makes sense only with devid filter */
2861 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2862 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2863 return 0;
2864 }
2865
2866 /* vrange filter */
2867 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2868 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2869 return 0;
2870 }
2871
2872 /* soft profile changing mode */
2873 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2874 chunk_soft_convert_filter(chunk_type, bargs)) {
2875 return 0;
2876 }
2877
2878 return 1;
2879 }
2880
2881 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2882 {
2883 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2884 struct btrfs_root *chunk_root = fs_info->chunk_root;
2885 struct btrfs_root *dev_root = fs_info->dev_root;
2886 struct list_head *devices;
2887 struct btrfs_device *device;
2888 u64 old_size;
2889 u64 size_to_free;
2890 struct btrfs_chunk *chunk;
2891 struct btrfs_path *path;
2892 struct btrfs_key key;
2893 struct btrfs_key found_key;
2894 struct btrfs_trans_handle *trans;
2895 struct extent_buffer *leaf;
2896 int slot;
2897 int ret;
2898 int enospc_errors = 0;
2899 bool counting = true;
2900
2901 /* step one make some room on all the devices */
2902 devices = &fs_info->fs_devices->devices;
2903 list_for_each_entry(device, devices, dev_list) {
2904 old_size = device->total_bytes;
2905 size_to_free = div_factor(old_size, 1);
2906 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2907 if (!device->writeable ||
2908 device->total_bytes - device->bytes_used > size_to_free ||
2909 device->is_tgtdev_for_dev_replace)
2910 continue;
2911
2912 ret = btrfs_shrink_device(device, old_size - size_to_free);
2913 if (ret == -ENOSPC)
2914 break;
2915 BUG_ON(ret);
2916
2917 trans = btrfs_start_transaction(dev_root, 0);
2918 BUG_ON(IS_ERR(trans));
2919
2920 ret = btrfs_grow_device(trans, device, old_size);
2921 BUG_ON(ret);
2922
2923 btrfs_end_transaction(trans, dev_root);
2924 }
2925
2926 /* step two, relocate all the chunks */
2927 path = btrfs_alloc_path();
2928 if (!path) {
2929 ret = -ENOMEM;
2930 goto error;
2931 }
2932
2933 /* zero out stat counters */
2934 spin_lock(&fs_info->balance_lock);
2935 memset(&bctl->stat, 0, sizeof(bctl->stat));
2936 spin_unlock(&fs_info->balance_lock);
2937 again:
2938 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2939 key.offset = (u64)-1;
2940 key.type = BTRFS_CHUNK_ITEM_KEY;
2941
2942 while (1) {
2943 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2944 atomic_read(&fs_info->balance_cancel_req)) {
2945 ret = -ECANCELED;
2946 goto error;
2947 }
2948
2949 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2950 if (ret < 0)
2951 goto error;
2952
2953 /*
2954 * this shouldn't happen, it means the last relocate
2955 * failed
2956 */
2957 if (ret == 0)
2958 BUG(); /* FIXME break ? */
2959
2960 ret = btrfs_previous_item(chunk_root, path, 0,
2961 BTRFS_CHUNK_ITEM_KEY);
2962 if (ret) {
2963 ret = 0;
2964 break;
2965 }
2966
2967 leaf = path->nodes[0];
2968 slot = path->slots[0];
2969 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2970
2971 if (found_key.objectid != key.objectid)
2972 break;
2973
2974 /* chunk zero is special */
2975 if (found_key.offset == 0)
2976 break;
2977
2978 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2979
2980 if (!counting) {
2981 spin_lock(&fs_info->balance_lock);
2982 bctl->stat.considered++;
2983 spin_unlock(&fs_info->balance_lock);
2984 }
2985
2986 ret = should_balance_chunk(chunk_root, leaf, chunk,
2987 found_key.offset);
2988 btrfs_release_path(path);
2989 if (!ret)
2990 goto loop;
2991
2992 if (counting) {
2993 spin_lock(&fs_info->balance_lock);
2994 bctl->stat.expected++;
2995 spin_unlock(&fs_info->balance_lock);
2996 goto loop;
2997 }
2998
2999 ret = btrfs_relocate_chunk(chunk_root,
3000 chunk_root->root_key.objectid,
3001 found_key.objectid,
3002 found_key.offset);
3003 if (ret && ret != -ENOSPC)
3004 goto error;
3005 if (ret == -ENOSPC) {
3006 enospc_errors++;
3007 } else {
3008 spin_lock(&fs_info->balance_lock);
3009 bctl->stat.completed++;
3010 spin_unlock(&fs_info->balance_lock);
3011 }
3012 loop:
3013 key.offset = found_key.offset - 1;
3014 }
3015
3016 if (counting) {
3017 btrfs_release_path(path);
3018 counting = false;
3019 goto again;
3020 }
3021 error:
3022 btrfs_free_path(path);
3023 if (enospc_errors) {
3024 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
3025 enospc_errors);
3026 if (!ret)
3027 ret = -ENOSPC;
3028 }
3029
3030 return ret;
3031 }
3032
3033 /**
3034 * alloc_profile_is_valid - see if a given profile is valid and reduced
3035 * @flags: profile to validate
3036 * @extended: if true @flags is treated as an extended profile
3037 */
3038 static int alloc_profile_is_valid(u64 flags, int extended)
3039 {
3040 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3041 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3042
3043 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3044
3045 /* 1) check that all other bits are zeroed */
3046 if (flags & ~mask)
3047 return 0;
3048
3049 /* 2) see if profile is reduced */
3050 if (flags == 0)
3051 return !extended; /* "0" is valid for usual profiles */
3052
3053 /* true if exactly one bit set */
3054 return (flags & (flags - 1)) == 0;
3055 }
3056
3057 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3058 {
3059 /* cancel requested || normal exit path */
3060 return atomic_read(&fs_info->balance_cancel_req) ||
3061 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3062 atomic_read(&fs_info->balance_cancel_req) == 0);
3063 }
3064
3065 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3066 {
3067 int ret;
3068
3069 unset_balance_control(fs_info);
3070 ret = del_balance_item(fs_info->tree_root);
3071 if (ret)
3072 btrfs_std_error(fs_info, ret);
3073
3074 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3075 }
3076
3077 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3078 struct btrfs_ioctl_balance_args *bargs);
3079
3080 /*
3081 * Should be called with both balance and volume mutexes held
3082 */
3083 int btrfs_balance(struct btrfs_balance_control *bctl,
3084 struct btrfs_ioctl_balance_args *bargs)
3085 {
3086 struct btrfs_fs_info *fs_info = bctl->fs_info;
3087 u64 allowed;
3088 int mixed = 0;
3089 int ret;
3090 u64 num_devices;
3091 unsigned seq;
3092
3093 if (btrfs_fs_closing(fs_info) ||
3094 atomic_read(&fs_info->balance_pause_req) ||
3095 atomic_read(&fs_info->balance_cancel_req)) {
3096 ret = -EINVAL;
3097 goto out;
3098 }
3099
3100 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3101 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3102 mixed = 1;
3103
3104 /*
3105 * In case of mixed groups both data and meta should be picked,
3106 * and identical options should be given for both of them.
3107 */
3108 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3109 if (mixed && (bctl->flags & allowed)) {
3110 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3111 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3112 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3113 printk(KERN_ERR "btrfs: with mixed groups data and "
3114 "metadata balance options must be the same\n");
3115 ret = -EINVAL;
3116 goto out;
3117 }
3118 }
3119
3120 num_devices = fs_info->fs_devices->num_devices;
3121 btrfs_dev_replace_lock(&fs_info->dev_replace);
3122 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3123 BUG_ON(num_devices < 1);
3124 num_devices--;
3125 }
3126 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3127 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3128 if (num_devices == 1)
3129 allowed |= BTRFS_BLOCK_GROUP_DUP;
3130 else if (num_devices > 1)
3131 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3132 if (num_devices > 2)
3133 allowed |= BTRFS_BLOCK_GROUP_RAID5;
3134 if (num_devices > 3)
3135 allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
3136 BTRFS_BLOCK_GROUP_RAID6);
3137 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3138 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3139 (bctl->data.target & ~allowed))) {
3140 printk(KERN_ERR "btrfs: unable to start balance with target "
3141 "data profile %llu\n",
3142 (unsigned long long)bctl->data.target);
3143 ret = -EINVAL;
3144 goto out;
3145 }
3146 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3147 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3148 (bctl->meta.target & ~allowed))) {
3149 printk(KERN_ERR "btrfs: unable to start balance with target "
3150 "metadata profile %llu\n",
3151 (unsigned long long)bctl->meta.target);
3152 ret = -EINVAL;
3153 goto out;
3154 }
3155 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3156 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3157 (bctl->sys.target & ~allowed))) {
3158 printk(KERN_ERR "btrfs: unable to start balance with target "
3159 "system profile %llu\n",
3160 (unsigned long long)bctl->sys.target);
3161 ret = -EINVAL;
3162 goto out;
3163 }
3164
3165 /* allow dup'ed data chunks only in mixed mode */
3166 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3167 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3168 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3169 ret = -EINVAL;
3170 goto out;
3171 }
3172
3173 /* allow to reduce meta or sys integrity only if force set */
3174 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3175 BTRFS_BLOCK_GROUP_RAID10 |
3176 BTRFS_BLOCK_GROUP_RAID5 |
3177 BTRFS_BLOCK_GROUP_RAID6;
3178 do {
3179 seq = read_seqbegin(&fs_info->profiles_lock);
3180
3181 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3182 (fs_info->avail_system_alloc_bits & allowed) &&
3183 !(bctl->sys.target & allowed)) ||
3184 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3185 (fs_info->avail_metadata_alloc_bits & allowed) &&
3186 !(bctl->meta.target & allowed))) {
3187 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3188 printk(KERN_INFO "btrfs: force reducing metadata "
3189 "integrity\n");
3190 } else {
3191 printk(KERN_ERR "btrfs: balance will reduce metadata "
3192 "integrity, use force if you want this\n");
3193 ret = -EINVAL;
3194 goto out;
3195 }
3196 }
3197 } while (read_seqretry(&fs_info->profiles_lock, seq));
3198
3199 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3200 int num_tolerated_disk_barrier_failures;
3201 u64 target = bctl->sys.target;
3202
3203 num_tolerated_disk_barrier_failures =
3204 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3205 if (num_tolerated_disk_barrier_failures > 0 &&
3206 (target &
3207 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3208 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3209 num_tolerated_disk_barrier_failures = 0;
3210 else if (num_tolerated_disk_barrier_failures > 1 &&
3211 (target &
3212 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3213 num_tolerated_disk_barrier_failures = 1;
3214
3215 fs_info->num_tolerated_disk_barrier_failures =
3216 num_tolerated_disk_barrier_failures;
3217 }
3218
3219 ret = insert_balance_item(fs_info->tree_root, bctl);
3220 if (ret && ret != -EEXIST)
3221 goto out;
3222
3223 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3224 BUG_ON(ret == -EEXIST);
3225 set_balance_control(bctl);
3226 } else {
3227 BUG_ON(ret != -EEXIST);
3228 spin_lock(&fs_info->balance_lock);
3229 update_balance_args(bctl);
3230 spin_unlock(&fs_info->balance_lock);
3231 }
3232
3233 atomic_inc(&fs_info->balance_running);
3234 mutex_unlock(&fs_info->balance_mutex);
3235
3236 ret = __btrfs_balance(fs_info);
3237
3238 mutex_lock(&fs_info->balance_mutex);
3239 atomic_dec(&fs_info->balance_running);
3240
3241 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3242 fs_info->num_tolerated_disk_barrier_failures =
3243 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3244 }
3245
3246 if (bargs) {
