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Merge branch 'for-john' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211
[mirror_ubuntu-artful-kernel.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_load(struct btrfs_device *device);
50
51 static DEFINE_MUTEX(uuid_mutex);
52 static LIST_HEAD(fs_uuids);
53
54 static void lock_chunks(struct btrfs_root *root)
55 {
56 mutex_lock(&root->fs_info->chunk_mutex);
57 }
58
59 static void unlock_chunks(struct btrfs_root *root)
60 {
61 mutex_unlock(&root->fs_info->chunk_mutex);
62 }
63
64 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
65 {
66 struct btrfs_device *device;
67 WARN_ON(fs_devices->opened);
68 while (!list_empty(&fs_devices->devices)) {
69 device = list_entry(fs_devices->devices.next,
70 struct btrfs_device, dev_list);
71 list_del(&device->dev_list);
72 rcu_string_free(device->name);
73 kfree(device);
74 }
75 kfree(fs_devices);
76 }
77
78 static void btrfs_kobject_uevent(struct block_device *bdev,
79 enum kobject_action action)
80 {
81 int ret;
82
83 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
84 if (ret)
85 pr_warn("Sending event '%d' to kobject: '%s' (%p): failed\n",
86 action,
87 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
88 &disk_to_dev(bdev->bd_disk)->kobj);
89 }
90
91 void btrfs_cleanup_fs_uuids(void)
92 {
93 struct btrfs_fs_devices *fs_devices;
94
95 while (!list_empty(&fs_uuids)) {
96 fs_devices = list_entry(fs_uuids.next,
97 struct btrfs_fs_devices, list);
98 list_del(&fs_devices->list);
99 free_fs_devices(fs_devices);
100 }
101 }
102
103 static noinline struct btrfs_device *__find_device(struct list_head *head,
104 u64 devid, u8 *uuid)
105 {
106 struct btrfs_device *dev;
107
108 list_for_each_entry(dev, head, dev_list) {
109 if (dev->devid == devid &&
110 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
111 return dev;
112 }
113 }
114 return NULL;
115 }
116
117 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
118 {
119 struct btrfs_fs_devices *fs_devices;
120
121 list_for_each_entry(fs_devices, &fs_uuids, list) {
122 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
123 return fs_devices;
124 }
125 return NULL;
126 }
127
128 static int
129 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
130 int flush, struct block_device **bdev,
131 struct buffer_head **bh)
132 {
133 int ret;
134
135 *bdev = blkdev_get_by_path(device_path, flags, holder);
136
137 if (IS_ERR(*bdev)) {
138 ret = PTR_ERR(*bdev);
139 printk(KERN_INFO "btrfs: open %s failed\n", device_path);
140 goto error;
141 }
142
143 if (flush)
144 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
145 ret = set_blocksize(*bdev, 4096);
146 if (ret) {
147 blkdev_put(*bdev, flags);
148 goto error;
149 }
150 invalidate_bdev(*bdev);
151 *bh = btrfs_read_dev_super(*bdev);
152 if (!*bh) {
153 ret = -EINVAL;
154 blkdev_put(*bdev, flags);
155 goto error;
156 }
157
158 return 0;
159
160 error:
161 *bdev = NULL;
162 *bh = NULL;
163 return ret;
164 }
165
166 static void requeue_list(struct btrfs_pending_bios *pending_bios,
167 struct bio *head, struct bio *tail)
168 {
169
170 struct bio *old_head;
171
172 old_head = pending_bios->head;
173 pending_bios->head = head;
174 if (pending_bios->tail)
175 tail->bi_next = old_head;
176 else
177 pending_bios->tail = tail;
178 }
179
180 /*
181 * we try to collect pending bios for a device so we don't get a large
182 * number of procs sending bios down to the same device. This greatly
183 * improves the schedulers ability to collect and merge the bios.
184 *
185 * But, it also turns into a long list of bios to process and that is sure
186 * to eventually make the worker thread block. The solution here is to
187 * make some progress and then put this work struct back at the end of
188 * the list if the block device is congested. This way, multiple devices
189 * can make progress from a single worker thread.
190 */
191 static noinline void run_scheduled_bios(struct btrfs_device *device)
192 {
193 struct bio *pending;
194 struct backing_dev_info *bdi;
195 struct btrfs_fs_info *fs_info;
196 struct btrfs_pending_bios *pending_bios;
197 struct bio *tail;
198 struct bio *cur;
199 int again = 0;
200 unsigned long num_run;
201 unsigned long batch_run = 0;
202 unsigned long limit;
203 unsigned long last_waited = 0;
204 int force_reg = 0;
205 int sync_pending = 0;
206 struct blk_plug plug;
207
208 /*
209 * this function runs all the bios we've collected for
210 * a particular device. We don't want to wander off to
211 * another device without first sending all of these down.
212 * So, setup a plug here and finish it off before we return
213 */
214 blk_start_plug(&plug);
215
216 bdi = blk_get_backing_dev_info(device->bdev);
217 fs_info = device->dev_root->fs_info;
218 limit = btrfs_async_submit_limit(fs_info);
219 limit = limit * 2 / 3;
220
221 loop:
222 spin_lock(&device->io_lock);
223
224 loop_lock:
225 num_run = 0;
226
227 /* take all the bios off the list at once and process them
228 * later on (without the lock held). But, remember the
229 * tail and other pointers so the bios can be properly reinserted
230 * into the list if we hit congestion
231 */
232 if (!force_reg && device->pending_sync_bios.head) {
233 pending_bios = &device->pending_sync_bios;
234 force_reg = 1;
235 } else {
236 pending_bios = &device->pending_bios;
237 force_reg = 0;
238 }
239
240 pending = pending_bios->head;
241 tail = pending_bios->tail;
242 WARN_ON(pending && !tail);
243
244 /*
245 * if pending was null this time around, no bios need processing
246 * at all and we can stop. Otherwise it'll loop back up again
247 * and do an additional check so no bios are missed.
248 *
249 * device->running_pending is used to synchronize with the
250 * schedule_bio code.
251 */
252 if (device->pending_sync_bios.head == NULL &&
253 device->pending_bios.head == NULL) {
254 again = 0;
255 device->running_pending = 0;
256 } else {
257 again = 1;
258 device->running_pending = 1;
259 }
260
261 pending_bios->head = NULL;
262 pending_bios->tail = NULL;
263
264 spin_unlock(&device->io_lock);
265
266 while (pending) {
267
268 rmb();
269 /* we want to work on both lists, but do more bios on the
270 * sync list than the regular list
271 */
272 if ((num_run > 32 &&
273 pending_bios != &device->pending_sync_bios &&
274 device->pending_sync_bios.head) ||
275 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
276 device->pending_bios.head)) {
277 spin_lock(&device->io_lock);
278 requeue_list(pending_bios, pending, tail);
279 goto loop_lock;
280 }
281
282 cur = pending;
283 pending = pending->bi_next;
284 cur->bi_next = NULL;
285
286 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
287 waitqueue_active(&fs_info->async_submit_wait))
288 wake_up(&fs_info->async_submit_wait);
289
290 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
291
292 /*
293 * if we're doing the sync list, record that our
294 * plug has some sync requests on it
295 *
296 * If we're doing the regular list and there are
297 * sync requests sitting around, unplug before
298 * we add more
299 */
300 if (pending_bios == &device->pending_sync_bios) {
301 sync_pending = 1;
302 } else if (sync_pending) {
303 blk_finish_plug(&plug);
304 blk_start_plug(&plug);
305 sync_pending = 0;
306 }
307
308 btrfsic_submit_bio(cur->bi_rw, cur);
309 num_run++;
310 batch_run++;
311 if (need_resched())
312 cond_resched();
313
314 /*
315 * we made progress, there is more work to do and the bdi
316 * is now congested. Back off and let other work structs
317 * run instead
318 */
319 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
320 fs_info->fs_devices->open_devices > 1) {
321 struct io_context *ioc;
322
323 ioc = current->io_context;
324
325 /*
326 * the main goal here is that we don't want to
327 * block if we're going to be able to submit
328 * more requests without blocking.
329 *
330 * This code does two great things, it pokes into
331 * the elevator code from a filesystem _and_
332 * it makes assumptions about how batching works.
333 */
334 if (ioc && ioc->nr_batch_requests > 0 &&
335 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
336 (last_waited == 0 ||
337 ioc->last_waited == last_waited)) {
338 /*
339 * we want to go through our batch of
340 * requests and stop. So, we copy out
341 * the ioc->last_waited time and test
342 * against it before looping
343 */
344 last_waited = ioc->last_waited;
345 if (need_resched())
346 cond_resched();
347 continue;
348 }
349 spin_lock(&device->io_lock);
350 requeue_list(pending_bios, pending, tail);
351 device->running_pending = 1;
352
353 spin_unlock(&device->io_lock);
354 btrfs_requeue_work(&device->work);
355 goto done;
356 }
357 /* unplug every 64 requests just for good measure */
358 if (batch_run % 64 == 0) {
359 blk_finish_plug(&plug);
360 blk_start_plug(&plug);
361 sync_pending = 0;
362 }
363 }
364
365 cond_resched();
366 if (again)
367 goto loop;
368
369 spin_lock(&device->io_lock);
370 if (device->pending_bios.head || device->pending_sync_bios.head)
371 goto loop_lock;
372 spin_unlock(&device->io_lock);
373
374 done:
375 blk_finish_plug(&plug);
376 }
377
378 static void pending_bios_fn(struct btrfs_work *work)
379 {
380 struct btrfs_device *device;
381
382 device = container_of(work, struct btrfs_device, work);
383 run_scheduled_bios(device);
384 }
385
386 static noinline int device_list_add(const char *path,
387 struct btrfs_super_block *disk_super,
388 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
389 {
390 struct btrfs_device *device;
391 struct btrfs_fs_devices *fs_devices;
392 struct rcu_string *name;
393 u64 found_transid = btrfs_super_generation(disk_super);
394
395 fs_devices = find_fsid(disk_super->fsid);
396 if (!fs_devices) {
397 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
398 if (!fs_devices)
399 return -ENOMEM;
400 INIT_LIST_HEAD(&fs_devices->devices);
401 INIT_LIST_HEAD(&fs_devices->alloc_list);
402 list_add(&fs_devices->list, &fs_uuids);
403 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
404 fs_devices->latest_devid = devid;
405 fs_devices->latest_trans = found_transid;
406 mutex_init(&fs_devices->device_list_mutex);
407 device = NULL;
408 } else {
409 device = __find_device(&fs_devices->devices, devid,
410 disk_super->dev_item.uuid);
411 }
412 if (!device) {
413 if (fs_devices->opened)
414 return -EBUSY;
415
416 device = kzalloc(sizeof(*device), GFP_NOFS);
417 if (!device) {
418 /* we can safely leave the fs_devices entry around */
419 return -ENOMEM;
420 }
421 device->devid = devid;
422 device->dev_stats_valid = 0;
423 device->work.func = pending_bios_fn;
424 memcpy(device->uuid, disk_super->dev_item.uuid,
425 BTRFS_UUID_SIZE);
426 spin_lock_init(&device->io_lock);
427
428 name = rcu_string_strdup(path, GFP_NOFS);
429 if (!name) {
430 kfree(device);
431 return -ENOMEM;
432 }
433 rcu_assign_pointer(device->name, name);
434 INIT_LIST_HEAD(&device->dev_alloc_list);
435
436 /* init readahead state */
437 spin_lock_init(&device->reada_lock);
438 device->reada_curr_zone = NULL;
439 atomic_set(&device->reada_in_flight, 0);
440 device->reada_next = 0;
441 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
442 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
443
444 mutex_lock(&fs_devices->device_list_mutex);
445 list_add_rcu(&device->dev_list, &fs_devices->devices);
446 mutex_unlock(&fs_devices->device_list_mutex);
447
448 device->fs_devices = fs_devices;
449 fs_devices->num_devices++;
450 } else if (!device->name || strcmp(device->name->str, path)) {
451 name = rcu_string_strdup(path, GFP_NOFS);
452 if (!name)
453 return -ENOMEM;
454 rcu_string_free(device->name);
455 rcu_assign_pointer(device->name, name);
456 if (device->missing) {
457 fs_devices->missing_devices--;
458 device->missing = 0;
459 }
460 }
461
462 if (found_transid > fs_devices->latest_trans) {
463 fs_devices->latest_devid = devid;
464 fs_devices->latest_trans = found_transid;
465 }
466 *fs_devices_ret = fs_devices;
467 return 0;
468 }
469
470 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
471 {
472 struct btrfs_fs_devices *fs_devices;
473 struct btrfs_device *device;
474 struct btrfs_device *orig_dev;
475
476 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
477 if (!fs_devices)
478 return ERR_PTR(-ENOMEM);
479
480 INIT_LIST_HEAD(&fs_devices->devices);
481 INIT_LIST_HEAD(&fs_devices->alloc_list);
482 INIT_LIST_HEAD(&fs_devices->list);
483 mutex_init(&fs_devices->device_list_mutex);
484 fs_devices->latest_devid = orig->latest_devid;
485 fs_devices->latest_trans = orig->latest_trans;
486 fs_devices->total_devices = orig->total_devices;
487 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
488
489 /* We have held the volume lock, it is safe to get the devices. */
490 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
491 struct rcu_string *name;
492
493 device = kzalloc(sizeof(*device), GFP_NOFS);
494 if (!device)
495 goto error;
496
497 /*
498 * This is ok to do without rcu read locked because we hold the
499 * uuid mutex so nothing we touch in here is going to disappear.
500 */
501 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
502 if (!name) {
503 kfree(device);
504 goto error;
505 }
506 rcu_assign_pointer(device->name, name);
507
508 device->devid = orig_dev->devid;
509 device->work.func = pending_bios_fn;
510 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
511 spin_lock_init(&device->io_lock);
512 INIT_LIST_HEAD(&device->dev_list);
513 INIT_LIST_HEAD(&device->dev_alloc_list);
514
515 list_add(&device->dev_list, &fs_devices->devices);
516 device->fs_devices = fs_devices;
517 fs_devices->num_devices++;
518 }
519 return fs_devices;
520 error:
521 free_fs_devices(fs_devices);
522 return ERR_PTR(-ENOMEM);
523 }
524
525 void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
526 struct btrfs_fs_devices *fs_devices, int step)
527 {
528 struct btrfs_device *device, *next;
529
530 struct block_device *latest_bdev = NULL;
531 u64 latest_devid = 0;
532 u64 latest_transid = 0;
533
534 mutex_lock(&uuid_mutex);
535 again:
536 /* This is the initialized path, it is safe to release the devices. */
537 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
538 if (device->in_fs_metadata) {
539 if (!device->is_tgtdev_for_dev_replace &&
540 (!latest_transid ||
541 device->generation > latest_transid)) {
542 latest_devid = device->devid;
543 latest_transid = device->generation;
544 latest_bdev = device->bdev;
545 }
546 continue;
547 }
548
549 if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
550 /*
551 * In the first step, keep the device which has
552 * the correct fsid and the devid that is used
553 * for the dev_replace procedure.
554 * In the second step, the dev_replace state is
555 * read from the device tree and it is known
556 * whether the procedure is really active or
557 * not, which means whether this device is
558 * used or whether it should be removed.
559 */
560 if (step == 0 || device->is_tgtdev_for_dev_replace) {
561 continue;
562 }
563 }
564 if (device->bdev) {
565 blkdev_put(device->bdev, device->mode);
566 device->bdev = NULL;
567 fs_devices->open_devices--;
568 }
569 if (device->writeable) {
570 list_del_init(&device->dev_alloc_list);
571 device->writeable = 0;
572 if (!device->is_tgtdev_for_dev_replace)
573 fs_devices->rw_devices--;
574 }
575 list_del_init(&device->dev_list);
576 fs_devices->num_devices--;
577 rcu_string_free(device->name);
578 kfree(device);
579 }
580
581 if (fs_devices->seed) {
582 fs_devices = fs_devices->seed;
583 goto again;
584 }
585
586 fs_devices->latest_bdev = latest_bdev;
587 fs_devices->latest_devid = latest_devid;
588 fs_devices->latest_trans = latest_transid;
589
590 mutex_unlock(&uuid_mutex);
591 }
592
593 static void __free_device(struct work_struct *work)
594 {
595 struct btrfs_device *device;
596
597 device = container_of(work, struct btrfs_device, rcu_work);
598
599 if (device->bdev)
600 blkdev_put(device->bdev, device->mode);
601
602 rcu_string_free(device->name);
603 kfree(device);
604 }
605
606 static void free_device(struct rcu_head *head)
607 {
608 struct btrfs_device *device;
609
610 device = container_of(head, struct btrfs_device, rcu);
611
612 INIT_WORK(&device->rcu_work, __free_device);
613 schedule_work(&device->rcu_work);
614 }
615
616 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
617 {
618 struct btrfs_device *device;
619
620 if (--fs_devices->opened > 0)
621 return 0;
622
623 mutex_lock(&fs_devices->device_list_mutex);
624 list_for_each_entry(device, &fs_devices->devices, dev_list) {
625 struct btrfs_device *new_device;
626 struct rcu_string *name;
627
628 if (device->bdev)
629 fs_devices->open_devices--;
630
631 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
632 list_del_init(&device->dev_alloc_list);
633 fs_devices->rw_devices--;
634 }
635
636 if (device->can_discard)
637 fs_devices->num_can_discard--;
638
639 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
640 BUG_ON(!new_device); /* -ENOMEM */
641 memcpy(new_device, device, sizeof(*new_device));
642
643 /* Safe because we are under uuid_mutex */
644 if (device->name) {
645 name = rcu_string_strdup(device->name->str, GFP_NOFS);
646 BUG_ON(device->name && !name); /* -ENOMEM */
647 rcu_assign_pointer(new_device->name, name);
648 }
649 new_device->bdev = NULL;
650 new_device->writeable = 0;
651 new_device->in_fs_metadata = 0;
652 new_device->can_discard = 0;
653 spin_lock_init(&new_device->io_lock);
654 list_replace_rcu(&device->dev_list, &new_device->dev_list);
655
656 call_rcu(&device->rcu, free_device);
657 }
658 mutex_unlock(&fs_devices->device_list_mutex);
659
660 WARN_ON(fs_devices->open_devices);
661 WARN_ON(fs_devices->rw_devices);
662 fs_devices->opened = 0;
663 fs_devices->seeding = 0;
664
665 return 0;
666 }
667
668 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
669 {
670 struct btrfs_fs_devices *seed_devices = NULL;
671 int ret;
672
673 mutex_lock(&uuid_mutex);
674 ret = __btrfs_close_devices(fs_devices);
675 if (!fs_devices->opened) {
676 seed_devices = fs_devices->seed;
677 fs_devices->seed = NULL;
678 }
679 mutex_unlock(&uuid_mutex);
680
681 while (seed_devices) {
682 fs_devices = seed_devices;
683 seed_devices = fs_devices->seed;
684 __btrfs_close_devices(fs_devices);
685 free_fs_devices(fs_devices);
686 }
687 return ret;
688 }
689
690 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
691 fmode_t flags, void *holder)
692 {
693 struct request_queue *q;
694 struct block_device *bdev;
695 struct list_head *head = &fs_devices->devices;
696 struct btrfs_device *device;
697 struct block_device *latest_bdev = NULL;
698 struct buffer_head *bh;
699 struct btrfs_super_block *disk_super;
700 u64 latest_devid = 0;
701 u64 latest_transid = 0;
702 u64 devid;
703 int seeding = 1;
704 int ret = 0;
705
706 flags |= FMODE_EXCL;
707
708 list_for_each_entry(device, head, dev_list) {
709 if (device->bdev)
710 continue;
711 if (!device->name)
712 continue;
713
714 ret = btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
715 &bdev, &bh);
716 if (ret)
717 continue;
718
719 disk_super = (struct btrfs_super_block *)bh->b_data;
720 devid = btrfs_stack_device_id(&disk_super->dev_item);
721 if (devid != device->devid)
722 goto error_brelse;
723
724 if (memcmp(device->uuid, disk_super->dev_item.uuid,
725 BTRFS_UUID_SIZE))
726 goto error_brelse;
727
728 device->generation = btrfs_super_generation(disk_super);
729 if (!latest_transid || device->generation > latest_transid) {
730 latest_devid = devid;
731 latest_transid = device->generation;
732 latest_bdev = bdev;
733 }
734
735 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
736 device->writeable = 0;
737 } else {
738 device->writeable = !bdev_read_only(bdev);
739 seeding = 0;
740 }
741
742 q = bdev_get_queue(bdev);
743 if (blk_queue_discard(q)) {
744 device->can_discard = 1;
745 fs_devices->num_can_discard++;
746 }
747
748 device->bdev = bdev;
749 device->in_fs_metadata = 0;
750 device->mode = flags;
751
752 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
753 fs_devices->rotating = 1;
754
755 fs_devices->open_devices++;
756 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
757 fs_devices->rw_devices++;
758 list_add(&device->dev_alloc_list,
759 &fs_devices->alloc_list);
760 }
761 brelse(bh);
762 continue;
763
764 error_brelse:
765 brelse(bh);
766 blkdev_put(bdev, flags);
767 continue;
768 }
769 if (fs_devices->open_devices == 0) {
770 ret = -EINVAL;
771 goto out;
772 }
773 fs_devices->seeding = seeding;
774 fs_devices->opened = 1;
775 fs_devices->latest_bdev = latest_bdev;
776 fs_devices->latest_devid = latest_devid;
777 fs_devices->latest_trans = latest_transid;
778 fs_devices->total_rw_bytes = 0;
779 out:
780 return ret;
781 }
782
783 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
784 fmode_t flags, void *holder)
785 {
786 int ret;
787
788 mutex_lock(&uuid_mutex);
789 if (fs_devices->opened) {
790 fs_devices->opened++;
791 ret = 0;
792 } else {
793 ret = __btrfs_open_devices(fs_devices, flags, holder);
794 }
795 mutex_unlock(&uuid_mutex);
796 return ret;
797 }
798
799 /*
800 * Look for a btrfs signature on a device. This may be called out of the mount path
801 * and we are not allowed to call set_blocksize during the scan. The superblock
802 * is read via pagecache
803 */
804 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
805 struct btrfs_fs_devices **fs_devices_ret)
806 {
807 struct btrfs_super_block *disk_super;
808 struct block_device *bdev;
809 struct page *page;
810 void *p;
811 int ret = -EINVAL;
812 u64 devid;
813 u64 transid;
814 u64 total_devices;
815 u64 bytenr;
816 pgoff_t index;
817
818 /*
819 * we would like to check all the supers, but that would make
820 * a btrfs mount succeed after a mkfs from a different FS.
