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Btrfs: set qgroup_ulist to be null after calling ulist_free()
[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 mutex_unlock(&uuid_mutex);
1566 ret = btrfs_shrink_device(device, 0);
1567 mutex_lock(&uuid_mutex);
1568 if (ret)
1569 goto error_undo;
1570
1571 /*
1572 * TODO: the superblock still includes this device in its num_devices
1573 * counter although write_all_supers() is not locked out. This
1574 * could give a filesystem state which requires a degraded mount.
1575 */
1576 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1577 if (ret)
1578 goto error_undo;
1579
1580 spin_lock(&root->fs_info->free_chunk_lock);
1581 root->fs_info->free_chunk_space = device->total_bytes -
1582 device->bytes_used;
1583 spin_unlock(&root->fs_info->free_chunk_lock);
1584
1585 device->in_fs_metadata = 0;
1586 btrfs_scrub_cancel_dev(root->fs_info, device);
1587
1588 /*
1589 * the device list mutex makes sure that we don't change
1590 * the device list while someone else is writing out all
1591 * the device supers.
1592 */
1593
1594 cur_devices = device->fs_devices;
1595 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1596 list_del_rcu(&device->dev_list);
1597
1598 device->fs_devices->num_devices--;
1599 device->fs_devices->total_devices--;
1600
1601 if (device->missing)
1602 root->fs_info->fs_devices->missing_devices--;
1603
1604 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1605 struct btrfs_device, dev_list);
1606 if (device->bdev == root->fs_info->sb->s_bdev)
1607 root->fs_info->sb->s_bdev = next_device->bdev;
1608 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1609 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1610
1611 if (device->bdev)
1612 device->fs_devices->open_devices--;
1613
1614 call_rcu(&device->rcu, free_device);
1615 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1616
1617 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1618 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1619
1620 if (cur_devices->open_devices == 0) {
1621 struct btrfs_fs_devices *fs_devices;
1622 fs_devices = root->fs_info->fs_devices;
1623 while (fs_devices) {
1624 if (fs_devices->seed == cur_devices)
1625 break;
1626 fs_devices = fs_devices->seed;
1627 }
1628 fs_devices->seed = cur_devices->seed;
1629 cur_devices->seed = NULL;
1630 lock_chunks(root);
1631 __btrfs_close_devices(cur_devices);
1632 unlock_chunks(root);
1633 free_fs_devices(cur_devices);
1634 }
1635
1636 root->fs_info->num_tolerated_disk_barrier_failures =
1637 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1638
1639 /*
1640 * at this point, the device is zero sized. We want to
1641 * remove it from the devices list and zero out the old super
1642 */
1643 if (clear_super && disk_super) {
1644 /* make sure this device isn't detected as part of
1645 * the FS anymore
1646 */
1647 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1648 set_buffer_dirty(bh);
1649 sync_dirty_buffer(bh);
1650 }
1651
1652 ret = 0;
1653
1654 /* Notify udev that device has changed */
1655 if (bdev)
1656 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1657
1658 error_brelse:
1659 brelse(bh);
1660 if (bdev)
1661 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1662 out:
1663 mutex_unlock(&uuid_mutex);
1664 return ret;
1665 error_undo:
1666 if (device->writeable) {
1667 lock_chunks(root);
1668 list_add(&device->dev_alloc_list,
1669 &root->fs_info->fs_devices->alloc_list);
1670 unlock_chunks(root);
1671 root->fs_info->fs_devices->rw_devices++;
1672 }
1673 goto error_brelse;
1674 }
1675
1676 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1677 struct btrfs_device *srcdev)
1678 {
1679 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1680 list_del_rcu(&srcdev->dev_list);
1681 list_del_rcu(&srcdev->dev_alloc_list);
1682 fs_info->fs_devices->num_devices--;
1683 if (srcdev->missing) {
1684 fs_info->fs_devices->missing_devices--;
1685 fs_info->fs_devices->rw_devices++;
1686 }
1687 if (srcdev->can_discard)
1688 fs_info->fs_devices->num_can_discard--;
1689 if (srcdev->bdev)
1690 fs_info->fs_devices->open_devices--;
1691
1692 call_rcu(&srcdev->rcu, free_device);
1693 }
1694
1695 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1696 struct btrfs_device *tgtdev)
1697 {
1698 struct btrfs_device *next_device;
1699
1700 WARN_ON(!tgtdev);
1701 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1702 if (tgtdev->bdev) {
1703 btrfs_scratch_superblock(tgtdev);
1704 fs_info->fs_devices->open_devices--;
1705 }
1706 fs_info->fs_devices->num_devices--;
1707 if (tgtdev->can_discard)
1708 fs_info->fs_devices->num_can_discard++;
1709
1710 next_device = list_entry(fs_info->fs_devices->devices.next,
1711 struct btrfs_device, dev_list);
1712 if (tgtdev->bdev == fs_info->sb->s_bdev)
1713 fs_info->sb->s_bdev = next_device->bdev;
1714 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1715 fs_info->fs_devices->latest_bdev = next_device->bdev;
1716 list_del_rcu(&tgtdev->dev_list);
1717
1718 call_rcu(&tgtdev->rcu, free_device);
1719
1720 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1721 }
1722
1723 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1724 struct btrfs_device **device)
1725 {
1726 int ret = 0;
1727 struct btrfs_super_block *disk_super;
1728 u64 devid;
1729 u8 *dev_uuid;
1730 struct block_device *bdev;
1731 struct buffer_head *bh;
1732
1733 *device = NULL;
1734 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1735 root->fs_info->bdev_holder, 0, &bdev, &bh);
1736 if (ret)
1737 return ret;
1738 disk_super = (struct btrfs_super_block *)bh->b_data;
1739 devid = btrfs_stack_device_id(&disk_super->dev_item);
1740 dev_uuid = disk_super->dev_item.uuid;
1741 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1742 disk_super->fsid);
1743 brelse(bh);
1744 if (!*device)
1745 ret = -ENOENT;
1746 blkdev_put(bdev, FMODE_READ);
1747 return ret;
1748 }
1749
1750 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1751 char *device_path,
1752 struct btrfs_device **device)
1753 {
1754 *device = NULL;
1755 if (strcmp(device_path, "missing") == 0) {
1756 struct list_head *devices;
1757 struct btrfs_device *tmp;
1758
1759 devices = &root->fs_info->fs_devices->devices;
1760 /*
1761 * It is safe to read the devices since the volume_mutex
1762 * is held by the caller.
1763 */
1764 list_for_each_entry(tmp, devices, dev_list) {
1765 if (tmp->in_fs_metadata && !tmp->bdev) {
1766 *device = tmp;
1767 break;
1768 }
1769 }
1770
1771 if (!*device) {
1772 pr_err("btrfs: no missing device found\n");
1773 return -ENOENT;
1774 }
1775
1776 return 0;
1777 } else {
1778 return btrfs_find_device_by_path(root, device_path, device);
1779 }
1780 }
1781
1782 /*
1783 * does all the dirty work required for changing file system's UUID.
1784 */
1785 static int btrfs_prepare_sprout(struct btrfs_root *root)
1786 {
1787 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1788 struct btrfs_fs_devices *old_devices;
1789 struct btrfs_fs_devices *seed_devices;
1790 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1791 struct btrfs_device *device;
1792 u64 super_flags;
1793
1794 BUG_ON(!mutex_is_locked(&uuid_mutex));
1795 if (!fs_devices->seeding)
1796 return -EINVAL;
1797
1798 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1799 if (!seed_devices)
1800 return -ENOMEM;
1801
1802 old_devices = clone_fs_devices(fs_devices);
1803 if (IS_ERR(old_devices)) {
1804 kfree(seed_devices);
1805 return PTR_ERR(old_devices);
1806 }
1807
1808 list_add(&old_devices->list, &fs_uuids);
1809
1810 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1811 seed_devices->opened = 1;
1812 INIT_LIST_HEAD(&seed_devices->devices);
1813 INIT_LIST_HEAD(&seed_devices->alloc_list);
1814 mutex_init(&seed_devices->device_list_mutex);
1815
1816 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1817 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1818 synchronize_rcu);
1819 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1820
1821 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1822 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1823 device->fs_devices = seed_devices;
1824 }
1825
1826 fs_devices->seeding = 0;
1827 fs_devices->num_devices = 0;
1828 fs_devices->open_devices = 0;
1829 fs_devices->total_devices = 0;
1830 fs_devices->seed = seed_devices;
1831
1832 generate_random_uuid(fs_devices->fsid);
1833 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1834 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1835 super_flags = btrfs_super_flags(disk_super) &
1836 ~BTRFS_SUPER_FLAG_SEEDING;
1837 btrfs_set_super_flags(disk_super, super_flags);
1838
1839 return 0;
1840 }
1841
1842 /*
1843 * strore the expected generation for seed devices in device items.
1844 */
1845 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1846 struct btrfs_root *root)
1847 {
1848 struct btrfs_path *path;
1849 struct extent_buffer *leaf;
1850 struct btrfs_dev_item *dev_item;
1851 struct btrfs_device *device;
1852 struct btrfs_key key;
1853 u8 fs_uuid[BTRFS_UUID_SIZE];
1854 u8 dev_uuid[BTRFS_UUID_SIZE];
1855 u64 devid;
1856 int ret;
1857
1858 path = btrfs_alloc_path();
1859 if (!path)
1860 return -ENOMEM;
1861
1862 root = root->fs_info->chunk_root;
1863 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1864 key.offset = 0;
1865 key.type = BTRFS_DEV_ITEM_KEY;
1866
1867 while (1) {
1868 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1869 if (ret < 0)
1870 goto error;
1871
1872 leaf = path->nodes[0];
1873 next_slot:
1874 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1875 ret = btrfs_next_leaf(root, path);
1876 if (ret > 0)
1877 break;
1878 if (ret < 0)
1879 goto error;
1880 leaf = path->nodes[0];
1881 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1882 btrfs_release_path(path);
1883 continue;
1884 }
1885
1886 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1887 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1888 key.type != BTRFS_DEV_ITEM_KEY)
1889 break;
1890
1891 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1892 struct btrfs_dev_item);
1893 devid = btrfs_device_id(leaf, dev_item);
1894 read_extent_buffer(leaf, dev_uuid,
1895 (unsigned long)btrfs_device_uuid(dev_item),
1896 BTRFS_UUID_SIZE);
1897 read_extent_buffer(leaf, fs_uuid,
1898 (unsigned long)btrfs_device_fsid(dev_item),
1899 BTRFS_UUID_SIZE);
1900 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1901 fs_uuid);
1902 BUG_ON(!device); /* Logic error */
1903
1904 if (device->fs_devices->seeding) {
1905 btrfs_set_device_generation(leaf, dev_item,
1906 device->generation);
1907 btrfs_mark_buffer_dirty(leaf);
1908 }
1909
1910 path->slots[0]++;
1911 goto next_slot;
1912 }
1913 ret = 0;
1914 error:
1915 btrfs_free_path(path);
1916 return ret;
1917 }
1918
1919 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1920 {
1921 struct request_queue *q;
1922 struct btrfs_trans_handle *trans;
1923 struct btrfs_device *device;
1924 struct block_device *bdev;
1925 struct list_head *devices;
1926 struct super_block *sb = root->fs_info->sb;
1927 struct rcu_string *name;
1928 u64 total_bytes;
1929 int seeding_dev = 0;
1930 int ret = 0;
1931
1932 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1933 return -EROFS;
1934
1935 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1936 root->fs_info->bdev_holder);
1937 if (IS_ERR(bdev))
1938 return PTR_ERR(bdev);
1939
1940 if (root->fs_info->fs_devices->seeding) {
1941 seeding_dev = 1;
1942 down_write(&sb->s_umount);
1943 mutex_lock(&uuid_mutex);
1944 }
1945
1946 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1947
1948 devices = &root->fs_info->fs_devices->devices;
1949
1950 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1951 list_for_each_entry(device, devices, dev_list) {
1952 if (device->bdev == bdev) {
1953 ret = -EEXIST;
1954 mutex_unlock(
1955 &root->fs_info->fs_devices->device_list_mutex);
1956 goto error;
1957 }
1958 }
1959 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1960
1961 device = kzalloc(sizeof(*device), GFP_NOFS);
1962 if (!device) {
1963 /* we can safely leave the fs_devices entry around */
1964 ret = -ENOMEM;
1965 goto error;
1966 }
1967
1968 name = rcu_string_strdup(device_path, GFP_NOFS);
1969 if (!name) {
1970 kfree(device);
1971 ret = -ENOMEM;
1972 goto error;
1973 }
1974 rcu_assign_pointer(device->name, name);
1975
1976 ret = find_next_devid(root, &device->devid);
1977 if (ret) {
1978 rcu_string_free(device->name);
1979 kfree(device);
1980 goto error;
1981 }
1982
1983 trans = btrfs_start_transaction(root, 0);
1984 if (IS_ERR(trans)) {
1985 rcu_string_free(device->name);
1986 kfree(device);
1987 ret = PTR_ERR(trans);
1988 goto error;
1989 }
1990
1991 lock_chunks(root);
1992
1993 q = bdev_get_queue(bdev);
1994 if (blk_queue_discard(q))
1995 device->can_discard = 1;
1996 device->writeable = 1;
1997 device->work.func = pending_bios_fn;
1998 generate_random_uuid(device->uuid);
1999 spin_lock_init(&device->io_lock);
2000 device->generation = trans->transid;
2001 device->io_width = root->sectorsize;
2002 device->io_align = root->sectorsize;
2003 device->sector_size = root->sectorsize;
2004 device->total_bytes = i_size_read(bdev->bd_inode);
2005 device->disk_total_bytes = device->total_bytes;
2006 device->dev_root = root->fs_info->dev_root;
2007 device->bdev = bdev;
2008 device->in_fs_metadata = 1;
2009 device->is_tgtdev_for_dev_replace = 0;
2010 device->mode = FMODE_EXCL;
2011 set_blocksize(device->bdev, 4096);
2012
2013 if (seeding_dev) {
2014 sb->s_flags &= ~MS_RDONLY;
2015 ret = btrfs_prepare_sprout(root);
2016 BUG_ON(ret); /* -ENOMEM */
2017 }
2018
2019 device->fs_devices = root->fs_info->fs_devices;
2020
2021 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2022 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2023 list_add(&device->dev_alloc_list,
2024 &root->fs_info->fs_devices->alloc_list);
2025 root->fs_info->fs_devices->num_devices++;
2026 root->fs_info->fs_devices->open_devices++;
2027 root->fs_info->fs_devices->rw_devices++;
2028 root->fs_info->fs_devices->total_devices++;
2029 if (device->can_discard)
2030 root->fs_info->fs_devices->num_can_discard++;
2031 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2032
2033 spin_lock(&root->fs_info->free_chunk_lock);
2034 root->fs_info->free_chunk_space += device->total_bytes;
2035 spin_unlock(&root->fs_info->free_chunk_lock);
2036
2037 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2038 root->fs_info->fs_devices->rotating = 1;
2039
2040 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2041 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2042 total_bytes + device->total_bytes);
2043
2044 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2045 btrfs_set_super_num_devices(root->fs_info->super_copy,
2046 total_bytes + 1);
2047 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2048
2049 if (seeding_dev) {
2050 ret = init_first_rw_device(trans, root, device);
2051 if (ret) {
2052 btrfs_abort_transaction(trans, root, ret);
2053 goto error_trans;
2054 }
2055 ret = btrfs_finish_sprout(trans, root);
2056 if (ret) {
2057 btrfs_abort_transaction(trans, root, ret);
2058 goto error_trans;
2059 }
2060 } else {
2061 ret = btrfs_add_device(trans, root, device);
2062 if (ret) {
2063 btrfs_abort_transaction(trans, root, ret);
2064 goto error_trans;
2065 }
2066 }
2067
2068 /*
2069 * we've got more storage, clear any full flags on the space
2070 * infos
2071 */
2072 btrfs_clear_space_info_full(root->fs_info);
2073
2074 unlock_chunks(root);
2075 root->fs_info->num_tolerated_disk_barrier_failures =
2076 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2077 ret = btrfs_commit_transaction(trans, root);
2078
2079 if (seeding_dev) {
2080 mutex_unlock(&uuid_mutex);
2081 up_write(&sb->s_umount);
2082
2083 if (ret) /* transaction commit */
2084 return ret;
2085
2086 ret = btrfs_relocate_sys_chunks(root);
2087 if (ret < 0)
2088 btrfs_error(root->fs_info, ret,
2089 "Failed to relocate sys chunks after "
2090 "device initialization. This can be fixed "
2091 "using the \"btrfs balance\" command.");
2092 trans = btrfs_attach_transaction(root);
2093 if (IS_ERR(trans)) {
2094 if (PTR_ERR(trans) == -ENOENT)
2095 return 0;