3247 memset(bargs, 0, sizeof(*bargs));
3248 update_ioctl_balance_args(fs_info, 0, bargs);
3249 }
3250
3251 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3252 balance_need_close(fs_info)) {
3253 __cancel_balance(fs_info);
3254 }
3255
3256 wake_up(&fs_info->balance_wait_q);
3257
3258 return ret;
3259 out:
3260 if (bctl->flags & BTRFS_BALANCE_RESUME)
3261 __cancel_balance(fs_info);
3262 else {
3263 kfree(bctl);
3264 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3265 }
3266 return ret;
3267 }
3268
3269 static int balance_kthread(void *data)
3270 {
3271 struct btrfs_fs_info *fs_info = data;
3272 int ret = 0;
3273
3274 mutex_lock(&fs_info->volume_mutex);
3275 mutex_lock(&fs_info->balance_mutex);
3276
3277 if (fs_info->balance_ctl) {
3278 printk(KERN_INFO "btrfs: continuing balance\n");
3279 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3280 }
3281
3282 mutex_unlock(&fs_info->balance_mutex);
3283 mutex_unlock(&fs_info->volume_mutex);
3284
3285 return ret;
3286 }
3287
3288 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3289 {
3290 struct task_struct *tsk;
3291
3292 spin_lock(&fs_info->balance_lock);
3293 if (!fs_info->balance_ctl) {
3294 spin_unlock(&fs_info->balance_lock);
3295 return 0;
3296 }
3297 spin_unlock(&fs_info->balance_lock);
3298
3299 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3300 printk(KERN_INFO "btrfs: force skipping balance\n");
3301 return 0;
3302 }
3303
3304 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3305 return PTR_RET(tsk);
3306 }
3307
3308 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3309 {
3310 struct btrfs_balance_control *bctl;
3311 struct btrfs_balance_item *item;
3312 struct btrfs_disk_balance_args disk_bargs;
3313 struct btrfs_path *path;
3314 struct extent_buffer *leaf;
3315 struct btrfs_key key;
3316 int ret;
3317
3318 path = btrfs_alloc_path();
3319 if (!path)
3320 return -ENOMEM;
3321
3322 key.objectid = BTRFS_BALANCE_OBJECTID;
3323 key.type = BTRFS_BALANCE_ITEM_KEY;
3324 key.offset = 0;
3325
3326 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3327 if (ret < 0)
3328 goto out;
3329 if (ret > 0) { /* ret = -ENOENT; */
3330 ret = 0;
3331 goto out;
3332 }
3333
3334 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3335 if (!bctl) {
3336 ret = -ENOMEM;
3337 goto out;
3338 }
3339
3340 leaf = path->nodes[0];
3341 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3342
3343 bctl->fs_info = fs_info;
3344 bctl->flags = btrfs_balance_flags(leaf, item);
3345 bctl->flags |= BTRFS_BALANCE_RESUME;
3346
3347 btrfs_balance_data(leaf, item, &disk_bargs);
3348 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3349 btrfs_balance_meta(leaf, item, &disk_bargs);
3350 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3351 btrfs_balance_sys(leaf, item, &disk_bargs);
3352 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3353
3354 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3355
3356 mutex_lock(&fs_info->volume_mutex);
3357 mutex_lock(&fs_info->balance_mutex);
3358
3359 set_balance_control(bctl);
3360
3361 mutex_unlock(&fs_info->balance_mutex);
3362 mutex_unlock(&fs_info->volume_mutex);
3363 out:
3364 btrfs_free_path(path);
3365 return ret;
3366 }
3367
3368 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3369 {
3370 int ret = 0;
3371
3372 mutex_lock(&fs_info->balance_mutex);
3373 if (!fs_info->balance_ctl) {
3374 mutex_unlock(&fs_info->balance_mutex);
3375 return -ENOTCONN;
3376 }
3377
3378 if (atomic_read(&fs_info->balance_running)) {
3379 atomic_inc(&fs_info->balance_pause_req);
3380 mutex_unlock(&fs_info->balance_mutex);
3381
3382 wait_event(fs_info->balance_wait_q,
3383 atomic_read(&fs_info->balance_running) == 0);
3384
3385 mutex_lock(&fs_info->balance_mutex);
3386 /* we are good with balance_ctl ripped off from under us */
3387 BUG_ON(atomic_read(&fs_info->balance_running));
3388 atomic_dec(&fs_info->balance_pause_req);
3389 } else {
3390 ret = -ENOTCONN;
3391 }
3392
3393 mutex_unlock(&fs_info->balance_mutex);
3394 return ret;
3395 }
3396
3397 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3398 {
3399 mutex_lock(&fs_info->balance_mutex);
3400 if (!fs_info->balance_ctl) {
3401 mutex_unlock(&fs_info->balance_mutex);
3402 return -ENOTCONN;
3403 }
3404
3405 atomic_inc(&fs_info->balance_cancel_req);
3406 /*
3407 * if we are running just wait and return, balance item is
3408 * deleted in btrfs_balance in this case
3409 */
3410 if (atomic_read(&fs_info->balance_running)) {
3411 mutex_unlock(&fs_info->balance_mutex);
3412 wait_event(fs_info->balance_wait_q,
3413 atomic_read(&fs_info->balance_running) == 0);
3414 mutex_lock(&fs_info->balance_mutex);
3415 } else {
3416 /* __cancel_balance needs volume_mutex */
3417 mutex_unlock(&fs_info->balance_mutex);
3418 mutex_lock(&fs_info->volume_mutex);
3419 mutex_lock(&fs_info->balance_mutex);
3420
3421 if (fs_info->balance_ctl)
3422 __cancel_balance(fs_info);
3423
3424 mutex_unlock(&fs_info->volume_mutex);
3425 }
3426
3427 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3428 atomic_dec(&fs_info->balance_cancel_req);
3429 mutex_unlock(&fs_info->balance_mutex);
3430 return 0;
3431 }
3432
3433 /*
3434 * shrinking a device means finding all of the device extents past
3435 * the new size, and then following the back refs to the chunks.
3436 * The chunk relocation code actually frees the device extent
3437 */
3438 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3439 {
3440 struct btrfs_trans_handle *trans;
3441 struct btrfs_root *root = device->dev_root;
3442 struct btrfs_dev_extent *dev_extent = NULL;
3443 struct btrfs_path *path;
3444 u64 length;
3445 u64 chunk_tree;
3446 u64 chunk_objectid;
3447 u64 chunk_offset;
3448 int ret;
3449 int slot;
3450 int failed = 0;
3451 bool retried = false;
3452 struct extent_buffer *l;
3453 struct btrfs_key key;
3454 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3455 u64 old_total = btrfs_super_total_bytes(super_copy);
3456 u64 old_size = device->total_bytes;
3457 u64 diff = device->total_bytes - new_size;
3458
3459 if (device->is_tgtdev_for_dev_replace)
3460 return -EINVAL;
3461
3462 path = btrfs_alloc_path();
3463 if (!path)
3464 return -ENOMEM;
3465
3466 path->reada = 2;
3467
3468 lock_chunks(root);
3469
3470 device->total_bytes = new_size;
3471 if (device->writeable) {
3472 device->fs_devices->total_rw_bytes -= diff;
3473 spin_lock(&root->fs_info->free_chunk_lock);
3474 root->fs_info->free_chunk_space -= diff;
3475 spin_unlock(&root->fs_info->free_chunk_lock);
3476 }
3477 unlock_chunks(root);
3478
3479 again:
3480 key.objectid = device->devid;
3481 key.offset = (u64)-1;
3482 key.type = BTRFS_DEV_EXTENT_KEY;
3483
3484 do {
3485 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3486 if (ret < 0)
3487 goto done;
3488
3489 ret = btrfs_previous_item(root, path, 0, key.type);
3490 if (ret < 0)
3491 goto done;
3492 if (ret) {
3493 ret = 0;
3494 btrfs_release_path(path);
3495 break;
3496 }
3497
3498 l = path->nodes[0];
3499 slot = path->slots[0];
3500 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3501
3502 if (key.objectid != device->devid) {
3503 btrfs_release_path(path);
3504 break;
3505 }
3506
3507 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3508 length = btrfs_dev_extent_length(l, dev_extent);
3509
3510 if (key.offset + length <= new_size) {
3511 btrfs_release_path(path);
3512 break;
3513 }
3514
3515 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3516 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3517 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3518 btrfs_release_path(path);
3519
3520 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3521 chunk_offset);
3522 if (ret && ret != -ENOSPC)
3523 goto done;
3524 if (ret == -ENOSPC)
3525 failed++;
3526 } while (key.offset-- > 0);
3527
3528 if (failed && !retried) {
3529 failed = 0;
3530 retried = true;
3531 goto again;
3532 } else if (failed && retried) {
3533 ret = -ENOSPC;
3534 lock_chunks(root);
3535
3536 device->total_bytes = old_size;
3537 if (device->writeable)
3538 device->fs_devices->total_rw_bytes += diff;
3539 spin_lock(&root->fs_info->free_chunk_lock);
3540 root->fs_info->free_chunk_space += diff;
3541 spin_unlock(&root->fs_info->free_chunk_lock);
3542 unlock_chunks(root);
3543 goto done;
3544 }
3545
3546 /* Shrinking succeeded, else we would be at "done". */
3547 trans = btrfs_start_transaction(root, 0);
3548 if (IS_ERR(trans)) {
3549 ret = PTR_ERR(trans);
3550 goto done;
3551 }
3552
3553 lock_chunks(root);
3554
3555 device->disk_total_bytes = new_size;
3556 /* Now btrfs_update_device() will change the on-disk size. */
3557 ret = btrfs_update_device(trans, device);
3558 if (ret) {
3559 unlock_chunks(root);
3560 btrfs_end_transaction(trans, root);
3561 goto done;
3562 }
3563 WARN_ON(diff > old_total);
3564 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3565 unlock_chunks(root);
3566 btrfs_end_transaction(trans, root);
3567 done:
3568 btrfs_free_path(path);
3569 return ret;
3570 }
3571
3572 static int btrfs_add_system_chunk(struct btrfs_root *root,
3573 struct btrfs_key *key,
3574 struct btrfs_chunk *chunk, int item_size)
3575 {
3576 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3577 struct btrfs_disk_key disk_key;
3578 u32 array_size;
3579 u8 *ptr;
3580
3581 array_size = btrfs_super_sys_array_size(super_copy);
3582 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3583 return -EFBIG;
3584
3585 ptr = super_copy->sys_chunk_array + array_size;
3586 btrfs_cpu_key_to_disk(&disk_key, key);
3587 memcpy(ptr, &disk_key, sizeof(disk_key));
3588 ptr += sizeof(disk_key);
3589 memcpy(ptr, chunk, item_size);
3590 item_size += sizeof(disk_key);
3591 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3592 return 0;
3593 }
3594
3595 /*
3596 * sort the devices in descending order by max_avail, total_avail
3597 */
3598 static int btrfs_cmp_device_info(const void *a, const void *b)
3599 {
3600 const struct btrfs_device_info *di_a = a;
3601 const struct btrfs_device_info *di_b = b;
3602
3603 if (di_a->max_avail > di_b->max_avail)
3604 return -1;
3605 if (di_a->max_avail < di_b->max_avail)
3606 return 1;
3607 if (di_a->total_avail > di_b->total_avail)
3608 return -1;
3609 if (di_a->total_avail < di_b->total_avail)
3610 return 1;
3611 return 0;
3612 }
3613
3614 static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3615 [BTRFS_RAID_RAID10] = {
3616 .sub_stripes = 2,
3617 .dev_stripes = 1,
3618 .devs_max = 0, /* 0 == as many as possible */
3619 .devs_min = 4,
3620 .devs_increment = 2,
3621 .ncopies = 2,
3622 },
3623 [BTRFS_RAID_RAID1] = {
3624 .sub_stripes = 1,
3625 .dev_stripes = 1,
3626 .devs_max = 2,
3627 .devs_min = 2,
3628 .devs_increment = 2,
3629 .ncopies = 2,
3630 },
3631 [BTRFS_RAID_DUP] = {
3632 .sub_stripes = 1,
3633 .dev_stripes = 2,
3634 .devs_max = 1,
3635 .devs_min = 1,
3636 .devs_increment = 1,
3637 .ncopies = 2,
3638 },
3639 [BTRFS_RAID_RAID0] = {
3640 .sub_stripes = 1,
3641 .dev_stripes = 1,
3642 .devs_max = 0,
3643 .devs_min = 2,
3644 .devs_increment = 1,
3645 .ncopies = 1,
3646 },
3647 [BTRFS_RAID_SINGLE] = {
3648 .sub_stripes = 1,
3649 .dev_stripes = 1,
3650 .devs_max = 1,
3651 .devs_min = 1,
3652 .devs_increment = 1,
3653 .ncopies = 1,
3654 },
3655 [BTRFS_RAID_RAID5] = {
3656 .sub_stripes = 1,
3657 .dev_stripes = 1,
3658 .devs_max = 0,
3659 .devs_min = 2,
3660 .devs_increment = 1,
3661 .ncopies = 2,
3662 },
3663 [BTRFS_RAID_RAID6] = {
3664 .sub_stripes = 1,
3665 .dev_stripes = 1,
3666 .devs_max = 0,
3667 .devs_min = 3,
3668 .devs_increment = 1,
3669 .ncopies = 3,
3670 },
3671 };
3672
3673 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3674 {
3675 /* TODO allow them to set a preferred stripe size */
3676 return 64 * 1024;
3677 }
3678
3679 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3680 {