821 * So, we need to add a special mount option to scan for
822 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
823 */
824 bytenr = btrfs_sb_offset(0);
825 flags |= FMODE_EXCL;
826 mutex_lock(&uuid_mutex);
827
828 bdev = blkdev_get_by_path(path, flags, holder);
829
830 if (IS_ERR(bdev)) {
831 ret = PTR_ERR(bdev);
832 goto error;
833 }
834
835 /* make sure our super fits in the device */
836 if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
837 goto error_bdev_put;
838
839 /* make sure our super fits in the page */
840 if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
841 goto error_bdev_put;
842
843 /* make sure our super doesn't straddle pages on disk */
844 index = bytenr >> PAGE_CACHE_SHIFT;
845 if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
846 goto error_bdev_put;
847
848 /* pull in the page with our super */
849 page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
850 index, GFP_NOFS);
851
852 if (IS_ERR_OR_NULL(page))
853 goto error_bdev_put;
854
855 p = kmap(page);
856
857 /* align our pointer to the offset of the super block */
858 disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
859
860 if (btrfs_super_bytenr(disk_super) != bytenr ||
861 disk_super->magic != cpu_to_le64(BTRFS_MAGIC))
862 goto error_unmap;
863
864 devid = btrfs_stack_device_id(&disk_super->dev_item);
865 transid = btrfs_super_generation(disk_super);
866 total_devices = btrfs_super_num_devices(disk_super);
867
868 if (disk_super->label[0]) {
869 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
870 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
871 printk(KERN_INFO "device label %s ", disk_super->label);
872 } else {
873 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
874 }
875
876 printk(KERN_CONT "devid %llu transid %llu %s\n",
877 (unsigned long long)devid, (unsigned long long)transid, path);
878
879 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
880 if (!ret && fs_devices_ret)
881 (*fs_devices_ret)->total_devices = total_devices;
882
883 error_unmap:
884 kunmap(page);
885 page_cache_release(page);
886
887 error_bdev_put:
888 blkdev_put(bdev, flags);
889 error:
890 mutex_unlock(&uuid_mutex);
891 return ret;
892 }
893
894 /* helper to account the used device space in the range */
895 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
896 u64 end, u64 *length)
897 {
898 struct btrfs_key key;
899 struct btrfs_root *root = device->dev_root;
900 struct btrfs_dev_extent *dev_extent;
901 struct btrfs_path *path;
902 u64 extent_end;
903 int ret;
904 int slot;
905 struct extent_buffer *l;
906
907 *length = 0;
908
909 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
910 return 0;
911
912 path = btrfs_alloc_path();
913 if (!path)
914 return -ENOMEM;
915 path->reada = 2;
916
917 key.objectid = device->devid;
918 key.offset = start;
919 key.type = BTRFS_DEV_EXTENT_KEY;
920
921 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
922 if (ret < 0)
923 goto out;
924 if (ret > 0) {
925 ret = btrfs_previous_item(root, path, key.objectid, key.type);
926 if (ret < 0)
927 goto out;
928 }
929
930 while (1) {
931 l = path->nodes[0];
932 slot = path->slots[0];
933 if (slot >= btrfs_header_nritems(l)) {
934 ret = btrfs_next_leaf(root, path);
935 if (ret == 0)
936 continue;
937 if (ret < 0)
938 goto out;
939
940 break;
941 }
942 btrfs_item_key_to_cpu(l, &key, slot);
943
944 if (key.objectid < device->devid)
945 goto next;
946
947 if (key.objectid > device->devid)
948 break;
949
950 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
951 goto next;
952
953 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
954 extent_end = key.offset + btrfs_dev_extent_length(l,
955 dev_extent);
956 if (key.offset <= start && extent_end > end) {
957 *length = end - start + 1;
958 break;
959 } else if (key.offset <= start && extent_end > start)
960 *length += extent_end - start;
961 else if (key.offset > start && extent_end <= end)
962 *length += extent_end - key.offset;
963 else if (key.offset > start && key.offset <= end) {
964 *length += end - key.offset + 1;
965 break;
966 } else if (key.offset > end)
967 break;
968
969 next:
970 path->slots[0]++;
971 }
972 ret = 0;
973 out:
974 btrfs_free_path(path);
975 return ret;
976 }
977
978 /*
979 * find_free_dev_extent - find free space in the specified device
980 * @device: the device which we search the free space in
981 * @num_bytes: the size of the free space that we need
982 * @start: store the start of the free space.
983 * @len: the size of the free space. that we find, or the size of the max
984 * free space if we don't find suitable free space
985 *
986 * this uses a pretty simple search, the expectation is that it is
987 * called very infrequently and that a given device has a small number
988 * of extents
989 *
990 * @start is used to store the start of the free space if we find. But if we
991 * don't find suitable free space, it will be used to store the start position
992 * of the max free space.
993 *
994 * @len is used to store the size of the free space that we find.
995 * But if we don't find suitable free space, it is used to store the size of
996 * the max free space.
997 */
998 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
999 u64 *start, u64 *len)
1000 {
1001 struct btrfs_key key;
1002 struct btrfs_root *root = device->dev_root;
1003 struct btrfs_dev_extent *dev_extent;
1004 struct btrfs_path *path;
1005 u64 hole_size;
1006 u64 max_hole_start;
1007 u64 max_hole_size;
1008 u64 extent_end;
1009 u64 search_start;
1010 u64 search_end = device->total_bytes;
1011 int ret;
1012 int slot;
1013 struct extent_buffer *l;
1014
1015 /* FIXME use last free of some kind */
1016
1017 /* we don't want to overwrite the superblock on the drive,
1018 * so we make sure to start at an offset of at least 1MB
1019 */
1020 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1021
1022 max_hole_start = search_start;
1023 max_hole_size = 0;
1024 hole_size = 0;
1025
1026 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1027 ret = -ENOSPC;
1028 goto error;
1029 }
1030
1031 path = btrfs_alloc_path();
1032 if (!path) {
1033 ret = -ENOMEM;
1034 goto error;
1035 }
1036 path->reada = 2;
1037
1038 key.objectid = device->devid;
1039 key.offset = search_start;
1040 key.type = BTRFS_DEV_EXTENT_KEY;
1041
1042 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1043 if (ret < 0)
1044 goto out;
1045 if (ret > 0) {
1046 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1047 if (ret < 0)
1048 goto out;
1049 }
1050
1051 while (1) {
1052 l = path->nodes[0];
1053 slot = path->slots[0];
1054 if (slot >= btrfs_header_nritems(l)) {
1055 ret = btrfs_next_leaf(root, path);
1056 if (ret == 0)
1057 continue;
1058 if (ret < 0)
1059 goto out;
1060
1061 break;
1062 }
1063 btrfs_item_key_to_cpu(l, &key, slot);
1064
1065 if (key.objectid < device->devid)
1066 goto next;
1067
1068 if (key.objectid > device->devid)
1069 break;
1070
1071 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1072 goto next;
1073
1074 if (key.offset > search_start) {
1075 hole_size = key.offset - search_start;
1076
1077 if (hole_size > max_hole_size) {
1078 max_hole_start = search_start;
1079 max_hole_size = hole_size;
1080 }
1081
1082 /*
1083 * If this free space is greater than which we need,
1084 * it must be the max free space that we have found
1085 * until now, so max_hole_start must point to the start
1086 * of this free space and the length of this free space
1087 * is stored in max_hole_size. Thus, we return
1088 * max_hole_start and max_hole_size and go back to the
1089 * caller.
1090 */
1091 if (hole_size >= num_bytes) {
1092 ret = 0;
1093 goto out;
1094 }
1095 }
1096
1097 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1098 extent_end = key.offset + btrfs_dev_extent_length(l,
1099 dev_extent);
1100 if (extent_end > search_start)
1101 search_start = extent_end;
1102 next:
1103 path->slots[0]++;
1104 cond_resched();
1105 }
1106
1107 /*
1108 * At this point, search_start should be the end of
1109 * allocated dev extents, and when shrinking the device,
1110 * search_end may be smaller than search_start.
1111 */
1112 if (search_end > search_start)
1113 hole_size = search_end - search_start;
1114
1115 if (hole_size > max_hole_size) {
1116 max_hole_start = search_start;
1117 max_hole_size = hole_size;
1118 }
1119
1120 /* See above. */
1121 if (hole_size < num_bytes)
1122 ret = -ENOSPC;
1123 else
1124 ret = 0;
1125
1126 out:
1127 btrfs_free_path(path);
1128 error:
1129 *start = max_hole_start;
1130 if (len)
1131 *len = max_hole_size;
1132 return ret;
1133 }
1134
1135 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1136 struct btrfs_device *device,
1137 u64 start)
1138 {
1139 int ret;
1140 struct btrfs_path *path;
1141 struct btrfs_root *root = device->dev_root;
1142 struct btrfs_key key;
1143 struct btrfs_key found_key;
1144 struct extent_buffer *leaf = NULL;
1145 struct btrfs_dev_extent *extent = NULL;
1146
1147 path = btrfs_alloc_path();
1148 if (!path)
1149 return -ENOMEM;
1150
1151 key.objectid = device->devid;
1152 key.offset = start;
1153 key.type = BTRFS_DEV_EXTENT_KEY;
1154 again:
1155 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1156 if (ret > 0) {
1157 ret = btrfs_previous_item(root, path, key.objectid,
1158 BTRFS_DEV_EXTENT_KEY);
1159 if (ret)
1160 goto out;
1161 leaf = path->nodes[0];
1162 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1163 extent = btrfs_item_ptr(leaf, path->slots[0],
1164 struct btrfs_dev_extent);
1165 BUG_ON(found_key.offset > start || found_key.offset +
1166 btrfs_dev_extent_length(leaf, extent) < start);
1167 key = found_key;
1168 btrfs_release_path(path);
1169 goto again;
1170 } else if (ret == 0) {
1171 leaf = path->nodes[0];
1172 extent = btrfs_item_ptr(leaf, path->slots[0],
1173 struct btrfs_dev_extent);
1174 } else {
1175 btrfs_error(root->fs_info, ret, "Slot search failed");
1176 goto out;
1177 }
1178
1179 if (device->bytes_used > 0) {
1180 u64 len = btrfs_dev_extent_length(leaf, extent);
1181 device->bytes_used -= len;
1182 spin_lock(&root->fs_info->free_chunk_lock);
1183 root->fs_info->free_chunk_space += len;
1184 spin_unlock(&root->fs_info->free_chunk_lock);
1185 }
1186 ret = btrfs_del_item(trans, root, path);
1187 if (ret) {
1188 btrfs_error(root->fs_info, ret,
1189 "Failed to remove dev extent item");
1190 }
1191 out:
1192 btrfs_free_path(path);
1193 return ret;
1194 }
1195
1196 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1197 struct btrfs_device *device,
1198 u64 chunk_tree, u64 chunk_objectid,
1199 u64 chunk_offset, u64 start, u64 num_bytes)
1200 {
1201 int ret;
1202 struct btrfs_path *path;
1203 struct btrfs_root *root = device->dev_root;
1204 struct btrfs_dev_extent *extent;
1205 struct extent_buffer *leaf;
1206 struct btrfs_key key;
1207
1208 WARN_ON(!device->in_fs_metadata);
1209 WARN_ON(device->is_tgtdev_for_dev_replace);
1210 path = btrfs_alloc_path();
1211 if (!path)
1212 return -ENOMEM;
1213
1214 key.objectid = device->devid;
1215 key.offset = start;
1216 key.type = BTRFS_DEV_EXTENT_KEY;
1217 ret = btrfs_insert_empty_item(trans, root, path, &key,
1218 sizeof(*extent));
1219 if (ret)
1220 goto out;
1221
1222 leaf = path->nodes[0];
1223 extent = btrfs_item_ptr(leaf, path->slots[0],
1224 struct btrfs_dev_extent);
1225 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1226 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1227 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1228
1229 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1230 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1231 BTRFS_UUID_SIZE);
1232
1233 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1234 btrfs_mark_buffer_dirty(leaf);
1235 out:
1236 btrfs_free_path(path);
1237 return ret;
1238 }
1239
1240 static noinline int find_next_chunk(struct btrfs_root *root,
1241 u64 objectid, u64 *offset)
1242 {
1243 struct btrfs_path *path;
1244 int ret;
1245 struct btrfs_key key;
1246 struct btrfs_chunk *chunk;
1247 struct btrfs_key found_key;
1248
1249 path = btrfs_alloc_path();
1250 if (!path)
1251 return -ENOMEM;
1252
1253 key.objectid = objectid;
1254 key.offset = (u64)-1;
1255 key.type = BTRFS_CHUNK_ITEM_KEY;
1256
1257 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1258 if (ret < 0)
1259 goto error;
1260
1261 BUG_ON(ret == 0); /* Corruption */
1262
1263 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1264 if (ret) {
1265 *offset = 0;
1266 } else {
1267 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1268 path->slots[0]);
1269 if (found_key.objectid != objectid)
1270 *offset = 0;
1271 else {
1272 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1273 struct btrfs_chunk);
1274 *offset = found_key.offset +
1275 btrfs_chunk_length(path->nodes[0], chunk);
1276 }
1277 }
1278 ret = 0;
1279 error:
1280 btrfs_free_path(path);
1281 return ret;
1282 }
1283
1284 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1285 {
1286 int ret;
1287 struct btrfs_key key;
1288 struct btrfs_key found_key;
1289 struct btrfs_path *path;
1290
1291 root = root->fs_info->chunk_root;
1292
1293 path = btrfs_alloc_path();
1294 if (!path)
1295 return -ENOMEM;
1296
1297 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1298 key.type = BTRFS_DEV_ITEM_KEY;
1299 key.offset = (u64)-1;
1300
1301 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1302 if (ret < 0)
1303 goto error;
1304
1305 BUG_ON(ret == 0); /* Corruption */
1306
1307 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1308 BTRFS_DEV_ITEM_KEY);
1309 if (ret) {
1310 *objectid = 1;
1311 } else {
1312 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1313 path->slots[0]);
1314 *objectid = found_key.offset + 1;
1315 }
1316 ret = 0;
1317 error:
1318 btrfs_free_path(path);
1319 return ret;
1320 }
1321
1322 /*
1323 * the device information is stored in the chunk root
1324 * the btrfs_device struct should be fully filled in
1325 */
1326 int btrfs_add_device(struct btrfs_trans_handle *trans,
1327 struct btrfs_root *root,
1328 struct btrfs_device *device)
1329 {
1330 int ret;
1331 struct btrfs_path *path;
1332 struct btrfs_dev_item *dev_item;
1333 struct extent_buffer *leaf;
1334 struct btrfs_key key;
1335 unsigned long ptr;
1336
1337 root = root->fs_info->chunk_root;
1338
1339 path = btrfs_alloc_path();
1340 if (!path)
1341 return -ENOMEM;
1342
1343 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1344 key.type = BTRFS_DEV_ITEM_KEY;
1345 key.offset = device->devid;
1346
1347 ret = btrfs_insert_empty_item(trans, root, path, &key,
1348 sizeof(*dev_item));
1349 if (ret)
1350 goto out;
1351
1352 leaf = path->nodes[0];
1353 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1354
1355 btrfs_set_device_id(leaf, dev_item, device->devid);
1356 btrfs_set_device_generation(leaf, dev_item, 0);
1357 btrfs_set_device_type(leaf, dev_item, device->type);
1358 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1359 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1360 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1361 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1362 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1363 btrfs_set_device_group(leaf, dev_item, 0);
1364 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1365 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1366 btrfs_set_device_start_offset(leaf, dev_item, 0);
1367
1368 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1369 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1370 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1371 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1372 btrfs_mark_buffer_dirty(leaf);
1373
1374 ret = 0;
1375 out:
1376 btrfs_free_path(path);
1377 return ret;
1378 }
1379
1380 static int btrfs_rm_dev_item(struct btrfs_root *root,
1381 struct btrfs_device *device)
1382 {
1383 int ret;
1384 struct btrfs_path *path;
1385 struct btrfs_key key;
1386 struct btrfs_trans_handle *trans;
1387
1388 root = root->fs_info->chunk_root;
1389
1390 path = btrfs_alloc_path();
1391 if (!path)
1392 return -ENOMEM;
1393
1394 trans = btrfs_start_transaction(root, 0);
1395 if (IS_ERR(trans)) {
1396 btrfs_free_path(path);
1397 return PTR_ERR(trans);
1398 }
1399 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1400 key.type = BTRFS_DEV_ITEM_KEY;
1401 key.offset = device->devid;
1402 lock_chunks(root);
1403
1404 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1405 if (ret < 0)
1406 goto out;
1407
1408 if (ret > 0) {
1409 ret = -ENOENT;
1410 goto out;
1411 }
1412
1413 ret = btrfs_del_item(trans, root, path);
1414 if (ret)
1415 goto out;
1416 out:
1417 btrfs_free_path(path);
1418 unlock_chunks(root);
1419 btrfs_commit_transaction(trans, root);
1420 return ret;
1421 }
1422
1423 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1424 {
1425 struct btrfs_device *device;
1426 struct btrfs_device *next_device;
1427 struct block_device *bdev;
1428 struct buffer_head *bh = NULL;
1429 struct btrfs_super_block *disk_super;
1430 struct btrfs_fs_devices *cur_devices;
1431 u64 all_avail;
1432 u64 devid;
1433 u64 num_devices;
1434 u8 *dev_uuid;
1435 unsigned seq;
1436 int ret = 0;
1437 bool clear_super = false;
1438
1439 mutex_lock(&uuid_mutex);
1440
1441 do {
1442 seq = read_seqbegin(&root->fs_info->profiles_lock);
1443
1444 all_avail = root->fs_info->avail_data_alloc_bits |
1445 root->fs_info->avail_system_alloc_bits |
1446 root->fs_info->avail_metadata_alloc_bits;
1447 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
1448
1449 num_devices = root->fs_info->fs_devices->num_devices;
1450 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1451 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1452 WARN_ON(num_devices < 1);
1453 num_devices--;
1454 }
1455 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1456
1457 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1458 printk(KERN_ERR "btrfs: unable to go below four devices "
1459 "on raid10\n");
1460 ret = -EINVAL;
1461 goto out;
1462 }
1463
1464 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1465 printk(KERN_ERR "btrfs: unable to go below two "
1466 "devices on raid1\n");
1467 ret = -EINVAL;
1468 goto out;
1469 }
1470
1471 if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1472 root->fs_info->fs_devices->rw_devices <= 2) {
1473 printk(KERN_ERR "btrfs: unable to go below two "
1474 "devices on raid5\n");
1475 ret = -EINVAL;
1476 goto out;
1477 }
1478 if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1479 root->fs_info->fs_devices->rw_devices <= 3) {
1480 printk(KERN_ERR "btrfs: unable to go below three "
1481 "devices on raid6\n");
1482 ret = -EINVAL;
1483 goto out;
1484 }
1485
1486 if (strcmp(device_path, "missing") == 0) {
1487 struct list_head *devices;
1488 struct btrfs_device *tmp;
1489
1490 device = NULL;
1491 devices = &root->fs_info->fs_devices->devices;
1492 /*
1493 * It is safe to read the devices since the volume_mutex
1494 * is held.