2096 return PTR_ERR(trans);
2097 }
2098 ret = btrfs_commit_transaction(trans, root);
2099 }
2100
2101 return ret;
2102
2103 error_trans:
2104 unlock_chunks(root);
2105 btrfs_end_transaction(trans, root);
2106 rcu_string_free(device->name);
2107 kfree(device);
2108 error:
2109 blkdev_put(bdev, FMODE_EXCL);
2110 if (seeding_dev) {
2111 mutex_unlock(&uuid_mutex);
2112 up_write(&sb->s_umount);
2113 }
2114 return ret;
2115 }
2116
2117 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2118 struct btrfs_device **device_out)
2119 {
2120 struct request_queue *q;
2121 struct btrfs_device *device;
2122 struct block_device *bdev;
2123 struct btrfs_fs_info *fs_info = root->fs_info;
2124 struct list_head *devices;
2125 struct rcu_string *name;
2126 int ret = 0;
2127
2128 *device_out = NULL;
2129 if (fs_info->fs_devices->seeding)
2130 return -EINVAL;
2131
2132 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2133 fs_info->bdev_holder);
2134 if (IS_ERR(bdev))
2135 return PTR_ERR(bdev);
2136
2137 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2138
2139 devices = &fs_info->fs_devices->devices;
2140 list_for_each_entry(device, devices, dev_list) {
2141 if (device->bdev == bdev) {
2142 ret = -EEXIST;
2143 goto error;
2144 }
2145 }
2146
2147 device = kzalloc(sizeof(*device), GFP_NOFS);
2148 if (!device) {
2149 ret = -ENOMEM;
2150 goto error;
2151 }
2152
2153 name = rcu_string_strdup(device_path, GFP_NOFS);
2154 if (!name) {
2155 kfree(device);
2156 ret = -ENOMEM;
2157 goto error;
2158 }
2159 rcu_assign_pointer(device->name, name);
2160
2161 q = bdev_get_queue(bdev);
2162 if (blk_queue_discard(q))
2163 device->can_discard = 1;
2164 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2165 device->writeable = 1;
2166 device->work.func = pending_bios_fn;
2167 generate_random_uuid(device->uuid);
2168 device->devid = BTRFS_DEV_REPLACE_DEVID;
2169 spin_lock_init(&device->io_lock);
2170 device->generation = 0;
2171 device->io_width = root->sectorsize;
2172 device->io_align = root->sectorsize;
2173 device->sector_size = root->sectorsize;
2174 device->total_bytes = i_size_read(bdev->bd_inode);
2175 device->disk_total_bytes = device->total_bytes;
2176 device->dev_root = fs_info->dev_root;
2177 device->bdev = bdev;
2178 device->in_fs_metadata = 1;
2179 device->is_tgtdev_for_dev_replace = 1;
2180 device->mode = FMODE_EXCL;
2181 set_blocksize(device->bdev, 4096);
2182 device->fs_devices = fs_info->fs_devices;
2183 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2184 fs_info->fs_devices->num_devices++;
2185 fs_info->fs_devices->open_devices++;
2186 if (device->can_discard)
2187 fs_info->fs_devices->num_can_discard++;
2188 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2189
2190 *device_out = device;
2191 return ret;
2192
2193 error:
2194 blkdev_put(bdev, FMODE_EXCL);
2195 return ret;
2196 }
2197
2198 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2199 struct btrfs_device *tgtdev)
2200 {
2201 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2202 tgtdev->io_width = fs_info->dev_root->sectorsize;
2203 tgtdev->io_align = fs_info->dev_root->sectorsize;
2204 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2205 tgtdev->dev_root = fs_info->dev_root;
2206 tgtdev->in_fs_metadata = 1;
2207 }
2208
2209 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2210 struct btrfs_device *device)
2211 {
2212 int ret;
2213 struct btrfs_path *path;
2214 struct btrfs_root *root;
2215 struct btrfs_dev_item *dev_item;
2216 struct extent_buffer *leaf;
2217 struct btrfs_key key;
2218
2219 root = device->dev_root->fs_info->chunk_root;
2220
2221 path = btrfs_alloc_path();
2222 if (!path)
2223 return -ENOMEM;
2224
2225 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2226 key.type = BTRFS_DEV_ITEM_KEY;
2227 key.offset = device->devid;
2228
2229 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2230 if (ret < 0)
2231 goto out;
2232
2233 if (ret > 0) {
2234 ret = -ENOENT;
2235 goto out;
2236 }
2237
2238 leaf = path->nodes[0];
2239 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2240
2241 btrfs_set_device_id(leaf, dev_item, device->devid);
2242 btrfs_set_device_type(leaf, dev_item, device->type);
2243 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2244 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2245 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2246 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2247 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2248 btrfs_mark_buffer_dirty(leaf);
2249
2250 out:
2251 btrfs_free_path(path);
2252 return ret;
2253 }
2254
2255 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2256 struct btrfs_device *device, u64 new_size)
2257 {
2258 struct btrfs_super_block *super_copy =
2259 device->dev_root->fs_info->super_copy;
2260 u64 old_total = btrfs_super_total_bytes(super_copy);
2261 u64 diff = new_size - device->total_bytes;
2262
2263 if (!device->writeable)
2264 return -EACCES;
2265 if (new_size <= device->total_bytes ||
2266 device->is_tgtdev_for_dev_replace)
2267 return -EINVAL;
2268
2269 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2270 device->fs_devices->total_rw_bytes += diff;
2271
2272 device->total_bytes = new_size;
2273 device->disk_total_bytes = new_size;
2274 btrfs_clear_space_info_full(device->dev_root->fs_info);
2275
2276 return btrfs_update_device(trans, device);
2277 }
2278
2279 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2280 struct btrfs_device *device, u64 new_size)
2281 {
2282 int ret;
2283 lock_chunks(device->dev_root);
2284 ret = __btrfs_grow_device(trans, device, new_size);
2285 unlock_chunks(device->dev_root);
2286 return ret;
2287 }
2288
2289 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2290 struct btrfs_root *root,
2291 u64 chunk_tree, u64 chunk_objectid,
2292 u64 chunk_offset)
2293 {
2294 int ret;
2295 struct btrfs_path *path;
2296 struct btrfs_key key;
2297
2298 root = root->fs_info->chunk_root;
2299 path = btrfs_alloc_path();
2300 if (!path)
2301 return -ENOMEM;
2302
2303 key.objectid = chunk_objectid;
2304 key.offset = chunk_offset;
2305 key.type = BTRFS_CHUNK_ITEM_KEY;
2306
2307 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2308 if (ret < 0)
2309 goto out;
2310 else if (ret > 0) { /* Logic error or corruption */
2311 btrfs_error(root->fs_info, -ENOENT,
2312 "Failed lookup while freeing chunk.");
2313 ret = -ENOENT;
2314 goto out;
2315 }
2316
2317 ret = btrfs_del_item(trans, root, path);
2318 if (ret < 0)
2319 btrfs_error(root->fs_info, ret,
2320 "Failed to delete chunk item.");
2321 out:
2322 btrfs_free_path(path);
2323 return ret;
2324 }
2325
2326 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2327 chunk_offset)
2328 {
2329 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2330 struct btrfs_disk_key *disk_key;
2331 struct btrfs_chunk *chunk;
2332 u8 *ptr;
2333 int ret = 0;
2334 u32 num_stripes;
2335 u32 array_size;
2336 u32 len = 0;
2337 u32 cur;
2338 struct btrfs_key key;
2339
2340 array_size = btrfs_super_sys_array_size(super_copy);
2341
2342 ptr = super_copy->sys_chunk_array;
2343 cur = 0;
2344
2345 while (cur < array_size) {
2346 disk_key = (struct btrfs_disk_key *)ptr;
2347 btrfs_disk_key_to_cpu(&key, disk_key);
2348
2349 len = sizeof(*disk_key);
2350
2351 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2352 chunk = (struct btrfs_chunk *)(ptr + len);
2353 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2354 len += btrfs_chunk_item_size(num_stripes);
2355 } else {
2356 ret = -EIO;
2357 break;
2358 }
2359 if (key.objectid == chunk_objectid &&
2360 key.offset == chunk_offset) {
2361 memmove(ptr, ptr + len, array_size - (cur + len));
2362 array_size -= len;
2363 btrfs_set_super_sys_array_size(super_copy, array_size);
2364 } else {
2365 ptr += len;
2366 cur += len;
2367 }
2368 }
2369 return ret;
2370 }
2371
2372 static int btrfs_relocate_chunk(struct btrfs_root *root,
2373 u64 chunk_tree, u64 chunk_objectid,
2374 u64 chunk_offset)
2375 {
2376 struct extent_map_tree *em_tree;
2377 struct btrfs_root *extent_root;
2378 struct btrfs_trans_handle *trans;
2379 struct extent_map *em;
2380 struct map_lookup *map;
2381 int ret;
2382 int i;
2383
2384 root = root->fs_info->chunk_root;
2385 extent_root = root->fs_info->extent_root;
2386 em_tree = &root->fs_info->mapping_tree.map_tree;
2387
2388 ret = btrfs_can_relocate(extent_root, chunk_offset);
2389 if (ret)
2390 return -ENOSPC;
2391
2392 /* step one, relocate all the extents inside this chunk */
2393 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2394 if (ret)
2395 return ret;
2396
2397 trans = btrfs_start_transaction(root, 0);
2398 if (IS_ERR(trans)) {
2399 ret = PTR_ERR(trans);
2400 btrfs_std_error(root->fs_info, ret);
2401 return ret;
2402 }
2403
2404 lock_chunks(root);
2405
2406 /*
2407 * step two, delete the device extents and the
2408 * chunk tree entries
2409 */
2410 read_lock(&em_tree->lock);
2411 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2412 read_unlock(&em_tree->lock);
2413
2414 BUG_ON(!em || em->start > chunk_offset ||
2415 em->start + em->len < chunk_offset);
2416 map = (struct map_lookup *)em->bdev;
2417
2418 for (i = 0; i < map->num_stripes; i++) {
2419 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2420 map->stripes[i].physical);
2421 BUG_ON(ret);
2422
2423 if (map->stripes[i].dev) {
2424 ret = btrfs_update_device(trans, map->stripes[i].dev);
2425 BUG_ON(ret);
2426 }
2427 }
2428 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2429 chunk_offset);
2430
2431 BUG_ON(ret);
2432
2433 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2434
2435 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2436 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2437 BUG_ON(ret);
2438 }
2439
2440 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2441 BUG_ON(ret);
2442
2443 write_lock(&em_tree->lock);
2444 remove_extent_mapping(em_tree, em);
2445 write_unlock(&em_tree->lock);
2446
2447 kfree(map);
2448 em->bdev = NULL;
2449
2450 /* once for the tree */
2451 free_extent_map(em);
2452 /* once for us */
2453 free_extent_map(em);
2454
2455 unlock_chunks(root);
2456 btrfs_end_transaction(trans, root);
2457 return 0;
2458 }
2459
2460 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2461 {
2462 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2463 struct btrfs_path *path;
2464 struct extent_buffer *leaf;
2465 struct btrfs_chunk *chunk;
2466 struct btrfs_key key;
2467 struct btrfs_key found_key;
2468 u64 chunk_tree = chunk_root->root_key.objectid;
2469 u64 chunk_type;
2470 bool retried = false;
2471 int failed = 0;
2472 int ret;
2473
2474 path = btrfs_alloc_path();
2475 if (!path)
2476 return -ENOMEM;
2477
2478 again:
2479 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2480 key.offset = (u64)-1;
2481 key.type = BTRFS_CHUNK_ITEM_KEY;
2482
2483 while (1) {
2484 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2485 if (ret < 0)
2486 goto error;
2487 BUG_ON(ret == 0); /* Corruption */
2488
2489 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2490 key.type);
2491 if (ret < 0)
2492 goto error;
2493 if (ret > 0)
2494 break;
2495
2496 leaf = path->nodes[0];
2497 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2498
2499 chunk = btrfs_item_ptr(leaf, path->slots[0],
2500 struct btrfs_chunk);
2501 chunk_type = btrfs_chunk_type(leaf, chunk);
2502 btrfs_release_path(path);
2503
2504 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2505 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2506 found_key.objectid,
2507 found_key.offset);
2508 if (ret == -ENOSPC)
2509 failed++;
2510 else if (ret)
2511 BUG();
2512 }
2513
2514 if (found_key.offset == 0)
2515 break;
2516 key.offset = found_key.offset - 1;
2517 }
2518 ret = 0;
2519 if (failed && !retried) {
2520 failed = 0;
2521 retried = true;
2522 goto again;
2523 } else if (failed && retried) {
2524 WARN_ON(1);
2525 ret = -ENOSPC;
2526 }
2527 error:
2528 btrfs_free_path(path);
2529 return ret;
2530 }
2531
2532 static int insert_balance_item(struct btrfs_root *root,
2533 struct btrfs_balance_control *bctl)
2534 {
2535 struct btrfs_trans_handle *trans;
2536 struct btrfs_balance_item *item;
2537 struct btrfs_disk_balance_args disk_bargs;
2538 struct btrfs_path *path;
2539 struct extent_buffer *leaf;
2540 struct btrfs_key key;
2541 int ret, err;
2542
2543 path = btrfs_alloc_path();
2544 if (!path)
2545 return -ENOMEM;
2546
2547 trans = btrfs_start_transaction(root, 0);
2548 if (IS_ERR(trans)) {
2549 btrfs_free_path(path);
2550 return PTR_ERR(trans);
2551 }
2552
2553 key.objectid = BTRFS_BALANCE_OBJECTID;
2554 key.type = BTRFS_BALANCE_ITEM_KEY;
2555 key.offset = 0;
2556
2557 ret = btrfs_insert_empty_item(trans, root, path, &key,
2558 sizeof(*item));
2559 if (ret)
2560 goto out;
2561
2562 leaf = path->nodes[0];
2563 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2564
2565 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2566
2567 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2568 btrfs_set_balance_data(leaf, item, &disk_bargs);
2569 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2570 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2571 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2572 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2573
2574 btrfs_set_balance_flags(leaf, item, bctl->flags);
2575
2576 btrfs_mark_buffer_dirty(leaf);
2577 out:
2578 btrfs_free_path(path);
2579 err = btrfs_commit_transaction(trans, root);
2580 if (err && !ret)
2581 ret = err;
2582 return ret;
2583 }
2584
2585 static int del_balance_item(struct btrfs_root *root)
2586 {
2587 struct btrfs_trans_handle *trans;
2588 struct btrfs_path *path;
2589 struct btrfs_key key;
2590 int ret, err;
2591
2592 path = btrfs_alloc_path();
2593 if (!path)
2594 return -ENOMEM;
2595
2596 trans = btrfs_start_transaction(root, 0);
2597 if (IS_ERR(trans)) {
2598 btrfs_free_path(path);
2599 return PTR_ERR(trans);
2600 }
2601
2602 key.objectid = BTRFS_BALANCE_OBJECTID;
2603 key.type = BTRFS_BALANCE_ITEM_KEY;
2604 key.offset = 0;
2605
2606 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2607 if (ret < 0)
2608 goto out;
2609 if (ret > 0) {
2610 ret = -ENOENT;
2611 goto out;
2612 }
2613
2614 ret = btrfs_del_item(trans, root, path);
2615 out:
2616 btrfs_free_path(path);
2617 err = btrfs_commit_transaction(trans, root);
2618 if (err && !ret)
2619 ret = err;
2620 return ret;
2621 }
2622
2623 /*
2624 * This is a heuristic used to reduce the number of chunks balanced on
2625 * resume after balance was interrupted.
2626 */
2627 static void update_balance_args(struct btrfs_balance_control *bctl)
2628 {
2629 /*
2630 * Turn on soft mode for chunk types that were being converted.
2631 */
2632 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2633 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2634 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2635 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2636 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2637 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2638
2639 /*
2640 * Turn on usage filter if is not already used. The idea is
2641 * that chunks that we have already balanced should be
2642 * reasonably full. Don't do it for chunks that are being
2643 * converted - that will keep us from relocating unconverted
2644 * (albeit full) chunks.
2645 */
2646 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2647 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2648 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2649 bctl->data.usage = 90;
2650 }
2651 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2652 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2653 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2654 bctl->sys.usage = 90;
2655 }
2656 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2657 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2658 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2659 bctl->meta.usage = 90;
2660 }
2661 }
2662
2663 /*
2664 * Should be called with both balance and volume mutexes held to
2665 * serialize other volume operations (add_dev/rm_dev/resize) with
2666 * restriper. Same goes for unset_balance_control.