3681 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3682 return;
3683
3684 btrfs_set_fs_incompat(info, RAID56);
3685 }
3686
3687 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3688 struct btrfs_root *extent_root, u64 start,
3689 u64 type)
3690 {
3691 struct btrfs_fs_info *info = extent_root->fs_info;
3692 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3693 struct list_head *cur;
3694 struct map_lookup *map = NULL;
3695 struct extent_map_tree *em_tree;
3696 struct extent_map *em;
3697 struct btrfs_device_info *devices_info = NULL;
3698 u64 total_avail;
3699 int num_stripes; /* total number of stripes to allocate */
3700 int data_stripes; /* number of stripes that count for
3701 block group size */
3702 int sub_stripes; /* sub_stripes info for map */
3703 int dev_stripes; /* stripes per dev */
3704 int devs_max; /* max devs to use */
3705 int devs_min; /* min devs needed */
3706 int devs_increment; /* ndevs has to be a multiple of this */
3707 int ncopies; /* how many copies to data has */
3708 int ret;
3709 u64 max_stripe_size;
3710 u64 max_chunk_size;
3711 u64 stripe_size;
3712 u64 num_bytes;
3713 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
3714 int ndevs;
3715 int i;
3716 int j;
3717 int index;
3718
3719 BUG_ON(!alloc_profile_is_valid(type, 0));
3720
3721 if (list_empty(&fs_devices->alloc_list))
3722 return -ENOSPC;
3723
3724 index = __get_raid_index(type);
3725
3726 sub_stripes = btrfs_raid_array[index].sub_stripes;
3727 dev_stripes = btrfs_raid_array[index].dev_stripes;
3728 devs_max = btrfs_raid_array[index].devs_max;
3729 devs_min = btrfs_raid_array[index].devs_min;
3730 devs_increment = btrfs_raid_array[index].devs_increment;
3731 ncopies = btrfs_raid_array[index].ncopies;
3732
3733 if (type & BTRFS_BLOCK_GROUP_DATA) {
3734 max_stripe_size = 1024 * 1024 * 1024;
3735 max_chunk_size = 10 * max_stripe_size;
3736 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3737 /* for larger filesystems, use larger metadata chunks */
3738 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3739 max_stripe_size = 1024 * 1024 * 1024;
3740 else
3741 max_stripe_size = 256 * 1024 * 1024;
3742 max_chunk_size = max_stripe_size;
3743 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3744 max_stripe_size = 32 * 1024 * 1024;
3745 max_chunk_size = 2 * max_stripe_size;
3746 } else {
3747 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3748 type);
3749 BUG_ON(1);
3750 }
3751
3752 /* we don't want a chunk larger than 10% of writeable space */
3753 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3754 max_chunk_size);
3755
3756 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3757 GFP_NOFS);
3758 if (!devices_info)
3759 return -ENOMEM;
3760
3761 cur = fs_devices->alloc_list.next;
3762
3763 /*
3764 * in the first pass through the devices list, we gather information
3765 * about the available holes on each device.
3766 */
3767 ndevs = 0;
3768 while (cur != &fs_devices->alloc_list) {
3769 struct btrfs_device *device;
3770 u64 max_avail;
3771 u64 dev_offset;
3772
3773 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3774
3775 cur = cur->next;
3776
3777 if (!device->writeable) {
3778 WARN(1, KERN_ERR
3779 "btrfs: read-only device in alloc_list\n");
3780 continue;
3781 }
3782
3783 if (!device->in_fs_metadata ||
3784 device->is_tgtdev_for_dev_replace)
3785 continue;
3786
3787 if (device->total_bytes > device->bytes_used)
3788 total_avail = device->total_bytes - device->bytes_used;
3789 else
3790 total_avail = 0;
3791
3792 /* If there is no space on this device, skip it. */
3793 if (total_avail == 0)
3794 continue;
3795
3796 ret = find_free_dev_extent(trans, device,
3797 max_stripe_size * dev_stripes,
3798 &dev_offset, &max_avail);
3799 if (ret && ret != -ENOSPC)
3800 goto error;
3801
3802 if (ret == 0)
3803 max_avail = max_stripe_size * dev_stripes;
3804
3805 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3806 continue;
3807
3808 if (ndevs == fs_devices->rw_devices) {
3809 WARN(1, "%s: found more than %llu devices\n",
3810 __func__, fs_devices->rw_devices);
3811 break;
3812 }
3813 devices_info[ndevs].dev_offset = dev_offset;
3814 devices_info[ndevs].max_avail = max_avail;
3815 devices_info[ndevs].total_avail = total_avail;
3816 devices_info[ndevs].dev = device;
3817 ++ndevs;
3818 }
3819
3820 /*
3821 * now sort the devices by hole size / available space
3822 */
3823 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3824 btrfs_cmp_device_info, NULL);
3825
3826 /* round down to number of usable stripes */
3827 ndevs -= ndevs % devs_increment;
3828
3829 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3830 ret = -ENOSPC;
3831 goto error;
3832 }
3833
3834 if (devs_max && ndevs > devs_max)
3835 ndevs = devs_max;
3836 /*
3837 * the primary goal is to maximize the number of stripes, so use as many
3838 * devices as possible, even if the stripes are not maximum sized.
3839 */
3840 stripe_size = devices_info[ndevs-1].max_avail;
3841 num_stripes = ndevs * dev_stripes;
3842
3843 /*
3844 * this will have to be fixed for RAID1 and RAID10 over
3845 * more drives
3846 */
3847 data_stripes = num_stripes / ncopies;
3848
3849 if (type & BTRFS_BLOCK_GROUP_RAID5) {
3850 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
3851 btrfs_super_stripesize(info->super_copy));
3852 data_stripes = num_stripes - 1;
3853 }
3854 if (type & BTRFS_BLOCK_GROUP_RAID6) {
3855 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
3856 btrfs_super_stripesize(info->super_copy));
3857 data_stripes = num_stripes - 2;
3858 }
3859
3860 /*
3861 * Use the number of data stripes to figure out how big this chunk
3862 * is really going to be in terms of logical address space,
3863 * and compare that answer with the max chunk size
3864 */
3865 if (stripe_size * data_stripes > max_chunk_size) {
3866 u64 mask = (1ULL << 24) - 1;
3867 stripe_size = max_chunk_size;
3868 do_div(stripe_size, data_stripes);
3869
3870 /* bump the answer up to a 16MB boundary */
3871 stripe_size = (stripe_size + mask) & ~mask;
3872
3873 /* but don't go higher than the limits we found
3874 * while searching for free extents
3875 */
3876 if (stripe_size > devices_info[ndevs-1].max_avail)
3877 stripe_size = devices_info[ndevs-1].max_avail;
3878 }
3879
3880 do_div(stripe_size, dev_stripes);
3881
3882 /* align to BTRFS_STRIPE_LEN */
3883 do_div(stripe_size, raid_stripe_len);
3884 stripe_size *= raid_stripe_len;
3885
3886 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3887 if (!map) {
3888 ret = -ENOMEM;
3889 goto error;
3890 }
3891 map->num_stripes = num_stripes;
3892
3893 for (i = 0; i < ndevs; ++i) {
3894 for (j = 0; j < dev_stripes; ++j) {
3895 int s = i * dev_stripes + j;
3896 map->stripes[s].dev = devices_info[i].dev;
3897 map->stripes[s].physical = devices_info[i].dev_offset +
3898 j * stripe_size;
3899 }
3900 }
3901 map->sector_size = extent_root->sectorsize;
3902 map->stripe_len = raid_stripe_len;
3903 map->io_align = raid_stripe_len;
3904 map->io_width = raid_stripe_len;
3905 map->type = type;
3906 map->sub_stripes = sub_stripes;
3907
3908 num_bytes = stripe_size * data_stripes;
3909
3910 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3911
3912 em = alloc_extent_map();
3913 if (!em) {
3914 ret = -ENOMEM;
3915 goto error;
3916 }
3917 em->bdev = (struct block_device *)map;
3918 em->start = start;
3919 em->len = num_bytes;
3920 em->block_start = 0;
3921 em->block_len = em->len;
3922 em->orig_block_len = stripe_size;
3923
3924 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3925 write_lock(&em_tree->lock);
3926 ret = add_extent_mapping(em_tree, em, 0);
3927 if (!ret) {
3928 list_add_tail(&em->list, &trans->transaction->pending_chunks);
3929 atomic_inc(&em->refs);
3930 }
3931 write_unlock(&em_tree->lock);
3932 if (ret) {
3933 free_extent_map(em);
3934 goto error;
3935 }
3936
3937 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3938 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3939 start, num_bytes);
3940 if (ret)
3941 goto error_del_extent;
3942
3943 free_extent_map(em);
3944 check_raid56_incompat_flag(extent_root->fs_info, type);
3945
3946 kfree(devices_info);
3947 return 0;
3948
3949 error_del_extent:
3950 write_lock(&em_tree->lock);
3951 remove_extent_mapping(em_tree, em);
3952 write_unlock(&em_tree->lock);
3953
3954 /* One for our allocation */
3955 free_extent_map(em);
3956 /* One for the tree reference */
3957 free_extent_map(em);
3958 error:
3959 kfree(map);
3960 kfree(devices_info);
3961 return ret;
3962 }
3963
3964 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
3965 struct btrfs_root *extent_root,
3966 u64 chunk_offset, u64 chunk_size)
3967 {
3968 struct btrfs_key key;
3969 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3970 struct btrfs_device *device;
3971 struct btrfs_chunk *chunk;
3972 struct btrfs_stripe *stripe;
3973 struct extent_map_tree *em_tree;
3974 struct extent_map *em;
3975 struct map_lookup *map;
3976 size_t item_size;
3977 u64 dev_offset;
3978 u64 stripe_size;
3979 int i = 0;
3980 int ret;
3981
3982 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3983 read_lock(&em_tree->lock);
3984 em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
3985 read_unlock(&em_tree->lock);
3986
3987 if (!em) {
3988 btrfs_crit(extent_root->fs_info, "unable to find logical "
3989 "%Lu len %Lu", chunk_offset, chunk_size);
3990 return -EINVAL;
3991 }
3992
3993 if (em->start != chunk_offset || em->len != chunk_size) {
3994 btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
3995 " %Lu-%Lu, found %Lu-%Lu\n", chunk_offset,
3996 chunk_size, em->start, em->len);
3997 free_extent_map(em);
3998 return -EINVAL;
3999 }
4000
4001 map = (struct map_lookup *)em->bdev;
4002 item_size = btrfs_chunk_item_size(map->num_stripes);
4003 stripe_size = em->orig_block_len;
4004
4005 chunk = kzalloc(item_size, GFP_NOFS);
4006 if (!chunk) {
4007 ret = -ENOMEM;
4008 goto out;
4009 }
4010
4011 for (i = 0; i < map->num_stripes; i++) {
4012 device = map->stripes[i].dev;
4013 dev_offset = map->stripes[i].physical;
4014
4015 device->bytes_used += stripe_size;
4016 ret = btrfs_update_device(trans, device);
4017 if (ret)
4018 goto out;
4019 ret = btrfs_alloc_dev_extent(trans, device,
4020 chunk_root->root_key.objectid,
4021 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4022 chunk_offset, dev_offset,
4023 stripe_size);
4024 if (ret)
4025 goto out;
4026 }
4027
4028 spin_lock(&extent_root->fs_info->free_chunk_lock);
4029 extent_root->fs_info->free_chunk_space -= (stripe_size *
4030 map->num_stripes);
4031 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4032
4033 stripe = &chunk->stripe;
4034 for (i = 0; i < map->num_stripes; i++) {
4035 device = map->stripes[i].dev;
4036 dev_offset = map->stripes[i].physical;
4037
4038 btrfs_set_stack_stripe_devid(stripe, device->devid);
4039 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4040 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4041 stripe++;
4042 }
4043
4044 btrfs_set_stack_chunk_length(chunk, chunk_size);
4045 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4046 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4047 btrfs_set_stack_chunk_type(chunk, map->type);
4048 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4049 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4050 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4051 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4052 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4053
4054 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4055 key.type = BTRFS_CHUNK_ITEM_KEY;
4056 key.offset = chunk_offset;
4057
4058 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4059 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4060 /*
4061 * TODO: Cleanup of inserted chunk root in case of
4062 * failure.