1495 */
1496 list_for_each_entry(tmp, devices, dev_list) {
1497 if (tmp->in_fs_metadata &&
1498 !tmp->is_tgtdev_for_dev_replace &&
1499 !tmp->bdev) {
1500 device = tmp;
1501 break;
1502 }
1503 }
1504 bdev = NULL;
1505 bh = NULL;
1506 disk_super = NULL;
1507 if (!device) {
1508 printk(KERN_ERR "btrfs: no missing devices found to "
1509 "remove\n");
1510 goto out;
1511 }
1512 } else {
1513 ret = btrfs_get_bdev_and_sb(device_path,
1514 FMODE_WRITE | FMODE_EXCL,
1515 root->fs_info->bdev_holder, 0,
1516 &bdev, &bh);
1517 if (ret)
1518 goto out;
1519 disk_super = (struct btrfs_super_block *)bh->b_data;
1520 devid = btrfs_stack_device_id(&disk_super->dev_item);
1521 dev_uuid = disk_super->dev_item.uuid;
1522 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1523 disk_super->fsid);
1524 if (!device) {
1525 ret = -ENOENT;
1526 goto error_brelse;
1527 }
1528 }
1529
1530 if (device->is_tgtdev_for_dev_replace) {
1531 pr_err("btrfs: unable to remove the dev_replace target dev\n");
1532 ret = -EINVAL;
1533 goto error_brelse;
1534 }
1535
1536 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1537 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1538 "device\n");
1539 ret = -EINVAL;
1540 goto error_brelse;
1541 }
1542
1543 if (device->writeable) {
1544 lock_chunks(root);
1545 list_del_init(&device->dev_alloc_list);
1546 unlock_chunks(root);
1547 root->fs_info->fs_devices->rw_devices--;
1548 clear_super = true;
1549 }
1550
1551 ret = btrfs_shrink_device(device, 0);
1552 if (ret)
1553 goto error_undo;
1554
1555 /*
1556 * TODO: the superblock still includes this device in its num_devices
1557 * counter although write_all_supers() is not locked out. This
1558 * could give a filesystem state which requires a degraded mount.
1559 */
1560 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1561 if (ret)
1562 goto error_undo;
1563
1564 spin_lock(&root->fs_info->free_chunk_lock);
1565 root->fs_info->free_chunk_space = device->total_bytes -
1566 device->bytes_used;
1567 spin_unlock(&root->fs_info->free_chunk_lock);
1568
1569 device->in_fs_metadata = 0;
1570 btrfs_scrub_cancel_dev(root->fs_info, device);
1571
1572 /*
1573 * the device list mutex makes sure that we don't change
1574 * the device list while someone else is writing out all
1575 * the device supers.
1576 */
1577
1578 cur_devices = device->fs_devices;
1579 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1580 list_del_rcu(&device->dev_list);
1581
1582 device->fs_devices->num_devices--;
1583 device->fs_devices->total_devices--;
1584
1585 if (device->missing)
1586 root->fs_info->fs_devices->missing_devices--;
1587
1588 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1589 struct btrfs_device, dev_list);
1590 if (device->bdev == root->fs_info->sb->s_bdev)
1591 root->fs_info->sb->s_bdev = next_device->bdev;
1592 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1593 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1594
1595 if (device->bdev)
1596 device->fs_devices->open_devices--;
1597
1598 call_rcu(&device->rcu, free_device);
1599 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1600
1601 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1602 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1603
1604 if (cur_devices->open_devices == 0) {
1605 struct btrfs_fs_devices *fs_devices;
1606 fs_devices = root->fs_info->fs_devices;
1607 while (fs_devices) {
1608 if (fs_devices->seed == cur_devices)
1609 break;
1610 fs_devices = fs_devices->seed;
1611 }
1612 fs_devices->seed = cur_devices->seed;
1613 cur_devices->seed = NULL;
1614 lock_chunks(root);
1615 __btrfs_close_devices(cur_devices);
1616 unlock_chunks(root);
1617 free_fs_devices(cur_devices);
1618 }
1619
1620 root->fs_info->num_tolerated_disk_barrier_failures =
1621 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1622
1623 /*
1624 * at this point, the device is zero sized. We want to
1625 * remove it from the devices list and zero out the old super
1626 */
1627 if (clear_super && disk_super) {
1628 /* make sure this device isn't detected as part of
1629 * the FS anymore
1630 */
1631 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1632 set_buffer_dirty(bh);
1633 sync_dirty_buffer(bh);
1634 }
1635
1636 ret = 0;
1637
1638 /* Notify udev that device has changed */
1639 if (bdev)
1640 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1641
1642 error_brelse:
1643 brelse(bh);
1644 if (bdev)
1645 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1646 out:
1647 mutex_unlock(&uuid_mutex);
1648 return ret;
1649 error_undo:
1650 if (device->writeable) {
1651 lock_chunks(root);
1652 list_add(&device->dev_alloc_list,
1653 &root->fs_info->fs_devices->alloc_list);
1654 unlock_chunks(root);
1655 root->fs_info->fs_devices->rw_devices++;
1656 }
1657 goto error_brelse;
1658 }
1659
1660 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1661 struct btrfs_device *srcdev)
1662 {
1663 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1664 list_del_rcu(&srcdev->dev_list);
1665 list_del_rcu(&srcdev->dev_alloc_list);
1666 fs_info->fs_devices->num_devices--;
1667 if (srcdev->missing) {
1668 fs_info->fs_devices->missing_devices--;
1669 fs_info->fs_devices->rw_devices++;
1670 }
1671 if (srcdev->can_discard)
1672 fs_info->fs_devices->num_can_discard--;
1673 if (srcdev->bdev)
1674 fs_info->fs_devices->open_devices--;
1675
1676 call_rcu(&srcdev->rcu, free_device);
1677 }
1678
1679 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1680 struct btrfs_device *tgtdev)
1681 {
1682 struct btrfs_device *next_device;
1683
1684 WARN_ON(!tgtdev);
1685 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1686 if (tgtdev->bdev) {
1687 btrfs_scratch_superblock(tgtdev);
1688 fs_info->fs_devices->open_devices--;
1689 }
1690 fs_info->fs_devices->num_devices--;
1691 if (tgtdev->can_discard)
1692 fs_info->fs_devices->num_can_discard++;
1693
1694 next_device = list_entry(fs_info->fs_devices->devices.next,
1695 struct btrfs_device, dev_list);
1696 if (tgtdev->bdev == fs_info->sb->s_bdev)
1697 fs_info->sb->s_bdev = next_device->bdev;
1698 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1699 fs_info->fs_devices->latest_bdev = next_device->bdev;
1700 list_del_rcu(&tgtdev->dev_list);
1701
1702 call_rcu(&tgtdev->rcu, free_device);
1703
1704 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1705 }
1706
1707 int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1708 struct btrfs_device **device)
1709 {
1710 int ret = 0;
1711 struct btrfs_super_block *disk_super;
1712 u64 devid;
1713 u8 *dev_uuid;
1714 struct block_device *bdev;
1715 struct buffer_head *bh;
1716
1717 *device = NULL;
1718 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1719 root->fs_info->bdev_holder, 0, &bdev, &bh);
1720 if (ret)
1721 return ret;
1722 disk_super = (struct btrfs_super_block *)bh->b_data;
1723 devid = btrfs_stack_device_id(&disk_super->dev_item);
1724 dev_uuid = disk_super->dev_item.uuid;
1725 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1726 disk_super->fsid);
1727 brelse(bh);
1728 if (!*device)
1729 ret = -ENOENT;
1730 blkdev_put(bdev, FMODE_READ);
1731 return ret;
1732 }
1733
1734 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1735 char *device_path,
1736 struct btrfs_device **device)
1737 {
1738 *device = NULL;
1739 if (strcmp(device_path, "missing") == 0) {
1740 struct list_head *devices;
1741 struct btrfs_device *tmp;
1742
1743 devices = &root->fs_info->fs_devices->devices;
1744 /*
1745 * It is safe to read the devices since the volume_mutex
1746 * is held by the caller.
1747 */
1748 list_for_each_entry(tmp, devices, dev_list) {
1749 if (tmp->in_fs_metadata && !tmp->bdev) {
1750 *device = tmp;
1751 break;
1752 }
1753 }
1754
1755 if (!*device) {
1756 pr_err("btrfs: no missing device found\n");
1757 return -ENOENT;
1758 }
1759
1760 return 0;
1761 } else {
1762 return btrfs_find_device_by_path(root, device_path, device);
1763 }
1764 }
1765
1766 /*
1767 * does all the dirty work required for changing file system's UUID.
1768 */
1769 static int btrfs_prepare_sprout(struct btrfs_root *root)
1770 {
1771 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1772 struct btrfs_fs_devices *old_devices;
1773 struct btrfs_fs_devices *seed_devices;
1774 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1775 struct btrfs_device *device;
1776 u64 super_flags;
1777
1778 BUG_ON(!mutex_is_locked(&uuid_mutex));
1779 if (!fs_devices->seeding)
1780 return -EINVAL;
1781
1782 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1783 if (!seed_devices)
1784 return -ENOMEM;
1785
1786 old_devices = clone_fs_devices(fs_devices);
1787 if (IS_ERR(old_devices)) {
1788 kfree(seed_devices);
1789 return PTR_ERR(old_devices);
1790 }
1791
1792 list_add(&old_devices->list, &fs_uuids);
1793
1794 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1795 seed_devices->opened = 1;
1796 INIT_LIST_HEAD(&seed_devices->devices);
1797 INIT_LIST_HEAD(&seed_devices->alloc_list);
1798 mutex_init(&seed_devices->device_list_mutex);
1799
1800 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1801 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1802 synchronize_rcu);
1803 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1804
1805 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1806 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1807 device->fs_devices = seed_devices;
1808 }
1809
1810 fs_devices->seeding = 0;
1811 fs_devices->num_devices = 0;
1812 fs_devices->open_devices = 0;
1813 fs_devices->total_devices = 0;
1814 fs_devices->seed = seed_devices;
1815
1816 generate_random_uuid(fs_devices->fsid);
1817 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1818 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1819 super_flags = btrfs_super_flags(disk_super) &
1820 ~BTRFS_SUPER_FLAG_SEEDING;
1821 btrfs_set_super_flags(disk_super, super_flags);
1822
1823 return 0;
1824 }
1825
1826 /*
1827 * strore the expected generation for seed devices in device items.
1828 */
1829 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1830 struct btrfs_root *root)
1831 {
1832 struct btrfs_path *path;
1833 struct extent_buffer *leaf;
1834 struct btrfs_dev_item *dev_item;
1835 struct btrfs_device *device;
1836 struct btrfs_key key;
1837 u8 fs_uuid[BTRFS_UUID_SIZE];
1838 u8 dev_uuid[BTRFS_UUID_SIZE];
1839 u64 devid;
1840 int ret;
1841
1842 path = btrfs_alloc_path();
1843 if (!path)
1844 return -ENOMEM;
1845
1846 root = root->fs_info->chunk_root;
1847 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1848 key.offset = 0;
1849 key.type = BTRFS_DEV_ITEM_KEY;
1850
1851 while (1) {
1852 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1853 if (ret < 0)
1854 goto error;
1855
1856 leaf = path->nodes[0];
1857 next_slot:
1858 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1859 ret = btrfs_next_leaf(root, path);
1860 if (ret > 0)
1861 break;
1862 if (ret < 0)
1863 goto error;
1864 leaf = path->nodes[0];
1865 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1866 btrfs_release_path(path);
1867 continue;
1868 }
1869
1870 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1871 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1872 key.type != BTRFS_DEV_ITEM_KEY)
1873 break;
1874
1875 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1876 struct btrfs_dev_item);
1877 devid = btrfs_device_id(leaf, dev_item);
1878 read_extent_buffer(leaf, dev_uuid,
1879 (unsigned long)btrfs_device_uuid(dev_item),
1880 BTRFS_UUID_SIZE);
1881 read_extent_buffer(leaf, fs_uuid,
1882 (unsigned long)btrfs_device_fsid(dev_item),
1883 BTRFS_UUID_SIZE);
1884 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1885 fs_uuid);
1886 BUG_ON(!device); /* Logic error */
1887
1888 if (device->fs_devices->seeding) {
1889 btrfs_set_device_generation(leaf, dev_item,
1890 device->generation);
1891 btrfs_mark_buffer_dirty(leaf);
1892 }
1893
1894 path->slots[0]++;
1895 goto next_slot;
1896 }
1897 ret = 0;
1898 error:
1899 btrfs_free_path(path);
1900 return ret;
1901 }
1902
1903 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1904 {
1905 struct request_queue *q;
1906 struct btrfs_trans_handle *trans;
1907 struct btrfs_device *device;
1908 struct block_device *bdev;
1909 struct list_head *devices;
1910 struct super_block *sb = root->fs_info->sb;
1911 struct rcu_string *name;
1912 u64 total_bytes;
1913 int seeding_dev = 0;
1914 int ret = 0;
1915
1916 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1917 return -EROFS;
1918
1919 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1920 root->fs_info->bdev_holder);
1921 if (IS_ERR(bdev))
1922 return PTR_ERR(bdev);
1923
1924 if (root->fs_info->fs_devices->seeding) {
1925 seeding_dev = 1;
1926 down_write(&sb->s_umount);
1927 mutex_lock(&uuid_mutex);
1928 }
1929
1930 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1931
1932 devices = &root->fs_info->fs_devices->devices;
1933
1934 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1935 list_for_each_entry(device, devices, dev_list) {
1936 if (device->bdev == bdev) {
1937 ret = -EEXIST;
1938 mutex_unlock(
1939 &root->fs_info->fs_devices->device_list_mutex);
1940 goto error;
1941 }
1942 }
1943 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1944
1945 device = kzalloc(sizeof(*device), GFP_NOFS);
1946 if (!device) {
1947 /* we can safely leave the fs_devices entry around */
1948 ret = -ENOMEM;
1949 goto error;
1950 }
1951
1952 name = rcu_string_strdup(device_path, GFP_NOFS);
1953 if (!name) {
1954 kfree(device);
1955 ret = -ENOMEM;
1956 goto error;
1957 }
1958 rcu_assign_pointer(device->name, name);
1959
1960 ret = find_next_devid(root, &device->devid);
1961 if (ret) {
1962 rcu_string_free(device->name);
1963 kfree(device);
1964 goto error;
1965 }
1966
1967 trans = btrfs_start_transaction(root, 0);
1968 if (IS_ERR(trans)) {
1969 rcu_string_free(device->name);
1970 kfree(device);
1971 ret = PTR_ERR(trans);
1972 goto error;
1973 }
1974
1975 lock_chunks(root);
1976
1977 q = bdev_get_queue(bdev);
1978 if (blk_queue_discard(q))
1979 device->can_discard = 1;
1980 device->writeable = 1;
1981 device->work.func = pending_bios_fn;
1982 generate_random_uuid(device->uuid);
1983 spin_lock_init(&device->io_lock);
1984 device->generation = trans->transid;
1985 device->io_width = root->sectorsize;
1986 device->io_align = root->sectorsize;
1987 device->sector_size = root->sectorsize;
1988 device->total_bytes = i_size_read(bdev->bd_inode);
1989 device->disk_total_bytes = device->total_bytes;
1990 device->dev_root = root->fs_info->dev_root;
1991 device->bdev = bdev;
1992 device->in_fs_metadata = 1;
1993 device->is_tgtdev_for_dev_replace = 0;
1994 device->mode = FMODE_EXCL;
1995 set_blocksize(device->bdev, 4096);
1996
1997 if (seeding_dev) {
1998 sb->s_flags &= ~MS_RDONLY;
1999 ret = btrfs_prepare_sprout(root);
2000 BUG_ON(ret); /* -ENOMEM */
2001 }
2002
2003 device->fs_devices = root->fs_info->fs_devices;
2004
2005 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2006 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2007 list_add(&device->dev_alloc_list,
2008 &root->fs_info->fs_devices->alloc_list);
2009 root->fs_info->fs_devices->num_devices++;
2010 root->fs_info->fs_devices->open_devices++;
2011 root->fs_info->fs_devices->rw_devices++;
2012 root->fs_info->fs_devices->total_devices++;
2013 if (device->can_discard)
2014 root->fs_info->fs_devices->num_can_discard++;
2015 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2016
2017 spin_lock(&root->fs_info->free_chunk_lock);
2018 root->fs_info->free_chunk_space += device->total_bytes;
2019 spin_unlock(&root->fs_info->free_chunk_lock);
2020
2021 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2022 root->fs_info->fs_devices->rotating = 1;
2023
2024 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2025 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2026 total_bytes + device->total_bytes);
2027
2028 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2029 btrfs_set_super_num_devices(root->fs_info->super_copy,
2030 total_bytes + 1);
2031 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2032
2033 if (seeding_dev) {
2034 ret = init_first_rw_device(trans, root, device);
2035 if (ret) {
2036 btrfs_abort_transaction(trans, root, ret);
2037 goto error_trans;
2038 }
2039 ret = btrfs_finish_sprout(trans, root);
2040 if (ret) {
2041 btrfs_abort_transaction(trans, root, ret);
2042 goto error_trans;
2043 }
2044 } else {
2045 ret = btrfs_add_device(trans, root, device);
2046 if (ret) {
2047 btrfs_abort_transaction(trans, root, ret);
2048 goto error_trans;
2049 }
2050 }
2051
2052 /*
2053 * we've got more storage, clear any full flags on the space
2054 * infos
2055 */
2056 btrfs_clear_space_info_full(root->fs_info);
2057
2058 unlock_chunks(root);
2059 root->fs_info->num_tolerated_disk_barrier_failures =
2060 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2061 ret = btrfs_commit_transaction(trans, root);
2062
2063 if (seeding_dev) {
2064 mutex_unlock(&uuid_mutex);
2065 up_write(&sb->s_umount);
2066
2067 if (ret) /* transaction commit */
2068 return ret;
2069
2070 ret = btrfs_relocate_sys_chunks(root);
2071 if (ret < 0)
2072 btrfs_error(root->fs_info, ret,
2073 "Failed to relocate sys chunks after "
2074 "device initialization. This can be fixed "
2075 "using the \"btrfs balance\" command.");
2076 trans = btrfs_attach_transaction(root);
2077 if (IS_ERR(trans)) {
2078 if (PTR_ERR(trans) == -ENOENT)
2079 return 0;
2080 return PTR_ERR(trans);
2081 }
2082 ret = btrfs_commit_transaction(trans, root);
2083 }
2084
2085 return ret;
2086
2087 error_trans:
2088 unlock_chunks(root);
2089 btrfs_end_transaction(trans, root);
2090 rcu_string_free(device->name);
2091 kfree(device);
2092 error:
2093 blkdev_put(bdev, FMODE_EXCL);
2094 if (seeding_dev) {
2095 mutex_unlock(&uuid_mutex);
2096 up_write(&sb->s_umount);
2097 }
2098 return ret;
2099 }
2100
2101 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2102 struct btrfs_device **device_out)
2103 {
2104 struct request_queue *q;
2105 struct btrfs_device *device;
2106 struct block_device *bdev;
2107 struct btrfs_fs_info *fs_info = root->fs_info;
2108 struct list_head *devices;
2109 struct rcu_string *name;
2110 int ret = 0;
2111
2112 *device_out = NULL;
2113 if (fs_info->fs_devices->seeding)
2114 return -EINVAL;
2115
2116 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2117 fs_info->bdev_holder);
2118 if (IS_ERR(bdev))
2119 return PTR_ERR(bdev);
2120
2121 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2122
2123 devices = &fs_info->fs_devices->devices;
2124 list_for_each_entry(device, devices, dev_list) {
2125 if (device->bdev == bdev) {
2126 ret = -EEXIST;
2127 goto error;
2128 }
2129 }
2130
2131 device = kzalloc(sizeof(*device), GFP_NOFS);
2132 if (!device) {
2133 ret = -ENOMEM;
2134 goto error;
2135 }
2136
2137 name = rcu_string_strdup(device_path, GFP_NOFS);
2138 if (!name) {
2139 kfree(device);
2140 ret = -ENOMEM;
2141 goto error;
2142 }
2143 rcu_assign_pointer(device->name, name);
2144
2145 q = bdev_get_queue(bdev);
2146 if (blk_queue_discard(q))
2147 device->can_discard = 1;
2148 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2149 device->writeable = 1;
2150 device->work.func = pending_bios_fn;
2151 generate_random_uuid(device->uuid);
2152 device->devid = BTRFS_DEV_REPLACE_DEVID;
2153 spin_lock_init(&device->io_lock);
2154 device->generation = 0;
2155 device->io_width = root->sectorsize;
2156 device->io_align = root->sectorsize;
2157 device->sector_size = root->sectorsize;
2158 device->total_bytes = i_size_read(bdev->bd_inode);
2159 device->disk_total_bytes = device->total_bytes;
2160 device->dev_root = fs_info->dev_root;
2161 device->bdev = bdev;
2162 device->in_fs_metadata = 1;
2163 device->is_tgtdev_for_dev_replace = 1;
2164 device->mode = FMODE_EXCL;
2165 set_blocksize(device->bdev, 4096);
2166 device->fs_devices = fs_info->fs_devices;
2167 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2168 fs_info->fs_devices->num_devices++;
2169 fs_info->fs_devices->open_devices++;
2170 if (device->can_discard)
2171 fs_info->fs_devices->num_can_discard++;
2172 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2173
2174 *device_out = device;
2175 return ret;
2176
2177 error:
2178 blkdev_put(bdev, FMODE_EXCL);
2179 return ret;
2180 }
2181
2182 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2183 struct btrfs_device *tgtdev)
2184 {
2185 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2186 tgtdev->io_width = fs_info->dev_root->sectorsize;
2187 tgtdev->io_align = fs_info->dev_root->sectorsize;
2188 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2189 tgtdev->dev_root = fs_info->dev_root;
2190 tgtdev->in_fs_metadata = 1;
2191 }
2192
2193 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2194 struct btrfs_device *device)
2195 {
2196 int ret;
2197 struct btrfs_path *path;
2198 struct btrfs_root *root;
2199 struct btrfs_dev_item *dev_item;
2200 struct extent_buffer *leaf;
2201 struct btrfs_key key;
2202
2203 root = device->dev_root->fs_info->chunk_root;
2204
2205 path = btrfs_alloc_path();
2206 if (!path)
2207 return -ENOMEM;
2208
2209 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2210 key.type = BTRFS_DEV_ITEM_KEY;
2211 key.offset = device->devid;
2212
2213 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2214 if (ret < 0)
2215 goto out;
2216
2217 if (ret > 0) {
2218 ret = -ENOENT;
2219 goto out;
2220 }
2221
2222 leaf = path->nodes[0];
2223 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2224
2225 btrfs_set_device_id(leaf, dev_item, device->devid);
2226 btrfs_set_device_type(leaf, dev_item, device->type);
2227 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2228 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2229 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2230 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2231 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2232 btrfs_mark_buffer_dirty(leaf);
2233
2234 out:
2235 btrfs_free_path(path);
2236 return ret;
2237 }
2238
2239 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2240 struct btrfs_device *device, u64 new_size)
2241 {
2242 struct btrfs_super_block *super_copy =
2243 device->dev_root->fs_info->super_copy;
2244 u64 old_total = btrfs_super_total_bytes(super_copy);
2245 u64 diff = new_size - device->total_bytes;
2246
2247 if (!device->writeable)
2248 return -EACCES;
2249 if (new_size <= device->total_bytes ||
2250 device->is_tgtdev_for_dev_replace)
2251 return -EINVAL;
2252
2253 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2254 device->fs_devices->total_rw_bytes += diff;
2255
2256 device->total_bytes = new_size;
2257 device->disk_total_bytes = new_size;
2258 btrfs_clear_space_info_full(device->dev_root->fs_info);
2259
2260 return btrfs_update_device(trans, device);
2261 }
2262
2263 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2264 struct btrfs_device *device, u64 new_size)