2667 */
2668 static void set_balance_control(struct btrfs_balance_control *bctl)
2669 {
2670 struct btrfs_fs_info *fs_info = bctl->fs_info;
2671
2672 BUG_ON(fs_info->balance_ctl);
2673
2674 spin_lock(&fs_info->balance_lock);
2675 fs_info->balance_ctl = bctl;
2676 spin_unlock(&fs_info->balance_lock);
2677 }
2678
2679 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2680 {
2681 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2682
2683 BUG_ON(!fs_info->balance_ctl);
2684
2685 spin_lock(&fs_info->balance_lock);
2686 fs_info->balance_ctl = NULL;
2687 spin_unlock(&fs_info->balance_lock);
2688
2689 kfree(bctl);
2690 }
2691
2692 /*
2693 * Balance filters. Return 1 if chunk should be filtered out
2694 * (should not be balanced).
2695 */
2696 static int chunk_profiles_filter(u64 chunk_type,
2697 struct btrfs_balance_args *bargs)
2698 {
2699 chunk_type = chunk_to_extended(chunk_type) &
2700 BTRFS_EXTENDED_PROFILE_MASK;
2701
2702 if (bargs->profiles & chunk_type)
2703 return 0;
2704
2705 return 1;
2706 }
2707
2708 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2709 struct btrfs_balance_args *bargs)
2710 {
2711 struct btrfs_block_group_cache *cache;
2712 u64 chunk_used, user_thresh;
2713 int ret = 1;
2714
2715 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2716 chunk_used = btrfs_block_group_used(&cache->item);
2717
2718 if (bargs->usage == 0)
2719 user_thresh = 1;
2720 else if (bargs->usage > 100)
2721 user_thresh = cache->key.offset;
2722 else
2723 user_thresh = div_factor_fine(cache->key.offset,
2724 bargs->usage);
2725
2726 if (chunk_used < user_thresh)
2727 ret = 0;
2728
2729 btrfs_put_block_group(cache);
2730 return ret;
2731 }
2732
2733 static int chunk_devid_filter(struct extent_buffer *leaf,
2734 struct btrfs_chunk *chunk,
2735 struct btrfs_balance_args *bargs)
2736 {
2737 struct btrfs_stripe *stripe;
2738 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2739 int i;
2740
2741 for (i = 0; i < num_stripes; i++) {
2742 stripe = btrfs_stripe_nr(chunk, i);
2743 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2744 return 0;
2745 }
2746
2747 return 1;
2748 }
2749
2750 /* [pstart, pend) */
2751 static int chunk_drange_filter(struct extent_buffer *leaf,
2752 struct btrfs_chunk *chunk,
2753 u64 chunk_offset,
2754 struct btrfs_balance_args *bargs)
2755 {
2756 struct btrfs_stripe *stripe;
2757 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2758 u64 stripe_offset;
2759 u64 stripe_length;
2760 int factor;
2761 int i;
2762
2763 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2764 return 0;
2765
2766 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2767 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2768 factor = num_stripes / 2;
2769 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2770 factor = num_stripes - 1;
2771 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2772 factor = num_stripes - 2;
2773 } else {
2774 factor = num_stripes;
2775 }
2776
2777 for (i = 0; i < num_stripes; i++) {
2778 stripe = btrfs_stripe_nr(chunk, i);
2779 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2780 continue;
2781
2782 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2783 stripe_length = btrfs_chunk_length(leaf, chunk);
2784 do_div(stripe_length, factor);
2785
2786 if (stripe_offset < bargs->pend &&
2787 stripe_offset + stripe_length > bargs->pstart)
2788 return 0;
2789 }
2790
2791 return 1;
2792 }
2793
2794 /* [vstart, vend) */
2795 static int chunk_vrange_filter(struct extent_buffer *leaf,
2796 struct btrfs_chunk *chunk,
2797 u64 chunk_offset,
2798 struct btrfs_balance_args *bargs)
2799 {
2800 if (chunk_offset < bargs->vend &&
2801 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2802 /* at least part of the chunk is inside this vrange */
2803 return 0;
2804
2805 return 1;
2806 }
2807
2808 static int chunk_soft_convert_filter(u64 chunk_type,
2809 struct btrfs_balance_args *bargs)
2810 {
2811 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2812 return 0;
2813
2814 chunk_type = chunk_to_extended(chunk_type) &
2815 BTRFS_EXTENDED_PROFILE_MASK;
2816
2817 if (bargs->target == chunk_type)
2818 return 1;
2819
2820 return 0;
2821 }
2822
2823 static int should_balance_chunk(struct btrfs_root *root,
2824 struct extent_buffer *leaf,
2825 struct btrfs_chunk *chunk, u64 chunk_offset)
2826 {
2827 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2828 struct btrfs_balance_args *bargs = NULL;
2829 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2830
2831 /* type filter */
2832 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2833 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2834 return 0;
2835 }
2836
2837 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2838 bargs = &bctl->data;
2839 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2840 bargs = &bctl->sys;
2841 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2842 bargs = &bctl->meta;
2843
2844 /* profiles filter */
2845 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2846 chunk_profiles_filter(chunk_type, bargs)) {
2847 return 0;
2848 }
2849
2850 /* usage filter */
2851 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2852 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2853 return 0;
2854 }
2855
2856 /* devid filter */
2857 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2858 chunk_devid_filter(leaf, chunk, bargs)) {
2859 return 0;
2860 }
2861
2862 /* drange filter, makes sense only with devid filter */
2863 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2864 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2865 return 0;
2866 }
2867
2868 /* vrange filter */
2869 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2870 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2871 return 0;
2872 }
2873
2874 /* soft profile changing mode */
2875 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2876 chunk_soft_convert_filter(chunk_type, bargs)) {
2877 return 0;
2878 }
2879
2880 return 1;
2881 }
2882
2883 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2884 {
2885 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2886 struct btrfs_root *chunk_root = fs_info->chunk_root;
2887 struct btrfs_root *dev_root = fs_info->dev_root;
2888 struct list_head *devices;
2889 struct btrfs_device *device;
2890 u64 old_size;
2891 u64 size_to_free;
2892 struct btrfs_chunk *chunk;
2893 struct btrfs_path *path;
2894 struct btrfs_key key;
2895 struct btrfs_key found_key;
2896 struct btrfs_trans_handle *trans;
2897 struct extent_buffer *leaf;
2898 int slot;
2899 int ret;
2900 int enospc_errors = 0;
2901 bool counting = true;
2902
2903 /* step one make some room on all the devices */
2904 devices = &fs_info->fs_devices->devices;
2905 list_for_each_entry(device, devices, dev_list) {
2906 old_size = device->total_bytes;
2907 size_to_free = div_factor(old_size, 1);
2908 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2909 if (!device->writeable ||
2910 device->total_bytes - device->bytes_used > size_to_free ||
2911 device->is_tgtdev_for_dev_replace)
2912 continue;
2913
2914 ret = btrfs_shrink_device(device, old_size - size_to_free);
2915 if (ret == -ENOSPC)
2916 break;
2917 BUG_ON(ret);
2918
2919 trans = btrfs_start_transaction(dev_root, 0);
2920 BUG_ON(IS_ERR(trans));
2921
2922 ret = btrfs_grow_device(trans, device, old_size);
2923 BUG_ON(ret);
2924
2925 btrfs_end_transaction(trans, dev_root);
2926 }
2927
2928 /* step two, relocate all the chunks */
2929 path = btrfs_alloc_path();
2930 if (!path) {
2931 ret = -ENOMEM;
2932 goto error;
2933 }
2934
2935 /* zero out stat counters */
2936 spin_lock(&fs_info->balance_lock);
2937 memset(&bctl->stat, 0, sizeof(bctl->stat));
2938 spin_unlock(&fs_info->balance_lock);
2939 again:
2940 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2941 key.offset = (u64)-1;
2942 key.type = BTRFS_CHUNK_ITEM_KEY;
2943
2944 while (1) {
2945 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2946 atomic_read(&fs_info->balance_cancel_req)) {
2947 ret = -ECANCELED;
2948 goto error;
2949 }
2950
2951 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2952 if (ret < 0)
2953 goto error;
2954
2955 /*
2956 * this shouldn't happen, it means the last relocate
2957 * failed
2958 */
2959 if (ret == 0)
2960 BUG(); /* FIXME break ? */
2961
2962 ret = btrfs_previous_item(chunk_root, path, 0,
2963 BTRFS_CHUNK_ITEM_KEY);
2964 if (ret) {
2965 ret = 0;
2966 break;
2967 }
2968
2969 leaf = path->nodes[0];
2970 slot = path->slots[0];
2971 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2972
2973 if (found_key.objectid != key.objectid)
2974 break;
2975
2976 /* chunk zero is special */
2977 if (found_key.offset == 0)
2978 break;
2979
2980 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2981
2982 if (!counting) {
2983 spin_lock(&fs_info->balance_lock);
2984 bctl->stat.considered++;
2985 spin_unlock(&fs_info->balance_lock);
2986 }
2987
2988 ret = should_balance_chunk(chunk_root, leaf, chunk,
2989 found_key.offset);
2990 btrfs_release_path(path);
2991 if (!ret)
2992 goto loop;
2993
2994 if (counting) {
2995 spin_lock(&fs_info->balance_lock);
2996 bctl->stat.expected++;
2997 spin_unlock(&fs_info->balance_lock);
2998 goto loop;
2999 }
3000
3001 ret = btrfs_relocate_chunk(chunk_root,
3002 chunk_root->root_key.objectid,
3003 found_key.objectid,
3004 found_key.offset);
3005 if (ret && ret != -ENOSPC)
3006 goto error;
3007 if (ret == -ENOSPC) {
3008 enospc_errors++;
3009 } else {
3010 spin_lock(&fs_info->balance_lock);
3011 bctl->stat.completed++;
3012 spin_unlock(&fs_info->balance_lock);
3013 }
3014 loop:
3015 key.offset = found_key.offset - 1;
3016 }
3017
3018 if (counting) {
3019 btrfs_release_path(path);
3020 counting = false;
3021 goto again;
3022 }
3023 error:
3024 btrfs_free_path(path);
3025 if (enospc_errors) {
3026 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
3027 enospc_errors);
3028 if (!ret)
3029 ret = -ENOSPC;
3030 }
3031
3032 return ret;
3033 }
3034
3035 /**
3036 * alloc_profile_is_valid - see if a given profile is valid and reduced
3037 * @flags: profile to validate
3038 * @extended: if true @flags is treated as an extended profile
3039 */
3040 static int alloc_profile_is_valid(u64 flags, int extended)
3041 {
3042 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3043 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3044
3045 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3046
3047 /* 1) check that all other bits are zeroed */
3048 if (flags & ~mask)
3049 return 0;
3050
3051 /* 2) see if profile is reduced */
3052 if (flags == 0)
3053 return !extended; /* "0" is valid for usual profiles */
3054
3055 /* true if exactly one bit set */
3056 return (flags & (flags - 1)) == 0;
3057 }
3058
3059 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3060 {
3061 /* cancel requested || normal exit path */
3062 return atomic_read(&fs_info->balance_cancel_req) ||
3063 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3064 atomic_read(&fs_info->balance_cancel_req) == 0);
3065 }
3066
3067 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3068 {
3069 int ret;
3070
3071 unset_balance_control(fs_info);
3072 ret = del_balance_item(fs_info->tree_root);
3073 if (ret)
3074 btrfs_std_error(fs_info, ret);
3075
3076 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3077 }
3078
3079 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3080 struct btrfs_ioctl_balance_args *bargs);
3081
3082 /*
3083 * Should be called with both balance and volume mutexes held
3084 */
3085 int btrfs_balance(struct btrfs_balance_control *bctl,
3086 struct btrfs_ioctl_balance_args *bargs)
3087 {
3088 struct btrfs_fs_info *fs_info = bctl->fs_info;
3089 u64 allowed;
3090 int mixed = 0;
3091 int ret;
3092 u64 num_devices;
3093 unsigned seq;
3094
3095 if (btrfs_fs_closing(fs_info) ||
3096 atomic_read(&fs_info->balance_pause_req) ||
3097 atomic_read(&fs_info->balance_cancel_req)) {
3098 ret = -EINVAL;
3099 goto out;
3100 }
3101
3102 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3103 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3104 mixed = 1;
3105
3106 /*
3107 * In case of mixed groups both data and meta should be picked,
3108 * and identical options should be given for both of them.