4063 */
4064 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4065 item_size);
4066 }
4067
4068 out:
4069 kfree(chunk);
4070 free_extent_map(em);
4071 return ret;
4072 }
4073
4074 /*
4075 * Chunk allocation falls into two parts. The first part does works
4076 * that make the new allocated chunk useable, but not do any operation
4077 * that modifies the chunk tree. The second part does the works that
4078 * require modifying the chunk tree. This division is important for the
4079 * bootstrap process of adding storage to a seed btrfs.
4080 */
4081 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4082 struct btrfs_root *extent_root, u64 type)
4083 {
4084 u64 chunk_offset;
4085
4086 chunk_offset = find_next_chunk(extent_root->fs_info);
4087 return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
4088 }
4089
4090 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4091 struct btrfs_root *root,
4092 struct btrfs_device *device)
4093 {
4094 u64 chunk_offset;
4095 u64 sys_chunk_offset;
4096 u64 alloc_profile;
4097 struct btrfs_fs_info *fs_info = root->fs_info;
4098 struct btrfs_root *extent_root = fs_info->extent_root;
4099 int ret;
4100
4101 chunk_offset = find_next_chunk(fs_info);
4102 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4103 ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
4104 alloc_profile);
4105 if (ret)
4106 return ret;
4107
4108 sys_chunk_offset = find_next_chunk(root->fs_info);
4109 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4110 ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
4111 alloc_profile);
4112 if (ret) {
4113 btrfs_abort_transaction(trans, root, ret);
4114 goto out;
4115 }
4116
4117 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4118 if (ret)
4119 btrfs_abort_transaction(trans, root, ret);
4120 out:
4121 return ret;
4122 }
4123
4124 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4125 {
4126 struct extent_map *em;
4127 struct map_lookup *map;
4128 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4129 int readonly = 0;
4130 int i;
4131
4132 read_lock(&map_tree->map_tree.lock);
4133 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4134 read_unlock(&map_tree->map_tree.lock);
4135 if (!em)
4136 return 1;
4137
4138 if (btrfs_test_opt(root, DEGRADED)) {
4139 free_extent_map(em);
4140 return 0;
4141 }
4142
4143 map = (struct map_lookup *)em->bdev;
4144 for (i = 0; i < map->num_stripes; i++) {
4145 if (!map->stripes[i].dev->writeable) {
4146 readonly = 1;
4147 break;
4148 }
4149 }
4150 free_extent_map(em);
4151 return readonly;
4152 }
4153
4154 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4155 {
4156 extent_map_tree_init(&tree->map_tree);
4157 }
4158
4159 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4160 {
4161 struct extent_map *em;
4162
4163 while (1) {
4164 write_lock(&tree->map_tree.lock);
4165 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4166 if (em)
4167 remove_extent_mapping(&tree->map_tree, em);
4168 write_unlock(&tree->map_tree.lock);
4169 if (!em)
4170 break;
4171 kfree(em->bdev);
4172 /* once for us */
4173 free_extent_map(em);
4174 /* once for the tree */
4175 free_extent_map(em);
4176 }
4177 }
4178
4179 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4180 {
4181 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4182 struct extent_map *em;
4183 struct map_lookup *map;
4184 struct extent_map_tree *em_tree = &map_tree->map_tree;
4185 int ret;
4186
4187 read_lock(&em_tree->lock);
4188 em = lookup_extent_mapping(em_tree, logical, len);
4189 read_unlock(&em_tree->lock);
4190
4191 /*
4192 * We could return errors for these cases, but that could get ugly and
4193 * we'd probably do the same thing which is just not do anything else
4194 * and exit, so return 1 so the callers don't try to use other copies.
4195 */
4196 if (!em) {
4197 btrfs_emerg(fs_info, "No mapping for %Lu-%Lu\n", logical,
4198 logical+len);
4199 return 1;
4200 }
4201
4202 if (em->start > logical || em->start + em->len < logical) {
4203 btrfs_emerg(fs_info, "Invalid mapping for %Lu-%Lu, got "
4204 "%Lu-%Lu\n", logical, logical+len, em->start,
4205 em->start + em->len);
4206 return 1;
4207 }
4208
4209 map = (struct map_lookup *)em->bdev;
4210 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4211 ret = map->num_stripes;
4212 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4213 ret = map->sub_stripes;
4214 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4215 ret = 2;
4216 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4217 ret = 3;
4218 else
4219 ret = 1;
4220 free_extent_map(em);
4221
4222 btrfs_dev_replace_lock(&fs_info->dev_replace);
4223 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4224 ret++;
4225 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4226
4227 return ret;
4228 }
4229
4230 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4231 struct btrfs_mapping_tree *map_tree,
4232 u64 logical)
4233 {
4234 struct extent_map *em;
4235 struct map_lookup *map;
4236 struct extent_map_tree *em_tree = &map_tree->map_tree;
4237 unsigned long len = root->sectorsize;
4238
4239 read_lock(&em_tree->lock);
4240 em = lookup_extent_mapping(em_tree, logical, len);
4241 read_unlock(&em_tree->lock);
4242 BUG_ON(!em);
4243
4244 BUG_ON(em->start > logical || em->start + em->len < logical);
4245 map = (struct map_lookup *)em->bdev;
4246 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4247 BTRFS_BLOCK_GROUP_RAID6)) {
4248 len = map->stripe_len * nr_data_stripes(map);
4249 }
4250 free_extent_map(em);
4251 return len;
4252 }
4253
4254 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4255 u64 logical, u64 len, int mirror_num)
4256 {
4257 struct extent_map *em;
4258 struct map_lookup *map;
4259 struct extent_map_tree *em_tree = &map_tree->map_tree;
4260 int ret = 0;
4261
4262 read_lock(&em_tree->lock);
4263 em = lookup_extent_mapping(em_tree, logical, len);
4264 read_unlock(&em_tree->lock);
4265 BUG_ON(!em);
4266
4267 BUG_ON(em->start > logical || em->start + em->len < logical);
4268 map = (struct map_lookup *)em->bdev;
4269 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4270 BTRFS_BLOCK_GROUP_RAID6))
4271 ret = 1;
4272 free_extent_map(em);
4273 return ret;
4274 }
4275
4276 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4277 struct map_lookup *map, int first, int num,
4278 int optimal, int dev_replace_is_ongoing)
4279 {
4280 int i;
4281 int tolerance;
4282 struct btrfs_device *srcdev;
4283
4284 if (dev_replace_is_ongoing &&
4285 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4286 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4287 srcdev = fs_info->dev_replace.srcdev;
4288 else
4289 srcdev = NULL;
4290
4291 /*
4292 * try to avoid the drive that is the source drive for a
4293 * dev-replace procedure, only choose it if no other non-missing
4294 * mirror is available
4295 */
4296 for (tolerance = 0; tolerance < 2; tolerance++) {
4297 if (map->stripes[optimal].dev->bdev &&
4298 (tolerance || map->stripes[optimal].dev != srcdev))
4299 return optimal;
4300 for (i = first; i < first + num; i++) {
4301 if (map->stripes[i].dev->bdev &&
4302 (tolerance || map->stripes[i].dev != srcdev))
4303 return i;
4304 }
4305 }
4306
4307 /* we couldn't find one that doesn't fail. Just return something
4308 * and the io error handling code will clean up eventually
4309 */
4310 return optimal;
4311 }
4312
4313 static inline int parity_smaller(u64 a, u64 b)
4314 {
4315 return a > b;
4316 }
4317
4318 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4319 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4320 {
4321 struct btrfs_bio_stripe s;
4322 int i;
4323 u64 l;
4324 int again = 1;
4325
4326 while (again) {
4327 again = 0;
4328 for (i = 0; i < bbio->num_stripes - 1; i++) {
4329 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4330 s = bbio->stripes[i];
4331 l = raid_map[i];
4332 bbio->stripes[i] = bbio->stripes[i+1];
4333 raid_map[i] = raid_map[i+1];
4334 bbio->stripes[i+1] = s;
4335 raid_map[i+1] = l;
4336 again = 1;
4337 }
4338 }
4339 }
4340 }
4341
4342 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4343 u64 logical, u64 *length,
4344 struct btrfs_bio **bbio_ret,
4345 int mirror_num, u64 **raid_map_ret)
4346 {
4347 struct extent_map *em;
4348 struct map_lookup *map;
4349 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4350 struct extent_map_tree *em_tree = &map_tree->map_tree;
4351 u64 offset;
4352 u64 stripe_offset;
4353 u64 stripe_end_offset;
4354 u64 stripe_nr;
4355 u64 stripe_nr_orig;
4356 u64 stripe_nr_end;
4357 u64 stripe_len;
4358 u64 *raid_map = NULL;
4359 int stripe_index;
4360 int i;
4361 int ret = 0;
4362 int num_stripes;
4363 int max_errors = 0;
4364 struct btrfs_bio *bbio = NULL;
4365 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4366 int dev_replace_is_ongoing = 0;
4367 int num_alloc_stripes;
4368 int patch_the_first_stripe_for_dev_replace = 0;
4369 u64 physical_to_patch_in_first_stripe = 0;
4370 u64 raid56_full_stripe_start = (u64)-1;
4371
4372 read_lock(&em_tree->lock);
4373 em = lookup_extent_mapping(em_tree, logical, *length);
4374 read_unlock(&em_tree->lock);
4375
4376 if (!em) {
4377 btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4378 (unsigned long long)logical,
4379 (unsigned long long)*length);
4380 return -EINVAL;
4381 }
4382
4383 if (em->start > logical || em->start + em->len < logical) {
4384 btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4385 "found %Lu-%Lu\n", logical, em->start,
4386 em->start + em->len);
4387 return -EINVAL;
4388 }
4389
4390 map = (struct map_lookup *)em->bdev;
4391 offset = logical - em->start;
4392
4393 stripe_len = map->stripe_len;
4394 stripe_nr = offset;
4395 /*
4396 * stripe_nr counts the total number of stripes we have to stride
4397 * to get to this block
4398 */
4399 do_div(stripe_nr, stripe_len);
4400
4401 stripe_offset = stripe_nr * stripe_len;
4402 BUG_ON(offset < stripe_offset);
4403
4404 /* stripe_offset is the offset of this block in its stripe*/
4405 stripe_offset = offset - stripe_offset;
4406
4407 /* if we're here for raid56, we need to know the stripe aligned start */
4408 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4409 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4410 raid56_full_stripe_start = offset;
4411
4412 /* allow a write of a full stripe, but make sure we don't
4413 * allow straddling of stripes
4414 */
4415 do_div(raid56_full_stripe_start, full_stripe_len);
4416 raid56_full_stripe_start *= full_stripe_len;
4417 }
4418
4419 if (rw & REQ_DISCARD) {
4420 /* we don't discard raid56 yet */
4421 if (map->type &
4422 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4423 ret = -EOPNOTSUPP;
4424 goto out;
4425 }
4426 *length = min_t(u64, em->len - offset, *length);
4427 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4428 u64 max_len;
4429 /* For writes to RAID[56], allow a full stripeset across all disks.