2265 {
2266 int ret;
2267 lock_chunks(device->dev_root);
2268 ret = __btrfs_grow_device(trans, device, new_size);
2269 unlock_chunks(device->dev_root);
2270 return ret;
2271 }
2272
2273 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2274 struct btrfs_root *root,
2275 u64 chunk_tree, u64 chunk_objectid,
2276 u64 chunk_offset)
2277 {
2278 int ret;
2279 struct btrfs_path *path;
2280 struct btrfs_key key;
2281
2282 root = root->fs_info->chunk_root;
2283 path = btrfs_alloc_path();
2284 if (!path)
2285 return -ENOMEM;
2286
2287 key.objectid = chunk_objectid;
2288 key.offset = chunk_offset;
2289 key.type = BTRFS_CHUNK_ITEM_KEY;
2290
2291 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2292 if (ret < 0)
2293 goto out;
2294 else if (ret > 0) { /* Logic error or corruption */
2295 btrfs_error(root->fs_info, -ENOENT,
2296 "Failed lookup while freeing chunk.");
2297 ret = -ENOENT;
2298 goto out;
2299 }
2300
2301 ret = btrfs_del_item(trans, root, path);
2302 if (ret < 0)
2303 btrfs_error(root->fs_info, ret,
2304 "Failed to delete chunk item.");
2305 out:
2306 btrfs_free_path(path);
2307 return ret;
2308 }
2309
2310 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2311 chunk_offset)
2312 {
2313 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2314 struct btrfs_disk_key *disk_key;
2315 struct btrfs_chunk *chunk;
2316 u8 *ptr;
2317 int ret = 0;
2318 u32 num_stripes;
2319 u32 array_size;
2320 u32 len = 0;
2321 u32 cur;
2322 struct btrfs_key key;
2323
2324 array_size = btrfs_super_sys_array_size(super_copy);
2325
2326 ptr = super_copy->sys_chunk_array;
2327 cur = 0;
2328
2329 while (cur < array_size) {
2330 disk_key = (struct btrfs_disk_key *)ptr;
2331 btrfs_disk_key_to_cpu(&key, disk_key);
2332
2333 len = sizeof(*disk_key);
2334
2335 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2336 chunk = (struct btrfs_chunk *)(ptr + len);
2337 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2338 len += btrfs_chunk_item_size(num_stripes);
2339 } else {
2340 ret = -EIO;
2341 break;
2342 }
2343 if (key.objectid == chunk_objectid &&
2344 key.offset == chunk_offset) {
2345 memmove(ptr, ptr + len, array_size - (cur + len));
2346 array_size -= len;
2347 btrfs_set_super_sys_array_size(super_copy, array_size);
2348 } else {
2349 ptr += len;
2350 cur += len;
2351 }
2352 }
2353 return ret;
2354 }
2355
2356 static int btrfs_relocate_chunk(struct btrfs_root *root,
2357 u64 chunk_tree, u64 chunk_objectid,
2358 u64 chunk_offset)
2359 {
2360 struct extent_map_tree *em_tree;
2361 struct btrfs_root *extent_root;
2362 struct btrfs_trans_handle *trans;
2363 struct extent_map *em;
2364 struct map_lookup *map;
2365 int ret;
2366 int i;
2367
2368 root = root->fs_info->chunk_root;
2369 extent_root = root->fs_info->extent_root;
2370 em_tree = &root->fs_info->mapping_tree.map_tree;
2371
2372 ret = btrfs_can_relocate(extent_root, chunk_offset);
2373 if (ret)
2374 return -ENOSPC;
2375
2376 /* step one, relocate all the extents inside this chunk */
2377 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2378 if (ret)
2379 return ret;
2380
2381 trans = btrfs_start_transaction(root, 0);
2382 BUG_ON(IS_ERR(trans));
2383
2384 lock_chunks(root);
2385
2386 /*
2387 * step two, delete the device extents and the
2388 * chunk tree entries
2389 */
2390 read_lock(&em_tree->lock);
2391 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2392 read_unlock(&em_tree->lock);
2393
2394 BUG_ON(!em || em->start > chunk_offset ||
2395 em->start + em->len < chunk_offset);
2396 map = (struct map_lookup *)em->bdev;
2397
2398 for (i = 0; i < map->num_stripes; i++) {
2399 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2400 map->stripes[i].physical);
2401 BUG_ON(ret);
2402
2403 if (map->stripes[i].dev) {
2404 ret = btrfs_update_device(trans, map->stripes[i].dev);
2405 BUG_ON(ret);
2406 }
2407 }
2408 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2409 chunk_offset);
2410
2411 BUG_ON(ret);
2412
2413 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2414
2415 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2416 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2417 BUG_ON(ret);
2418 }
2419
2420 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2421 BUG_ON(ret);
2422
2423 write_lock(&em_tree->lock);
2424 remove_extent_mapping(em_tree, em);
2425 write_unlock(&em_tree->lock);
2426
2427 kfree(map);
2428 em->bdev = NULL;
2429
2430 /* once for the tree */
2431 free_extent_map(em);
2432 /* once for us */
2433 free_extent_map(em);
2434
2435 unlock_chunks(root);
2436 btrfs_end_transaction(trans, root);
2437 return 0;
2438 }
2439
2440 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2441 {
2442 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2443 struct btrfs_path *path;
2444 struct extent_buffer *leaf;
2445 struct btrfs_chunk *chunk;
2446 struct btrfs_key key;
2447 struct btrfs_key found_key;
2448 u64 chunk_tree = chunk_root->root_key.objectid;
2449 u64 chunk_type;
2450 bool retried = false;
2451 int failed = 0;
2452 int ret;
2453
2454 path = btrfs_alloc_path();
2455 if (!path)
2456 return -ENOMEM;
2457
2458 again:
2459 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2460 key.offset = (u64)-1;
2461 key.type = BTRFS_CHUNK_ITEM_KEY;
2462
2463 while (1) {
2464 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2465 if (ret < 0)
2466 goto error;
2467 BUG_ON(ret == 0); /* Corruption */
2468
2469 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2470 key.type);
2471 if (ret < 0)
2472 goto error;
2473 if (ret > 0)
2474 break;
2475
2476 leaf = path->nodes[0];
2477 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2478
2479 chunk = btrfs_item_ptr(leaf, path->slots[0],
2480 struct btrfs_chunk);
2481 chunk_type = btrfs_chunk_type(leaf, chunk);
2482 btrfs_release_path(path);
2483
2484 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2485 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2486 found_key.objectid,
2487 found_key.offset);
2488 if (ret == -ENOSPC)
2489 failed++;
2490 else if (ret)
2491 BUG();
2492 }
2493
2494 if (found_key.offset == 0)
2495 break;
2496 key.offset = found_key.offset - 1;
2497 }
2498 ret = 0;
2499 if (failed && !retried) {
2500 failed = 0;
2501 retried = true;
2502 goto again;
2503 } else if (failed && retried) {
2504 WARN_ON(1);
2505 ret = -ENOSPC;
2506 }
2507 error:
2508 btrfs_free_path(path);
2509 return ret;
2510 }
2511
2512 static int insert_balance_item(struct btrfs_root *root,
2513 struct btrfs_balance_control *bctl)
2514 {
2515 struct btrfs_trans_handle *trans;
2516 struct btrfs_balance_item *item;
2517 struct btrfs_disk_balance_args disk_bargs;
2518 struct btrfs_path *path;
2519 struct extent_buffer *leaf;
2520 struct btrfs_key key;
2521 int ret, err;
2522
2523 path = btrfs_alloc_path();
2524 if (!path)
2525 return -ENOMEM;
2526
2527 trans = btrfs_start_transaction(root, 0);
2528 if (IS_ERR(trans)) {
2529 btrfs_free_path(path);
2530 return PTR_ERR(trans);
2531 }
2532
2533 key.objectid = BTRFS_BALANCE_OBJECTID;
2534 key.type = BTRFS_BALANCE_ITEM_KEY;
2535 key.offset = 0;
2536
2537 ret = btrfs_insert_empty_item(trans, root, path, &key,
2538 sizeof(*item));
2539 if (ret)
2540 goto out;
2541
2542 leaf = path->nodes[0];
2543 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2544
2545 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2546
2547 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2548 btrfs_set_balance_data(leaf, item, &disk_bargs);
2549 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2550 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2551 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2552 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2553
2554 btrfs_set_balance_flags(leaf, item, bctl->flags);
2555
2556 btrfs_mark_buffer_dirty(leaf);
2557 out:
2558 btrfs_free_path(path);
2559 err = btrfs_commit_transaction(trans, root);
2560 if (err && !ret)
2561 ret = err;
2562 return ret;
2563 }
2564
2565 static int del_balance_item(struct btrfs_root *root)
2566 {
2567 struct btrfs_trans_handle *trans;
2568 struct btrfs_path *path;
2569 struct btrfs_key key;
2570 int ret, err;
2571
2572 path = btrfs_alloc_path();
2573 if (!path)
2574 return -ENOMEM;
2575
2576 trans = btrfs_start_transaction(root, 0);
2577 if (IS_ERR(trans)) {
2578 btrfs_free_path(path);
2579 return PTR_ERR(trans);
2580 }
2581
2582 key.objectid = BTRFS_BALANCE_OBJECTID;
2583 key.type = BTRFS_BALANCE_ITEM_KEY;
2584 key.offset = 0;
2585
2586 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2587 if (ret < 0)
2588 goto out;
2589 if (ret > 0) {
2590 ret = -ENOENT;
2591 goto out;
2592 }
2593
2594 ret = btrfs_del_item(trans, root, path);
2595 out:
2596 btrfs_free_path(path);
2597 err = btrfs_commit_transaction(trans, root);
2598 if (err && !ret)
2599 ret = err;
2600 return ret;
2601 }
2602
2603 /*
2604 * This is a heuristic used to reduce the number of chunks balanced on
2605 * resume after balance was interrupted.
2606 */
2607 static void update_balance_args(struct btrfs_balance_control *bctl)
2608 {
2609 /*
2610 * Turn on soft mode for chunk types that were being converted.
2611 */
2612 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2613 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2614 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2615 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2616 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2617 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2618
2619 /*
2620 * Turn on usage filter if is not already used. The idea is
2621 * that chunks that we have already balanced should be
2622 * reasonably full. Don't do it for chunks that are being
2623 * converted - that will keep us from relocating unconverted
2624 * (albeit full) chunks.
2625 */
2626 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2627 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2628 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2629 bctl->data.usage = 90;
2630 }
2631 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2632 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2633 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2634 bctl->sys.usage = 90;
2635 }
2636 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2637 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2638 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2639 bctl->meta.usage = 90;
2640 }
2641 }
2642
2643 /*
2644 * Should be called with both balance and volume mutexes held to
2645 * serialize other volume operations (add_dev/rm_dev/resize) with
2646 * restriper. Same goes for unset_balance_control.
2647 */
2648 static void set_balance_control(struct btrfs_balance_control *bctl)
2649 {
2650 struct btrfs_fs_info *fs_info = bctl->fs_info;
2651
2652 BUG_ON(fs_info->balance_ctl);
2653
2654 spin_lock(&fs_info->balance_lock);
2655 fs_info->balance_ctl = bctl;
2656 spin_unlock(&fs_info->balance_lock);
2657 }
2658
2659 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2660 {
2661 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2662
2663 BUG_ON(!fs_info->balance_ctl);
2664
2665 spin_lock(&fs_info->balance_lock);
2666 fs_info->balance_ctl = NULL;
2667 spin_unlock(&fs_info->balance_lock);
2668
2669 kfree(bctl);
2670 }
2671
2672 /*
2673 * Balance filters. Return 1 if chunk should be filtered out
2674 * (should not be balanced).
2675 */
2676 static int chunk_profiles_filter(u64 chunk_type,
2677 struct btrfs_balance_args *bargs)
2678 {
2679 chunk_type = chunk_to_extended(chunk_type) &
2680 BTRFS_EXTENDED_PROFILE_MASK;
2681
2682 if (bargs->profiles & chunk_type)
2683 return 0;
2684
2685 return 1;
2686 }
2687
2688 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2689 struct btrfs_balance_args *bargs)
2690 {
2691 struct btrfs_block_group_cache *cache;
2692 u64 chunk_used, user_thresh;
2693 int ret = 1;
2694
2695 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2696 chunk_used = btrfs_block_group_used(&cache->item);
2697
2698 if (bargs->usage == 0)
2699 user_thresh = 1;
2700 else if (bargs->usage > 100)
2701 user_thresh = cache->key.offset;
2702 else
2703 user_thresh = div_factor_fine(cache->key.offset,
2704 bargs->usage);
2705
2706 if (chunk_used < user_thresh)
2707 ret = 0;
2708
2709 btrfs_put_block_group(cache);
2710 return ret;
2711 }
2712
2713 static int chunk_devid_filter(struct extent_buffer *leaf,
2714 struct btrfs_chunk *chunk,
2715 struct btrfs_balance_args *bargs)
2716 {
2717 struct btrfs_stripe *stripe;
2718 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2719 int i;
2720
2721 for (i = 0; i < num_stripes; i++) {
2722 stripe = btrfs_stripe_nr(chunk, i);
2723 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2724 return 0;
2725 }
2726
2727 return 1;
2728 }
2729
2730 /* [pstart, pend) */
2731 static int chunk_drange_filter(struct extent_buffer *leaf,
2732 struct btrfs_chunk *chunk,
2733 u64 chunk_offset,
2734 struct btrfs_balance_args *bargs)
2735 {
2736 struct btrfs_stripe *stripe;
2737 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2738 u64 stripe_offset;
2739 u64 stripe_length;
2740 int factor;
2741 int i;
2742
2743 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2744 return 0;
2745
2746 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2747 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2748 factor = num_stripes / 2;
2749 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2750 factor = num_stripes - 1;
2751 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2752 factor = num_stripes - 2;
2753 } else {
2754 factor = num_stripes;
2755 }
2756
2757 for (i = 0; i < num_stripes; i++) {
2758 stripe = btrfs_stripe_nr(chunk, i);
2759 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2760 continue;
2761
2762 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2763 stripe_length = btrfs_chunk_length(leaf, chunk);
2764 do_div(stripe_length, factor);
2765
2766 if (stripe_offset < bargs->pend &&
2767 stripe_offset + stripe_length > bargs->pstart)
2768 return 0;
2769 }
2770
2771 return 1;
2772 }
2773
2774 /* [vstart, vend) */
2775 static int chunk_vrange_filter(struct extent_buffer *leaf,
2776 struct btrfs_chunk *chunk,
2777 u64 chunk_offset,
2778 struct btrfs_balance_args *bargs)
2779 {
2780 if (chunk_offset < bargs->vend &&
2781 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2782 /* at least part of the chunk is inside this vrange */
2783 return 0;
2784
2785 return 1;
2786 }
2787
2788 static int chunk_soft_convert_filter(u64 chunk_type,
2789 struct btrfs_balance_args *bargs)
2790 {
2791 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2792 return 0;
2793
2794 chunk_type = chunk_to_extended(chunk_type) &
2795 BTRFS_EXTENDED_PROFILE_MASK;
2796
2797 if (bargs->target == chunk_type)
2798 return 1;
2799
2800 return 0;
2801 }
2802
2803 static int should_balance_chunk(struct btrfs_root *root,
2804 struct extent_buffer *leaf,
2805 struct btrfs_chunk *chunk, u64 chunk_offset)
2806 {
2807 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2808 struct btrfs_balance_args *bargs = NULL;
2809 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2810
2811 /* type filter */
2812 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2813 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2814 return 0;
2815 }
2816
2817 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2818 bargs = &bctl->data;
2819 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2820 bargs = &bctl->sys;
2821 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2822 bargs = &bctl->meta;
2823
2824 /* profiles filter */
2825 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2826 chunk_profiles_filter(chunk_type, bargs)) {
2827 return 0;
2828 }
2829
2830 /* usage filter */
2831 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2832 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2833 return 0;
2834 }
2835
2836 /* devid filter */
2837 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2838 chunk_devid_filter(leaf, chunk, bargs)) {
2839 return 0;
2840 }
2841
2842 /* drange filter, makes sense only with devid filter */
2843 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2844 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2845 return 0;
2846 }
2847
2848 /* vrange filter */
2849 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2850 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2851 return 0;
2852 }
2853
2854 /* soft profile changing mode */
2855 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2856 chunk_soft_convert_filter(chunk_type, bargs)) {
2857 return 0;
2858 }
2859
2860 return 1;
2861 }
2862
2863 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2864 {
2865 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2866 struct btrfs_root *chunk_root = fs_info->chunk_root;
2867 struct btrfs_root *dev_root = fs_info->dev_root;
2868 struct list_head *devices;
2869 struct btrfs_device *device;
2870 u64 old_size;
2871 u64 size_to_free;
2872 struct btrfs_chunk *chunk;
2873 struct btrfs_path *path;
2874 struct btrfs_key key;
2875 struct btrfs_key found_key;
2876 struct btrfs_trans_handle *trans;
2877 struct extent_buffer *leaf;
2878 int slot;
2879 int ret;
2880 int enospc_errors = 0;
2881 bool counting = true;
2882
2883 /* step one make some room on all the devices */
2884 devices = &fs_info->fs_devices->devices;
2885 list_for_each_entry(device, devices, dev_list) {
2886 old_size = device->total_bytes;
2887 size_to_free = div_factor(old_size, 1);
2888 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2889 if (!device->writeable ||
2890 device->total_bytes - device->bytes_used > size_to_free ||
2891 device->is_tgtdev_for_dev_replace)
2892 continue;
2893
2894 ret = btrfs_shrink_device(device, old_size - size_to_free);
2895 if (ret == -ENOSPC)
2896 break;
2897 BUG_ON(ret);
2898
2899 trans = btrfs_start_transaction(dev_root, 0);
2900 BUG_ON(IS_ERR(trans));
2901
2902 ret = btrfs_grow_device(trans, device, old_size);
2903 BUG_ON(ret);
2904
2905 btrfs_end_transaction(trans, dev_root);
2906 }
2907
2908 /* step two, relocate all the chunks */
2909 path = btrfs_alloc_path();
2910 if (!path) {
2911 ret = -ENOMEM;
2912 goto error;
2913 }
2914
2915 /* zero out stat counters */
2916 spin_lock(&fs_info->balance_lock);
2917 memset(&bctl->stat, 0, sizeof(bctl->stat));
2918 spin_unlock(&fs_info->balance_lock);
2919 again:
2920 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2921 key.offset = (u64)-1;
2922 key.type = BTRFS_CHUNK_ITEM_KEY;
2923
2924 while (1) {
2925 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2926 atomic_read(&fs_info->balance_cancel_req)) {
2927 ret = -ECANCELED;
2928 goto error;
2929 }
2930
2931 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2932 if (ret < 0)
2933 goto error;
2934
2935 /*
2936 * this shouldn't happen, it means the last relocate
2937 * failed
2938 */
2939 if (ret == 0)
2940 BUG(); /* FIXME break ? */
2941
2942 ret = btrfs_previous_item(chunk_root, path, 0,
2943 BTRFS_CHUNK_ITEM_KEY);
2944 if (ret) {
2945 ret = 0;
2946 break;
2947 }
2948
2949 leaf = path->nodes[0];
2950 slot = path->slots[0];
2951 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2952
2953 if (found_key.objectid != key.objectid)
2954 break;
2955
2956 /* chunk zero is special */
2957 if (found_key.offset == 0)
2958 break;
2959
2960 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2961
2962 if (!counting) {
2963 spin_lock(&fs_info->balance_lock);
2964 bctl->stat.considered++;
2965 spin_unlock(&fs_info->balance_lock);
2966 }
2967
2968 ret = should_balance_chunk(chunk_root, leaf, chunk,
2969 found_key.offset);
2970 btrfs_release_path(path);
2971 if (!ret)
2972 goto loop;
2973
2974 if (counting) {
2975 spin_lock(&fs_info->balance_lock);
2976 bctl->stat.expected++;
2977 spin_unlock(&fs_info->balance_lock);
2978 goto loop;
2979 }
2980
2981 ret = btrfs_relocate_chunk(chunk_root,
2982 chunk_root->root_key.objectid,
2983 found_key.objectid,
2984 found_key.offset);
2985 if (ret && ret != -ENOSPC)
2986 goto error;
2987 if (ret == -ENOSPC) {
2988 enospc_errors++;
2989 } else {
2990 spin_lock(&fs_info->balance_lock);
2991 bctl->stat.completed++;
2992 spin_unlock(&fs_info->balance_lock);
2993 }
2994 loop:
2995 key.offset = found_key.offset - 1;
2996 }
2997
2998 if (counting) {
2999 btrfs_release_path(path);
3000 counting = false;
3001 goto again;
3002 }
3003 error:
3004 btrfs_free_path(path);
3005 if (enospc_errors) {
3006 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
3007 enospc_errors);
3008 if (!ret)
3009 ret = -ENOSPC;
3010 }
3011
3012 return ret;
3013 }
3014
3015 /**
3016 * alloc_profile_is_valid - see if a given profile is valid and reduced
3017 * @flags: profile to validate
3018 * @extended: if true @flags is treated as an extended profile
3019 */
3020 static int alloc_profile_is_valid(u64 flags, int extended)
3021 {
3022 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3023 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3024
3025 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3026
3027 /* 1) check that all other bits are zeroed */
3028 if (flags & ~mask)
3029 return 0;
3030
3031 /* 2) see if profile is reduced */
3032 if (flags == 0)
3033 return !extended; /* "0" is valid for usual profiles */
3034
3035 /* true if exactly one bit set */
3036 return (flags & (flags - 1)) == 0;
3037 }
3038
3039 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3040 {
3041 /* cancel requested || normal exit path */
3042 return atomic_read(&fs_info->balance_cancel_req) ||
3043 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3044 atomic_read(&fs_info->balance_cancel_req) == 0);
3045 }
3046
3047 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3048 {
3049 int ret;
3050
3051 unset_balance_control(fs_info);
3052 ret = del_balance_item(fs_info->tree_root);
3053 BUG_ON(ret);
3054
3055 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3056 }
3057
3058 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3059 struct btrfs_ioctl_balance_args *bargs);
3060
3061 /*
3062 * Should be called with both balance and volume mutexes held
3063 */
3064 int btrfs_balance(struct btrfs_balance_control *bctl,
3065 struct btrfs_ioctl_balance_args *bargs)
3066 {
3067 struct btrfs_fs_info *fs_info = bctl->fs_info;
3068 u64 allowed;
3069 int mixed = 0;
3070 int ret;
3071 u64 num_devices;
3072 unsigned seq;
3073
3074 if (btrfs_fs_closing(fs_info) ||
3075 atomic_read(&fs_info->balance_pause_req) ||
3076 atomic_read(&fs_info->balance_cancel_req)) {
3077 ret = -EINVAL;
3078 goto out;
3079 }
3080
3081 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3082 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3083 mixed = 1;
3084
3085 /*
3086 * In case of mixed groups both data and meta should be picked,
3087 * and identical options should be given for both of them.