3109 */
3110 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3111 if (mixed && (bctl->flags & allowed)) {
3112 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3113 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3114 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3115 printk(KERN_ERR "btrfs: with mixed groups data and "
3116 "metadata balance options must be the same\n");
3117 ret = -EINVAL;
3118 goto out;
3119 }
3120 }
3121
3122 num_devices = fs_info->fs_devices->num_devices;
3123 btrfs_dev_replace_lock(&fs_info->dev_replace);
3124 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3125 BUG_ON(num_devices < 1);
3126 num_devices--;
3127 }
3128 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3129 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3130 if (num_devices == 1)
3131 allowed |= BTRFS_BLOCK_GROUP_DUP;
3132 else if (num_devices > 1)
3133 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3134 if (num_devices > 2)
3135 allowed |= BTRFS_BLOCK_GROUP_RAID5;
3136 if (num_devices > 3)
3137 allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
3138 BTRFS_BLOCK_GROUP_RAID6);
3139 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3140 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3141 (bctl->data.target & ~allowed))) {
3142 printk(KERN_ERR "btrfs: unable to start balance with target "
3143 "data profile %llu\n",
3144 (unsigned long long)bctl->data.target);
3145 ret = -EINVAL;
3146 goto out;
3147 }
3148 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3149 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3150 (bctl->meta.target & ~allowed))) {
3151 printk(KERN_ERR "btrfs: unable to start balance with target "
3152 "metadata profile %llu\n",
3153 (unsigned long long)bctl->meta.target);
3154 ret = -EINVAL;
3155 goto out;
3156 }
3157 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3158 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3159 (bctl->sys.target & ~allowed))) {
3160 printk(KERN_ERR "btrfs: unable to start balance with target "
3161 "system profile %llu\n",
3162 (unsigned long long)bctl->sys.target);
3163 ret = -EINVAL;
3164 goto out;
3165 }
3166
3167 /* allow dup'ed data chunks only in mixed mode */
3168 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3169 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3170 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3171 ret = -EINVAL;
3172 goto out;
3173 }
3174
3175 /* allow to reduce meta or sys integrity only if force set */
3176 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3177 BTRFS_BLOCK_GROUP_RAID10 |
3178 BTRFS_BLOCK_GROUP_RAID5 |
3179 BTRFS_BLOCK_GROUP_RAID6;
3180 do {
3181 seq = read_seqbegin(&fs_info->profiles_lock);
3182
3183 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3184 (fs_info->avail_system_alloc_bits & allowed) &&
3185 !(bctl->sys.target & allowed)) ||
3186 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3187 (fs_info->avail_metadata_alloc_bits & allowed) &&
3188 !(bctl->meta.target & allowed))) {
3189 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3190 printk(KERN_INFO "btrfs: force reducing metadata "
3191 "integrity\n");
3192 } else {
3193 printk(KERN_ERR "btrfs: balance will reduce metadata "
3194 "integrity, use force if you want this\n");
3195 ret = -EINVAL;
3196 goto out;
3197 }
3198 }
3199 } while (read_seqretry(&fs_info->profiles_lock, seq));
3200
3201 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3202 int num_tolerated_disk_barrier_failures;
3203 u64 target = bctl->sys.target;
3204
3205 num_tolerated_disk_barrier_failures =
3206 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3207 if (num_tolerated_disk_barrier_failures > 0 &&
3208 (target &
3209 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3210 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3211 num_tolerated_disk_barrier_failures = 0;
3212 else if (num_tolerated_disk_barrier_failures > 1 &&
3213 (target &
3214 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3215 num_tolerated_disk_barrier_failures = 1;
3216
3217 fs_info->num_tolerated_disk_barrier_failures =
3218 num_tolerated_disk_barrier_failures;
3219 }
3220
3221 ret = insert_balance_item(fs_info->tree_root, bctl);
3222 if (ret && ret != -EEXIST)
3223 goto out;
3224
3225 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3226 BUG_ON(ret == -EEXIST);
3227 set_balance_control(bctl);
3228 } else {
3229 BUG_ON(ret != -EEXIST);
3230 spin_lock(&fs_info->balance_lock);
3231 update_balance_args(bctl);
3232 spin_unlock(&fs_info->balance_lock);
3233 }
3234
3235 atomic_inc(&fs_info->balance_running);
3236 mutex_unlock(&fs_info->balance_mutex);
3237
3238 ret = __btrfs_balance(fs_info);
3239
3240 mutex_lock(&fs_info->balance_mutex);
3241 atomic_dec(&fs_info->balance_running);
3242
3243 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3244 fs_info->num_tolerated_disk_barrier_failures =
3245 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3246 }
3247
3248 if (bargs) {
3249 memset(bargs, 0, sizeof(*bargs));
3250 update_ioctl_balance_args(fs_info, 0, bargs);
3251 }
3252
3253 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3254 balance_need_close(fs_info)) {
3255 __cancel_balance(fs_info);
3256 }
3257
3258 wake_up(&fs_info->balance_wait_q);
3259
3260 return ret;
3261 out:
3262 if (bctl->flags & BTRFS_BALANCE_RESUME)
3263 __cancel_balance(fs_info);
3264 else {
3265 kfree(bctl);
3266 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3267 }
3268 return ret;
3269 }
3270
3271 static int balance_kthread(void *data)
3272 {
3273 struct btrfs_fs_info *fs_info = data;
3274 int ret = 0;
3275
3276 mutex_lock(&fs_info->volume_mutex);
3277 mutex_lock(&fs_info->balance_mutex);
3278
3279 if (fs_info->balance_ctl) {
3280 printk(KERN_INFO "btrfs: continuing balance\n");
3281 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3282 }
3283
3284 mutex_unlock(&fs_info->balance_mutex);
3285 mutex_unlock(&fs_info->volume_mutex);
3286
3287 return ret;
3288 }
3289
3290 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3291 {
3292 struct task_struct *tsk;
3293
3294 spin_lock(&fs_info->balance_lock);
3295 if (!fs_info->balance_ctl) {
3296 spin_unlock(&fs_info->balance_lock);
3297 return 0;
3298 }
3299 spin_unlock(&fs_info->balance_lock);
3300
3301 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3302 printk(KERN_INFO "btrfs: force skipping balance\n");
3303 return 0;
3304 }
3305
3306 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3307 return PTR_RET(tsk);
3308 }
3309
3310 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3311 {
3312 struct btrfs_balance_control *bctl;
3313 struct btrfs_balance_item *item;
3314 struct btrfs_disk_balance_args disk_bargs;
3315 struct btrfs_path *path;
3316 struct extent_buffer *leaf;
3317 struct btrfs_key key;
3318 int ret;
3319
3320 path = btrfs_alloc_path();
3321 if (!path)
3322 return -ENOMEM;
3323
3324 key.objectid = BTRFS_BALANCE_OBJECTID;
3325 key.type = BTRFS_BALANCE_ITEM_KEY;
3326 key.offset = 0;
3327
3328 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3329 if (ret < 0)
3330 goto out;
3331 if (ret > 0) { /* ret = -ENOENT; */
3332 ret = 0;
3333 goto out;
3334 }
3335
3336 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3337 if (!bctl) {
3338 ret = -ENOMEM;
3339 goto out;
3340 }
3341
3342 leaf = path->nodes[0];
3343 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3344
3345 bctl->fs_info = fs_info;
3346 bctl->flags = btrfs_balance_flags(leaf, item);
3347 bctl->flags |= BTRFS_BALANCE_RESUME;
3348
3349 btrfs_balance_data(leaf, item, &disk_bargs);
3350 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3351 btrfs_balance_meta(leaf, item, &disk_bargs);
3352 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3353 btrfs_balance_sys(leaf, item, &disk_bargs);
3354 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3355
3356 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3357
3358 mutex_lock(&fs_info->volume_mutex);
3359 mutex_lock(&fs_info->balance_mutex);
3360
3361 set_balance_control(bctl);
3362
3363 mutex_unlock(&fs_info->balance_mutex);
3364 mutex_unlock(&fs_info->volume_mutex);
3365 out:
3366 btrfs_free_path(path);
3367 return ret;
3368 }
3369
3370 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3371 {
3372 int ret = 0;
3373
3374 mutex_lock(&fs_info->balance_mutex);
3375 if (!fs_info->balance_ctl) {
3376 mutex_unlock(&fs_info->balance_mutex);
3377 return -ENOTCONN;
3378 }
3379
3380 if (atomic_read(&fs_info->balance_running)) {
3381 atomic_inc(&fs_info->balance_pause_req);
3382 mutex_unlock(&fs_info->balance_mutex);
3383
3384 wait_event(fs_info->balance_wait_q,
3385 atomic_read(&fs_info->balance_running) == 0);
3386
3387 mutex_lock(&fs_info->balance_mutex);
3388 /* we are good with balance_ctl ripped off from under us */
3389 BUG_ON(atomic_read(&fs_info->balance_running));
3390 atomic_dec(&fs_info->balance_pause_req);
3391 } else {
3392 ret = -ENOTCONN;
3393 }
3394
3395 mutex_unlock(&fs_info->balance_mutex);
3396 return ret;
3397 }
3398
3399 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3400 {
3401 mutex_lock(&fs_info->balance_mutex);
3402 if (!fs_info->balance_ctl) {
3403 mutex_unlock(&fs_info->balance_mutex);
3404 return -ENOTCONN;
3405 }
3406
3407 atomic_inc(&fs_info->balance_cancel_req);
3408 /*
3409 * if we are running just wait and return, balance item is
3410 * deleted in btrfs_balance in this case
3411 */
3412 if (atomic_read(&fs_info->balance_running)) {
3413 mutex_unlock(&fs_info->balance_mutex);
3414 wait_event(fs_info->balance_wait_q,
3415 atomic_read(&fs_info->balance_running) == 0);
3416 mutex_lock(&fs_info->balance_mutex);
3417 } else {
3418 /* __cancel_balance needs volume_mutex */
3419 mutex_unlock(&fs_info->balance_mutex);
3420 mutex_lock(&fs_info->volume_mutex);
3421 mutex_lock(&fs_info->balance_mutex);
3422
3423 if (fs_info->balance_ctl)
3424 __cancel_balance(fs_info);
3425
3426 mutex_unlock(&fs_info->volume_mutex);
3427 }
3428
3429 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3430 atomic_dec(&fs_info->balance_cancel_req);
3431 mutex_unlock(&fs_info->balance_mutex);
3432 return 0;
3433 }
3434
3435 /*
3436 * shrinking a device means finding all of the device extents past
3437 * the new size, and then following the back refs to the chunks.
3438 * The chunk relocation code actually frees the device extent
3439 */
3440 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3441 {
3442 struct btrfs_trans_handle *trans;
3443 struct btrfs_root *root = device->dev_root;
3444 struct btrfs_dev_extent *dev_extent = NULL;
3445 struct btrfs_path *path;
3446 u64 length;
3447 u64 chunk_tree;
3448 u64 chunk_objectid;
3449 u64 chunk_offset;
3450 int ret;
3451 int slot;
3452 int failed = 0;
3453 bool retried = false;
3454 struct extent_buffer *l;
3455 struct btrfs_key key;
3456 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3457 u64 old_total = btrfs_super_total_bytes(super_copy);
3458 u64 old_size = device->total_bytes;
3459 u64 diff = device->total_bytes - new_size;
3460
3461 if (device->is_tgtdev_for_dev_replace)
3462 return -EINVAL;
3463
3464 path = btrfs_alloc_path();
3465 if (!path)
3466 return -ENOMEM;
3467
3468 path->reada = 2;
3469
3470 lock_chunks(root);
3471
3472 device->total_bytes = new_size;
3473 if (device->writeable) {
3474 device->fs_devices->total_rw_bytes -= diff;
3475 spin_lock(&root->fs_info->free_chunk_lock);
3476 root->fs_info->free_chunk_space -= diff;
3477 spin_unlock(&root->fs_info->free_chunk_lock);
3478 }
3479 unlock_chunks(root);
3480
3481 again:
3482 key.objectid = device->devid;
3483 key.offset = (u64)-1;
3484 key.type = BTRFS_DEV_EXTENT_KEY;
3485
3486 do {
3487 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3488 if (ret < 0)
3489 goto done;
3490
3491 ret = btrfs_previous_item(root, path, 0, key.type);
3492 if (ret < 0)
3493 goto done;
3494 if (ret) {
3495 ret = 0;
3496 btrfs_release_path(path);
3497 break;
3498 }
3499
3500 l = path->nodes[0];
3501 slot = path->slots[0];
3502 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3503
3504 if (key.objectid != device->devid) {
3505 btrfs_release_path(path);
3506 break;
3507 }
3508
3509 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3510 length = btrfs_dev_extent_length(l, dev_extent);
3511
3512 if (key.offset + length <= new_size) {
3513 btrfs_release_path(path);
3514 break;
3515 }
3516
3517 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3518 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3519 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3520 btrfs_release_path(path);
3521
3522 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3523 chunk_offset);
3524 if (ret && ret != -ENOSPC)
3525 goto done;
3526 if (ret == -ENOSPC)
3527 failed++;
3528 } while (key.offset-- > 0);
3529
3530 if (failed && !retried) {
3531 failed = 0;
3532 retried = true;
3533 goto again;
3534 } else if (failed && retried) {
3535 ret = -ENOSPC;
3536 lock_chunks(root);
3537
3538 device->total_bytes = old_size;
3539 if (device->writeable)
3540 device->fs_devices->total_rw_bytes += diff;
3541 spin_lock(&root->fs_info->free_chunk_lock);
3542 root->fs_info->free_chunk_space += diff;
3543 spin_unlock(&root->fs_info->free_chunk_lock);
3544 unlock_chunks(root);
3545 goto done;
3546 }
3547
3548 /* Shrinking succeeded, else we would be at "done". */
3549 trans = btrfs_start_transaction(root, 0);
3550 if (IS_ERR(trans)) {
3551 ret = PTR_ERR(trans);
3552 goto done;
3553 }
3554
3555 lock_chunks(root);
3556
3557 device->disk_total_bytes = new_size;
3558 /* Now btrfs_update_device() will change the on-disk size. */
3559 ret = btrfs_update_device(trans, device);
3560 if (ret) {
3561 unlock_chunks(root);
3562 btrfs_end_transaction(trans, root);
3563 goto done;
3564 }
3565 WARN_ON(diff > old_total);
3566 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3567 unlock_chunks(root);
3568 btrfs_end_transaction(trans, root);
3569 done:
3570 btrfs_free_path(path);
3571 return ret;
3572 }
3573
3574 static int btrfs_add_system_chunk(struct btrfs_root *root,
3575 struct btrfs_key *key,
3576 struct btrfs_chunk *chunk, int item_size)
3577 {
3578 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3579 struct btrfs_disk_key disk_key;
3580 u32 array_size;
3581 u8 *ptr;
3582
3583 array_size = btrfs_super_sys_array_size(super_copy);
3584 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3585 return -EFBIG;
3586
3587 ptr = super_copy->sys_chunk_array + array_size;
3588 btrfs_cpu_key_to_disk(&disk_key, key);
3589 memcpy(ptr, &disk_key, sizeof(disk_key));
3590 ptr += sizeof(disk_key);
3591 memcpy(ptr, chunk, item_size);
3592 item_size += sizeof(disk_key);
3593 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3594 return 0;
3595 }
3596
3597 /*
3598 * sort the devices in descending order by max_avail, total_avail
3599 */
3600 static int btrfs_cmp_device_info(const void *a, const void *b)
3601 {
3602 const struct btrfs_device_info *di_a = a;
3603 const struct btrfs_device_info *di_b = b;
3604
3605 if (di_a->max_avail > di_b->max_avail)
3606 return -1;
3607 if (di_a->max_avail < di_b->max_avail)
3608 return 1;
3609 if (di_a->total_avail > di_b->total_avail)
3610 return -1;
3611 if (di_a->total_avail < di_b->total_avail)
3612 return 1;
3613 return 0;
3614 }
3615
3616 static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3617 [BTRFS_RAID_RAID10] = {
3618 .sub_stripes = 2,
3619 .dev_stripes = 1,
3620 .devs_max = 0, /* 0 == as many as possible */
3621 .devs_min = 4,
3622 .devs_increment = 2,
3623 .ncopies = 2,
3624 },
3625 [BTRFS_RAID_RAID1] = {
3626 .sub_stripes = 1,
3627 .dev_stripes = 1,
3628 .devs_max = 2,
3629 .devs_min = 2,
3630 .devs_increment = 2,
3631 .ncopies = 2,
3632 },
3633 [BTRFS_RAID_DUP] = {
3634 .sub_stripes = 1,
3635 .dev_stripes = 2,
3636 .devs_max = 1,
3637 .devs_min = 1,
3638 .devs_increment = 1,
3639 .ncopies = 2,
3640 },
3641 [BTRFS_RAID_RAID0] = {
3642 .sub_stripes = 1,
3643 .dev_stripes = 1,
3644 .devs_max = 0,
3645 .devs_min = 2,
3646 .devs_increment = 1,
3647 .ncopies = 1,
3648 },
3649 [BTRFS_RAID_SINGLE] = {
3650 .sub_stripes = 1,
3651 .dev_stripes = 1,
3652 .devs_max = 1,
3653 .devs_min = 1,
3654 .devs_increment = 1,
3655 .ncopies = 1,
3656 },
3657 [BTRFS_RAID_RAID5] = {
3658 .sub_stripes = 1,
3659 .dev_stripes = 1,
3660 .devs_max = 0,
3661 .devs_min = 2,
3662 .devs_increment = 1,
3663 .ncopies = 2,
3664 },
3665 [BTRFS_RAID_RAID6] = {
3666 .sub_stripes = 1,
3667 .dev_stripes = 1,
3668 .devs_max = 0,
3669 .devs_min = 3,
3670 .devs_increment = 1,
3671 .ncopies = 3,
3672 },
3673 };
3674
3675 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3676 {
3677 /* TODO allow them to set a preferred stripe size */
3678 return 64 * 1024;
3679 }
3680
3681 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3682 {
3683 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3684 return;
3685
3686 btrfs_set_fs_incompat(info, RAID56);
3687 }
3688
3689 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3690 struct btrfs_root *extent_root, u64 start,
3691 u64 type)
3692 {
3693 struct btrfs_fs_info *info = extent_root->fs_info;
3694 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3695 struct list_head *cur;
3696 struct map_lookup *map = NULL;
3697 struct extent_map_tree *em_tree;
3698 struct extent_map *em;
3699 struct btrfs_device_info *devices_info = NULL;
3700 u64 total_avail;
3701 int num_stripes; /* total number of stripes to allocate */
3702 int data_stripes; /* number of stripes that count for
3703 block group size */
3704 int sub_stripes; /* sub_stripes info for map */
3705 int dev_stripes; /* stripes per dev */
3706 int devs_max; /* max devs to use */
3707 int devs_min; /* min devs needed */
3708 int devs_increment; /* ndevs has to be a multiple of this */
3709 int ncopies; /* how many copies to data has */
3710 int ret;
3711 u64 max_stripe_size;
3712 u64 max_chunk_size;
3713 u64 stripe_size;
3714 u64 num_bytes;
3715 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
3716 int ndevs;
3717 int i;
3718 int j;
3719 int index;
3720
3721 BUG_ON(!alloc_profile_is_valid(type, 0));
3722
3723 if (list_empty(&fs_devices->alloc_list))
3724 return -ENOSPC;
3725
3726 index = __get_raid_index(type);
3727
3728 sub_stripes = btrfs_raid_array[index].sub_stripes;
3729 dev_stripes = btrfs_raid_array[index].dev_stripes;
3730 devs_max = btrfs_raid_array[index].devs_max;
3731 devs_min = btrfs_raid_array[index].devs_min;
3732 devs_increment = btrfs_raid_array[index].devs_increment;
3733 ncopies = btrfs_raid_array[index].ncopies;
3734
3735 if (type & BTRFS_BLOCK_GROUP_DATA) {
3736 max_stripe_size = 1024 * 1024 * 1024;
3737 max_chunk_size = 10 * max_stripe_size;
3738 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3739 /* for larger filesystems, use larger metadata chunks */
3740 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3741 max_stripe_size = 1024 * 1024 * 1024;
3742 else
3743 max_stripe_size = 256 * 1024 * 1024;
3744 max_chunk_size = max_stripe_size;
3745 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3746 max_stripe_size = 32 * 1024 * 1024;
3747 max_chunk_size = 2 * max_stripe_size;
3748 } else {
3749 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3750 type);
3751 BUG_ON(1);
3752 }
3753
3754 /* we don't want a chunk larger than 10% of writeable space */
3755 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3756 max_chunk_size);
3757
3758 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3759 GFP_NOFS);
3760 if (!devices_info)
3761 return -ENOMEM;
3762
3763 cur = fs_devices->alloc_list.next;
3764
3765 /*
3766 * in the first pass through the devices list, we gather information
3767 * about the available holes on each device.