4430 For other RAID types and for RAID[56] reads, just allow a single
4431 stripe (on a single disk). */
4432 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4433 (rw & REQ_WRITE)) {
4434 max_len = stripe_len * nr_data_stripes(map) -
4435 (offset - raid56_full_stripe_start);
4436 } else {
4437 /* we limit the length of each bio to what fits in a stripe */
4438 max_len = stripe_len - stripe_offset;
4439 }
4440 *length = min_t(u64, em->len - offset, max_len);
4441 } else {
4442 *length = em->len - offset;
4443 }
4444
4445 /* This is for when we're called from btrfs_merge_bio_hook() and all
4446 it cares about is the length */
4447 if (!bbio_ret)
4448 goto out;
4449
4450 btrfs_dev_replace_lock(dev_replace);
4451 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4452 if (!dev_replace_is_ongoing)
4453 btrfs_dev_replace_unlock(dev_replace);
4454
4455 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4456 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4457 dev_replace->tgtdev != NULL) {
4458 /*
4459 * in dev-replace case, for repair case (that's the only
4460 * case where the mirror is selected explicitly when
4461 * calling btrfs_map_block), blocks left of the left cursor
4462 * can also be read from the target drive.
4463 * For REQ_GET_READ_MIRRORS, the target drive is added as
4464 * the last one to the array of stripes. For READ, it also
4465 * needs to be supported using the same mirror number.
4466 * If the requested block is not left of the left cursor,
4467 * EIO is returned. This can happen because btrfs_num_copies()
4468 * returns one more in the dev-replace case.
4469 */
4470 u64 tmp_length = *length;
4471 struct btrfs_bio *tmp_bbio = NULL;
4472 int tmp_num_stripes;
4473 u64 srcdev_devid = dev_replace->srcdev->devid;
4474 int index_srcdev = 0;
4475 int found = 0;
4476 u64 physical_of_found = 0;
4477
4478 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4479 logical, &tmp_length, &tmp_bbio, 0, NULL);
4480 if (ret) {
4481 WARN_ON(tmp_bbio != NULL);
4482 goto out;
4483 }
4484
4485 tmp_num_stripes = tmp_bbio->num_stripes;
4486 if (mirror_num > tmp_num_stripes) {
4487 /*
4488 * REQ_GET_READ_MIRRORS does not contain this
4489 * mirror, that means that the requested area
4490 * is not left of the left cursor
4491 */
4492 ret = -EIO;
4493 kfree(tmp_bbio);
4494 goto out;
4495 }
4496
4497 /*
4498 * process the rest of the function using the mirror_num
4499 * of the source drive. Therefore look it up first.
4500 * At the end, patch the device pointer to the one of the
4501 * target drive.
4502 */
4503 for (i = 0; i < tmp_num_stripes; i++) {
4504 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4505 /*
4506 * In case of DUP, in order to keep it
4507 * simple, only add the mirror with the
4508 * lowest physical address
4509 */
4510 if (found &&
4511 physical_of_found <=
4512 tmp_bbio->stripes[i].physical)
4513 continue;
4514 index_srcdev = i;
4515 found = 1;
4516 physical_of_found =
4517 tmp_bbio->stripes[i].physical;
4518 }
4519 }
4520
4521 if (found) {
4522 mirror_num = index_srcdev + 1;
4523 patch_the_first_stripe_for_dev_replace = 1;
4524 physical_to_patch_in_first_stripe = physical_of_found;
4525 } else {
4526 WARN_ON(1);
4527 ret = -EIO;
4528 kfree(tmp_bbio);
4529 goto out;
4530 }
4531
4532 kfree(tmp_bbio);
4533 } else if (mirror_num > map->num_stripes) {
4534 mirror_num = 0;
4535 }
4536
4537 num_stripes = 1;
4538 stripe_index = 0;
4539 stripe_nr_orig = stripe_nr;
4540 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
4541 do_div(stripe_nr_end, map->stripe_len);
4542 stripe_end_offset = stripe_nr_end * map->stripe_len -
4543 (offset + *length);
4544
4545 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4546 if (rw & REQ_DISCARD)
4547 num_stripes = min_t(u64, map->num_stripes,
4548 stripe_nr_end - stripe_nr_orig);
4549 stripe_index = do_div(stripe_nr, map->num_stripes);
4550 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4551 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4552 num_stripes = map->num_stripes;
4553 else if (mirror_num)
4554 stripe_index = mirror_num - 1;
4555 else {
4556 stripe_index = find_live_mirror(fs_info, map, 0,
4557 map->num_stripes,
4558 current->pid % map->num_stripes,
4559 dev_replace_is_ongoing);
4560 mirror_num = stripe_index + 1;
4561 }
4562
4563 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4564 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4565 num_stripes = map->num_stripes;
4566 } else if (mirror_num) {
4567 stripe_index = mirror_num - 1;
4568 } else {
4569 mirror_num = 1;
4570 }
4571
4572 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4573 int factor = map->num_stripes / map->sub_stripes;
4574
4575 stripe_index = do_div(stripe_nr, factor);
4576 stripe_index *= map->sub_stripes;
4577
4578 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4579 num_stripes = map->sub_stripes;
4580 else if (rw & REQ_DISCARD)
4581 num_stripes = min_t(u64, map->sub_stripes *
4582 (stripe_nr_end - stripe_nr_orig),
4583 map->num_stripes);
4584 else if (mirror_num)
4585 stripe_index += mirror_num - 1;
4586 else {
4587 int old_stripe_index = stripe_index;
4588 stripe_index = find_live_mirror(fs_info, map,
4589 stripe_index,
4590 map->sub_stripes, stripe_index +
4591 current->pid % map->sub_stripes,
4592 dev_replace_is_ongoing);
4593 mirror_num = stripe_index - old_stripe_index + 1;
4594 }
4595
4596 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4597 BTRFS_BLOCK_GROUP_RAID6)) {
4598 u64 tmp;
4599
4600 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4601 && raid_map_ret) {
4602 int i, rot;
4603
4604 /* push stripe_nr back to the start of the full stripe */
4605 stripe_nr = raid56_full_stripe_start;
4606 do_div(stripe_nr, stripe_len);
4607
4608 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4609
4610 /* RAID[56] write or recovery. Return all stripes */
4611 num_stripes = map->num_stripes;
4612 max_errors = nr_parity_stripes(map);
4613
4614 raid_map = kmalloc(sizeof(u64) * num_stripes,
4615 GFP_NOFS);
4616 if (!raid_map) {
4617 ret = -ENOMEM;
4618 goto out;
4619 }
4620
4621 /* Work out the disk rotation on this stripe-set */
4622 tmp = stripe_nr;
4623 rot = do_div(tmp, num_stripes);
4624
4625 /* Fill in the logical address of each stripe */
4626 tmp = stripe_nr * nr_data_stripes(map);
4627 for (i = 0; i < nr_data_stripes(map); i++)
4628 raid_map[(i+rot) % num_stripes] =
4629 em->start + (tmp + i) * map->stripe_len;
4630
4631 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4632 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4633 raid_map[(i+rot+1) % num_stripes] =
4634 RAID6_Q_STRIPE;
4635
4636 *length = map->stripe_len;
4637 stripe_index = 0;
4638 stripe_offset = 0;
4639 } else {
4640 /*
4641 * Mirror #0 or #1 means the original data block.
4642 * Mirror #2 is RAID5 parity block.
4643 * Mirror #3 is RAID6 Q block.
4644 */
4645 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4646 if (mirror_num > 1)
4647 stripe_index = nr_data_stripes(map) +
4648 mirror_num - 2;
4649
4650 /* We distribute the parity blocks across stripes */
4651 tmp = stripe_nr + stripe_index;
4652 stripe_index = do_div(tmp, map->num_stripes);
4653 }
4654 } else {
4655 /*
4656 * after this do_div call, stripe_nr is the number of stripes
4657 * on this device we have to walk to find the data, and
4658 * stripe_index is the number of our device in the stripe array
4659 */
4660 stripe_index = do_div(stripe_nr, map->num_stripes);
4661 mirror_num = stripe_index + 1;
4662 }
4663 BUG_ON(stripe_index >= map->num_stripes);
4664
4665 num_alloc_stripes = num_stripes;
4666 if (dev_replace_is_ongoing) {
4667 if (rw & (REQ_WRITE | REQ_DISCARD))
4668 num_alloc_stripes <<= 1;
4669 if (rw & REQ_GET_READ_MIRRORS)
4670 num_alloc_stripes++;
4671 }
4672 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4673 if (!bbio) {
4674 ret = -ENOMEM;
4675 goto out;
4676 }
4677 atomic_set(&bbio->error, 0);
4678
4679 if (rw & REQ_DISCARD) {
4680 int factor = 0;
4681 int sub_stripes = 0;
4682 u64 stripes_per_dev = 0;
4683 u32 remaining_stripes = 0;
4684 u32 last_stripe = 0;
4685
4686 if (map->type &
4687 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4688 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4689 sub_stripes = 1;
4690 else
4691 sub_stripes = map->sub_stripes;
4692
4693 factor = map->num_stripes / sub_stripes;
4694 stripes_per_dev = div_u64_rem(stripe_nr_end -
4695 stripe_nr_orig,
4696 factor,
4697 &remaining_stripes);
4698 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4699 last_stripe *= sub_stripes;
4700 }
4701
4702 for (i = 0; i < num_stripes; i++) {
4703 bbio->stripes[i].physical =
4704 map->stripes[stripe_index].physical +
4705 stripe_offset + stripe_nr * map->stripe_len;
4706 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4707
4708 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4709 BTRFS_BLOCK_GROUP_RAID10)) {
4710 bbio->stripes[i].length = stripes_per_dev *
4711 map->stripe_len;
4712
4713 if (i / sub_stripes < remaining_stripes)
4714 bbio->stripes[i].length +=
4715 map->stripe_len;
4716
4717 /*
4718 * Special for the first stripe and
4719 * the last stripe:
4720 *
4721 * |-------|...|-------|
4722 * |----------|
4723 * off end_off
4724 */
4725 if (i < sub_stripes)
4726 bbio->stripes[i].length -=
4727 stripe_offset;
4728
4729 if (stripe_index >= last_stripe &&
4730 stripe_index <= (last_stripe +
4731 sub_stripes - 1))
4732 bbio->stripes[i].length -=
4733 stripe_end_offset;
4734
4735 if (i == sub_stripes - 1)
4736 stripe_offset = 0;
4737 } else
4738 bbio->stripes[i].length = *length;
4739
4740 stripe_index++;
4741 if (stripe_index == map->num_stripes) {
4742 /* This could only happen for RAID0/10 */
4743 stripe_index = 0;
4744 stripe_nr++;
4745 }
4746 }
4747 } else {
4748 for (i = 0; i < num_stripes; i++) {
4749 bbio->stripes[i].physical =
4750 map->stripes[stripe_index].physical +
4751 stripe_offset +
4752 stripe_nr * map->stripe_len;
4753 bbio->stripes[i].dev =
4754 map->stripes[stripe_index].dev;
4755 stripe_index++;
4756 }
4757 }
4758
4759 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
4760 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4761 BTRFS_BLOCK_GROUP_RAID10 |
4762 BTRFS_BLOCK_GROUP_RAID5 |
4763 BTRFS_BLOCK_GROUP_DUP)) {
4764 max_errors = 1;
4765 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
4766 max_errors = 2;
4767 }
4768 }
4769
4770 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
4771 dev_replace->tgtdev != NULL) {
4772 int index_where_to_add;
4773 u64 srcdev_devid = dev_replace->srcdev->devid;
4774
4775 /*
4776 * duplicate the write operations while the dev replace
4777 * procedure is running. Since the copying of the old disk
4778 * to the new disk takes place at run time while the
4779 * filesystem is mounted writable, the regular write
4780 * operations to the old disk have to be duplicated to go
4781 * to the new disk as well.
4782 * Note that device->missing is handled by the caller, and
4783 * that the write to the old disk is already set up in the
4784 * stripes array.