3088 */
3089 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3090 if (mixed && (bctl->flags & allowed)) {
3091 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3092 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3093 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3094 printk(KERN_ERR "btrfs: with mixed groups data and "
3095 "metadata balance options must be the same\n");
3096 ret = -EINVAL;
3097 goto out;
3098 }
3099 }
3100
3101 num_devices = fs_info->fs_devices->num_devices;
3102 btrfs_dev_replace_lock(&fs_info->dev_replace);
3103 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3104 BUG_ON(num_devices < 1);
3105 num_devices--;
3106 }
3107 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3108 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3109 if (num_devices == 1)
3110 allowed |= BTRFS_BLOCK_GROUP_DUP;
3111 else if (num_devices < 4)
3112 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3113 else
3114 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
3115 BTRFS_BLOCK_GROUP_RAID10 |
3116 BTRFS_BLOCK_GROUP_RAID5 |
3117 BTRFS_BLOCK_GROUP_RAID6);
3118
3119 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3120 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3121 (bctl->data.target & ~allowed))) {
3122 printk(KERN_ERR "btrfs: unable to start balance with target "
3123 "data profile %llu\n",
3124 (unsigned long long)bctl->data.target);
3125 ret = -EINVAL;
3126 goto out;
3127 }
3128 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3129 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3130 (bctl->meta.target & ~allowed))) {
3131 printk(KERN_ERR "btrfs: unable to start balance with target "
3132 "metadata profile %llu\n",
3133 (unsigned long long)bctl->meta.target);
3134 ret = -EINVAL;
3135 goto out;
3136 }
3137 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3138 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3139 (bctl->sys.target & ~allowed))) {
3140 printk(KERN_ERR "btrfs: unable to start balance with target "
3141 "system profile %llu\n",
3142 (unsigned long long)bctl->sys.target);
3143 ret = -EINVAL;
3144 goto out;
3145 }
3146
3147 /* allow dup'ed data chunks only in mixed mode */
3148 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3149 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3150 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3151 ret = -EINVAL;
3152 goto out;
3153 }
3154
3155 /* allow to reduce meta or sys integrity only if force set */
3156 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3157 BTRFS_BLOCK_GROUP_RAID10 |
3158 BTRFS_BLOCK_GROUP_RAID5 |
3159 BTRFS_BLOCK_GROUP_RAID6;
3160 do {
3161 seq = read_seqbegin(&fs_info->profiles_lock);
3162
3163 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3164 (fs_info->avail_system_alloc_bits & allowed) &&
3165 !(bctl->sys.target & allowed)) ||
3166 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3167 (fs_info->avail_metadata_alloc_bits & allowed) &&
3168 !(bctl->meta.target & allowed))) {
3169 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3170 printk(KERN_INFO "btrfs: force reducing metadata "
3171 "integrity\n");
3172 } else {
3173 printk(KERN_ERR "btrfs: balance will reduce metadata "
3174 "integrity, use force if you want this\n");
3175 ret = -EINVAL;
3176 goto out;
3177 }
3178 }
3179 } while (read_seqretry(&fs_info->profiles_lock, seq));
3180
3181 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3182 int num_tolerated_disk_barrier_failures;
3183 u64 target = bctl->sys.target;
3184
3185 num_tolerated_disk_barrier_failures =
3186 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3187 if (num_tolerated_disk_barrier_failures > 0 &&
3188 (target &
3189 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3190 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3191 num_tolerated_disk_barrier_failures = 0;
3192 else if (num_tolerated_disk_barrier_failures > 1 &&
3193 (target &
3194 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3195 num_tolerated_disk_barrier_failures = 1;
3196
3197 fs_info->num_tolerated_disk_barrier_failures =
3198 num_tolerated_disk_barrier_failures;
3199 }
3200
3201 ret = insert_balance_item(fs_info->tree_root, bctl);
3202 if (ret && ret != -EEXIST)
3203 goto out;
3204
3205 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3206 BUG_ON(ret == -EEXIST);
3207 set_balance_control(bctl);
3208 } else {
3209 BUG_ON(ret != -EEXIST);
3210 spin_lock(&fs_info->balance_lock);
3211 update_balance_args(bctl);
3212 spin_unlock(&fs_info->balance_lock);
3213 }
3214
3215 atomic_inc(&fs_info->balance_running);
3216 mutex_unlock(&fs_info->balance_mutex);
3217
3218 ret = __btrfs_balance(fs_info);
3219
3220 mutex_lock(&fs_info->balance_mutex);
3221 atomic_dec(&fs_info->balance_running);
3222
3223 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3224 fs_info->num_tolerated_disk_barrier_failures =
3225 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3226 }
3227
3228 if (bargs) {
3229 memset(bargs, 0, sizeof(*bargs));
3230 update_ioctl_balance_args(fs_info, 0, bargs);
3231 }
3232
3233 wake_up(&fs_info->balance_wait_q);
3234
3235 return ret;
3236 out:
3237 if (bctl->flags & BTRFS_BALANCE_RESUME)
3238 __cancel_balance(fs_info);
3239 else {
3240 kfree(bctl);
3241 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3242 }
3243 return ret;
3244 }
3245
3246 static int balance_kthread(void *data)
3247 {
3248 struct btrfs_fs_info *fs_info = data;
3249 int ret = 0;
3250
3251 mutex_lock(&fs_info->volume_mutex);
3252 mutex_lock(&fs_info->balance_mutex);
3253
3254 if (fs_info->balance_ctl) {
3255 printk(KERN_INFO "btrfs: continuing balance\n");
3256 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3257 }
3258
3259 mutex_unlock(&fs_info->balance_mutex);
3260 mutex_unlock(&fs_info->volume_mutex);
3261
3262 return ret;
3263 }
3264
3265 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3266 {
3267 struct task_struct *tsk;
3268
3269 spin_lock(&fs_info->balance_lock);
3270 if (!fs_info->balance_ctl) {
3271 spin_unlock(&fs_info->balance_lock);
3272 return 0;
3273 }
3274 spin_unlock(&fs_info->balance_lock);
3275
3276 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3277 printk(KERN_INFO "btrfs: force skipping balance\n");
3278 return 0;
3279 }
3280
3281 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3282 if (IS_ERR(tsk))
3283 return PTR_ERR(tsk);
3284
3285 return 0;
3286 }
3287
3288 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3289 {
3290 struct btrfs_balance_control *bctl;
3291 struct btrfs_balance_item *item;
3292 struct btrfs_disk_balance_args disk_bargs;
3293 struct btrfs_path *path;
3294 struct extent_buffer *leaf;
3295 struct btrfs_key key;
3296 int ret;
3297
3298 path = btrfs_alloc_path();
3299 if (!path)
3300 return -ENOMEM;
3301
3302 key.objectid = BTRFS_BALANCE_OBJECTID;
3303 key.type = BTRFS_BALANCE_ITEM_KEY;
3304 key.offset = 0;
3305
3306 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3307 if (ret < 0)
3308 goto out;
3309 if (ret > 0) { /* ret = -ENOENT; */
3310 ret = 0;
3311 goto out;
3312 }
3313
3314 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3315 if (!bctl) {
3316 ret = -ENOMEM;
3317 goto out;
3318 }
3319
3320 leaf = path->nodes[0];
3321 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3322
3323 bctl->fs_info = fs_info;
3324 bctl->flags = btrfs_balance_flags(leaf, item);
3325 bctl->flags |= BTRFS_BALANCE_RESUME;
3326
3327 btrfs_balance_data(leaf, item, &disk_bargs);
3328 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3329 btrfs_balance_meta(leaf, item, &disk_bargs);
3330 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3331 btrfs_balance_sys(leaf, item, &disk_bargs);
3332 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3333
3334 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3335
3336 mutex_lock(&fs_info->volume_mutex);
3337 mutex_lock(&fs_info->balance_mutex);
3338
3339 set_balance_control(bctl);
3340
3341 mutex_unlock(&fs_info->balance_mutex);
3342 mutex_unlock(&fs_info->volume_mutex);
3343 out:
3344 btrfs_free_path(path);
3345 return ret;
3346 }
3347
3348 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3349 {
3350 int ret = 0;
3351
3352 mutex_lock(&fs_info->balance_mutex);
3353 if (!fs_info->balance_ctl) {
3354 mutex_unlock(&fs_info->balance_mutex);
3355 return -ENOTCONN;
3356 }
3357
3358 if (atomic_read(&fs_info->balance_running)) {
3359 atomic_inc(&fs_info->balance_pause_req);
3360 mutex_unlock(&fs_info->balance_mutex);
3361
3362 wait_event(fs_info->balance_wait_q,
3363 atomic_read(&fs_info->balance_running) == 0);
3364
3365 mutex_lock(&fs_info->balance_mutex);
3366 /* we are good with balance_ctl ripped off from under us */
3367 BUG_ON(atomic_read(&fs_info->balance_running));
3368 atomic_dec(&fs_info->balance_pause_req);
3369 } else {
3370 ret = -ENOTCONN;
3371 }
3372
3373 mutex_unlock(&fs_info->balance_mutex);
3374 return ret;
3375 }
3376
3377 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3378 {
3379 mutex_lock(&fs_info->balance_mutex);
3380 if (!fs_info->balance_ctl) {
3381 mutex_unlock(&fs_info->balance_mutex);
3382 return -ENOTCONN;
3383 }
3384
3385 atomic_inc(&fs_info->balance_cancel_req);
3386 /*
3387 * if we are running just wait and return, balance item is
3388 * deleted in btrfs_balance in this case
3389 */
3390 if (atomic_read(&fs_info->balance_running)) {
3391 mutex_unlock(&fs_info->balance_mutex);
3392 wait_event(fs_info->balance_wait_q,
3393 atomic_read(&fs_info->balance_running) == 0);
3394 mutex_lock(&fs_info->balance_mutex);
3395 } else {
3396 /* __cancel_balance needs volume_mutex */
3397 mutex_unlock(&fs_info->balance_mutex);
3398 mutex_lock(&fs_info->volume_mutex);
3399 mutex_lock(&fs_info->balance_mutex);
3400
3401 if (fs_info->balance_ctl)
3402 __cancel_balance(fs_info);
3403
3404 mutex_unlock(&fs_info->volume_mutex);
3405 }
3406
3407 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3408 atomic_dec(&fs_info->balance_cancel_req);
3409 mutex_unlock(&fs_info->balance_mutex);
3410 return 0;
3411 }
3412
3413 /*
3414 * shrinking a device means finding all of the device extents past
3415 * the new size, and then following the back refs to the chunks.
3416 * The chunk relocation code actually frees the device extent
3417 */
3418 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3419 {
3420 struct btrfs_trans_handle *trans;
3421 struct btrfs_root *root = device->dev_root;
3422 struct btrfs_dev_extent *dev_extent = NULL;
3423 struct btrfs_path *path;
3424 u64 length;
3425 u64 chunk_tree;
3426 u64 chunk_objectid;
3427 u64 chunk_offset;
3428 int ret;
3429 int slot;
3430 int failed = 0;
3431 bool retried = false;
3432 struct extent_buffer *l;
3433 struct btrfs_key key;
3434 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3435 u64 old_total = btrfs_super_total_bytes(super_copy);
3436 u64 old_size = device->total_bytes;
3437 u64 diff = device->total_bytes - new_size;
3438
3439 if (device->is_tgtdev_for_dev_replace)
3440 return -EINVAL;
3441
3442 path = btrfs_alloc_path();
3443 if (!path)
3444 return -ENOMEM;
3445
3446 path->reada = 2;
3447
3448 lock_chunks(root);
3449
3450 device->total_bytes = new_size;
3451 if (device->writeable) {
3452 device->fs_devices->total_rw_bytes -= diff;
3453 spin_lock(&root->fs_info->free_chunk_lock);
3454 root->fs_info->free_chunk_space -= diff;
3455 spin_unlock(&root->fs_info->free_chunk_lock);
3456 }
3457 unlock_chunks(root);
3458
3459 again:
3460 key.objectid = device->devid;
3461 key.offset = (u64)-1;
3462 key.type = BTRFS_DEV_EXTENT_KEY;
3463
3464 do {
3465 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3466 if (ret < 0)
3467 goto done;
3468
3469 ret = btrfs_previous_item(root, path, 0, key.type);
3470 if (ret < 0)
3471 goto done;
3472 if (ret) {
3473 ret = 0;
3474 btrfs_release_path(path);
3475 break;
3476 }
3477
3478 l = path->nodes[0];
3479 slot = path->slots[0];
3480 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3481
3482 if (key.objectid != device->devid) {
3483 btrfs_release_path(path);
3484 break;
3485 }
3486
3487 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3488 length = btrfs_dev_extent_length(l, dev_extent);
3489
3490 if (key.offset + length <= new_size) {
3491 btrfs_release_path(path);
3492 break;
3493 }
3494
3495 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3496 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3497 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3498 btrfs_release_path(path);
3499
3500 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3501 chunk_offset);
3502 if (ret && ret != -ENOSPC)
3503 goto done;
3504 if (ret == -ENOSPC)
3505 failed++;
3506 } while (key.offset-- > 0);
3507
3508 if (failed && !retried) {
3509 failed = 0;
3510 retried = true;
3511 goto again;
3512 } else if (failed && retried) {
3513 ret = -ENOSPC;
3514 lock_chunks(root);
3515
3516 device->total_bytes = old_size;
3517 if (device->writeable)
3518 device->fs_devices->total_rw_bytes += diff;
3519 spin_lock(&root->fs_info->free_chunk_lock);
3520 root->fs_info->free_chunk_space += diff;
3521 spin_unlock(&root->fs_info->free_chunk_lock);
3522 unlock_chunks(root);
3523 goto done;
3524 }
3525
3526 /* Shrinking succeeded, else we would be at "done". */
3527 trans = btrfs_start_transaction(root, 0);
3528 if (IS_ERR(trans)) {
3529 ret = PTR_ERR(trans);
3530 goto done;
3531 }
3532
3533 lock_chunks(root);
3534
3535 device->disk_total_bytes = new_size;
3536 /* Now btrfs_update_device() will change the on-disk size. */
3537 ret = btrfs_update_device(trans, device);
3538 if (ret) {
3539 unlock_chunks(root);
3540 btrfs_end_transaction(trans, root);
3541 goto done;
3542 }
3543 WARN_ON(diff > old_total);
3544 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3545 unlock_chunks(root);
3546 btrfs_end_transaction(trans, root);
3547 done:
3548 btrfs_free_path(path);
3549 return ret;
3550 }
3551
3552 static int btrfs_add_system_chunk(struct btrfs_root *root,
3553 struct btrfs_key *key,
3554 struct btrfs_chunk *chunk, int item_size)
3555 {
3556 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3557 struct btrfs_disk_key disk_key;
3558 u32 array_size;
3559 u8 *ptr;
3560
3561 array_size = btrfs_super_sys_array_size(super_copy);
3562 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3563 return -EFBIG;
3564
3565 ptr = super_copy->sys_chunk_array + array_size;
3566 btrfs_cpu_key_to_disk(&disk_key, key);
3567 memcpy(ptr, &disk_key, sizeof(disk_key));
3568 ptr += sizeof(disk_key);
3569 memcpy(ptr, chunk, item_size);
3570 item_size += sizeof(disk_key);
3571 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3572 return 0;
3573 }
3574
3575 /*
3576 * sort the devices in descending order by max_avail, total_avail
3577 */
3578 static int btrfs_cmp_device_info(const void *a, const void *b)
3579 {
3580 const struct btrfs_device_info *di_a = a;
3581 const struct btrfs_device_info *di_b = b;
3582
3583 if (di_a->max_avail > di_b->max_avail)
3584 return -1;
3585 if (di_a->max_avail < di_b->max_avail)
3586 return 1;
3587 if (di_a->total_avail > di_b->total_avail)
3588 return -1;
3589 if (di_a->total_avail < di_b->total_avail)
3590 return 1;
3591 return 0;
3592 }
3593
3594 struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3595 [BTRFS_RAID_RAID10] = {
3596 .sub_stripes = 2,
3597 .dev_stripes = 1,
3598 .devs_max = 0, /* 0 == as many as possible */
3599 .devs_min = 4,
3600 .devs_increment = 2,
3601 .ncopies = 2,
3602 },
3603 [BTRFS_RAID_RAID1] = {
3604 .sub_stripes = 1,
3605 .dev_stripes = 1,
3606 .devs_max = 2,
3607 .devs_min = 2,
3608 .devs_increment = 2,
3609 .ncopies = 2,
3610 },
3611 [BTRFS_RAID_DUP] = {
3612 .sub_stripes = 1,
3613 .dev_stripes = 2,
3614 .devs_max = 1,
3615 .devs_min = 1,
3616 .devs_increment = 1,
3617 .ncopies = 2,
3618 },
3619 [BTRFS_RAID_RAID0] = {
3620 .sub_stripes = 1,
3621 .dev_stripes = 1,
3622 .devs_max = 0,
3623 .devs_min = 2,
3624 .devs_increment = 1,
3625 .ncopies = 1,
3626 },
3627 [BTRFS_RAID_SINGLE] = {
3628 .sub_stripes = 1,
3629 .dev_stripes = 1,
3630 .devs_max = 1,
3631 .devs_min = 1,
3632 .devs_increment = 1,
3633 .ncopies = 1,
3634 },
3635 [BTRFS_RAID_RAID5] = {
3636 .sub_stripes = 1,
3637 .dev_stripes = 1,
3638 .devs_max = 0,
3639 .devs_min = 2,
3640 .devs_increment = 1,
3641 .ncopies = 2,
3642 },
3643 [BTRFS_RAID_RAID6] = {
3644 .sub_stripes = 1,
3645 .dev_stripes = 1,
3646 .devs_max = 0,
3647 .devs_min = 3,
3648 .devs_increment = 1,
3649 .ncopies = 3,
3650 },
3651 };
3652
3653 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3654 {
3655 /* TODO allow them to set a preferred stripe size */
3656 return 64 * 1024;
3657 }
3658
3659 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3660 {
3661 u64 features;
3662
3663 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3664 return;
3665
3666 features = btrfs_super_incompat_flags(info->super_copy);
3667 if (features & BTRFS_FEATURE_INCOMPAT_RAID56)
3668 return;
3669
3670 features |= BTRFS_FEATURE_INCOMPAT_RAID56;
3671 btrfs_set_super_incompat_flags(info->super_copy, features);
3672 printk(KERN_INFO "btrfs: setting RAID5/6 feature flag\n");
3673 }
3674
3675 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3676 struct btrfs_root *extent_root,
3677 struct map_lookup **map_ret,
3678 u64 *num_bytes_out, u64 *stripe_size_out,
3679 u64 start, u64 type)
3680 {
3681 struct btrfs_fs_info *info = extent_root->fs_info;
3682 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3683 struct list_head *cur;
3684 struct map_lookup *map = NULL;
3685 struct extent_map_tree *em_tree;
3686 struct extent_map *em;
3687 struct btrfs_device_info *devices_info = NULL;
3688 u64 total_avail;
3689 int num_stripes; /* total number of stripes to allocate */
3690 int data_stripes; /* number of stripes that count for
3691 block group size */
3692 int sub_stripes; /* sub_stripes info for map */
3693 int dev_stripes; /* stripes per dev */
3694 int devs_max; /* max devs to use */
3695 int devs_min; /* min devs needed */
3696 int devs_increment; /* ndevs has to be a multiple of this */
3697 int ncopies; /* how many copies to data has */
3698 int ret;
3699 u64 max_stripe_size;
3700 u64 max_chunk_size;
3701 u64 stripe_size;
3702 u64 num_bytes;
3703 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
3704 int ndevs;
3705 int i;
3706 int j;
3707 int index;
3708
3709 BUG_ON(!alloc_profile_is_valid(type, 0));
3710
3711 if (list_empty(&fs_devices->alloc_list))
3712 return -ENOSPC;
3713
3714 index = __get_raid_index(type);
3715
3716 sub_stripes = btrfs_raid_array[index].sub_stripes;
3717 dev_stripes = btrfs_raid_array[index].dev_stripes;
3718 devs_max = btrfs_raid_array[index].devs_max;
3719 devs_min = btrfs_raid_array[index].devs_min;
3720 devs_increment = btrfs_raid_array[index].devs_increment;
3721 ncopies = btrfs_raid_array[index].ncopies;
3722
3723 if (type & BTRFS_BLOCK_GROUP_DATA) {
3724 max_stripe_size = 1024 * 1024 * 1024;
3725 max_chunk_size = 10 * max_stripe_size;
3726 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3727 /* for larger filesystems, use larger metadata chunks */
3728 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3729 max_stripe_size = 1024 * 1024 * 1024;
3730 else
3731 max_stripe_size = 256 * 1024 * 1024;
3732 max_chunk_size = max_stripe_size;
3733 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3734 max_stripe_size = 32 * 1024 * 1024;
3735 max_chunk_size = 2 * max_stripe_size;
3736 } else {
3737 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3738 type);
3739 BUG_ON(1);
3740 }
3741
3742 /* we don't want a chunk larger than 10% of writeable space */
3743 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3744 max_chunk_size);
3745
3746 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3747 GFP_NOFS);
3748 if (!devices_info)
3749 return -ENOMEM;
3750
3751 cur = fs_devices->alloc_list.next;
3752
3753 /*
3754 * in the first pass through the devices list, we gather information
3755 * about the available holes on each device.