3768 */
3769 ndevs = 0;
3770 while (cur != &fs_devices->alloc_list) {
3771 struct btrfs_device *device;
3772 u64 max_avail;
3773 u64 dev_offset;
3774
3775 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3776
3777 cur = cur->next;
3778
3779 if (!device->writeable) {
3780 WARN(1, KERN_ERR
3781 "btrfs: read-only device in alloc_list\n");
3782 continue;
3783 }
3784
3785 if (!device->in_fs_metadata ||
3786 device->is_tgtdev_for_dev_replace)
3787 continue;
3788
3789 if (device->total_bytes > device->bytes_used)
3790 total_avail = device->total_bytes - device->bytes_used;
3791 else
3792 total_avail = 0;
3793
3794 /* If there is no space on this device, skip it. */
3795 if (total_avail == 0)
3796 continue;
3797
3798 ret = find_free_dev_extent(trans, device,
3799 max_stripe_size * dev_stripes,
3800 &dev_offset, &max_avail);
3801 if (ret && ret != -ENOSPC)
3802 goto error;
3803
3804 if (ret == 0)
3805 max_avail = max_stripe_size * dev_stripes;
3806
3807 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3808 continue;
3809
3810 if (ndevs == fs_devices->rw_devices) {
3811 WARN(1, "%s: found more than %llu devices\n",
3812 __func__, fs_devices->rw_devices);
3813 break;
3814 }
3815 devices_info[ndevs].dev_offset = dev_offset;
3816 devices_info[ndevs].max_avail = max_avail;
3817 devices_info[ndevs].total_avail = total_avail;
3818 devices_info[ndevs].dev = device;
3819 ++ndevs;
3820 }
3821
3822 /*
3823 * now sort the devices by hole size / available space
3824 */
3825 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3826 btrfs_cmp_device_info, NULL);
3827
3828 /* round down to number of usable stripes */
3829 ndevs -= ndevs % devs_increment;
3830
3831 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3832 ret = -ENOSPC;
3833 goto error;
3834 }
3835
3836 if (devs_max && ndevs > devs_max)
3837 ndevs = devs_max;
3838 /*
3839 * the primary goal is to maximize the number of stripes, so use as many
3840 * devices as possible, even if the stripes are not maximum sized.
3841 */
3842 stripe_size = devices_info[ndevs-1].max_avail;
3843 num_stripes = ndevs * dev_stripes;
3844
3845 /*
3846 * this will have to be fixed for RAID1 and RAID10 over
3847 * more drives
3848 */
3849 data_stripes = num_stripes / ncopies;
3850
3851 if (type & BTRFS_BLOCK_GROUP_RAID5) {
3852 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
3853 btrfs_super_stripesize(info->super_copy));
3854 data_stripes = num_stripes - 1;
3855 }
3856 if (type & BTRFS_BLOCK_GROUP_RAID6) {
3857 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
3858 btrfs_super_stripesize(info->super_copy));
3859 data_stripes = num_stripes - 2;
3860 }
3861
3862 /*
3863 * Use the number of data stripes to figure out how big this chunk
3864 * is really going to be in terms of logical address space,
3865 * and compare that answer with the max chunk size
3866 */
3867 if (stripe_size * data_stripes > max_chunk_size) {
3868 u64 mask = (1ULL << 24) - 1;
3869 stripe_size = max_chunk_size;
3870 do_div(stripe_size, data_stripes);
3871
3872 /* bump the answer up to a 16MB boundary */
3873 stripe_size = (stripe_size + mask) & ~mask;
3874
3875 /* but don't go higher than the limits we found
3876 * while searching for free extents
3877 */
3878 if (stripe_size > devices_info[ndevs-1].max_avail)
3879 stripe_size = devices_info[ndevs-1].max_avail;
3880 }
3881
3882 do_div(stripe_size, dev_stripes);
3883
3884 /* align to BTRFS_STRIPE_LEN */
3885 do_div(stripe_size, raid_stripe_len);
3886 stripe_size *= raid_stripe_len;
3887
3888 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3889 if (!map) {
3890 ret = -ENOMEM;
3891 goto error;
3892 }
3893 map->num_stripes = num_stripes;
3894
3895 for (i = 0; i < ndevs; ++i) {
3896 for (j = 0; j < dev_stripes; ++j) {
3897 int s = i * dev_stripes + j;
3898 map->stripes[s].dev = devices_info[i].dev;
3899 map->stripes[s].physical = devices_info[i].dev_offset +
3900 j * stripe_size;
3901 }
3902 }
3903 map->sector_size = extent_root->sectorsize;
3904 map->stripe_len = raid_stripe_len;
3905 map->io_align = raid_stripe_len;
3906 map->io_width = raid_stripe_len;
3907 map->type = type;
3908 map->sub_stripes = sub_stripes;
3909
3910 num_bytes = stripe_size * data_stripes;
3911
3912 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3913
3914 em = alloc_extent_map();
3915 if (!em) {
3916 ret = -ENOMEM;
3917 goto error;
3918 }
3919 em->bdev = (struct block_device *)map;
3920 em->start = start;
3921 em->len = num_bytes;
3922 em->block_start = 0;
3923 em->block_len = em->len;
3924 em->orig_block_len = stripe_size;
3925
3926 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3927 write_lock(&em_tree->lock);
3928 ret = add_extent_mapping(em_tree, em, 0);
3929 if (!ret) {
3930 list_add_tail(&em->list, &trans->transaction->pending_chunks);
3931 atomic_inc(&em->refs);
3932 }
3933 write_unlock(&em_tree->lock);
3934 if (ret) {
3935 free_extent_map(em);
3936 goto error;
3937 }
3938
3939 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3940 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3941 start, num_bytes);
3942 if (ret)
3943 goto error_del_extent;
3944
3945 free_extent_map(em);
3946 check_raid56_incompat_flag(extent_root->fs_info, type);
3947
3948 kfree(devices_info);
3949 return 0;
3950
3951 error_del_extent:
3952 write_lock(&em_tree->lock);
3953 remove_extent_mapping(em_tree, em);
3954 write_unlock(&em_tree->lock);
3955
3956 /* One for our allocation */
3957 free_extent_map(em);
3958 /* One for the tree reference */
3959 free_extent_map(em);
3960 error:
3961 kfree(map);
3962 kfree(devices_info);
3963 return ret;
3964 }
3965
3966 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
3967 struct btrfs_root *extent_root,
3968 u64 chunk_offset, u64 chunk_size)
3969 {
3970 struct btrfs_key key;
3971 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3972 struct btrfs_device *device;
3973 struct btrfs_chunk *chunk;
3974 struct btrfs_stripe *stripe;
3975 struct extent_map_tree *em_tree;
3976 struct extent_map *em;
3977 struct map_lookup *map;
3978 size_t item_size;
3979 u64 dev_offset;
3980 u64 stripe_size;
3981 int i = 0;
3982 int ret;
3983
3984 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3985 read_lock(&em_tree->lock);
3986 em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
3987 read_unlock(&em_tree->lock);
3988
3989 if (!em) {
3990 btrfs_crit(extent_root->fs_info, "unable to find logical "
3991 "%Lu len %Lu", chunk_offset, chunk_size);
3992 return -EINVAL;
3993 }
3994
3995 if (em->start != chunk_offset || em->len != chunk_size) {
3996 btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
3997 " %Lu-%Lu, found %Lu-%Lu\n", chunk_offset,
3998 chunk_size, em->start, em->len);
3999 free_extent_map(em);
4000 return -EINVAL;
4001 }
4002
4003 map = (struct map_lookup *)em->bdev;
4004 item_size = btrfs_chunk_item_size(map->num_stripes);
4005 stripe_size = em->orig_block_len;
4006
4007 chunk = kzalloc(item_size, GFP_NOFS);
4008 if (!chunk) {
4009 ret = -ENOMEM;
4010 goto out;
4011 }
4012
4013 for (i = 0; i < map->num_stripes; i++) {
4014 device = map->stripes[i].dev;
4015 dev_offset = map->stripes[i].physical;
4016
4017 device->bytes_used += stripe_size;
4018 ret = btrfs_update_device(trans, device);
4019 if (ret)
4020 goto out;
4021 ret = btrfs_alloc_dev_extent(trans, device,
4022 chunk_root->root_key.objectid,
4023 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4024 chunk_offset, dev_offset,
4025 stripe_size);
4026 if (ret)
4027 goto out;
4028 }
4029
4030 spin_lock(&extent_root->fs_info->free_chunk_lock);
4031 extent_root->fs_info->free_chunk_space -= (stripe_size *
4032 map->num_stripes);
4033 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4034
4035 stripe = &chunk->stripe;
4036 for (i = 0; i < map->num_stripes; i++) {
4037 device = map->stripes[i].dev;
4038 dev_offset = map->stripes[i].physical;
4039
4040 btrfs_set_stack_stripe_devid(stripe, device->devid);
4041 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4042 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4043 stripe++;
4044 }
4045
4046 btrfs_set_stack_chunk_length(chunk, chunk_size);
4047 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4048 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4049 btrfs_set_stack_chunk_type(chunk, map->type);
4050 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4051 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4052 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4053 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4054 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4055
4056 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4057 key.type = BTRFS_CHUNK_ITEM_KEY;
4058 key.offset = chunk_offset;
4059
4060 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4061 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4062 /*
4063 * TODO: Cleanup of inserted chunk root in case of
4064 * failure.
4065 */
4066 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4067 item_size);
4068 }
4069
4070 out:
4071 kfree(chunk);
4072 free_extent_map(em);
4073 return ret;
4074 }
4075
4076 /*
4077 * Chunk allocation falls into two parts. The first part does works
4078 * that make the new allocated chunk useable, but not do any operation
4079 * that modifies the chunk tree. The second part does the works that
4080 * require modifying the chunk tree. This division is important for the
4081 * bootstrap process of adding storage to a seed btrfs.
4082 */
4083 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4084 struct btrfs_root *extent_root, u64 type)
4085 {
4086 u64 chunk_offset;
4087
4088 chunk_offset = find_next_chunk(extent_root->fs_info);
4089 return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
4090 }
4091
4092 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4093 struct btrfs_root *root,
4094 struct btrfs_device *device)
4095 {
4096 u64 chunk_offset;
4097 u64 sys_chunk_offset;
4098 u64 alloc_profile;
4099 struct btrfs_fs_info *fs_info = root->fs_info;
4100 struct btrfs_root *extent_root = fs_info->extent_root;
4101 int ret;
4102
4103 chunk_offset = find_next_chunk(fs_info);
4104 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4105 ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
4106 alloc_profile);
4107 if (ret)
4108 return ret;
4109
4110 sys_chunk_offset = find_next_chunk(root->fs_info);
4111 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4112 ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
4113 alloc_profile);
4114 if (ret) {
4115 btrfs_abort_transaction(trans, root, ret);
4116 goto out;
4117 }
4118
4119 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4120 if (ret)
4121 btrfs_abort_transaction(trans, root, ret);
4122 out:
4123 return ret;
4124 }
4125
4126 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4127 {
4128 struct extent_map *em;
4129 struct map_lookup *map;
4130 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4131 int readonly = 0;
4132 int i;
4133
4134 read_lock(&map_tree->map_tree.lock);
4135 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4136 read_unlock(&map_tree->map_tree.lock);
4137 if (!em)
4138 return 1;
4139
4140 if (btrfs_test_opt(root, DEGRADED)) {
4141 free_extent_map(em);
4142 return 0;
4143 }
4144
4145 map = (struct map_lookup *)em->bdev;
4146 for (i = 0; i < map->num_stripes; i++) {
4147 if (!map->stripes[i].dev->writeable) {
4148 readonly = 1;
4149 break;
4150 }
4151 }
4152 free_extent_map(em);
4153 return readonly;
4154 }
4155
4156 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4157 {
4158 extent_map_tree_init(&tree->map_tree);
4159 }
4160
4161 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4162 {
4163 struct extent_map *em;
4164
4165 while (1) {
4166 write_lock(&tree->map_tree.lock);
4167 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4168 if (em)
4169 remove_extent_mapping(&tree->map_tree, em);
4170 write_unlock(&tree->map_tree.lock);
4171 if (!em)
4172 break;
4173 kfree(em->bdev);
4174 /* once for us */
4175 free_extent_map(em);
4176 /* once for the tree */
4177 free_extent_map(em);
4178 }
4179 }
4180
4181 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4182 {
4183 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4184 struct extent_map *em;
4185 struct map_lookup *map;
4186 struct extent_map_tree *em_tree = &map_tree->map_tree;
4187 int ret;
4188
4189 read_lock(&em_tree->lock);
4190 em = lookup_extent_mapping(em_tree, logical, len);
4191 read_unlock(&em_tree->lock);
4192
4193 /*
4194 * We could return errors for these cases, but that could get ugly and
4195 * we'd probably do the same thing which is just not do anything else
4196 * and exit, so return 1 so the callers don't try to use other copies.
4197 */
4198 if (!em) {
4199 btrfs_crit(fs_info, "No mapping for %Lu-%Lu\n", logical,
4200 logical+len);
4201 return 1;
4202 }
4203
4204 if (em->start > logical || em->start + em->len < logical) {
4205 btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got "
4206 "%Lu-%Lu\n", logical, logical+len, em->start,
4207 em->start + em->len);
4208 return 1;
4209 }
4210
4211 map = (struct map_lookup *)em->bdev;
4212 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4213 ret = map->num_stripes;
4214 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4215 ret = map->sub_stripes;
4216 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4217 ret = 2;
4218 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4219 ret = 3;
4220 else
4221 ret = 1;
4222 free_extent_map(em);
4223
4224 btrfs_dev_replace_lock(&fs_info->dev_replace);
4225 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4226 ret++;
4227 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4228
4229 return ret;
4230 }
4231
4232 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4233 struct btrfs_mapping_tree *map_tree,
4234 u64 logical)
4235 {
4236 struct extent_map *em;
4237 struct map_lookup *map;
4238 struct extent_map_tree *em_tree = &map_tree->map_tree;
4239 unsigned long len = root->sectorsize;
4240
4241 read_lock(&em_tree->lock);
4242 em = lookup_extent_mapping(em_tree, logical, len);
4243 read_unlock(&em_tree->lock);
4244 BUG_ON(!em);
4245
4246 BUG_ON(em->start > logical || em->start + em->len < logical);
4247 map = (struct map_lookup *)em->bdev;
4248 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4249 BTRFS_BLOCK_GROUP_RAID6)) {
4250 len = map->stripe_len * nr_data_stripes(map);
4251 }
4252 free_extent_map(em);
4253 return len;
4254 }
4255
4256 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4257 u64 logical, u64 len, int mirror_num)
4258 {
4259 struct extent_map *em;
4260 struct map_lookup *map;
4261 struct extent_map_tree *em_tree = &map_tree->map_tree;
4262 int ret = 0;
4263
4264 read_lock(&em_tree->lock);
4265 em = lookup_extent_mapping(em_tree, logical, len);
4266 read_unlock(&em_tree->lock);
4267 BUG_ON(!em);
4268
4269 BUG_ON(em->start > logical || em->start + em->len < logical);
4270 map = (struct map_lookup *)em->bdev;
4271 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4272 BTRFS_BLOCK_GROUP_RAID6))
4273 ret = 1;
4274 free_extent_map(em);
4275 return ret;
4276 }
4277
4278 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4279 struct map_lookup *map, int first, int num,
4280 int optimal, int dev_replace_is_ongoing)
4281 {
4282 int i;
4283 int tolerance;
4284 struct btrfs_device *srcdev;
4285
4286 if (dev_replace_is_ongoing &&
4287 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4288 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4289 srcdev = fs_info->dev_replace.srcdev;
4290 else
4291 srcdev = NULL;
4292
4293 /*
4294 * try to avoid the drive that is the source drive for a
4295 * dev-replace procedure, only choose it if no other non-missing
4296 * mirror is available
4297 */
4298 for (tolerance = 0; tolerance < 2; tolerance++) {
4299 if (map->stripes[optimal].dev->bdev &&
4300 (tolerance || map->stripes[optimal].dev != srcdev))
4301 return optimal;
4302 for (i = first; i < first + num; i++) {
4303 if (map->stripes[i].dev->bdev &&
4304 (tolerance || map->stripes[i].dev != srcdev))
4305 return i;
4306 }
4307 }
4308
4309 /* we couldn't find one that doesn't fail. Just return something
4310 * and the io error handling code will clean up eventually
4311 */
4312 return optimal;
4313 }
4314
4315 static inline int parity_smaller(u64 a, u64 b)
4316 {
4317 return a > b;
4318 }
4319
4320 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4321 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4322 {
4323 struct btrfs_bio_stripe s;
4324 int i;
4325 u64 l;
4326 int again = 1;
4327
4328 while (again) {
4329 again = 0;
4330 for (i = 0; i < bbio->num_stripes - 1; i++) {
4331 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4332 s = bbio->stripes[i];
4333 l = raid_map[i];
4334 bbio->stripes[i] = bbio->stripes[i+1];
4335 raid_map[i] = raid_map[i+1];
4336 bbio->stripes[i+1] = s;
4337 raid_map[i+1] = l;
4338 again = 1;
4339 }
4340 }
4341 }
4342 }
4343
4344 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4345 u64 logical, u64 *length,
4346 struct btrfs_bio **bbio_ret,
4347 int mirror_num, u64 **raid_map_ret)
4348 {
4349 struct extent_map *em;
4350 struct map_lookup *map;
4351 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4352 struct extent_map_tree *em_tree = &map_tree->map_tree;
4353 u64 offset;
4354 u64 stripe_offset;
4355 u64 stripe_end_offset;
4356 u64 stripe_nr;
4357 u64 stripe_nr_orig;
4358 u64 stripe_nr_end;
4359 u64 stripe_len;
4360 u64 *raid_map = NULL;
4361 int stripe_index;
4362 int i;
4363 int ret = 0;
4364 int num_stripes;
4365 int max_errors = 0;
4366 struct btrfs_bio *bbio = NULL;
4367 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4368 int dev_replace_is_ongoing = 0;
4369 int num_alloc_stripes;
4370 int patch_the_first_stripe_for_dev_replace = 0;
4371 u64 physical_to_patch_in_first_stripe = 0;
4372 u64 raid56_full_stripe_start = (u64)-1;
4373
4374 read_lock(&em_tree->lock);
4375 em = lookup_extent_mapping(em_tree, logical, *length);
4376 read_unlock(&em_tree->lock);
4377
4378 if (!em) {
4379 btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4380 (unsigned long long)logical,
4381 (unsigned long long)*length);
4382 return -EINVAL;
4383 }
4384
4385 if (em->start > logical || em->start + em->len < logical) {
4386 btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4387 "found %Lu-%Lu\n", logical, em->start,
4388 em->start + em->len);
4389 return -EINVAL;
4390 }
4391
4392 map = (struct map_lookup *)em->bdev;
4393 offset = logical - em->start;
4394
4395 stripe_len = map->stripe_len;
4396 stripe_nr = offset;
4397 /*
4398 * stripe_nr counts the total number of stripes we have to stride
4399 * to get to this block
4400 */
4401 do_div(stripe_nr, stripe_len);
4402
4403 stripe_offset = stripe_nr * stripe_len;
4404 BUG_ON(offset < stripe_offset);
4405
4406 /* stripe_offset is the offset of this block in its stripe*/
4407 stripe_offset = offset - stripe_offset;
4408
4409 /* if we're here for raid56, we need to know the stripe aligned start */
4410 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4411 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4412 raid56_full_stripe_start = offset;
4413
4414 /* allow a write of a full stripe, but make sure we don't
4415 * allow straddling of stripes
4416 */
4417 do_div(raid56_full_stripe_start, full_stripe_len);
4418 raid56_full_stripe_start *= full_stripe_len;
4419 }
4420
4421 if (rw & REQ_DISCARD) {
4422 /* we don't discard raid56 yet */
4423 if (map->type &
4424 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4425 ret = -EOPNOTSUPP;
4426 goto out;
4427 }
4428 *length = min_t(u64, em->len - offset, *length);
4429 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4430 u64 max_len;
4431 /* For writes to RAID[56], allow a full stripeset across all disks.