4785 */
4786 index_where_to_add = num_stripes;
4787 for (i = 0; i < num_stripes; i++) {
4788 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4789 /* write to new disk, too */
4790 struct btrfs_bio_stripe *new =
4791 bbio->stripes + index_where_to_add;
4792 struct btrfs_bio_stripe *old =
4793 bbio->stripes + i;
4794
4795 new->physical = old->physical;
4796 new->length = old->length;
4797 new->dev = dev_replace->tgtdev;
4798 index_where_to_add++;
4799 max_errors++;
4800 }
4801 }
4802 num_stripes = index_where_to_add;
4803 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
4804 dev_replace->tgtdev != NULL) {
4805 u64 srcdev_devid = dev_replace->srcdev->devid;
4806 int index_srcdev = 0;
4807 int found = 0;
4808 u64 physical_of_found = 0;
4809
4810 /*
4811 * During the dev-replace procedure, the target drive can
4812 * also be used to read data in case it is needed to repair
4813 * a corrupt block elsewhere. This is possible if the
4814 * requested area is left of the left cursor. In this area,
4815 * the target drive is a full copy of the source drive.
4816 */
4817 for (i = 0; i < num_stripes; i++) {
4818 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4819 /*
4820 * In case of DUP, in order to keep it
4821 * simple, only add the mirror with the
4822 * lowest physical address
4823 */
4824 if (found &&
4825 physical_of_found <=
4826 bbio->stripes[i].physical)
4827 continue;
4828 index_srcdev = i;
4829 found = 1;
4830 physical_of_found = bbio->stripes[i].physical;
4831 }
4832 }
4833 if (found) {
4834 u64 length = map->stripe_len;
4835
4836 if (physical_of_found + length <=
4837 dev_replace->cursor_left) {
4838 struct btrfs_bio_stripe *tgtdev_stripe =
4839 bbio->stripes + num_stripes;
4840
4841 tgtdev_stripe->physical = physical_of_found;
4842 tgtdev_stripe->length =
4843 bbio->stripes[index_srcdev].length;
4844 tgtdev_stripe->dev = dev_replace->tgtdev;
4845
4846 num_stripes++;
4847 }
4848 }
4849 }
4850
4851 *bbio_ret = bbio;
4852 bbio->num_stripes = num_stripes;
4853 bbio->max_errors = max_errors;
4854 bbio->mirror_num = mirror_num;
4855
4856 /*
4857 * this is the case that REQ_READ && dev_replace_is_ongoing &&
4858 * mirror_num == num_stripes + 1 && dev_replace target drive is
4859 * available as a mirror
4860 */
4861 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
4862 WARN_ON(num_stripes > 1);
4863 bbio->stripes[0].dev = dev_replace->tgtdev;
4864 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
4865 bbio->mirror_num = map->num_stripes + 1;
4866 }
4867 if (raid_map) {
4868 sort_parity_stripes(bbio, raid_map);
4869 *raid_map_ret = raid_map;
4870 }
4871 out:
4872 if (dev_replace_is_ongoing)
4873 btrfs_dev_replace_unlock(dev_replace);
4874 free_extent_map(em);
4875 return ret;
4876 }
4877
4878 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4879 u64 logical, u64 *length,
4880 struct btrfs_bio **bbio_ret, int mirror_num)
4881 {
4882 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
4883 mirror_num, NULL);
4884 }
4885
4886 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4887 u64 chunk_start, u64 physical, u64 devid,
4888 u64 **logical, int *naddrs, int *stripe_len)
4889 {
4890 struct extent_map_tree *em_tree = &map_tree->map_tree;
4891 struct extent_map *em;
4892 struct map_lookup *map;
4893 u64 *buf;
4894 u64 bytenr;
4895 u64 length;
4896 u64 stripe_nr;
4897 u64 rmap_len;
4898 int i, j, nr = 0;
4899
4900 read_lock(&em_tree->lock);
4901 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4902 read_unlock(&em_tree->lock);
4903
4904 if (!em) {
4905 printk(KERN_ERR "btrfs: couldn't find em for chunk %Lu\n",
4906 chunk_start);
4907 return -EIO;
4908 }
4909
4910 if (em->start != chunk_start) {
4911 printk(KERN_ERR "btrfs: bad chunk start, em=%Lu, wanted=%Lu\n",
4912 em->start, chunk_start);
4913 free_extent_map(em);
4914 return -EIO;
4915 }
4916 map = (struct map_lookup *)em->bdev;
4917
4918 length = em->len;
4919 rmap_len = map->stripe_len;
4920
4921 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4922 do_div(length, map->num_stripes / map->sub_stripes);
4923 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4924 do_div(length, map->num_stripes);
4925 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4926 BTRFS_BLOCK_GROUP_RAID6)) {
4927 do_div(length, nr_data_stripes(map));
4928 rmap_len = map->stripe_len * nr_data_stripes(map);
4929 }
4930
4931 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4932 BUG_ON(!buf); /* -ENOMEM */
4933
4934 for (i = 0; i < map->num_stripes; i++) {
4935 if (devid && map->stripes[i].dev->devid != devid)
4936 continue;
4937 if (map->stripes[i].physical > physical ||
4938 map->stripes[i].physical + length <= physical)
4939 continue;
4940
4941 stripe_nr = physical - map->stripes[i].physical;
4942 do_div(stripe_nr, map->stripe_len);
4943
4944 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4945 stripe_nr = stripe_nr * map->num_stripes + i;
4946 do_div(stripe_nr, map->sub_stripes);
4947 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4948 stripe_nr = stripe_nr * map->num_stripes + i;
4949 } /* else if RAID[56], multiply by nr_data_stripes().
4950 * Alternatively, just use rmap_len below instead of
4951 * map->stripe_len */
4952
4953 bytenr = chunk_start + stripe_nr * rmap_len;
4954 WARN_ON(nr >= map->num_stripes);
4955 for (j = 0; j < nr; j++) {
4956 if (buf[j] == bytenr)
4957 break;
4958 }
4959 if (j == nr) {
4960 WARN_ON(nr >= map->num_stripes);
4961 buf[nr++] = bytenr;
4962 }
4963 }
4964
4965 *logical = buf;
4966 *naddrs = nr;
4967 *stripe_len = rmap_len;
4968
4969 free_extent_map(em);
4970 return 0;
4971 }
4972
4973 static void btrfs_end_bio(struct bio *bio, int err)
4974 {
4975 struct btrfs_bio *bbio = bio->bi_private;
4976 int is_orig_bio = 0;
4977
4978 if (err) {
4979 atomic_inc(&bbio->error);
4980 if (err == -EIO || err == -EREMOTEIO) {
4981 unsigned int stripe_index =
4982 btrfs_io_bio(bio)->stripe_index;
4983 struct btrfs_device *dev;
4984
4985 BUG_ON(stripe_index >= bbio->num_stripes);
4986 dev = bbio->stripes[stripe_index].dev;
4987 if (dev->bdev) {
4988 if (bio->bi_rw & WRITE)
4989 btrfs_dev_stat_inc(dev,
4990 BTRFS_DEV_STAT_WRITE_ERRS);
4991 else
4992 btrfs_dev_stat_inc(dev,
4993 BTRFS_DEV_STAT_READ_ERRS);
4994 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4995 btrfs_dev_stat_inc(dev,
4996 BTRFS_DEV_STAT_FLUSH_ERRS);
4997 btrfs_dev_stat_print_on_error(dev);
4998 }
4999 }
5000 }
5001
5002 if (bio == bbio->orig_bio)
5003 is_orig_bio = 1;
5004
5005 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5006 if (!is_orig_bio) {
5007 bio_put(bio);
5008 bio = bbio->orig_bio;
5009 }
5010 bio->bi_private = bbio->private;
5011 bio->bi_end_io = bbio->end_io;
5012 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5013 /* only send an error to the higher layers if it is
5014 * beyond the tolerance of the btrfs bio
5015 */
5016 if (atomic_read(&bbio->error) > bbio->max_errors) {
5017 err = -EIO;
5018 } else {
5019 /*
5020 * this bio is actually up to date, we didn't
5021 * go over the max number of errors
5022 */
5023 set_bit(BIO_UPTODATE, &bio->bi_flags);
5024 err = 0;
5025 }
5026 kfree(bbio);
5027
5028 bio_endio(bio, err);
5029 } else if (!is_orig_bio) {
5030 bio_put(bio);
5031 }
5032 }
5033
5034 struct async_sched {
5035 struct bio *bio;
5036 int rw;
5037 struct btrfs_fs_info *info;
5038 struct btrfs_work work;
5039 };
5040
5041 /*
5042 * see run_scheduled_bios for a description of why bios are collected for
5043 * async submit.
5044 *
5045 * This will add one bio to the pending list for a device and make sure
5046 * the work struct is scheduled.
5047 */
5048 static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5049 struct btrfs_device *device,
5050 int rw, struct bio *bio)
5051 {
5052 int should_queue = 1;
5053 struct btrfs_pending_bios *pending_bios;
5054
5055 if (device->missing || !device->bdev) {
5056 bio_endio(bio, -EIO);
5057 return;
5058 }
5059
5060 /* don't bother with additional async steps for reads, right now */
5061 if (!(rw & REQ_WRITE)) {
5062 bio_get(bio);
5063 btrfsic_submit_bio(rw, bio);
5064 bio_put(bio);
5065 return;
5066 }
5067
5068 /*
5069 * nr_async_bios allows us to reliably return congestion to the
5070 * higher layers. Otherwise, the async bio makes it appear we have
5071 * made progress against dirty pages when we've really just put it
5072 * on a queue for later
5073 */
5074 atomic_inc(&root->fs_info->nr_async_bios);
5075 WARN_ON(bio->bi_next);
5076 bio->bi_next = NULL;
5077 bio->bi_rw |= rw;
5078
5079 spin_lock(&device->io_lock);
5080 if (bio->bi_rw & REQ_SYNC)
5081 pending_bios = &device->pending_sync_bios;
5082 else
5083 pending_bios = &device->pending_bios;
5084
5085 if (pending_bios->tail)
5086 pending_bios->tail->bi_next = bio;
5087
5088 pending_bios->tail = bio;
5089 if (!pending_bios->head)
5090 pending_bios->head = bio;
5091 if (device->running_pending)
5092 should_queue = 0;
5093
5094 spin_unlock(&device->io_lock);
5095
5096 if (should_queue)
5097 btrfs_queue_worker(&root->fs_info->submit_workers,
5098 &device->work);
5099 }
5100
5101 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5102 sector_t sector)
5103 {
5104 struct bio_vec *prev;
5105 struct request_queue *q = bdev_get_queue(bdev);
5106 unsigned short max_sectors = queue_max_sectors(q);
5107 struct bvec_merge_data bvm = {
5108 .bi_bdev = bdev,
5109 .bi_sector = sector,
5110 .bi_rw = bio->bi_rw,
5111 };
5112
5113 if (bio->bi_vcnt == 0) {
5114 WARN_ON(1);
5115 return 1;
5116 }
5117
5118 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5119 if (bio_sectors(bio) > max_sectors)
5120 return 0;
5121
5122 if (!q->merge_bvec_fn)
5123 return 1;
5124
5125 bvm.bi_size = bio->bi_size - prev->bv_len;
5126 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5127 return 0;
5128 return 1;
5129 }
5130
5131 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5132 struct bio *bio, u64 physical, int dev_nr,
5133 int rw, int async)
5134 {
5135 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5136
5137 bio->bi_private = bbio;
5138 btrfs_io_bio(bio)->stripe_index = dev_nr;
5139 bio->bi_end_io = btrfs_end_bio;
5140 bio->bi_sector = physical >> 9;
5141 #ifdef DEBUG
5142 {
5143 struct rcu_string *name;
5144
5145 rcu_read_lock();
5146 name = rcu_dereference(dev->name);
5147 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5148 "(%s id %llu), size=%u\n", rw,
5149 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5150 name->str, dev->devid, bio->bi_size);
5151 rcu_read_unlock();
5152 }
5153 #endif
5154 bio->bi_bdev = dev->bdev;
5155 if (async)
5156 btrfs_schedule_bio(root, dev, rw, bio);
5157 else
5158 btrfsic_submit_bio(rw, bio);
5159 }
5160
5161 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5162 struct bio *first_bio, struct btrfs_device *dev,
5163 int dev_nr, int rw, int async)
5164 {
5165 struct bio_vec *bvec = first_bio->bi_io_vec;
5166 struct bio *bio;
5167 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5168 u64 physical = bbio->stripes[dev_nr].physical;
5169
5170 again:
5171 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5172 if (!bio)
5173 return -ENOMEM;
5174
5175 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5176 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5177 bvec->bv_offset) < bvec->bv_len) {
5178 u64 len = bio->bi_size;
5179
5180 atomic_inc(&bbio->stripes_pending);
5181 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5182 rw, async);
5183 physical += len;
5184 goto again;
5185 }
5186 bvec++;
5187 }
5188
5189 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5190 return 0;
5191 }
5192
5193 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5194 {
5195 atomic_inc(&bbio->error);
5196 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5197 bio->bi_private = bbio->private;
5198 bio->bi_end_io = bbio->end_io;
5199 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5200 bio->bi_sector = logical >> 9;
5201 kfree(bbio);
5202 bio_endio(bio, -EIO);
5203 }
5204 }
5205
5206 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5207 int mirror_num, int async_submit)
5208 {
5209 struct btrfs_device *dev;
5210 struct bio *first_bio = bio;
5211 u64 logical = (u64)bio->bi_sector << 9;
5212 u64 length = 0;
5213 u64 map_length;
5214 u64 *raid_map = NULL;
5215 int ret;
5216 int dev_nr = 0;
5217 int total_devs = 1;
5218 struct btrfs_bio *bbio = NULL;
5219
5220 length = bio->bi_size;
5221 map_length = length;
5222
5223 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5224 mirror_num, &raid_map);
5225 if (ret) /* -ENOMEM */
5226 return ret;
5227
5228 total_devs = bbio->num_stripes;
5229 bbio->orig_bio = first_bio;
5230 bbio->private = first_bio->bi_private;
5231 bbio->end_io = first_bio->bi_end_io;
5232 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5233
5234 if (raid_map) {
5235 /* In this case, map_length has been set to the length of
5236 a single stripe; not the whole write */
5237 if (rw & WRITE) {
5238 return raid56_parity_write(root, bio, bbio,
5239 raid_map, map_length);
5240 } else {
5241 return raid56_parity_recover(root, bio, bbio,
5242 raid_map, map_length,
5243 mirror_num);
5244 }
5245 }
5246
5247 if (map_length < length) {
5248 btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5249 (unsigned long long)logical,
5250 (unsigned long long)length,
5251 (unsigned long long)map_length);
5252 BUG();
5253 }
5254
5255 while (dev_nr < total_devs) {
5256 dev = bbio->stripes[dev_nr].dev;
5257 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5258 bbio_error(bbio, first_bio, logical);
5259 dev_nr++;
5260 continue;
5261 }
5262
5263 /*
5264 * Check and see if we're ok with this bio based on it's size
5265 * and offset with the given device.