3756 */
3757 ndevs = 0;
3758 while (cur != &fs_devices->alloc_list) {
3759 struct btrfs_device *device;
3760 u64 max_avail;
3761 u64 dev_offset;
3762
3763 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3764
3765 cur = cur->next;
3766
3767 if (!device->writeable) {
3768 WARN(1, KERN_ERR
3769 "btrfs: read-only device in alloc_list\n");
3770 continue;
3771 }
3772
3773 if (!device->in_fs_metadata ||
3774 device->is_tgtdev_for_dev_replace)
3775 continue;
3776
3777 if (device->total_bytes > device->bytes_used)
3778 total_avail = device->total_bytes - device->bytes_used;
3779 else
3780 total_avail = 0;
3781
3782 /* If there is no space on this device, skip it. */
3783 if (total_avail == 0)
3784 continue;
3785
3786 ret = find_free_dev_extent(device,
3787 max_stripe_size * dev_stripes,
3788 &dev_offset, &max_avail);
3789 if (ret && ret != -ENOSPC)
3790 goto error;
3791
3792 if (ret == 0)
3793 max_avail = max_stripe_size * dev_stripes;
3794
3795 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3796 continue;
3797
3798 if (ndevs == fs_devices->rw_devices) {
3799 WARN(1, "%s: found more than %llu devices\n",
3800 __func__, fs_devices->rw_devices);
3801 break;
3802 }
3803 devices_info[ndevs].dev_offset = dev_offset;
3804 devices_info[ndevs].max_avail = max_avail;
3805 devices_info[ndevs].total_avail = total_avail;
3806 devices_info[ndevs].dev = device;
3807 ++ndevs;
3808 }
3809
3810 /*
3811 * now sort the devices by hole size / available space
3812 */
3813 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3814 btrfs_cmp_device_info, NULL);
3815
3816 /* round down to number of usable stripes */
3817 ndevs -= ndevs % devs_increment;
3818
3819 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3820 ret = -ENOSPC;
3821 goto error;
3822 }
3823
3824 if (devs_max && ndevs > devs_max)
3825 ndevs = devs_max;
3826 /*
3827 * the primary goal is to maximize the number of stripes, so use as many
3828 * devices as possible, even if the stripes are not maximum sized.
3829 */
3830 stripe_size = devices_info[ndevs-1].max_avail;
3831 num_stripes = ndevs * dev_stripes;
3832
3833 /*
3834 * this will have to be fixed for RAID1 and RAID10 over
3835 * more drives
3836 */
3837 data_stripes = num_stripes / ncopies;
3838
3839 if (type & BTRFS_BLOCK_GROUP_RAID5) {
3840 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
3841 btrfs_super_stripesize(info->super_copy));
3842 data_stripes = num_stripes - 1;
3843 }
3844 if (type & BTRFS_BLOCK_GROUP_RAID6) {
3845 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
3846 btrfs_super_stripesize(info->super_copy));
3847 data_stripes = num_stripes - 2;
3848 }
3849
3850 /*
3851 * Use the number of data stripes to figure out how big this chunk
3852 * is really going to be in terms of logical address space,
3853 * and compare that answer with the max chunk size
3854 */
3855 if (stripe_size * data_stripes > max_chunk_size) {
3856 u64 mask = (1ULL << 24) - 1;
3857 stripe_size = max_chunk_size;
3858 do_div(stripe_size, data_stripes);
3859
3860 /* bump the answer up to a 16MB boundary */
3861 stripe_size = (stripe_size + mask) & ~mask;
3862
3863 /* but don't go higher than the limits we found
3864 * while searching for free extents
3865 */
3866 if (stripe_size > devices_info[ndevs-1].max_avail)
3867 stripe_size = devices_info[ndevs-1].max_avail;
3868 }
3869
3870 do_div(stripe_size, dev_stripes);
3871
3872 /* align to BTRFS_STRIPE_LEN */
3873 do_div(stripe_size, raid_stripe_len);
3874 stripe_size *= raid_stripe_len;
3875
3876 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3877 if (!map) {
3878 ret = -ENOMEM;
3879 goto error;
3880 }
3881 map->num_stripes = num_stripes;
3882
3883 for (i = 0; i < ndevs; ++i) {
3884 for (j = 0; j < dev_stripes; ++j) {
3885 int s = i * dev_stripes + j;
3886 map->stripes[s].dev = devices_info[i].dev;
3887 map->stripes[s].physical = devices_info[i].dev_offset +
3888 j * stripe_size;
3889 }
3890 }
3891 map->sector_size = extent_root->sectorsize;
3892 map->stripe_len = raid_stripe_len;
3893 map->io_align = raid_stripe_len;
3894 map->io_width = raid_stripe_len;
3895 map->type = type;
3896 map->sub_stripes = sub_stripes;
3897
3898 *map_ret = map;
3899 num_bytes = stripe_size * data_stripes;
3900
3901 *stripe_size_out = stripe_size;
3902 *num_bytes_out = num_bytes;
3903
3904 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3905
3906 em = alloc_extent_map();
3907 if (!em) {
3908 ret = -ENOMEM;
3909 goto error;
3910 }
3911 em->bdev = (struct block_device *)map;
3912 em->start = start;
3913 em->len = num_bytes;
3914 em->block_start = 0;
3915 em->block_len = em->len;
3916
3917 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3918 write_lock(&em_tree->lock);
3919 ret = add_extent_mapping(em_tree, em);
3920 write_unlock(&em_tree->lock);
3921 if (ret) {
3922 free_extent_map(em);
3923 goto error;
3924 }
3925
3926 for (i = 0; i < map->num_stripes; ++i) {
3927 struct btrfs_device *device;
3928 u64 dev_offset;
3929
3930 device = map->stripes[i].dev;
3931 dev_offset = map->stripes[i].physical;
3932
3933 ret = btrfs_alloc_dev_extent(trans, device,
3934 info->chunk_root->root_key.objectid,
3935 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3936 start, dev_offset, stripe_size);
3937 if (ret)
3938 goto error_dev_extent;
3939 }
3940
3941 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3942 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3943 start, num_bytes);
3944 if (ret) {
3945 i = map->num_stripes - 1;
3946 goto error_dev_extent;
3947 }
3948
3949 free_extent_map(em);
3950 check_raid56_incompat_flag(extent_root->fs_info, type);
3951
3952 kfree(devices_info);
3953 return 0;
3954
3955 error_dev_extent:
3956 for (; i >= 0; i--) {
3957 struct btrfs_device *device;
3958 int err;
3959
3960 device = map->stripes[i].dev;
3961 err = btrfs_free_dev_extent(trans, device, start);
3962 if (err) {
3963 btrfs_abort_transaction(trans, extent_root, err);
3964 break;
3965 }
3966 }
3967 write_lock(&em_tree->lock);
3968 remove_extent_mapping(em_tree, em);
3969 write_unlock(&em_tree->lock);
3970
3971 /* One for our allocation */
3972 free_extent_map(em);
3973 /* One for the tree reference */
3974 free_extent_map(em);
3975 error:
3976 kfree(map);
3977 kfree(devices_info);
3978 return ret;
3979 }
3980
3981 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3982 struct btrfs_root *extent_root,
3983 struct map_lookup *map, u64 chunk_offset,
3984 u64 chunk_size, u64 stripe_size)
3985 {
3986 u64 dev_offset;
3987 struct btrfs_key key;
3988 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3989 struct btrfs_device *device;
3990 struct btrfs_chunk *chunk;
3991 struct btrfs_stripe *stripe;
3992 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3993 int index = 0;
3994 int ret;
3995
3996 chunk = kzalloc(item_size, GFP_NOFS);
3997 if (!chunk)
3998 return -ENOMEM;
3999
4000 index = 0;
4001 while (index < map->num_stripes) {
4002 device = map->stripes[index].dev;
4003 device->bytes_used += stripe_size;
4004 ret = btrfs_update_device(trans, device);
4005 if (ret)
4006 goto out_free;
4007 index++;
4008 }
4009
4010 spin_lock(&extent_root->fs_info->free_chunk_lock);
4011 extent_root->fs_info->free_chunk_space -= (stripe_size *
4012 map->num_stripes);
4013 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4014
4015 index = 0;
4016 stripe = &chunk->stripe;
4017 while (index < map->num_stripes) {
4018 device = map->stripes[index].dev;
4019 dev_offset = map->stripes[index].physical;
4020
4021 btrfs_set_stack_stripe_devid(stripe, device->devid);
4022 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4023 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4024 stripe++;
4025 index++;
4026 }
4027
4028 btrfs_set_stack_chunk_length(chunk, chunk_size);
4029 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4030 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4031 btrfs_set_stack_chunk_type(chunk, map->type);
4032 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4033 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4034 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4035 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4036 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4037
4038 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4039 key.type = BTRFS_CHUNK_ITEM_KEY;
4040 key.offset = chunk_offset;
4041
4042 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4043
4044 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4045 /*
4046 * TODO: Cleanup of inserted chunk root in case of
4047 * failure.
4048 */
4049 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4050 item_size);
4051 }
4052
4053 out_free:
4054 kfree(chunk);
4055 return ret;
4056 }
4057
4058 /*
4059 * Chunk allocation falls into two parts. The first part does works
4060 * that make the new allocated chunk useable, but not do any operation
4061 * that modifies the chunk tree. The second part does the works that
4062 * require modifying the chunk tree. This division is important for the
4063 * bootstrap process of adding storage to a seed btrfs.
4064 */
4065 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4066 struct btrfs_root *extent_root, u64 type)
4067 {
4068 u64 chunk_offset;
4069 u64 chunk_size;
4070 u64 stripe_size;
4071 struct map_lookup *map;
4072 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4073 int ret;
4074
4075 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4076 &chunk_offset);
4077 if (ret)
4078 return ret;
4079
4080 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
4081 &stripe_size, chunk_offset, type);
4082 if (ret)
4083 return ret;
4084
4085 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
4086 chunk_size, stripe_size);
4087 if (ret)
4088 return ret;
4089 return 0;
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 chunk_size;
4099 u64 sys_chunk_size;
4100 u64 stripe_size;
4101 u64 sys_stripe_size;
4102 u64 alloc_profile;
4103 struct map_lookup *map;
4104 struct map_lookup *sys_map;
4105 struct btrfs_fs_info *fs_info = root->fs_info;
4106 struct btrfs_root *extent_root = fs_info->extent_root;
4107 int ret;
4108
4109 ret = find_next_chunk(fs_info->chunk_root,
4110 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
4111 if (ret)
4112 return ret;
4113
4114 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4115 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
4116 &stripe_size, chunk_offset, alloc_profile);
4117 if (ret)
4118 return ret;
4119
4120 sys_chunk_offset = chunk_offset + chunk_size;
4121
4122 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4123 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
4124 &sys_chunk_size, &sys_stripe_size,
4125 sys_chunk_offset, alloc_profile);
4126 if (ret) {
4127 btrfs_abort_transaction(trans, root, ret);
4128 goto out;
4129 }
4130
4131 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4132 if (ret) {
4133 btrfs_abort_transaction(trans, root, ret);
4134 goto out;
4135 }
4136
4137 /*
4138 * Modifying chunk tree needs allocating new blocks from both
4139 * system block group and metadata block group. So we only can
4140 * do operations require modifying the chunk tree after both
4141 * block groups were created.
4142 */
4143 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
4144 chunk_size, stripe_size);
4145 if (ret) {
4146 btrfs_abort_transaction(trans, root, ret);
4147 goto out;
4148 }
4149
4150 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
4151 sys_chunk_offset, sys_chunk_size,
4152 sys_stripe_size);
4153 if (ret)
4154 btrfs_abort_transaction(trans, root, ret);
4155
4156 out:
4157
4158 return ret;
4159 }
4160
4161 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4162 {
4163 struct extent_map *em;
4164 struct map_lookup *map;
4165 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4166 int readonly = 0;
4167 int i;
4168
4169 read_lock(&map_tree->map_tree.lock);
4170 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4171 read_unlock(&map_tree->map_tree.lock);
4172 if (!em)
4173 return 1;
4174
4175 if (btrfs_test_opt(root, DEGRADED)) {
4176 free_extent_map(em);
4177 return 0;
4178 }
4179
4180 map = (struct map_lookup *)em->bdev;
4181 for (i = 0; i < map->num_stripes; i++) {
4182 if (!map->stripes[i].dev->writeable) {
4183 readonly = 1;
4184 break;
4185 }
4186 }
4187 free_extent_map(em);
4188 return readonly;
4189 }
4190
4191 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4192 {
4193 extent_map_tree_init(&tree->map_tree);
4194 }
4195
4196 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4197 {
4198 struct extent_map *em;
4199
4200 while (1) {
4201 write_lock(&tree->map_tree.lock);
4202 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4203 if (em)
4204 remove_extent_mapping(&tree->map_tree, em);
4205 write_unlock(&tree->map_tree.lock);
4206 if (!em)
4207 break;
4208 kfree(em->bdev);
4209 /* once for us */
4210 free_extent_map(em);
4211 /* once for the tree */
4212 free_extent_map(em);
4213 }
4214 }
4215
4216 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4217 {
4218 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4219 struct extent_map *em;
4220 struct map_lookup *map;
4221 struct extent_map_tree *em_tree = &map_tree->map_tree;
4222 int ret;
4223
4224 read_lock(&em_tree->lock);
4225 em = lookup_extent_mapping(em_tree, logical, len);
4226 read_unlock(&em_tree->lock);
4227 BUG_ON(!em);
4228
4229 BUG_ON(em->start > logical || em->start + em->len < logical);
4230 map = (struct map_lookup *)em->bdev;
4231 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4232 ret = map->num_stripes;
4233 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4234 ret = map->sub_stripes;
4235 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4236 ret = 2;
4237 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4238 ret = 3;
4239 else
4240 ret = 1;
4241 free_extent_map(em);
4242
4243 btrfs_dev_replace_lock(&fs_info->dev_replace);
4244 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4245 ret++;
4246 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4247
4248 return ret;
4249 }
4250
4251 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4252 struct btrfs_mapping_tree *map_tree,
4253 u64 logical)
4254 {
4255 struct extent_map *em;
4256 struct map_lookup *map;
4257 struct extent_map_tree *em_tree = &map_tree->map_tree;
4258 unsigned long len = root->sectorsize;
4259
4260 read_lock(&em_tree->lock);
4261 em = lookup_extent_mapping(em_tree, logical, len);
4262 read_unlock(&em_tree->lock);
4263 BUG_ON(!em);
4264
4265 BUG_ON(em->start > logical || em->start + em->len < logical);
4266 map = (struct map_lookup *)em->bdev;
4267 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4268 BTRFS_BLOCK_GROUP_RAID6)) {
4269 len = map->stripe_len * nr_data_stripes(map);
4270 }
4271 free_extent_map(em);
4272 return len;
4273 }
4274
4275 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4276 u64 logical, u64 len, int mirror_num)
4277 {
4278 struct extent_map *em;
4279 struct map_lookup *map;
4280 struct extent_map_tree *em_tree = &map_tree->map_tree;
4281 int ret = 0;
4282
4283 read_lock(&em_tree->lock);
4284 em = lookup_extent_mapping(em_tree, logical, len);
4285 read_unlock(&em_tree->lock);
4286 BUG_ON(!em);
4287
4288 BUG_ON(em->start > logical || em->start + em->len < logical);
4289 map = (struct map_lookup *)em->bdev;
4290 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4291 BTRFS_BLOCK_GROUP_RAID6))
4292 ret = 1;
4293 free_extent_map(em);
4294 return ret;
4295 }
4296
4297 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4298 struct map_lookup *map, int first, int num,
4299 int optimal, int dev_replace_is_ongoing)
4300 {
4301 int i;
4302 int tolerance;
4303 struct btrfs_device *srcdev;
4304
4305 if (dev_replace_is_ongoing &&
4306 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4307 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4308 srcdev = fs_info->dev_replace.srcdev;
4309 else
4310 srcdev = NULL;
4311
4312 /*
4313 * try to avoid the drive that is the source drive for a
4314 * dev-replace procedure, only choose it if no other non-missing
4315 * mirror is available
4316 */
4317 for (tolerance = 0; tolerance < 2; tolerance++) {
4318 if (map->stripes[optimal].dev->bdev &&
4319 (tolerance || map->stripes[optimal].dev != srcdev))
4320 return optimal;
4321 for (i = first; i < first + num; i++) {
4322 if (map->stripes[i].dev->bdev &&
4323 (tolerance || map->stripes[i].dev != srcdev))
4324 return i;
4325 }
4326 }
4327
4328 /* we couldn't find one that doesn't fail. Just return something
4329 * and the io error handling code will clean up eventually
4330 */
4331 return optimal;
4332 }
4333
4334 static inline int parity_smaller(u64 a, u64 b)
4335 {
4336 return a > b;
4337 }
4338
4339 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4340 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4341 {
4342 struct btrfs_bio_stripe s;
4343 int i;
4344 u64 l;
4345 int again = 1;
4346
4347 while (again) {
4348 again = 0;
4349 for (i = 0; i < bbio->num_stripes - 1; i++) {
4350 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4351 s = bbio->stripes[i];
4352 l = raid_map[i];
4353 bbio->stripes[i] = bbio->stripes[i+1];
4354 raid_map[i] = raid_map[i+1];
4355 bbio->stripes[i+1] = s;
4356 raid_map[i+1] = l;
4357 again = 1;
4358 }
4359 }
4360 }
4361 }
4362
4363 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4364 u64 logical, u64 *length,
4365 struct btrfs_bio **bbio_ret,
4366 int mirror_num, u64 **raid_map_ret)
4367 {
4368 struct extent_map *em;
4369 struct map_lookup *map;
4370 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4371 struct extent_map_tree *em_tree = &map_tree->map_tree;
4372 u64 offset;
4373 u64 stripe_offset;
4374 u64 stripe_end_offset;
4375 u64 stripe_nr;
4376 u64 stripe_nr_orig;
4377 u64 stripe_nr_end;
4378 u64 stripe_len;
4379 u64 *raid_map = NULL;
4380 int stripe_index;
4381 int i;
4382 int ret = 0;
4383 int num_stripes;
4384 int max_errors = 0;
4385 struct btrfs_bio *bbio = NULL;
4386 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4387 int dev_replace_is_ongoing = 0;
4388 int num_alloc_stripes;
4389 int patch_the_first_stripe_for_dev_replace = 0;
4390 u64 physical_to_patch_in_first_stripe = 0;
4391 u64 raid56_full_stripe_start = (u64)-1;
4392
4393 read_lock(&em_tree->lock);
4394 em = lookup_extent_mapping(em_tree, logical, *length);
4395 read_unlock(&em_tree->lock);
4396
4397 if (!em) {
4398 printk(KERN_CRIT "btrfs: unable to find logical %llu len %llu\n",
4399 (unsigned long long)logical,
4400 (unsigned long long)*length);
4401 BUG();
4402 }
4403
4404 BUG_ON(em->start > logical || em->start + em->len < logical);
4405 map = (struct map_lookup *)em->bdev;
4406 offset = logical - em->start;
4407
4408 if (mirror_num > map->num_stripes)
4409 mirror_num = 0;
4410
4411 stripe_len = map->stripe_len;
4412 stripe_nr = offset;
4413 /*
4414 * stripe_nr counts the total number of stripes we have to stride
4415 * to get to this block
4416 */
4417 do_div(stripe_nr, stripe_len);
4418
4419 stripe_offset = stripe_nr * stripe_len;
4420 BUG_ON(offset < stripe_offset);
4421
4422 /* stripe_offset is the offset of this block in its stripe*/
4423 stripe_offset = offset - stripe_offset;
4424
4425 /* if we're here for raid56, we need to know the stripe aligned start */
4426 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4427 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4428 raid56_full_stripe_start = offset;
4429
4430 /* allow a write of a full stripe, but make sure we don't
4431 * allow straddling of stripes
4432 */
4433 do_div(raid56_full_stripe_start, full_stripe_len);
4434 raid56_full_stripe_start *= full_stripe_len;
4435 }
4436
4437 if (rw & REQ_DISCARD) {
4438 /* we don't discard raid56 yet */
4439 if (map->type &
4440 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4441 ret = -EOPNOTSUPP;
4442 goto out;
4443 }
4444 *length = min_t(u64, em->len - offset, *length);
4445 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4446 u64 max_len;
4447 /* For writes to RAID[56], allow a full stripeset across all disks.