4432 For other RAID types and for RAID[56] reads, just allow a single
4433 stripe (on a single disk). */
4434 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4435 (rw & REQ_WRITE)) {
4436 max_len = stripe_len * nr_data_stripes(map) -
4437 (offset - raid56_full_stripe_start);
4438 } else {
4439 /* we limit the length of each bio to what fits in a stripe */
4440 max_len = stripe_len - stripe_offset;
4441 }
4442 *length = min_t(u64, em->len - offset, max_len);
4443 } else {
4444 *length = em->len - offset;
4445 }
4446
4447 /* This is for when we're called from btrfs_merge_bio_hook() and all
4448 it cares about is the length */
4449 if (!bbio_ret)
4450 goto out;
4451
4452 btrfs_dev_replace_lock(dev_replace);
4453 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4454 if (!dev_replace_is_ongoing)
4455 btrfs_dev_replace_unlock(dev_replace);
4456
4457 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4458 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4459 dev_replace->tgtdev != NULL) {
4460 /*
4461 * in dev-replace case, for repair case (that's the only
4462 * case where the mirror is selected explicitly when
4463 * calling btrfs_map_block), blocks left of the left cursor
4464 * can also be read from the target drive.
4465 * For REQ_GET_READ_MIRRORS, the target drive is added as
4466 * the last one to the array of stripes. For READ, it also
4467 * needs to be supported using the same mirror number.
4468 * If the requested block is not left of the left cursor,
4469 * EIO is returned. This can happen because btrfs_num_copies()
4470 * returns one more in the dev-replace case.
4471 */
4472 u64 tmp_length = *length;
4473 struct btrfs_bio *tmp_bbio = NULL;
4474 int tmp_num_stripes;
4475 u64 srcdev_devid = dev_replace->srcdev->devid;
4476 int index_srcdev = 0;
4477 int found = 0;
4478 u64 physical_of_found = 0;
4479
4480 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4481 logical, &tmp_length, &tmp_bbio, 0, NULL);
4482 if (ret) {
4483 WARN_ON(tmp_bbio != NULL);
4484 goto out;
4485 }
4486
4487 tmp_num_stripes = tmp_bbio->num_stripes;
4488 if (mirror_num > tmp_num_stripes) {
4489 /*
4490 * REQ_GET_READ_MIRRORS does not contain this
4491 * mirror, that means that the requested area
4492 * is not left of the left cursor
4493 */
4494 ret = -EIO;
4495 kfree(tmp_bbio);
4496 goto out;
4497 }
4498
4499 /*
4500 * process the rest of the function using the mirror_num
4501 * of the source drive. Therefore look it up first.
4502 * At the end, patch the device pointer to the one of the
4503 * target drive.
4504 */
4505 for (i = 0; i < tmp_num_stripes; i++) {
4506 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4507 /*
4508 * In case of DUP, in order to keep it
4509 * simple, only add the mirror with the
4510 * lowest physical address
4511 */
4512 if (found &&
4513 physical_of_found <=
4514 tmp_bbio->stripes[i].physical)
4515 continue;
4516 index_srcdev = i;
4517 found = 1;
4518 physical_of_found =
4519 tmp_bbio->stripes[i].physical;
4520 }
4521 }
4522
4523 if (found) {
4524 mirror_num = index_srcdev + 1;
4525 patch_the_first_stripe_for_dev_replace = 1;
4526 physical_to_patch_in_first_stripe = physical_of_found;
4527 } else {
4528 WARN_ON(1);
4529 ret = -EIO;
4530 kfree(tmp_bbio);
4531 goto out;
4532 }
4533
4534 kfree(tmp_bbio);
4535 } else if (mirror_num > map->num_stripes) {
4536 mirror_num = 0;
4537 }
4538
4539 num_stripes = 1;
4540 stripe_index = 0;
4541 stripe_nr_orig = stripe_nr;
4542 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
4543 do_div(stripe_nr_end, map->stripe_len);
4544 stripe_end_offset = stripe_nr_end * map->stripe_len -
4545 (offset + *length);
4546
4547 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4548 if (rw & REQ_DISCARD)
4549 num_stripes = min_t(u64, map->num_stripes,
4550 stripe_nr_end - stripe_nr_orig);
4551 stripe_index = do_div(stripe_nr, map->num_stripes);
4552 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4553 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4554 num_stripes = map->num_stripes;
4555 else if (mirror_num)
4556 stripe_index = mirror_num - 1;
4557 else {
4558 stripe_index = find_live_mirror(fs_info, map, 0,
4559 map->num_stripes,
4560 current->pid % map->num_stripes,
4561 dev_replace_is_ongoing);
4562 mirror_num = stripe_index + 1;
4563 }
4564
4565 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4566 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4567 num_stripes = map->num_stripes;
4568 } else if (mirror_num) {
4569 stripe_index = mirror_num - 1;
4570 } else {
4571 mirror_num = 1;
4572 }
4573
4574 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4575 int factor = map->num_stripes / map->sub_stripes;
4576
4577 stripe_index = do_div(stripe_nr, factor);
4578 stripe_index *= map->sub_stripes;
4579
4580 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4581 num_stripes = map->sub_stripes;
4582 else if (rw & REQ_DISCARD)
4583 num_stripes = min_t(u64, map->sub_stripes *
4584 (stripe_nr_end - stripe_nr_orig),
4585 map->num_stripes);
4586 else if (mirror_num)
4587 stripe_index += mirror_num - 1;
4588 else {
4589 int old_stripe_index = stripe_index;
4590 stripe_index = find_live_mirror(fs_info, map,
4591 stripe_index,
4592 map->sub_stripes, stripe_index +
4593 current->pid % map->sub_stripes,
4594 dev_replace_is_ongoing);
4595 mirror_num = stripe_index - old_stripe_index + 1;
4596 }
4597
4598 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4599 BTRFS_BLOCK_GROUP_RAID6)) {
4600 u64 tmp;
4601
4602 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4603 && raid_map_ret) {
4604 int i, rot;
4605
4606 /* push stripe_nr back to the start of the full stripe */
4607 stripe_nr = raid56_full_stripe_start;
4608 do_div(stripe_nr, stripe_len);
4609
4610 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4611
4612 /* RAID[56] write or recovery. Return all stripes */
4613 num_stripes = map->num_stripes;
4614 max_errors = nr_parity_stripes(map);
4615
4616 raid_map = kmalloc(sizeof(u64) * num_stripes,
4617 GFP_NOFS);
4618 if (!raid_map) {
4619 ret = -ENOMEM;
4620 goto out;
4621 }
4622
4623 /* Work out the disk rotation on this stripe-set */
4624 tmp = stripe_nr;
4625 rot = do_div(tmp, num_stripes);
4626
4627 /* Fill in the logical address of each stripe */
4628 tmp = stripe_nr * nr_data_stripes(map);
4629 for (i = 0; i < nr_data_stripes(map); i++)
4630 raid_map[(i+rot) % num_stripes] =
4631 em->start + (tmp + i) * map->stripe_len;
4632
4633 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4634 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4635 raid_map[(i+rot+1) % num_stripes] =
4636 RAID6_Q_STRIPE;
4637
4638 *length = map->stripe_len;
4639 stripe_index = 0;
4640 stripe_offset = 0;
4641 } else {
4642 /*
4643 * Mirror #0 or #1 means the original data block.
4644 * Mirror #2 is RAID5 parity block.
4645 * Mirror #3 is RAID6 Q block.
4646 */
4647 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4648 if (mirror_num > 1)
4649 stripe_index = nr_data_stripes(map) +
4650 mirror_num - 2;
4651
4652 /* We distribute the parity blocks across stripes */
4653 tmp = stripe_nr + stripe_index;
4654 stripe_index = do_div(tmp, map->num_stripes);
4655 }
4656 } else {
4657 /*
4658 * after this do_div call, stripe_nr is the number of stripes
4659 * on this device we have to walk to find the data, and
4660 * stripe_index is the number of our device in the stripe array
4661 */
4662 stripe_index = do_div(stripe_nr, map->num_stripes);
4663 mirror_num = stripe_index + 1;
4664 }
4665 BUG_ON(stripe_index >= map->num_stripes);
4666
4667 num_alloc_stripes = num_stripes;
4668 if (dev_replace_is_ongoing) {
4669 if (rw & (REQ_WRITE | REQ_DISCARD))
4670 num_alloc_stripes <<= 1;
4671 if (rw & REQ_GET_READ_MIRRORS)
4672 num_alloc_stripes++;
4673 }
4674 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4675 if (!bbio) {
4676 ret = -ENOMEM;
4677 goto out;
4678 }
4679 atomic_set(&bbio->error, 0);
4680
4681 if (rw & REQ_DISCARD) {
4682 int factor = 0;
4683 int sub_stripes = 0;
4684 u64 stripes_per_dev = 0;
4685 u32 remaining_stripes = 0;
4686 u32 last_stripe = 0;
4687
4688 if (map->type &
4689 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4690 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4691 sub_stripes = 1;
4692 else
4693 sub_stripes = map->sub_stripes;
4694
4695 factor = map->num_stripes / sub_stripes;
4696 stripes_per_dev = div_u64_rem(stripe_nr_end -
4697 stripe_nr_orig,
4698 factor,
4699 &remaining_stripes);
4700 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4701 last_stripe *= sub_stripes;
4702 }
4703
4704 for (i = 0; i < num_stripes; i++) {
4705 bbio->stripes[i].physical =
4706 map->stripes[stripe_index].physical +
4707 stripe_offset + stripe_nr * map->stripe_len;
4708 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4709
4710 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4711 BTRFS_BLOCK_GROUP_RAID10)) {
4712 bbio->stripes[i].length = stripes_per_dev *
4713 map->stripe_len;
4714
4715 if (i / sub_stripes < remaining_stripes)
4716 bbio->stripes[i].length +=
4717 map->stripe_len;
4718
4719 /*
4720 * Special for the first stripe and
4721 * the last stripe:
4722 *
4723 * |-------|...|-------|
4724 * |----------|
4725 * off end_off
4726 */
4727 if (i < sub_stripes)
4728 bbio->stripes[i].length -=
4729 stripe_offset;
4730
4731 if (stripe_index >= last_stripe &&
4732 stripe_index <= (last_stripe +
4733 sub_stripes - 1))
4734 bbio->stripes[i].length -=
4735 stripe_end_offset;
4736
4737 if (i == sub_stripes - 1)
4738 stripe_offset = 0;
4739 } else
4740 bbio->stripes[i].length = *length;
4741
4742 stripe_index++;
4743 if (stripe_index == map->num_stripes) {
4744 /* This could only happen for RAID0/10 */
4745 stripe_index = 0;
4746 stripe_nr++;
4747 }
4748 }
4749 } else {
4750 for (i = 0; i < num_stripes; i++) {
4751 bbio->stripes[i].physical =
4752 map->stripes[stripe_index].physical +
4753 stripe_offset +
4754 stripe_nr * map->stripe_len;
4755 bbio->stripes[i].dev =
4756 map->stripes[stripe_index].dev;
4757 stripe_index++;
4758 }
4759 }
4760
4761 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
4762 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4763 BTRFS_BLOCK_GROUP_RAID10 |
4764 BTRFS_BLOCK_GROUP_RAID5 |
4765 BTRFS_BLOCK_GROUP_DUP)) {
4766 max_errors = 1;
4767 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
4768 max_errors = 2;
4769 }
4770 }
4771
4772 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
4773 dev_replace->tgtdev != NULL) {
4774 int index_where_to_add;
4775 u64 srcdev_devid = dev_replace->srcdev->devid;
4776
4777 /*
4778 * duplicate the write operations while the dev replace
4779 * procedure is running. Since the copying of the old disk
4780 * to the new disk takes place at run time while the
4781 * filesystem is mounted writable, the regular write
4782 * operations to the old disk have to be duplicated to go
4783 * to the new disk as well.
4784 * Note that device->missing is handled by the caller, and
4785 * that the write to the old disk is already set up in the
4786 * stripes array.
4787 */
4788 index_where_to_add = num_stripes;
4789 for (i = 0; i < num_stripes; i++) {
4790 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4791 /* write to new disk, too */
4792 struct btrfs_bio_stripe *new =
4793 bbio->stripes + index_where_to_add;
4794 struct btrfs_bio_stripe *old =
4795 bbio->stripes + i;
4796
4797 new->physical = old->physical;
4798 new->length = old->length;
4799 new->dev = dev_replace->tgtdev;
4800 index_where_to_add++;
4801 max_errors++;
4802 }
4803 }
4804 num_stripes = index_where_to_add;
4805 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
4806 dev_replace->tgtdev != NULL) {
4807 u64 srcdev_devid = dev_replace->srcdev->devid;
4808 int index_srcdev = 0;
4809 int found = 0;
4810 u64 physical_of_found = 0;
4811
4812 /*
4813 * During the dev-replace procedure, the target drive can
4814 * also be used to read data in case it is needed to repair
4815 * a corrupt block elsewhere. This is possible if the
4816 * requested area is left of the left cursor. In this area,
4817 * the target drive is a full copy of the source drive.