5266 */
5267 if (!bio_size_ok(dev->bdev, first_bio,
5268 bbio->stripes[dev_nr].physical >> 9)) {
5269 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5270 dev_nr, rw, async_submit);
5271 BUG_ON(ret);
5272 dev_nr++;
5273 continue;
5274 }
5275
5276 if (dev_nr < total_devs - 1) {
5277 bio = btrfs_bio_clone(first_bio, GFP_NOFS);
5278 BUG_ON(!bio); /* -ENOMEM */
5279 } else {
5280 bio = first_bio;
5281 }
5282
5283 submit_stripe_bio(root, bbio, bio,
5284 bbio->stripes[dev_nr].physical, dev_nr, rw,
5285 async_submit);
5286 dev_nr++;
5287 }
5288 return 0;
5289 }
5290
5291 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5292 u8 *uuid, u8 *fsid)
5293 {
5294 struct btrfs_device *device;
5295 struct btrfs_fs_devices *cur_devices;
5296
5297 cur_devices = fs_info->fs_devices;
5298 while (cur_devices) {
5299 if (!fsid ||
5300 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5301 device = __find_device(&cur_devices->devices,
5302 devid, uuid);
5303 if (device)
5304 return device;
5305 }
5306 cur_devices = cur_devices->seed;
5307 }
5308 return NULL;
5309 }
5310
5311 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5312 u64 devid, u8 *dev_uuid)
5313 {
5314 struct btrfs_device *device;
5315 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5316
5317 device = kzalloc(sizeof(*device), GFP_NOFS);
5318 if (!device)
5319 return NULL;
5320 list_add(&device->dev_list,
5321 &fs_devices->devices);
5322 device->devid = devid;
5323 device->work.func = pending_bios_fn;
5324 device->fs_devices = fs_devices;
5325 device->missing = 1;
5326 fs_devices->num_devices++;
5327 fs_devices->missing_devices++;
5328 spin_lock_init(&device->io_lock);
5329 INIT_LIST_HEAD(&device->dev_alloc_list);
5330 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
5331 return device;
5332 }
5333
5334 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5335 struct extent_buffer *leaf,
5336 struct btrfs_chunk *chunk)
5337 {
5338 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5339 struct map_lookup *map;
5340 struct extent_map *em;
5341 u64 logical;
5342 u64 length;
5343 u64 devid;
5344 u8 uuid[BTRFS_UUID_SIZE];
5345 int num_stripes;
5346 int ret;
5347 int i;
5348
5349 logical = key->offset;
5350 length = btrfs_chunk_length(leaf, chunk);
5351
5352 read_lock(&map_tree->map_tree.lock);
5353 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5354 read_unlock(&map_tree->map_tree.lock);
5355
5356 /* already mapped? */
5357 if (em && em->start <= logical && em->start + em->len > logical) {
5358 free_extent_map(em);
5359 return 0;
5360 } else if (em) {
5361 free_extent_map(em);
5362 }
5363
5364 em = alloc_extent_map();
5365 if (!em)
5366 return -ENOMEM;
5367 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5368 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5369 if (!map) {
5370 free_extent_map(em);
5371 return -ENOMEM;
5372 }
5373
5374 em->bdev = (struct block_device *)map;
5375 em->start = logical;
5376 em->len = length;
5377 em->orig_start = 0;
5378 em->block_start = 0;
5379 em->block_len = em->len;
5380
5381 map->num_stripes = num_stripes;
5382 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5383 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5384 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5385 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5386 map->type = btrfs_chunk_type(leaf, chunk);
5387 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5388 for (i = 0; i < num_stripes; i++) {
5389 map->stripes[i].physical =
5390 btrfs_stripe_offset_nr(leaf, chunk, i);
5391 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5392 read_extent_buffer(leaf, uuid, (unsigned long)
5393 btrfs_stripe_dev_uuid_nr(chunk, i),
5394 BTRFS_UUID_SIZE);
5395 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5396 uuid, NULL);
5397 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5398 kfree(map);
5399 free_extent_map(em);
5400 return -EIO;
5401 }
5402 if (!map->stripes[i].dev) {
5403 map->stripes[i].dev =
5404 add_missing_dev(root, devid, uuid);
5405 if (!map->stripes[i].dev) {
5406 kfree(map);
5407 free_extent_map(em);
5408 return -EIO;
5409 }
5410 }
5411 map->stripes[i].dev->in_fs_metadata = 1;
5412 }
5413
5414 write_lock(&map_tree->map_tree.lock);
5415 ret = add_extent_mapping(&map_tree->map_tree, em, 0);
5416 write_unlock(&map_tree->map_tree.lock);
5417 BUG_ON(ret); /* Tree corruption */
5418 free_extent_map(em);
5419
5420 return 0;
5421 }
5422
5423 static void fill_device_from_item(struct extent_buffer *leaf,
5424 struct btrfs_dev_item *dev_item,
5425 struct btrfs_device *device)
5426 {
5427 unsigned long ptr;
5428
5429 device->devid = btrfs_device_id(leaf, dev_item);
5430 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5431 device->total_bytes = device->disk_total_bytes;
5432 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5433 device->type = btrfs_device_type(leaf, dev_item);
5434 device->io_align = btrfs_device_io_align(leaf, dev_item);
5435 device->io_width = btrfs_device_io_width(leaf, dev_item);
5436 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5437 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5438 device->is_tgtdev_for_dev_replace = 0;
5439
5440 ptr = (unsigned long)btrfs_device_uuid(dev_item);
5441 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5442 }
5443
5444 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5445 {
5446 struct btrfs_fs_devices *fs_devices;
5447 int ret;
5448
5449 BUG_ON(!mutex_is_locked(&uuid_mutex));
5450
5451 fs_devices = root->fs_info->fs_devices->seed;
5452 while (fs_devices) {
5453 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5454 ret = 0;
5455 goto out;
5456 }
5457 fs_devices = fs_devices->seed;
5458 }
5459
5460 fs_devices = find_fsid(fsid);
5461 if (!fs_devices) {
5462 ret = -ENOENT;
5463 goto out;
5464 }
5465
5466 fs_devices = clone_fs_devices(fs_devices);
5467 if (IS_ERR(fs_devices)) {
5468 ret = PTR_ERR(fs_devices);
5469 goto out;
5470 }
5471
5472 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5473 root->fs_info->bdev_holder);
5474 if (ret) {
5475 free_fs_devices(fs_devices);
5476 goto out;
5477 }
5478
5479 if (!fs_devices->seeding) {
5480 __btrfs_close_devices(fs_devices);
5481 free_fs_devices(fs_devices);
5482 ret = -EINVAL;
5483 goto out;
5484 }
5485
5486 fs_devices->seed = root->fs_info->fs_devices->seed;
5487 root->fs_info->fs_devices->seed = fs_devices;
5488 out:
5489 return ret;
5490 }
5491
5492 static int read_one_dev(struct btrfs_root *root,
5493 struct extent_buffer *leaf,
5494 struct btrfs_dev_item *dev_item)
5495 {
5496 struct btrfs_device *device;
5497 u64 devid;
5498 int ret;
5499 u8 fs_uuid[BTRFS_UUID_SIZE];
5500 u8 dev_uuid[BTRFS_UUID_SIZE];
5501
5502 devid = btrfs_device_id(leaf, dev_item);
5503 read_extent_buffer(leaf, dev_uuid,
5504 (unsigned long)btrfs_device_uuid(dev_item),
5505 BTRFS_UUID_SIZE);
5506 read_extent_buffer(leaf, fs_uuid,
5507 (unsigned long)btrfs_device_fsid(dev_item),
5508 BTRFS_UUID_SIZE);
5509
5510 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5511 ret = open_seed_devices(root, fs_uuid);
5512 if (ret && !btrfs_test_opt(root, DEGRADED))
5513 return ret;
5514 }
5515
5516 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5517 if (!device || !device->bdev) {
5518 if (!btrfs_test_opt(root, DEGRADED))
5519 return -EIO;
5520
5521 if (!device) {
5522 btrfs_warn(root->fs_info, "devid %llu missing",
5523 (unsigned long long)devid);
5524 device = add_missing_dev(root, devid, dev_uuid);
5525 if (!device)
5526 return -ENOMEM;
5527 } else if (!device->missing) {
5528 /*
5529 * this happens when a device that was properly setup
5530 * in the device info lists suddenly goes bad.