4448 For other RAID types and for RAID[56] reads, just allow a single
4449 stripe (on a single disk). */
4450 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4451 (rw & REQ_WRITE)) {
4452 max_len = stripe_len * nr_data_stripes(map) -
4453 (offset - raid56_full_stripe_start);
4454 } else {
4455 /* we limit the length of each bio to what fits in a stripe */
4456 max_len = stripe_len - stripe_offset;
4457 }
4458 *length = min_t(u64, em->len - offset, max_len);
4459 } else {
4460 *length = em->len - offset;
4461 }
4462
4463 /* This is for when we're called from btrfs_merge_bio_hook() and all
4464 it cares about is the length */
4465 if (!bbio_ret)
4466 goto out;
4467
4468 btrfs_dev_replace_lock(dev_replace);
4469 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4470 if (!dev_replace_is_ongoing)
4471 btrfs_dev_replace_unlock(dev_replace);
4472
4473 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4474 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4475 dev_replace->tgtdev != NULL) {
4476 /*
4477 * in dev-replace case, for repair case (that's the only
4478 * case where the mirror is selected explicitly when
4479 * calling btrfs_map_block), blocks left of the left cursor
4480 * can also be read from the target drive.
4481 * For REQ_GET_READ_MIRRORS, the target drive is added as
4482 * the last one to the array of stripes. For READ, it also
4483 * needs to be supported using the same mirror number.
4484 * If the requested block is not left of the left cursor,
4485 * EIO is returned. This can happen because btrfs_num_copies()
4486 * returns one more in the dev-replace case.
4487 */
4488 u64 tmp_length = *length;
4489 struct btrfs_bio *tmp_bbio = NULL;
4490 int tmp_num_stripes;
4491 u64 srcdev_devid = dev_replace->srcdev->devid;
4492 int index_srcdev = 0;
4493 int found = 0;
4494 u64 physical_of_found = 0;
4495
4496 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4497 logical, &tmp_length, &tmp_bbio, 0, NULL);
4498 if (ret) {
4499 WARN_ON(tmp_bbio != NULL);
4500 goto out;
4501 }
4502
4503 tmp_num_stripes = tmp_bbio->num_stripes;
4504 if (mirror_num > tmp_num_stripes) {
4505 /*
4506 * REQ_GET_READ_MIRRORS does not contain this
4507 * mirror, that means that the requested area
4508 * is not left of the left cursor
4509 */
4510 ret = -EIO;
4511 kfree(tmp_bbio);
4512 goto out;
4513 }
4514
4515 /*
4516 * process the rest of the function using the mirror_num
4517 * of the source drive. Therefore look it up first.
4518 * At the end, patch the device pointer to the one of the
4519 * target drive.
4520 */
4521 for (i = 0; i < tmp_num_stripes; i++) {
4522 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4523 /*
4524 * In case of DUP, in order to keep it
4525 * simple, only add the mirror with the
4526 * lowest physical address
4527 */
4528 if (found &&
4529 physical_of_found <=
4530 tmp_bbio->stripes[i].physical)
4531 continue;
4532 index_srcdev = i;
4533 found = 1;
4534 physical_of_found =
4535 tmp_bbio->stripes[i].physical;
4536 }
4537 }
4538
4539 if (found) {
4540 mirror_num = index_srcdev + 1;
4541 patch_the_first_stripe_for_dev_replace = 1;
4542 physical_to_patch_in_first_stripe = physical_of_found;
4543 } else {
4544 WARN_ON(1);
4545 ret = -EIO;
4546 kfree(tmp_bbio);
4547 goto out;
4548 }
4549
4550 kfree(tmp_bbio);
4551 } else if (mirror_num > map->num_stripes) {
4552 mirror_num = 0;
4553 }
4554
4555 num_stripes = 1;
4556 stripe_index = 0;
4557 stripe_nr_orig = stripe_nr;
4558 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
4559 do_div(stripe_nr_end, map->stripe_len);
4560 stripe_end_offset = stripe_nr_end * map->stripe_len -
4561 (offset + *length);
4562
4563 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4564 if (rw & REQ_DISCARD)
4565 num_stripes = min_t(u64, map->num_stripes,
4566 stripe_nr_end - stripe_nr_orig);
4567 stripe_index = do_div(stripe_nr, map->num_stripes);
4568 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4569 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4570 num_stripes = map->num_stripes;
4571 else if (mirror_num)
4572 stripe_index = mirror_num - 1;
4573 else {
4574 stripe_index = find_live_mirror(fs_info, map, 0,
4575 map->num_stripes,
4576 current->pid % map->num_stripes,
4577 dev_replace_is_ongoing);
4578 mirror_num = stripe_index + 1;
4579 }
4580
4581 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4582 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4583 num_stripes = map->num_stripes;
4584 } else if (mirror_num) {
4585 stripe_index = mirror_num - 1;
4586 } else {
4587 mirror_num = 1;
4588 }
4589
4590 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4591 int factor = map->num_stripes / map->sub_stripes;
4592
4593 stripe_index = do_div(stripe_nr, factor);
4594 stripe_index *= map->sub_stripes;
4595
4596 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4597 num_stripes = map->sub_stripes;
4598 else if (rw & REQ_DISCARD)
4599 num_stripes = min_t(u64, map->sub_stripes *
4600 (stripe_nr_end - stripe_nr_orig),
4601 map->num_stripes);
4602 else if (mirror_num)
4603 stripe_index += mirror_num - 1;
4604 else {
4605 int old_stripe_index = stripe_index;
4606 stripe_index = find_live_mirror(fs_info, map,
4607 stripe_index,
4608 map->sub_stripes, stripe_index +
4609 current->pid % map->sub_stripes,
4610 dev_replace_is_ongoing);
4611 mirror_num = stripe_index - old_stripe_index + 1;
4612 }
4613
4614 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4615 BTRFS_BLOCK_GROUP_RAID6)) {
4616 u64 tmp;
4617
4618 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4619 && raid_map_ret) {
4620 int i, rot;
4621
4622 /* push stripe_nr back to the start of the full stripe */
4623 stripe_nr = raid56_full_stripe_start;
4624 do_div(stripe_nr, stripe_len);
4625
4626 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4627
4628 /* RAID[56] write or recovery. Return all stripes */
4629 num_stripes = map->num_stripes;
4630 max_errors = nr_parity_stripes(map);
4631
4632 raid_map = kmalloc(sizeof(u64) * num_stripes,
4633 GFP_NOFS);
4634 if (!raid_map) {
4635 ret = -ENOMEM;
4636 goto out;
4637 }
4638
4639 /* Work out the disk rotation on this stripe-set */
4640 tmp = stripe_nr;
4641 rot = do_div(tmp, num_stripes);
4642
4643 /* Fill in the logical address of each stripe */
4644 tmp = stripe_nr * nr_data_stripes(map);
4645 for (i = 0; i < nr_data_stripes(map); i++)
4646 raid_map[(i+rot) % num_stripes] =
4647 em->start + (tmp + i) * map->stripe_len;
4648
4649 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4650 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4651 raid_map[(i+rot+1) % num_stripes] =
4652 RAID6_Q_STRIPE;
4653
4654 *length = map->stripe_len;
4655 stripe_index = 0;
4656 stripe_offset = 0;
4657 } else {
4658 /*
4659 * Mirror #0 or #1 means the original data block.
4660 * Mirror #2 is RAID5 parity block.
4661 * Mirror #3 is RAID6 Q block.
4662 */
4663 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4664 if (mirror_num > 1)
4665 stripe_index = nr_data_stripes(map) +
4666 mirror_num - 2;
4667
4668 /* We distribute the parity blocks across stripes */
4669 tmp = stripe_nr + stripe_index;
4670 stripe_index = do_div(tmp, map->num_stripes);
4671 }
4672 } else {
4673 /*
4674 * after this do_div call, stripe_nr is the number of stripes
4675 * on this device we have to walk to find the data, and
4676 * stripe_index is the number of our device in the stripe array
4677 */
4678 stripe_index = do_div(stripe_nr, map->num_stripes);
4679 mirror_num = stripe_index + 1;
4680 }
4681 BUG_ON(stripe_index >= map->num_stripes);
4682
4683 num_alloc_stripes = num_stripes;
4684 if (dev_replace_is_ongoing) {
4685 if (rw & (REQ_WRITE | REQ_DISCARD))
4686 num_alloc_stripes <<= 1;
4687 if (rw & REQ_GET_READ_MIRRORS)
4688 num_alloc_stripes++;
4689 }
4690 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4691 if (!bbio) {
4692 ret = -ENOMEM;
4693 goto out;
4694 }
4695 atomic_set(&bbio->error, 0);
4696
4697 if (rw & REQ_DISCARD) {
4698 int factor = 0;
4699 int sub_stripes = 0;
4700 u64 stripes_per_dev = 0;
4701 u32 remaining_stripes = 0;
4702 u32 last_stripe = 0;
4703
4704 if (map->type &
4705 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4706 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4707 sub_stripes = 1;
4708 else
4709 sub_stripes = map->sub_stripes;
4710
4711 factor = map->num_stripes / sub_stripes;
4712 stripes_per_dev = div_u64_rem(stripe_nr_end -
4713 stripe_nr_orig,
4714 factor,
4715 &remaining_stripes);
4716 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4717 last_stripe *= sub_stripes;
4718 }
4719
4720 for (i = 0; i < num_stripes; i++) {
4721 bbio->stripes[i].physical =
4722 map->stripes[stripe_index].physical +
4723 stripe_offset + stripe_nr * map->stripe_len;
4724 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4725
4726 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4727 BTRFS_BLOCK_GROUP_RAID10)) {
4728 bbio->stripes[i].length = stripes_per_dev *
4729 map->stripe_len;
4730
4731 if (i / sub_stripes < remaining_stripes)
4732 bbio->stripes[i].length +=
4733 map->stripe_len;
4734
4735 /*
4736 * Special for the first stripe and
4737 * the last stripe:
4738 *
4739 * |-------|...|-------|
4740 * |----------|
4741 * off end_off
4742 */
4743 if (i < sub_stripes)
4744 bbio->stripes[i].length -=
4745 stripe_offset;
4746
4747 if (stripe_index >= last_stripe &&
4748 stripe_index <= (last_stripe +
4749 sub_stripes - 1))
4750 bbio->stripes[i].length -=
4751 stripe_end_offset;
4752
4753 if (i == sub_stripes - 1)
4754 stripe_offset = 0;
4755 } else
4756 bbio->stripes[i].length = *length;
4757
4758 stripe_index++;
4759 if (stripe_index == map->num_stripes) {
4760 /* This could only happen for RAID0/10 */
4761 stripe_index = 0;
4762 stripe_nr++;
4763 }
4764 }
4765 } else {
4766 for (i = 0; i < num_stripes; i++) {
4767 bbio->stripes[i].physical =
4768 map->stripes[stripe_index].physical +
4769 stripe_offset +
4770 stripe_nr * map->stripe_len;
4771 bbio->stripes[i].dev =
4772 map->stripes[stripe_index].dev;
4773 stripe_index++;
4774 }
4775 }
4776
4777 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
4778 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4779 BTRFS_BLOCK_GROUP_RAID10 |
4780 BTRFS_BLOCK_GROUP_RAID5 |
4781 BTRFS_BLOCK_GROUP_DUP)) {
4782 max_errors = 1;
4783 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
4784 max_errors = 2;
4785 }
4786 }
4787
4788 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
4789 dev_replace->tgtdev != NULL) {
4790 int index_where_to_add;
4791 u64 srcdev_devid = dev_replace->srcdev->devid;
4792
4793 /*
4794 * duplicate the write operations while the dev replace
4795 * procedure is running. Since the copying of the old disk
4796 * to the new disk takes place at run time while the
4797 * filesystem is mounted writable, the regular write
4798 * operations to the old disk have to be duplicated to go
4799 * to the new disk as well.
4800 * Note that device->missing is handled by the caller, and
4801 * that the write to the old disk is already set up in the
4802 * stripes array.
4803 */
4804 index_where_to_add = num_stripes;
4805 for (i = 0; i < num_stripes; i++) {
4806 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4807 /* write to new disk, too */
4808 struct btrfs_bio_stripe *new =
4809 bbio->stripes + index_where_to_add;
4810 struct btrfs_bio_stripe *old =
4811 bbio->stripes + i;
4812
4813 new->physical = old->physical;
4814 new->length = old->length;
4815 new->dev = dev_replace->tgtdev;
4816 index_where_to_add++;
4817 max_errors++;
4818 }
4819 }
4820 num_stripes = index_where_to_add;
4821 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
4822 dev_replace->tgtdev != NULL) {
4823 u64 srcdev_devid = dev_replace->srcdev->devid;
4824 int index_srcdev = 0;
4825 int found = 0;
4826 u64 physical_of_found = 0;
4827
4828 /*
4829 * During the dev-replace procedure, the target drive can
4830 * also be used to read data in case it is needed to repair
4831 * a corrupt block elsewhere. This is possible if the
4832 * requested area is left of the left cursor. In this area,
4833 * the target drive is a full copy of the source drive.
4834 */
4835 for (i = 0; i < num_stripes; i++) {
4836 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4837 /*
4838 * In case of DUP, in order to keep it
4839 * simple, only add the mirror with the
4840 * lowest physical address
4841 */
4842 if (found &&
4843 physical_of_found <=
4844 bbio->stripes[i].physical)
4845 continue;
4846 index_srcdev = i;
4847 found = 1;
4848 physical_of_found = bbio->stripes[i].physical;
4849 }
4850 }
4851 if (found) {
4852 u64 length = map->stripe_len;
4853
4854 if (physical_of_found + length <=
4855 dev_replace->cursor_left) {
4856 struct btrfs_bio_stripe *tgtdev_stripe =
4857 bbio->stripes + num_stripes;
4858
4859 tgtdev_stripe->physical = physical_of_found;
4860 tgtdev_stripe->length =
4861 bbio->stripes[index_srcdev].length;
4862 tgtdev_stripe->dev = dev_replace->tgtdev;
4863
4864 num_stripes++;
4865 }
4866 }
4867 }
4868
4869 *bbio_ret = bbio;
4870 bbio->num_stripes = num_stripes;
4871 bbio->max_errors = max_errors;
4872 bbio->mirror_num = mirror_num;
4873
4874 /*
4875 * this is the case that REQ_READ && dev_replace_is_ongoing &&
4876 * mirror_num == num_stripes + 1 && dev_replace target drive is
4877 * available as a mirror
4878 */
4879 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
4880 WARN_ON(num_stripes > 1);
4881 bbio->stripes[0].dev = dev_replace->tgtdev;
4882 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
4883 bbio->mirror_num = map->num_stripes + 1;
4884 }
4885 if (raid_map) {
4886 sort_parity_stripes(bbio, raid_map);
4887 *raid_map_ret = raid_map;
4888 }
4889 out:
4890 if (dev_replace_is_ongoing)
4891 btrfs_dev_replace_unlock(dev_replace);
4892 free_extent_map(em);
4893 return ret;
4894 }
4895
4896 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4897 u64 logical, u64 *length,
4898 struct btrfs_bio **bbio_ret, int mirror_num)
4899 {
4900 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
4901 mirror_num, NULL);
4902 }
4903
4904 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4905 u64 chunk_start, u64 physical, u64 devid,
4906 u64 **logical, int *naddrs, int *stripe_len)
4907 {
4908 struct extent_map_tree *em_tree = &map_tree->map_tree;
4909 struct extent_map *em;
4910 struct map_lookup *map;
4911 u64 *buf;
4912 u64 bytenr;
4913 u64 length;
4914 u64 stripe_nr;
4915 u64 rmap_len;
4916 int i, j, nr = 0;
4917
4918 read_lock(&em_tree->lock);
4919 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4920 read_unlock(&em_tree->lock);
4921
4922 BUG_ON(!em || em->start != chunk_start);
4923 map = (struct map_lookup *)em->bdev;
4924
4925 length = em->len;
4926 rmap_len = map->stripe_len;
4927
4928 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4929 do_div(length, map->num_stripes / map->sub_stripes);
4930 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4931 do_div(length, map->num_stripes);
4932 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4933 BTRFS_BLOCK_GROUP_RAID6)) {
4934 do_div(length, nr_data_stripes(map));
4935 rmap_len = map->stripe_len * nr_data_stripes(map);
4936 }
4937
4938 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4939 BUG_ON(!buf); /* -ENOMEM */
4940
4941 for (i = 0; i < map->num_stripes; i++) {
4942 if (devid && map->stripes[i].dev->devid != devid)
4943 continue;
4944 if (map->stripes[i].physical > physical ||
4945 map->stripes[i].physical + length <= physical)
4946 continue;
4947
4948 stripe_nr = physical - map->stripes[i].physical;
4949 do_div(stripe_nr, map->stripe_len);
4950
4951 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4952 stripe_nr = stripe_nr * map->num_stripes + i;
4953 do_div(stripe_nr, map->sub_stripes);
4954 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4955 stripe_nr = stripe_nr * map->num_stripes + i;
4956 } /* else if RAID[56], multiply by nr_data_stripes().
4957 * Alternatively, just use rmap_len below instead of
4958 * map->stripe_len */
4959
4960 bytenr = chunk_start + stripe_nr * rmap_len;
4961 WARN_ON(nr >= map->num_stripes);
4962 for (j = 0; j < nr; j++) {
4963 if (buf[j] == bytenr)
4964 break;
4965 }
4966 if (j == nr) {
4967 WARN_ON(nr >= map->num_stripes);
4968 buf[nr++] = bytenr;
4969 }
4970 }
4971
4972 *logical = buf;
4973 *naddrs = nr;
4974 *stripe_len = rmap_len;
4975
4976 free_extent_map(em);
4977 return 0;
4978 }
4979
4980 static void *merge_stripe_index_into_bio_private(void *bi_private,
4981 unsigned int stripe_index)
4982 {
4983 /*
4984 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4985 * at most 1.
4986 * The alternative solution (instead of stealing bits from the
4987 * pointer) would be to allocate an intermediate structure
4988 * that contains the old private pointer plus the stripe_index.