4818 */
4819 for (i = 0; i < num_stripes; i++) {
4820 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4821 /*
4822 * In case of DUP, in order to keep it
4823 * simple, only add the mirror with the
4824 * lowest physical address
4825 */
4826 if (found &&
4827 physical_of_found <=
4828 bbio->stripes[i].physical)
4829 continue;
4830 index_srcdev = i;
4831 found = 1;
4832 physical_of_found = bbio->stripes[i].physical;
4833 }
4834 }
4835 if (found) {
4836 u64 length = map->stripe_len;
4837
4838 if (physical_of_found + length <=
4839 dev_replace->cursor_left) {
4840 struct btrfs_bio_stripe *tgtdev_stripe =
4841 bbio->stripes + num_stripes;
4842
4843 tgtdev_stripe->physical = physical_of_found;
4844 tgtdev_stripe->length =
4845 bbio->stripes[index_srcdev].length;
4846 tgtdev_stripe->dev = dev_replace->tgtdev;
4847
4848 num_stripes++;
4849 }
4850 }
4851 }
4852
4853 *bbio_ret = bbio;
4854 bbio->num_stripes = num_stripes;
4855 bbio->max_errors = max_errors;
4856 bbio->mirror_num = mirror_num;
4857
4858 /*
4859 * this is the case that REQ_READ && dev_replace_is_ongoing &&
4860 * mirror_num == num_stripes + 1 && dev_replace target drive is
4861 * available as a mirror
4862 */
4863 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
4864 WARN_ON(num_stripes > 1);
4865 bbio->stripes[0].dev = dev_replace->tgtdev;
4866 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
4867 bbio->mirror_num = map->num_stripes + 1;
4868 }
4869 if (raid_map) {
4870 sort_parity_stripes(bbio, raid_map);
4871 *raid_map_ret = raid_map;
4872 }
4873 out:
4874 if (dev_replace_is_ongoing)
4875 btrfs_dev_replace_unlock(dev_replace);
4876 free_extent_map(em);
4877 return ret;
4878 }
4879
4880 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4881 u64 logical, u64 *length,
4882 struct btrfs_bio **bbio_ret, int mirror_num)
4883 {
4884 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
4885 mirror_num, NULL);
4886 }
4887
4888 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4889 u64 chunk_start, u64 physical, u64 devid,
4890 u64 **logical, int *naddrs, int *stripe_len)
4891 {
4892 struct extent_map_tree *em_tree = &map_tree->map_tree;
4893 struct extent_map *em;
4894 struct map_lookup *map;
4895 u64 *buf;
4896 u64 bytenr;
4897 u64 length;
4898 u64 stripe_nr;
4899 u64 rmap_len;
4900 int i, j, nr = 0;
4901
4902 read_lock(&em_tree->lock);
4903 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4904 read_unlock(&em_tree->lock);
4905
4906 if (!em) {
4907 printk(KERN_ERR "btrfs: couldn't find em for chunk %Lu\n",
4908 chunk_start);
4909 return -EIO;
4910 }
4911
4912 if (em->start != chunk_start) {
4913 printk(KERN_ERR "btrfs: bad chunk start, em=%Lu, wanted=%Lu\n",
4914 em->start, chunk_start);
4915 free_extent_map(em);
4916 return -EIO;
4917 }
4918 map = (struct map_lookup *)em->bdev;
4919
4920 length = em->len;
4921 rmap_len = map->stripe_len;
4922
4923 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4924 do_div(length, map->num_stripes / map->sub_stripes);
4925 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4926 do_div(length, map->num_stripes);
4927 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4928 BTRFS_BLOCK_GROUP_RAID6)) {
4929 do_div(length, nr_data_stripes(map));
4930 rmap_len = map->stripe_len * nr_data_stripes(map);
4931 }
4932
4933 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4934 BUG_ON(!buf); /* -ENOMEM */
4935
4936 for (i = 0; i < map->num_stripes; i++) {
4937 if (devid && map->stripes[i].dev->devid != devid)
4938 continue;
4939 if (map->stripes[i].physical > physical ||
4940 map->stripes[i].physical + length <= physical)
4941 continue;
4942
4943 stripe_nr = physical - map->stripes[i].physical;
4944 do_div(stripe_nr, map->stripe_len);
4945
4946 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4947 stripe_nr = stripe_nr * map->num_stripes + i;
4948 do_div(stripe_nr, map->sub_stripes);
4949 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4950 stripe_nr = stripe_nr * map->num_stripes + i;
4951 } /* else if RAID[56], multiply by nr_data_stripes().
4952 * Alternatively, just use rmap_len below instead of
4953 * map->stripe_len */
4954
4955 bytenr = chunk_start + stripe_nr * rmap_len;
4956 WARN_ON(nr >= map->num_stripes);
4957 for (j = 0; j < nr; j++) {
4958 if (buf[j] == bytenr)
4959 break;
4960 }
4961 if (j == nr) {
4962 WARN_ON(nr >= map->num_stripes);
4963 buf[nr++] = bytenr;
4964 }
4965 }
4966
4967 *logical = buf;
4968 *naddrs = nr;
4969 *stripe_len = rmap_len;
4970
4971 free_extent_map(em);
4972 return 0;
4973 }
4974
4975 static void btrfs_end_bio(struct bio *bio, int err)
4976 {
4977 struct btrfs_bio *bbio = bio->bi_private;
4978 int is_orig_bio = 0;
4979
4980 if (err) {
4981 atomic_inc(&bbio->error);
4982 if (err == -EIO || err == -EREMOTEIO) {
4983 unsigned int stripe_index =
4984 btrfs_io_bio(bio)->stripe_index;
4985 struct btrfs_device *dev;
4986
4987 BUG_ON(stripe_index >= bbio->num_stripes);
4988 dev = bbio->stripes[stripe_index].dev;
4989 if (dev->bdev) {
4990 if (bio->bi_rw & WRITE)
4991 btrfs_dev_stat_inc(dev,
4992 BTRFS_DEV_STAT_WRITE_ERRS);
4993 else
4994 btrfs_dev_stat_inc(dev,
4995 BTRFS_DEV_STAT_READ_ERRS);
4996 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4997 btrfs_dev_stat_inc(dev,
4998 BTRFS_DEV_STAT_FLUSH_ERRS);
4999 btrfs_dev_stat_print_on_error(dev);
5000 }
5001 }
5002 }
5003
5004 if (bio == bbio->orig_bio)
5005 is_orig_bio = 1;
5006
5007 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5008 if (!is_orig_bio) {
5009 bio_put(bio);
5010 bio = bbio->orig_bio;
5011 }
5012 bio->bi_private = bbio->private;
5013 bio->bi_end_io = bbio->end_io;
5014 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5015 /* only send an error to the higher layers if it is
5016 * beyond the tolerance of the btrfs bio
5017 */
5018 if (atomic_read(&bbio->error) > bbio->max_errors) {
5019 err = -EIO;
5020 } else {
5021 /*
5022 * this bio is actually up to date, we didn't
5023 * go over the max number of errors
5024 */
5025 set_bit(BIO_UPTODATE, &bio->bi_flags);
5026 err = 0;
5027 }
5028 kfree(bbio);
5029
5030 bio_endio(bio, err);
5031 } else if (!is_orig_bio) {
5032 bio_put(bio);
5033 }
5034 }
5035
5036 struct async_sched {
5037 struct bio *bio;
5038 int rw;
5039 struct btrfs_fs_info *info;
5040 struct btrfs_work work;
5041 };
5042
5043 /*
5044 * see run_scheduled_bios for a description of why bios are collected for
5045 * async submit.
5046 *
5047 * This will add one bio to the pending list for a device and make sure
5048 * the work struct is scheduled.
5049 */
5050 static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5051 struct btrfs_device *device,
5052 int rw, struct bio *bio)
5053 {
5054 int should_queue = 1;
5055 struct btrfs_pending_bios *pending_bios;
5056
5057 if (device->missing || !device->bdev) {
5058 bio_endio(bio, -EIO);
5059 return;
5060 }
5061
5062 /* don't bother with additional async steps for reads, right now */
5063 if (!(rw & REQ_WRITE)) {
5064 bio_get(bio);
5065 btrfsic_submit_bio(rw, bio);
5066 bio_put(bio);
5067 return;
5068 }
5069
5070 /*
5071 * nr_async_bios allows us to reliably return congestion to the
5072 * higher layers. Otherwise, the async bio makes it appear we have
5073 * made progress against dirty pages when we've really just put it
5074 * on a queue for later
5075 */
5076 atomic_inc(&root->fs_info->nr_async_bios);
5077 WARN_ON(bio->bi_next);
5078 bio->bi_next = NULL;
5079 bio->bi_rw |= rw;
5080
5081 spin_lock(&device->io_lock);
5082 if (bio->bi_rw & REQ_SYNC)
5083 pending_bios = &device->pending_sync_bios;
5084 else
5085 pending_bios = &device->pending_bios;
5086
5087 if (pending_bios->tail)
5088 pending_bios->tail->bi_next = bio;
5089
5090 pending_bios->tail = bio;
5091 if (!pending_bios->head)
5092 pending_bios->head = bio;
5093 if (device->running_pending)
5094 should_queue = 0;
5095
5096 spin_unlock(&device->io_lock);
5097
5098 if (should_queue)
5099 btrfs_queue_worker(&root->fs_info->submit_workers,
5100 &device->work);
5101 }
5102
5103 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5104 sector_t sector)
5105 {
5106 struct bio_vec *prev;
5107 struct request_queue *q = bdev_get_queue(bdev);
5108 unsigned short max_sectors = queue_max_sectors(q);
5109 struct bvec_merge_data bvm = {
5110 .bi_bdev = bdev,
5111 .bi_sector = sector,
5112 .bi_rw = bio->bi_rw,
5113 };
5114
5115 if (bio->bi_vcnt == 0) {
5116 WARN_ON(1);
5117 return 1;
5118 }
5119
5120 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5121 if (bio_sectors(bio) > max_sectors)
5122 return 0;
5123
5124 if (!q->merge_bvec_fn)
5125 return 1;
5126
5127 bvm.bi_size = bio->bi_size - prev->bv_len;
5128 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5129 return 0;
5130 return 1;
5131 }
5132
5133 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5134 struct bio *bio, u64 physical, int dev_nr,
5135 int rw, int async)
5136 {
5137 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5138
5139 bio->bi_private = bbio;
5140 btrfs_io_bio(bio)->stripe_index = dev_nr;
5141 bio->bi_end_io = btrfs_end_bio;
5142 bio->bi_sector = physical >> 9;
5143 #ifdef DEBUG
5144 {
5145 struct rcu_string *name;
5146
5147 rcu_read_lock();
5148 name = rcu_dereference(dev->name);
5149 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5150 "(%s id %llu), size=%u\n", rw,
5151 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5152 name->str, dev->devid, bio->bi_size);
5153 rcu_read_unlock();
5154 }
5155 #endif
5156 bio->bi_bdev = dev->bdev;
5157 if (async)
5158 btrfs_schedule_bio(root, dev, rw, bio);
5159 else
5160 btrfsic_submit_bio(rw, bio);
5161 }
5162
5163 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5164 struct bio *first_bio, struct btrfs_device *dev,
5165 int dev_nr, int rw, int async)
5166 {
5167 struct bio_vec *bvec = first_bio->bi_io_vec;
5168 struct bio *bio;
5169 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5170 u64 physical = bbio->stripes[dev_nr].physical;
5171
5172 again:
5173 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5174 if (!bio)
5175 return -ENOMEM;
5176
5177 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5178 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5179 bvec->bv_offset) < bvec->bv_len) {
5180 u64 len = bio->bi_size;
5181
5182 atomic_inc(&bbio->stripes_pending);
5183 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5184 rw, async);
5185 physical += len;
5186 goto again;
5187 }
5188 bvec++;
5189 }
5190
5191 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5192 return 0;
5193 }
5194
5195 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5196 {
5197 atomic_inc(&bbio->error);
5198 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5199 bio->bi_private = bbio->private;
5200 bio->bi_end_io = bbio->end_io;
5201 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5202 bio->bi_sector = logical >> 9;
5203 kfree(bbio);
5204 bio_endio(bio, -EIO);
5205 }
5206 }
5207
5208 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5209 int mirror_num, int async_submit)
5210 {
5211 struct btrfs_device *dev;
5212 struct bio *first_bio = bio;
5213 u64 logical = (u64)bio->bi_sector << 9;
5214 u64 length = 0;
5215 u64 map_length;
5216 u64 *raid_map = NULL;
5217 int ret;
5218 int dev_nr = 0;
5219 int total_devs = 1;
5220 struct btrfs_bio *bbio = NULL;
5221
5222 length = bio->bi_size;
5223 map_length = length;
5224
5225 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5226 mirror_num, &raid_map);
5227 if (ret) /* -ENOMEM */
5228 return ret;
5229
5230 total_devs = bbio->num_stripes;
5231 bbio->orig_bio = first_bio;
5232 bbio->private = first_bio->bi_private;
5233 bbio->end_io = first_bio->bi_end_io;
5234 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5235
5236 if (raid_map) {
5237 /* In this case, map_length has been set to the length of
5238 a single stripe; not the whole write */
5239 if (rw & WRITE) {
5240 return raid56_parity_write(root, bio, bbio,
5241 raid_map, map_length);
5242 } else {
5243 return raid56_parity_recover(root, bio, bbio,
5244 raid_map, map_length,
5245 mirror_num);
5246 }
5247 }
5248
5249 if (map_length < length) {
5250 btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5251 (unsigned long long)logical,
5252 (unsigned long long)length,
5253 (unsigned long long)map_length);
5254 BUG();
5255 }
5256
5257 while (dev_nr < total_devs) {
5258 dev = bbio->stripes[dev_nr].dev;
5259 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5260 bbio_error(bbio, first_bio, logical);
5261 dev_nr++;
5262 continue;
5263 }
5264
5265 /*
5266 * Check and see if we're ok with this bio based on it's size
5267 * and offset with the given device.
5268 */
5269 if (!bio_size_ok(dev->bdev, first_bio,
5270 bbio->stripes[dev_nr].physical >> 9)) {
5271 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5272 dev_nr, rw, async_submit);
5273 BUG_ON(ret);
5274 dev_nr++;
5275 continue;
5276 }
5277
5278 if (dev_nr < total_devs - 1) {
5279 bio = btrfs_bio_clone(first_bio, GFP_NOFS);
5280 BUG_ON(!bio); /* -ENOMEM */
5281 } else {
5282 bio = first_bio;
5283 }
5284
5285 submit_stripe_bio(root, bbio, bio,
5286 bbio->stripes[dev_nr].physical, dev_nr, rw,
5287 async_submit);
5288 dev_nr++;
5289 }
5290 return 0;
5291 }
5292
5293 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5294 u8 *uuid, u8 *fsid)
5295 {
5296 struct btrfs_device *device;
5297 struct btrfs_fs_devices *cur_devices;
5298
5299 cur_devices = fs_info->fs_devices;
5300 while (cur_devices) {
5301 if (!fsid ||
5302 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5303 device = __find_device(&cur_devices->devices,
5304 devid, uuid);
5305 if (device)
5306 return device;
5307 }
5308 cur_devices = cur_devices->seed;
5309 }
5310 return NULL;
5311 }
5312
5313 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5314 u64 devid, u8 *dev_uuid)
5315 {
5316 struct btrfs_device *device;
5317 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5318
5319 device = kzalloc(sizeof(*device), GFP_NOFS);
5320 if (!device)
5321 return NULL;
5322 list_add(&device->dev_list,
5323 &fs_devices->devices);
5324 device->devid = devid;
5325 device->work.func = pending_bios_fn;
5326 device->fs_devices = fs_devices;
5327 device->missing = 1;
5328 fs_devices->num_devices++;
5329 fs_devices->missing_devices++;
5330 spin_lock_init(&device->io_lock);
5331 INIT_LIST_HEAD(&device->dev_alloc_list);
5332 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
5333 return device;
5334 }
5335
5336 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5337 struct extent_buffer *leaf,
5338 struct btrfs_chunk *chunk)
5339 {
5340 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5341 struct map_lookup *map;
5342 struct extent_map *em;
5343 u64 logical;
5344 u64 length;
5345 u64 devid;
5346 u8 uuid[BTRFS_UUID_SIZE];
5347 int num_stripes;
5348 int ret;
5349 int i;
5350
5351 logical = key->offset;
5352 length = btrfs_chunk_length(leaf, chunk);
5353
5354 read_lock(&map_tree->map_tree.lock);
5355 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5356 read_unlock(&map_tree->map_tree.lock);
5357
5358 /* already mapped? */
5359 if (em && em->start <= logical && em->start + em->len > logical) {
5360 free_extent_map(em);
5361 return 0;
5362 } else if (em) {
5363 free_extent_map(em);
5364 }
5365
5366 em = alloc_extent_map();
5367 if (!em)
5368 return -ENOMEM;
5369 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5370 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5371 if (!map) {
5372 free_extent_map(em);
5373 return -ENOMEM;
5374 }
5375
5376 em->bdev = (struct block_device *)map;
5377 em->start = logical;
5378 em->len = length;
5379 em->orig_start = 0;
5380 em->block_start = 0;
5381 em->block_len = em->len;
5382
5383 map->num_stripes = num_stripes;
5384 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5385 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5386 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5387 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5388 map->type = btrfs_chunk_type(leaf, chunk);
5389 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5390 for (i = 0; i < num_stripes; i++) {
5391 map->stripes[i].physical =
5392 btrfs_stripe_offset_nr(leaf, chunk, i);
5393 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5394 read_extent_buffer(leaf, uuid, (unsigned long)
5395 btrfs_stripe_dev_uuid_nr(chunk, i),
5396 BTRFS_UUID_SIZE);
5397 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5398 uuid, NULL);
5399 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5400 kfree(map);
5401 free_extent_map(em);
5402 return -EIO;
5403 }
5404 if (!map->stripes[i].dev) {
5405 map->stripes[i].dev =
5406 add_missing_dev(root, devid, uuid);
5407 if (!map->stripes[i].dev) {
5408 kfree(map);
5409 free_extent_map(em);
5410 return -EIO;
5411 }
5412 }
5413 map->stripes[i].dev->in_fs_metadata = 1;
5414 }
5415
5416 write_lock(&map_tree->map_tree.lock);
5417 ret = add_extent_mapping(&map_tree->map_tree, em, 0);
5418 write_unlock(&map_tree->map_tree.lock);
5419 BUG_ON(ret); /* Tree corruption */
5420 free_extent_map(em);
5421
5422 return 0;
5423 }
5424
5425 static void fill_device_from_item(struct extent_buffer *leaf,
5426 struct btrfs_dev_item *dev_item,
5427 struct btrfs_device *device)
5428 {
5429 unsigned long ptr;
5430
5431 device->devid = btrfs_device_id(leaf, dev_item);
5432 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5433 device->total_bytes = device->disk_total_bytes;
5434 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5435 device->type = btrfs_device_type(leaf, dev_item);
5436 device->io_align = btrfs_device_io_align(leaf, dev_item);
5437 device->io_width = btrfs_device_io_width(leaf, dev_item);
5438 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5439 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5440 device->is_tgtdev_for_dev_replace = 0;
5441
5442 ptr = (unsigned long)btrfs_device_uuid(dev_item);
5443 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5444 }
5445
5446 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5447 {
5448 struct btrfs_fs_devices *fs_devices;
5449 int ret;
5450
5451 BUG_ON(!mutex_is_locked(&uuid_mutex));
5452
5453 fs_devices = root->fs_info->fs_devices->seed;
5454 while (fs_devices) {
5455 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5456 ret = 0;
5457 goto out;
5458 }
5459 fs_devices = fs_devices->seed;
5460 }
5461
5462 fs_devices = find_fsid(fsid);
5463 if (!fs_devices) {
5464 ret = -ENOENT;
5465 goto out;
5466 }
5467
5468 fs_devices = clone_fs_devices(fs_devices);
5469 if (IS_ERR(fs_devices)) {
5470 ret = PTR_ERR(fs_devices);
5471 goto out;
5472 }
5473
5474 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5475 root->fs_info->bdev_holder);
5476 if (ret) {
5477 free_fs_devices(fs_devices);
5478 goto out;
5479 }
5480
5481 if (!fs_devices->seeding) {
5482 __btrfs_close_devices(fs_devices);
5483 free_fs_devices(fs_devices);
5484 ret = -EINVAL;
5485 goto out;
5486 }
5487
5488 fs_devices->seed = root->fs_info->fs_devices->seed;
5489 root->fs_info->fs_devices->seed = fs_devices;
5490 out:
5491 return ret;
5492 }
5493
5494 static int read_one_dev(struct btrfs_root *root,
5495 struct extent_buffer *leaf,
5496 struct btrfs_dev_item *dev_item)
5497 {
5498 struct btrfs_device *device;
5499 u64 devid;
5500 int ret;
5501 u8 fs_uuid[BTRFS_UUID_SIZE];
5502 u8 dev_uuid[BTRFS_UUID_SIZE];
5503
5504 devid = btrfs_device_id(leaf, dev_item);
5505 read_extent_buffer(leaf, dev_uuid,
5506 (unsigned long)btrfs_device_uuid(dev_item),
5507 BTRFS_UUID_SIZE);
5508 read_extent_buffer(leaf, fs_uuid,
5509 (unsigned long)btrfs_device_fsid(dev_item),
5510 BTRFS_UUID_SIZE);
5511
5512 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5513 ret = open_seed_devices(root, fs_uuid);
5514 if (ret && !btrfs_test_opt(root, DEGRADED))
5515 return ret;
5516 }
5517
5518 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5519 if (!device || !device->bdev) {
5520 if (!btrfs_test_opt(root, DEGRADED))
5521 return -EIO;
5522
5523 if (!device) {
5524 btrfs_warn(root->fs_info, "devid %llu missing",
5525 (unsigned long long)devid);
5526 device = add_missing_dev(root, devid, dev_uuid);
5527 if (!device)
5528 return -ENOMEM;
5529 } else if (!device->missing) {
5530 /*
5531 * this happens when a device that was properly setup
5532 * in the device info lists suddenly goes bad.