5531 * device->bdev is NULL, and so we have to set
5532 * device->missing to one here
5533 */
5534 root->fs_info->fs_devices->missing_devices++;
5535 device->missing = 1;
5536 }
5537 }
5538
5539 if (device->fs_devices != root->fs_info->fs_devices) {
5540 BUG_ON(device->writeable);
5541 if (device->generation !=
5542 btrfs_device_generation(leaf, dev_item))
5543 return -EINVAL;
5544 }
5545
5546 fill_device_from_item(leaf, dev_item, device);
5547 device->in_fs_metadata = 1;
5548 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5549 device->fs_devices->total_rw_bytes += device->total_bytes;
5550 spin_lock(&root->fs_info->free_chunk_lock);
5551 root->fs_info->free_chunk_space += device->total_bytes -
5552 device->bytes_used;
5553 spin_unlock(&root->fs_info->free_chunk_lock);
5554 }
5555 ret = 0;
5556 return ret;
5557 }
5558
5559 int btrfs_read_sys_array(struct btrfs_root *root)
5560 {
5561 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5562 struct extent_buffer *sb;
5563 struct btrfs_disk_key *disk_key;
5564 struct btrfs_chunk *chunk;
5565 u8 *ptr;
5566 unsigned long sb_ptr;
5567 int ret = 0;
5568 u32 num_stripes;
5569 u32 array_size;
5570 u32 len = 0;
5571 u32 cur;
5572 struct btrfs_key key;
5573
5574 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5575 BTRFS_SUPER_INFO_SIZE);
5576 if (!sb)
5577 return -ENOMEM;
5578 btrfs_set_buffer_uptodate(sb);
5579 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5580 /*
5581 * The sb extent buffer is artifical and just used to read the system array.
5582 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5583 * pages up-to-date when the page is larger: extent does not cover the
5584 * whole page and consequently check_page_uptodate does not find all
5585 * the page's extents up-to-date (the hole beyond sb),
5586 * write_extent_buffer then triggers a WARN_ON.
5587 *
5588 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5589 * but sb spans only this function. Add an explicit SetPageUptodate call
5590 * to silence the warning eg. on PowerPC 64.
5591 */
5592 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5593 SetPageUptodate(sb->pages[0]);
5594
5595 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5596 array_size = btrfs_super_sys_array_size(super_copy);
5597
5598 ptr = super_copy->sys_chunk_array;
5599 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5600 cur = 0;
5601
5602 while (cur < array_size) {
5603 disk_key = (struct btrfs_disk_key *)ptr;
5604 btrfs_disk_key_to_cpu(&key, disk_key);
5605
5606 len = sizeof(*disk_key); ptr += len;
5607 sb_ptr += len;
5608 cur += len;
5609
5610 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5611 chunk = (struct btrfs_chunk *)sb_ptr;
5612 ret = read_one_chunk(root, &key, sb, chunk);
5613 if (ret)
5614 break;
5615 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5616 len = btrfs_chunk_item_size(num_stripes);
5617 } else {
5618 ret = -EIO;
5619 break;
5620 }
5621 ptr += len;
5622 sb_ptr += len;
5623 cur += len;
5624 }
5625 free_extent_buffer(sb);
5626 return ret;
5627 }
5628
5629 int btrfs_read_chunk_tree(struct btrfs_root *root)
5630 {
5631 struct btrfs_path *path;
5632 struct extent_buffer *leaf;
5633 struct btrfs_key key;
5634 struct btrfs_key found_key;
5635 int ret;
5636 int slot;
5637
5638 root = root->fs_info->chunk_root;
5639
5640 path = btrfs_alloc_path();
5641 if (!path)
5642 return -ENOMEM;
5643
5644 mutex_lock(&uuid_mutex);
5645 lock_chunks(root);
5646
5647 /* first we search for all of the device items, and then we
5648 * read in all of the chunk items. This way we can create chunk
5649 * mappings that reference all of the devices that are afound
5650 */
5651 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5652 key.offset = 0;
5653 key.type = 0;
5654 again:
5655 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5656 if (ret < 0)
5657 goto error;
5658 while (1) {
5659 leaf = path->nodes[0];
5660 slot = path->slots[0];
5661 if (slot >= btrfs_header_nritems(leaf)) {
5662 ret = btrfs_next_leaf(root, path);
5663 if (ret == 0)
5664 continue;
5665 if (ret < 0)
5666 goto error;
5667 break;
5668 }
5669 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5670 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5671 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
5672 break;
5673 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
5674 struct btrfs_dev_item *dev_item;
5675 dev_item = btrfs_item_ptr(leaf, slot,
5676 struct btrfs_dev_item);
5677 ret = read_one_dev(root, leaf, dev_item);
5678 if (ret)
5679 goto error;
5680 }
5681 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
5682 struct btrfs_chunk *chunk;
5683 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
5684 ret = read_one_chunk(root, &found_key, leaf, chunk);
5685 if (ret)
5686 goto error;
5687 }
5688 path->slots[0]++;
5689 }
5690 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5691 key.objectid = 0;
5692 btrfs_release_path(path);
5693 goto again;
5694 }
5695 ret = 0;
5696 error:
5697 unlock_chunks(root);
5698 mutex_unlock(&uuid_mutex);
5699
5700 btrfs_free_path(path);
5701 return ret;
5702 }
5703
5704 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
5705 {
5706 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5707 struct btrfs_device *device;
5708
5709 mutex_lock(&fs_devices->device_list_mutex);
5710 list_for_each_entry(device, &fs_devices->devices, dev_list)
5711 device->dev_root = fs_info->dev_root;
5712 mutex_unlock(&fs_devices->device_list_mutex);
5713 }
5714
5715 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
5716 {
5717 int i;
5718
5719 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5720 btrfs_dev_stat_reset(dev, i);
5721 }
5722
5723 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
5724 {
5725 struct btrfs_key key;
5726 struct btrfs_key found_key;
5727 struct btrfs_root *dev_root = fs_info->dev_root;
5728 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5729 struct extent_buffer *eb;
5730 int slot;
5731 int ret = 0;
5732 struct btrfs_device *device;
5733 struct btrfs_path *path = NULL;
5734 int i;
5735
5736 path = btrfs_alloc_path();
5737 if (!path) {
5738 ret = -ENOMEM;
5739 goto out;
5740 }
5741
5742 mutex_lock(&fs_devices->device_list_mutex);
5743 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5744 int item_size;
5745 struct btrfs_dev_stats_item *ptr;
5746
5747 key.objectid = 0;
5748 key.type = BTRFS_DEV_STATS_KEY;
5749 key.offset = device->devid;
5750 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
5751 if (ret) {
5752 __btrfs_reset_dev_stats(device);
5753 device->dev_stats_valid = 1;
5754 btrfs_release_path(path);
5755 continue;
5756 }
5757 slot = path->slots[0];
5758 eb = path->nodes[0];
5759 btrfs_item_key_to_cpu(eb, &found_key, slot);
5760 item_size = btrfs_item_size_nr(eb, slot);
5761
5762 ptr = btrfs_item_ptr(eb, slot,
5763 struct btrfs_dev_stats_item);
5764
5765 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5766 if (item_size >= (1 + i) * sizeof(__le64))
5767 btrfs_dev_stat_set(device, i,
5768 btrfs_dev_stats_value(eb, ptr, i));
5769 else
5770 btrfs_dev_stat_reset(device, i);
5771 }
5772
5773 device->dev_stats_valid = 1;
5774 btrfs_dev_stat_print_on_load(device);
5775 btrfs_release_path(path);
5776 }
5777 mutex_unlock(&fs_devices->device_list_mutex);
5778
5779 out:
5780 btrfs_free_path(path);
5781 return ret < 0 ? ret : 0;
5782 }
5783
5784 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
5785 struct btrfs_root *dev_root,
5786 struct btrfs_device *device)
5787 {
5788 struct btrfs_path *path;
5789 struct btrfs_key key;
5790 struct extent_buffer *eb;
5791 struct btrfs_dev_stats_item *ptr;
5792 int ret;
5793 int i;
5794
5795 key.objectid = 0;
5796 key.type = BTRFS_DEV_STATS_KEY;
5797 key.offset = device->devid;
5798
5799 path = btrfs_alloc_path();
5800 BUG_ON(!path);
5801 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
5802 if (ret < 0) {
5803 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
5804 ret, rcu_str_deref(device->name));
5805 goto out;
5806 }
5807
5808 if (ret == 0 &&
5809 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
5810 /* need to delete old one and insert a new one */
5811 ret = btrfs_del_item(trans, dev_root, path);
5812 if (ret != 0) {
5813 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
5814 rcu_str_deref(device->name), ret);
5815 goto out;
5816 }
5817 ret = 1;
5818 }
5819
5820 if (ret == 1) {
5821 /* need to insert a new item */
5822 btrfs_release_path(path);
5823 ret = btrfs_insert_empty_item(trans, dev_root, path,
5824 &key, sizeof(*ptr));
5825 if (ret < 0) {
5826 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
5827 rcu_str_deref(device->name), ret);
5828 goto out;
5829 }
5830 }
5831
5832 eb = path->nodes[0];
5833 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
5834 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5835 btrfs_set_dev_stats_value(eb, ptr, i,
5836 btrfs_dev_stat_read(device, i));
5837 btrfs_mark_buffer_dirty(eb);
5838
5839 out:
5840 btrfs_free_path(path);
5841 return ret;
5842 }
5843
5844 /*
5845 * called from commit_transaction. Writes all changed device stats to disk.
5846 */
5847 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
5848 struct btrfs_fs_info *fs_info)
5849 {
5850 struct btrfs_root *dev_root = fs_info->dev_root;
5851 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5852 struct btrfs_device *device;
5853 int ret = 0;
5854
5855 mutex_lock(&fs_devices->device_list_mutex);
5856 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5857 if (!device->dev_stats_valid || !device->dev_stats_dirty)
5858 continue;
5859
5860 ret = update_dev_stat_item(trans, dev_root, device);
5861 if (!ret)
5862 device->dev_stats_dirty = 0;
5863 }
5864 mutex_unlock(&fs_devices->device_list_mutex);
5865
5866 return ret;
5867 }
5868
5869 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
5870 {
5871 btrfs_dev_stat_inc(dev, index);
5872 btrfs_dev_stat_print_on_error(dev);
5873 }
5874
5875 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
5876 {
5877 if (!dev->dev_stats_valid)
5878 return;
5879 printk_ratelimited_in_rcu(KERN_ERR
5880 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5881 rcu_str_deref(dev->name),
5882 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5883 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5884 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5885 btrfs_dev_stat_read(dev,
5886 BTRFS_DEV_STAT_CORRUPTION_ERRS),
5887 btrfs_dev_stat_read(dev,
5888 BTRFS_DEV_STAT_GENERATION_ERRS));
5889 }
5890
5891 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
5892 {
5893 int i;
5894
5895 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5896 if (btrfs_dev_stat_read(dev, i) != 0)
5897 break;
5898 if (i == BTRFS_DEV_STAT_VALUES_MAX)
5899 return; /* all values == 0, suppress message */
5900
5901 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5902 rcu_str_deref(dev->name),
5903 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5904 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5905 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5906 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
5907 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
5908 }
5909
5910 int btrfs_get_dev_stats(struct btrfs_root *root,
5911 struct btrfs_ioctl_get_dev_stats *stats)
5912 {
5913 struct btrfs_device *dev;
5914 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5915 int i;
5916
5917 mutex_lock(&fs_devices->device_list_mutex);
5918 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
5919 mutex_unlock(&fs_devices->device_list_mutex);
5920
5921 if (!dev) {
5922 printk(KERN_WARNING
5923 "btrfs: get dev_stats failed, device not found\n");
5924 return -ENODEV;
5925 } else if (!dev->dev_stats_valid) {
5926 printk(KERN_WARNING
5927 "btrfs: get dev_stats failed, not yet valid\n");
5928 return -ENODEV;
5929 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
5930 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5931 if (stats->nr_items > i)
5932 stats->values[i] =
5933 btrfs_dev_stat_read_and_reset(dev, i);
5934 else
5935 btrfs_dev_stat_reset(dev, i);
5936 }
5937 } else {
5938 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5939 if (stats->nr_items > i)
5940 stats->values[i] = btrfs_dev_stat_read(dev, i);
5941 }
5942 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
5943 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
5944 return 0;
5945 }
5946
5947 int btrfs_scratch_superblock(struct btrfs_device *device)
5948 {
5949 struct buffer_head *bh;
5950 struct btrfs_super_block *disk_super;
5951
5952 bh = btrfs_read_dev_super(device->bdev);
5953 if (!bh)
5954 return -EINVAL;
5955 disk_super = (struct btrfs_super_block *)bh->b_data;
5956
5957 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
5958 set_buffer_dirty(bh);
5959 sync_dirty_buffer(bh);
5960 brelse(bh);
5961
5962 return 0;
5963 }
Linux kernel - Deliverables
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