5533 * device->bdev is NULL, and so we have to set
5534 * device->missing to one here
5535 */
5536 root->fs_info->fs_devices->missing_devices++;
5537 device->missing = 1;
5538 }
5539 }
5540
5541 if (device->fs_devices != root->fs_info->fs_devices) {
5542 BUG_ON(device->writeable);
5543 if (device->generation !=
5544 btrfs_device_generation(leaf, dev_item))
5545 return -EINVAL;
5546 }
5547
5548 fill_device_from_item(leaf, dev_item, device);
5549 device->in_fs_metadata = 1;
5550 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5551 device->fs_devices->total_rw_bytes += device->total_bytes;
5552 spin_lock(&root->fs_info->free_chunk_lock);
5553 root->fs_info->free_chunk_space += device->total_bytes -
5554 device->bytes_used;
5555 spin_unlock(&root->fs_info->free_chunk_lock);
5556 }
5557 ret = 0;
5558 return ret;
5559 }
5560
5561 int btrfs_read_sys_array(struct btrfs_root *root)
5562 {
5563 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5564 struct extent_buffer *sb;
5565 struct btrfs_disk_key *disk_key;
5566 struct btrfs_chunk *chunk;
5567 u8 *ptr;
5568 unsigned long sb_ptr;
5569 int ret = 0;
5570 u32 num_stripes;
5571 u32 array_size;
5572 u32 len = 0;
5573 u32 cur;
5574 struct btrfs_key key;
5575
5576 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5577 BTRFS_SUPER_INFO_SIZE);
5578 if (!sb)
5579 return -ENOMEM;
5580 btrfs_set_buffer_uptodate(sb);
5581 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5582 /*
5583 * The sb extent buffer is artifical and just used to read the system array.
5584 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5585 * pages up-to-date when the page is larger: extent does not cover the
5586 * whole page and consequently check_page_uptodate does not find all
5587 * the page's extents up-to-date (the hole beyond sb),
5588 * write_extent_buffer then triggers a WARN_ON.
5589 *
5590 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5591 * but sb spans only this function. Add an explicit SetPageUptodate call
5592 * to silence the warning eg. on PowerPC 64.
5593 */
5594 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5595 SetPageUptodate(sb->pages[0]);
5596
5597 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5598 array_size = btrfs_super_sys_array_size(super_copy);
5599
5600 ptr = super_copy->sys_chunk_array;
5601 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5602 cur = 0;
5603
5604 while (cur < array_size) {
5605 disk_key = (struct btrfs_disk_key *)ptr;
5606 btrfs_disk_key_to_cpu(&key, disk_key);
5607
5608 len = sizeof(*disk_key); ptr += len;
5609 sb_ptr += len;
5610 cur += len;
5611
5612 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5613 chunk = (struct btrfs_chunk *)sb_ptr;
5614 ret = read_one_chunk(root, &key, sb, chunk);
5615 if (ret)
5616 break;
5617 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5618 len = btrfs_chunk_item_size(num_stripes);
5619 } else {
5620 ret = -EIO;
5621 break;
5622 }
5623 ptr += len;
5624 sb_ptr += len;
5625 cur += len;
5626 }
5627 free_extent_buffer(sb);
5628 return ret;
5629 }
5630
5631 int btrfs_read_chunk_tree(struct btrfs_root *root)
5632 {
5633 struct btrfs_path *path;
5634 struct extent_buffer *leaf;
5635 struct btrfs_key key;
5636 struct btrfs_key found_key;
5637 int ret;
5638 int slot;
5639
5640 root = root->fs_info->chunk_root;
5641
5642 path = btrfs_alloc_path();
5643 if (!path)
5644 return -ENOMEM;
5645
5646 mutex_lock(&uuid_mutex);
5647 lock_chunks(root);
5648
5649 /* first we search for all of the device items, and then we
5650 * read in all of the chunk items. This way we can create chunk
5651 * mappings that reference all of the devices that are afound
5652 */
5653 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5654 key.offset = 0;
5655 key.type = 0;
5656 again:
5657 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5658 if (ret < 0)
5659 goto error;
5660 while (1) {
5661 leaf = path->nodes[0];
5662 slot = path->slots[0];
5663 if (slot >= btrfs_header_nritems(leaf)) {
5664 ret = btrfs_next_leaf(root, path);
5665 if (ret == 0)
5666 continue;
5667 if (ret < 0)
5668 goto error;
5669 break;
5670 }
5671 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5672 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5673 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
5674 break;
5675 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
5676 struct btrfs_dev_item *dev_item;
5677 dev_item = btrfs_item_ptr(leaf, slot,
5678 struct btrfs_dev_item);
5679 ret = read_one_dev(root, leaf, dev_item);
5680 if (ret)
5681 goto error;
5682 }
5683 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
5684 struct btrfs_chunk *chunk;
5685 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
5686 ret = read_one_chunk(root, &found_key, leaf, chunk);
5687 if (ret)
5688 goto error;
5689 }
5690 path->slots[0]++;
5691 }
5692 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5693 key.objectid = 0;
5694 btrfs_release_path(path);
5695 goto again;
5696 }
5697 ret = 0;
5698 error:
5699 unlock_chunks(root);
5700 mutex_unlock(&uuid_mutex);
5701
5702 btrfs_free_path(path);
5703 return ret;
5704 }
5705
5706 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
5707 {
5708 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5709 struct btrfs_device *device;
5710
5711 mutex_lock(&fs_devices->device_list_mutex);
5712 list_for_each_entry(device, &fs_devices->devices, dev_list)
5713 device->dev_root = fs_info->dev_root;
5714 mutex_unlock(&fs_devices->device_list_mutex);
5715 }
5716
5717 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
5718 {
5719 int i;
5720
5721 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5722 btrfs_dev_stat_reset(dev, i);
5723 }
5724
5725 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
5726 {
5727 struct btrfs_key key;
5728 struct btrfs_key found_key;
5729 struct btrfs_root *dev_root = fs_info->dev_root;
5730 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5731 struct extent_buffer *eb;
5732 int slot;
5733 int ret = 0;
5734 struct btrfs_device *device;
5735 struct btrfs_path *path = NULL;
5736 int i;
5737
5738 path = btrfs_alloc_path();
5739 if (!path) {
5740 ret = -ENOMEM;
5741 goto out;
5742 }
5743
5744 mutex_lock(&fs_devices->device_list_mutex);
5745 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5746 int item_size;
5747 struct btrfs_dev_stats_item *ptr;
5748
5749 key.objectid = 0;
5750 key.type = BTRFS_DEV_STATS_KEY;
5751 key.offset = device->devid;
5752 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
5753 if (ret) {
5754 __btrfs_reset_dev_stats(device);
5755 device->dev_stats_valid = 1;
5756 btrfs_release_path(path);
5757 continue;
5758 }
5759 slot = path->slots[0];
5760 eb = path->nodes[0];
5761 btrfs_item_key_to_cpu(eb, &found_key, slot);
5762 item_size = btrfs_item_size_nr(eb, slot);
5763
5764 ptr = btrfs_item_ptr(eb, slot,
5765 struct btrfs_dev_stats_item);
5766
5767 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5768 if (item_size >= (1 + i) * sizeof(__le64))
5769 btrfs_dev_stat_set(device, i,
5770 btrfs_dev_stats_value(eb, ptr, i));
5771 else
5772 btrfs_dev_stat_reset(device, i);
5773 }
5774
5775 device->dev_stats_valid = 1;
5776 btrfs_dev_stat_print_on_load(device);
5777 btrfs_release_path(path);
5778 }
5779 mutex_unlock(&fs_devices->device_list_mutex);
5780
5781 out:
5782 btrfs_free_path(path);
5783 return ret < 0 ? ret : 0;
5784 }
5785
5786 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
5787 struct btrfs_root *dev_root,
5788 struct btrfs_device *device)
5789 {
5790 struct btrfs_path *path;
5791 struct btrfs_key key;
5792 struct extent_buffer *eb;
5793 struct btrfs_dev_stats_item *ptr;
5794 int ret;
5795 int i;
5796
5797 key.objectid = 0;
5798 key.type = BTRFS_DEV_STATS_KEY;
5799 key.offset = device->devid;
5800
5801 path = btrfs_alloc_path();
5802 BUG_ON(!path);
5803 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
5804 if (ret < 0) {
5805 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
5806 ret, rcu_str_deref(device->name));
5807 goto out;
5808 }
5809
5810 if (ret == 0 &&
5811 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
5812 /* need to delete old one and insert a new one */
5813 ret = btrfs_del_item(trans, dev_root, path);
5814 if (ret != 0) {
5815 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
5816 rcu_str_deref(device->name), ret);
5817 goto out;
5818 }
5819 ret = 1;
5820 }
5821
5822 if (ret == 1) {
5823 /* need to insert a new item */
5824 btrfs_release_path(path);
5825 ret = btrfs_insert_empty_item(trans, dev_root, path,
5826 &key, sizeof(*ptr));
5827 if (ret < 0) {
5828 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
5829 rcu_str_deref(device->name), ret);
5830 goto out;
5831 }
5832 }
5833
5834 eb = path->nodes[0];
5835 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
5836 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5837 btrfs_set_dev_stats_value(eb, ptr, i,
5838 btrfs_dev_stat_read(device, i));
5839 btrfs_mark_buffer_dirty(eb);
5840
5841 out:
5842 btrfs_free_path(path);
5843 return ret;
5844 }
5845
5846 /*
5847 * called from commit_transaction. Writes all changed device stats to disk.
5848 */
5849 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
5850 struct btrfs_fs_info *fs_info)
5851 {
5852 struct btrfs_root *dev_root = fs_info->dev_root;
5853 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5854 struct btrfs_device *device;
5855 int ret = 0;
5856
5857 mutex_lock(&fs_devices->device_list_mutex);
5858 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5859 if (!device->dev_stats_valid || !device->dev_stats_dirty)
5860 continue;
5861
5862 ret = update_dev_stat_item(trans, dev_root, device);
5863 if (!ret)
5864 device->dev_stats_dirty = 0;
5865 }
5866 mutex_unlock(&fs_devices->device_list_mutex);
5867
5868 return ret;
5869 }
5870
5871 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
5872 {
5873 btrfs_dev_stat_inc(dev, index);
5874 btrfs_dev_stat_print_on_error(dev);
5875 }
5876
5877 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
5878 {
5879 if (!dev->dev_stats_valid)
5880 return;
5881 printk_ratelimited_in_rcu(KERN_ERR
5882 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5883 rcu_str_deref(dev->name),
5884 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5885 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5886 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5887 btrfs_dev_stat_read(dev,
5888 BTRFS_DEV_STAT_CORRUPTION_ERRS),
5889 btrfs_dev_stat_read(dev,
5890 BTRFS_DEV_STAT_GENERATION_ERRS));
5891 }
5892
5893 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
5894 {
5895 int i;
5896
5897 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5898 if (btrfs_dev_stat_read(dev, i) != 0)
5899 break;
5900 if (i == BTRFS_DEV_STAT_VALUES_MAX)
5901 return; /* all values == 0, suppress message */
5902
5903 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5904 rcu_str_deref(dev->name),
5905 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5906 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5907 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5908 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
5909 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
5910 }
5911
5912 int btrfs_get_dev_stats(struct btrfs_root *root,
5913 struct btrfs_ioctl_get_dev_stats *stats)
5914 {
5915 struct btrfs_device *dev;
5916 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5917 int i;
5918
5919 mutex_lock(&fs_devices->device_list_mutex);
5920 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
5921 mutex_unlock(&fs_devices->device_list_mutex);
5922
5923 if (!dev) {
5924 printk(KERN_WARNING
5925 "btrfs: get dev_stats failed, device not found\n");
5926 return -ENODEV;
5927 } else if (!dev->dev_stats_valid) {
5928 printk(KERN_WARNING
5929 "btrfs: get dev_stats failed, not yet valid\n");
5930 return -ENODEV;
5931 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
5932 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5933 if (stats->nr_items > i)
5934 stats->values[i] =
5935 btrfs_dev_stat_read_and_reset(dev, i);
5936 else
5937 btrfs_dev_stat_reset(dev, i);
5938 }
5939 } else {
5940 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5941 if (stats->nr_items > i)
5942 stats->values[i] = btrfs_dev_stat_read(dev, i);
5943 }
5944 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
5945 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
5946 return 0;
5947 }
5948
5949 int btrfs_scratch_superblock(struct btrfs_device *device)
5950 {
5951 struct buffer_head *bh;
5952 struct btrfs_super_block *disk_super;
5953
5954 bh = btrfs_read_dev_super(device->bdev);
5955 if (!bh)
5956 return -EINVAL;
5957 disk_super = (struct btrfs_super_block *)bh->b_data;
5958
5959 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
5960 set_buffer_dirty(bh);
5961 sync_dirty_buffer(bh);
5962 brelse(bh);
5963
5964 return 0;
5965 }
Linux kernel - Deliverables
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