4989 */
4990 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4991 BUG_ON(stripe_index > 3);
4992 return (void *)(((uintptr_t)bi_private) | stripe_index);
4993 }
4994
4995 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4996 {
4997 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4998 }
4999
5000 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
5001 {
5002 return (unsigned int)((uintptr_t)bi_private) & 3;
5003 }
5004
5005 static void btrfs_end_bio(struct bio *bio, int err)
5006 {
5007 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
5008 int is_orig_bio = 0;
5009
5010 if (err) {
5011 atomic_inc(&bbio->error);
5012 if (err == -EIO || err == -EREMOTEIO) {
5013 unsigned int stripe_index =
5014 extract_stripe_index_from_bio_private(
5015 bio->bi_private);
5016 struct btrfs_device *dev;
5017
5018 BUG_ON(stripe_index >= bbio->num_stripes);
5019 dev = bbio->stripes[stripe_index].dev;
5020 if (dev->bdev) {
5021 if (bio->bi_rw & WRITE)
5022 btrfs_dev_stat_inc(dev,
5023 BTRFS_DEV_STAT_WRITE_ERRS);
5024 else
5025 btrfs_dev_stat_inc(dev,
5026 BTRFS_DEV_STAT_READ_ERRS);
5027 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5028 btrfs_dev_stat_inc(dev,
5029 BTRFS_DEV_STAT_FLUSH_ERRS);
5030 btrfs_dev_stat_print_on_error(dev);
5031 }
5032 }
5033 }
5034
5035 if (bio == bbio->orig_bio)
5036 is_orig_bio = 1;
5037
5038 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5039 if (!is_orig_bio) {
5040 bio_put(bio);
5041 bio = bbio->orig_bio;
5042 }
5043 bio->bi_private = bbio->private;
5044 bio->bi_end_io = bbio->end_io;
5045 bio->bi_bdev = (struct block_device *)
5046 (unsigned long)bbio->mirror_num;
5047 /* only send an error to the higher layers if it is
5048 * beyond the tolerance of the btrfs bio
5049 */
5050 if (atomic_read(&bbio->error) > bbio->max_errors) {
5051 err = -EIO;
5052 } else {
5053 /*
5054 * this bio is actually up to date, we didn't
5055 * go over the max number of errors
5056 */
5057 set_bit(BIO_UPTODATE, &bio->bi_flags);
5058 err = 0;
5059 }
5060 kfree(bbio);
5061
5062 bio_endio(bio, err);
5063 } else if (!is_orig_bio) {
5064 bio_put(bio);
5065 }
5066 }
5067
5068 struct async_sched {
5069 struct bio *bio;
5070 int rw;
5071 struct btrfs_fs_info *info;
5072 struct btrfs_work work;
5073 };
5074
5075 /*
5076 * see run_scheduled_bios for a description of why bios are collected for
5077 * async submit.
5078 *
5079 * This will add one bio to the pending list for a device and make sure
5080 * the work struct is scheduled.
5081 */
5082 noinline void btrfs_schedule_bio(struct btrfs_root *root,
5083 struct btrfs_device *device,
5084 int rw, struct bio *bio)
5085 {
5086 int should_queue = 1;
5087 struct btrfs_pending_bios *pending_bios;
5088
5089 if (device->missing || !device->bdev) {
5090 bio_endio(bio, -EIO);
5091 return;
5092 }
5093
5094 /* don't bother with additional async steps for reads, right now */
5095 if (!(rw & REQ_WRITE)) {
5096 bio_get(bio);
5097 btrfsic_submit_bio(rw, bio);
5098 bio_put(bio);
5099 return;
5100 }
5101
5102 /*
5103 * nr_async_bios allows us to reliably return congestion to the
5104 * higher layers. Otherwise, the async bio makes it appear we have
5105 * made progress against dirty pages when we've really just put it
5106 * on a queue for later
5107 */
5108 atomic_inc(&root->fs_info->nr_async_bios);
5109 WARN_ON(bio->bi_next);
5110 bio->bi_next = NULL;
5111 bio->bi_rw |= rw;
5112
5113 spin_lock(&device->io_lock);
5114 if (bio->bi_rw & REQ_SYNC)
5115 pending_bios = &device->pending_sync_bios;
5116 else
5117 pending_bios = &device->pending_bios;
5118
5119 if (pending_bios->tail)
5120 pending_bios->tail->bi_next = bio;
5121
5122 pending_bios->tail = bio;
5123 if (!pending_bios->head)
5124 pending_bios->head = bio;
5125 if (device->running_pending)
5126 should_queue = 0;
5127
5128 spin_unlock(&device->io_lock);
5129
5130 if (should_queue)
5131 btrfs_queue_worker(&root->fs_info->submit_workers,
5132 &device->work);
5133 }
5134
5135 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5136 sector_t sector)
5137 {
5138 struct bio_vec *prev;
5139 struct request_queue *q = bdev_get_queue(bdev);
5140 unsigned short max_sectors = queue_max_sectors(q);
5141 struct bvec_merge_data bvm = {
5142 .bi_bdev = bdev,
5143 .bi_sector = sector,
5144 .bi_rw = bio->bi_rw,
5145 };
5146
5147 if (bio->bi_vcnt == 0) {
5148 WARN_ON(1);
5149 return 1;
5150 }
5151
5152 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5153 if ((bio->bi_size >> 9) > max_sectors)
5154 return 0;
5155
5156 if (!q->merge_bvec_fn)
5157 return 1;
5158
5159 bvm.bi_size = bio->bi_size - prev->bv_len;
5160 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5161 return 0;
5162 return 1;
5163 }
5164
5165 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5166 struct bio *bio, u64 physical, int dev_nr,
5167 int rw, int async)
5168 {
5169 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5170
5171 bio->bi_private = bbio;
5172 bio->bi_private = merge_stripe_index_into_bio_private(
5173 bio->bi_private, (unsigned int)dev_nr);
5174 bio->bi_end_io = btrfs_end_bio;
5175 bio->bi_sector = physical >> 9;
5176 #ifdef DEBUG
5177 {
5178 struct rcu_string *name;
5179
5180 rcu_read_lock();
5181 name = rcu_dereference(dev->name);
5182 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5183 "(%s id %llu), size=%u\n", rw,
5184 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5185 name->str, dev->devid, bio->bi_size);
5186 rcu_read_unlock();
5187 }
5188 #endif
5189 bio->bi_bdev = dev->bdev;
5190 if (async)
5191 btrfs_schedule_bio(root, dev, rw, bio);
5192 else
5193 btrfsic_submit_bio(rw, bio);
5194 }
5195
5196 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5197 struct bio *first_bio, struct btrfs_device *dev,
5198 int dev_nr, int rw, int async)
5199 {
5200 struct bio_vec *bvec = first_bio->bi_io_vec;
5201 struct bio *bio;
5202 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5203 u64 physical = bbio->stripes[dev_nr].physical;
5204
5205 again:
5206 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5207 if (!bio)
5208 return -ENOMEM;
5209
5210 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5211 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5212 bvec->bv_offset) < bvec->bv_len) {
5213 u64 len = bio->bi_size;
5214
5215 atomic_inc(&bbio->stripes_pending);
5216 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5217 rw, async);
5218 physical += len;
5219 goto again;
5220 }
5221 bvec++;
5222 }
5223
5224 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5225 return 0;
5226 }
5227
5228 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5229 {
5230 atomic_inc(&bbio->error);
5231 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5232 bio->bi_private = bbio->private;
5233 bio->bi_end_io = bbio->end_io;
5234 bio->bi_bdev = (struct block_device *)
5235 (unsigned long)bbio->mirror_num;
5236 bio->bi_sector = logical >> 9;
5237 kfree(bbio);
5238 bio_endio(bio, -EIO);
5239 }
5240 }
5241
5242 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5243 int mirror_num, int async_submit)
5244 {
5245 struct btrfs_device *dev;
5246 struct bio *first_bio = bio;
5247 u64 logical = (u64)bio->bi_sector << 9;
5248 u64 length = 0;
5249 u64 map_length;
5250 u64 *raid_map = NULL;
5251 int ret;
5252 int dev_nr = 0;
5253 int total_devs = 1;
5254 struct btrfs_bio *bbio = NULL;
5255
5256 length = bio->bi_size;
5257 map_length = length;
5258
5259 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5260 mirror_num, &raid_map);
5261 if (ret) /* -ENOMEM */
5262 return ret;
5263
5264 total_devs = bbio->num_stripes;
5265 bbio->orig_bio = first_bio;
5266 bbio->private = first_bio->bi_private;
5267 bbio->end_io = first_bio->bi_end_io;
5268 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5269
5270 if (raid_map) {
5271 /* In this case, map_length has been set to the length of
5272 a single stripe; not the whole write */
5273 if (rw & WRITE) {
5274 return raid56_parity_write(root, bio, bbio,
5275 raid_map, map_length);
5276 } else {
5277 return raid56_parity_recover(root, bio, bbio,
5278 raid_map, map_length,
5279 mirror_num);
5280 }
5281 }
5282
5283 if (map_length < length) {
5284 printk(KERN_CRIT "btrfs: mapping failed logical %llu bio len %llu "
5285 "len %llu\n", (unsigned long long)logical,
5286 (unsigned long long)length,
5287 (unsigned long long)map_length);
5288 BUG();
5289 }
5290
5291 while (dev_nr < total_devs) {
5292 dev = bbio->stripes[dev_nr].dev;
5293 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5294 bbio_error(bbio, first_bio, logical);
5295 dev_nr++;
5296 continue;
5297 }
5298
5299 /*
5300 * Check and see if we're ok with this bio based on it's size
5301 * and offset with the given device.
5302 */
5303 if (!bio_size_ok(dev->bdev, first_bio,
5304 bbio->stripes[dev_nr].physical >> 9)) {
5305 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5306 dev_nr, rw, async_submit);
5307 BUG_ON(ret);
5308 dev_nr++;
5309 continue;
5310 }
5311
5312 if (dev_nr < total_devs - 1) {
5313 bio = bio_clone(first_bio, GFP_NOFS);
5314 BUG_ON(!bio); /* -ENOMEM */
5315 } else {
5316 bio = first_bio;
5317 }
5318
5319 submit_stripe_bio(root, bbio, bio,
5320 bbio->stripes[dev_nr].physical, dev_nr, rw,
5321 async_submit);
5322 dev_nr++;
5323 }
5324 return 0;
5325 }
5326
5327 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5328 u8 *uuid, u8 *fsid)
5329 {
5330 struct btrfs_device *device;
5331 struct btrfs_fs_devices *cur_devices;
5332
5333 cur_devices = fs_info->fs_devices;
5334 while (cur_devices) {
5335 if (!fsid ||
5336 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5337 device = __find_device(&cur_devices->devices,
5338 devid, uuid);
5339 if (device)
5340 return device;
5341 }
5342 cur_devices = cur_devices->seed;
5343 }
5344 return NULL;
5345 }
5346
5347 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5348 u64 devid, u8 *dev_uuid)
5349 {
5350 struct btrfs_device *device;
5351 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5352
5353 device = kzalloc(sizeof(*device), GFP_NOFS);
5354 if (!device)
5355 return NULL;
5356 list_add(&device->dev_list,
5357 &fs_devices->devices);
5358 device->dev_root = root->fs_info->dev_root;
5359 device->devid = devid;
5360 device->work.func = pending_bios_fn;
5361 device->fs_devices = fs_devices;
5362 device->missing = 1;
5363 fs_devices->num_devices++;
5364 fs_devices->missing_devices++;
5365 spin_lock_init(&device->io_lock);
5366 INIT_LIST_HEAD(&device->dev_alloc_list);
5367 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
5368 return device;
5369 }
5370
5371 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5372 struct extent_buffer *leaf,
5373 struct btrfs_chunk *chunk)
5374 {
5375 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5376 struct map_lookup *map;
5377 struct extent_map *em;
5378 u64 logical;
5379 u64 length;
5380 u64 devid;
5381 u8 uuid[BTRFS_UUID_SIZE];
5382 int num_stripes;
5383 int ret;
5384 int i;
5385
5386 logical = key->offset;
5387 length = btrfs_chunk_length(leaf, chunk);
5388
5389 read_lock(&map_tree->map_tree.lock);
5390 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5391 read_unlock(&map_tree->map_tree.lock);
5392
5393 /* already mapped? */
5394 if (em && em->start <= logical && em->start + em->len > logical) {
5395 free_extent_map(em);
5396 return 0;
5397 } else if (em) {
5398 free_extent_map(em);
5399 }
5400
5401 em = alloc_extent_map();
5402 if (!em)
5403 return -ENOMEM;
5404 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5405 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5406 if (!map) {
5407 free_extent_map(em);
5408 return -ENOMEM;
5409 }
5410
5411 em->bdev = (struct block_device *)map;
5412 em->start = logical;
5413 em->len = length;
5414 em->orig_start = 0;
5415 em->block_start = 0;
5416 em->block_len = em->len;
5417
5418 map->num_stripes = num_stripes;
5419 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5420 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5421 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5422 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5423 map->type = btrfs_chunk_type(leaf, chunk);
5424 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5425 for (i = 0; i < num_stripes; i++) {
5426 map->stripes[i].physical =
5427 btrfs_stripe_offset_nr(leaf, chunk, i);
5428 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5429 read_extent_buffer(leaf, uuid, (unsigned long)
5430 btrfs_stripe_dev_uuid_nr(chunk, i),
5431 BTRFS_UUID_SIZE);
5432 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5433 uuid, NULL);
5434 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5435 kfree(map);
5436 free_extent_map(em);
5437 return -EIO;
5438 }
5439 if (!map->stripes[i].dev) {
5440 map->stripes[i].dev =
5441 add_missing_dev(root, devid, uuid);
5442 if (!map->stripes[i].dev) {
5443 kfree(map);
5444 free_extent_map(em);
5445 return -EIO;
5446 }
5447 }
5448 map->stripes[i].dev->in_fs_metadata = 1;
5449 }
5450
5451 write_lock(&map_tree->map_tree.lock);
5452 ret = add_extent_mapping(&map_tree->map_tree, em);
5453 write_unlock(&map_tree->map_tree.lock);
5454 BUG_ON(ret); /* Tree corruption */
5455 free_extent_map(em);
5456
5457 return 0;
5458 }
5459
5460 static void fill_device_from_item(struct extent_buffer *leaf,
5461 struct btrfs_dev_item *dev_item,
5462 struct btrfs_device *device)
5463 {
5464 unsigned long ptr;
5465
5466 device->devid = btrfs_device_id(leaf, dev_item);
5467 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5468 device->total_bytes = device->disk_total_bytes;
5469 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5470 device->type = btrfs_device_type(leaf, dev_item);
5471 device->io_align = btrfs_device_io_align(leaf, dev_item);
5472 device->io_width = btrfs_device_io_width(leaf, dev_item);
5473 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5474 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5475 device->is_tgtdev_for_dev_replace = 0;
5476
5477 ptr = (unsigned long)btrfs_device_uuid(dev_item);
5478 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5479 }
5480
5481 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5482 {
5483 struct btrfs_fs_devices *fs_devices;
5484 int ret;
5485
5486 BUG_ON(!mutex_is_locked(&uuid_mutex));
5487
5488 fs_devices = root->fs_info->fs_devices->seed;
5489 while (fs_devices) {
5490 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5491 ret = 0;
5492 goto out;
5493 }
5494 fs_devices = fs_devices->seed;
5495 }
5496
5497 fs_devices = find_fsid(fsid);
5498 if (!fs_devices) {
5499 ret = -ENOENT;
5500 goto out;
5501 }
5502
5503 fs_devices = clone_fs_devices(fs_devices);
5504 if (IS_ERR(fs_devices)) {
5505 ret = PTR_ERR(fs_devices);
5506 goto out;
5507 }
5508
5509 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5510 root->fs_info->bdev_holder);
5511 if (ret) {
5512 free_fs_devices(fs_devices);
5513 goto out;
5514 }
5515
5516 if (!fs_devices->seeding) {
5517 __btrfs_close_devices(fs_devices);
5518 free_fs_devices(fs_devices);
5519 ret = -EINVAL;
5520 goto out;
5521 }
5522
5523 fs_devices->seed = root->fs_info->fs_devices->seed;
5524 root->fs_info->fs_devices->seed = fs_devices;
5525 out:
5526 return ret;
5527 }
5528
5529 static int read_one_dev(struct btrfs_root *root,
5530 struct extent_buffer *leaf,
5531 struct btrfs_dev_item *dev_item)
5532 {
5533 struct btrfs_device *device;
5534 u64 devid;
5535 int ret;
5536 u8 fs_uuid[BTRFS_UUID_SIZE];
5537 u8 dev_uuid[BTRFS_UUID_SIZE];
5538
5539 devid = btrfs_device_id(leaf, dev_item);
5540 read_extent_buffer(leaf, dev_uuid,
5541 (unsigned long)btrfs_device_uuid(dev_item),
5542 BTRFS_UUID_SIZE);
5543 read_extent_buffer(leaf, fs_uuid,
5544 (unsigned long)btrfs_device_fsid(dev_item),
5545 BTRFS_UUID_SIZE);
5546
5547 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5548 ret = open_seed_devices(root, fs_uuid);
5549 if (ret && !btrfs_test_opt(root, DEGRADED))
5550 return ret;
5551 }
5552
5553 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5554 if (!device || !device->bdev) {
5555 if (!btrfs_test_opt(root, DEGRADED))
5556 return -EIO;
5557
5558 if (!device) {
5559 printk(KERN_WARNING "warning devid %llu missing\n",
5560 (unsigned long long)devid);
5561 device = add_missing_dev(root, devid, dev_uuid);
5562 if (!device)
5563 return -ENOMEM;
5564 } else if (!device->missing) {
5565 /*
5566 * this happens when a device that was properly setup
5567 * in the device info lists suddenly goes bad.
5568 * device->bdev is NULL, and so we have to set
5569 * device->missing to one here
5570 */
5571 root->fs_info->fs_devices->missing_devices++;
5572 device->missing = 1;
5573 }
5574 }
5575
5576 if (device->fs_devices != root->fs_info->fs_devices) {
5577 BUG_ON(device->writeable);
5578 if (device->generation !=
5579 btrfs_device_generation(leaf, dev_item))
5580 return -EINVAL;
5581 }
5582
5583 fill_device_from_item(leaf, dev_item, device);
5584 device->dev_root = root->fs_info->dev_root;
5585 device->in_fs_metadata = 1;
5586 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5587 device->fs_devices->total_rw_bytes += device->total_bytes;
5588 spin_lock(&root->fs_info->free_chunk_lock);
5589 root->fs_info->free_chunk_space += device->total_bytes -
5590 device->bytes_used;
5591 spin_unlock(&root->fs_info->free_chunk_lock);
5592 }
5593 ret = 0;
5594 return ret;
5595 }
5596
5597 int btrfs_read_sys_array(struct btrfs_root *root)
5598 {
5599 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5600 struct extent_buffer *sb;
5601 struct btrfs_disk_key *disk_key;
5602 struct btrfs_chunk *chunk;
5603 u8 *ptr;
5604 unsigned long sb_ptr;
5605 int ret = 0;
5606 u32 num_stripes;
5607 u32 array_size;
5608 u32 len = 0;
5609 u32 cur;
5610 struct btrfs_key key;
5611
5612 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5613 BTRFS_SUPER_INFO_SIZE);
5614 if (!sb)
5615 return -ENOMEM;
5616 btrfs_set_buffer_uptodate(sb);
5617 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5618 /*
5619 * The sb extent buffer is artifical and just used to read the system array.
5620 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5621 * pages up-to-date when the page is larger: extent does not cover the
5622 * whole page and consequently check_page_uptodate does not find all
5623 * the page's extents up-to-date (the hole beyond sb),
5624 * write_extent_buffer then triggers a WARN_ON.
5625 *
5626 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5627 * but sb spans only this function. Add an explicit SetPageUptodate call
5628 * to silence the warning eg. on PowerPC 64.
5629 */
5630 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5631 SetPageUptodate(sb->pages[0]);
5632
5633 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5634 array_size = btrfs_super_sys_array_size(super_copy);
5635
5636 ptr = super_copy->sys_chunk_array;
5637 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5638 cur = 0;
5639
5640 while (cur < array_size) {
5641 disk_key = (struct btrfs_disk_key *)ptr;
5642 btrfs_disk_key_to_cpu(&key, disk_key);
5643
5644 len = sizeof(*disk_key); ptr += len;
5645 sb_ptr += len;
5646 cur += len;
5647
5648 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5649 chunk = (struct btrfs_chunk *)sb_ptr;
5650 ret = read_one_chunk(root, &key, sb, chunk);
5651 if (ret)
5652 break;
5653 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5654 len = btrfs_chunk_item_size(num_stripes);
5655 } else {
5656 ret = -EIO;
5657 break;
5658 }
5659 ptr += len;
5660 sb_ptr += len;
5661 cur += len;
5662 }
5663 free_extent_buffer(sb);
5664 return ret;
5665 }
5666
5667 int btrfs_read_chunk_tree(struct btrfs_root *root)
5668 {
5669 struct btrfs_path *path;
5670 struct extent_buffer *leaf;
5671 struct btrfs_key key;
5672 struct btrfs_key found_key;
5673 int ret;
5674 int slot;
5675
5676 root = root->fs_info->chunk_root;
5677
5678 path = btrfs_alloc_path();
5679 if (!path)
5680 return -ENOMEM;
5681
5682 mutex_lock(&uuid_mutex);
5683 lock_chunks(root);
5684
5685 /* first we search for all of the device items, and then we
5686 * read in all of the chunk items. This way we can create chunk
5687 * mappings that reference all of the devices that are afound
5688 */
5689 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5690 key.offset = 0;
5691 key.type = 0;
5692 again:
5693 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5694 if (ret < 0)
5695 goto error;
5696 while (1) {
5697 leaf = path->nodes[0];
5698 slot = path->slots[0];
5699 if (slot >= btrfs_header_nritems(leaf)) {
5700 ret = btrfs_next_leaf(root, path);
5701 if (ret == 0)
5702 continue;
5703 if (ret < 0)
5704 goto error;
5705 break;
5706 }
5707 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5708 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5709 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
5710 break;
5711 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
5712 struct btrfs_dev_item *dev_item;
5713 dev_item = btrfs_item_ptr(leaf, slot,
5714 struct btrfs_dev_item);
5715 ret = read_one_dev(root, leaf, dev_item);
5716 if (ret)
5717 goto error;
5718 }
5719 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
5720 struct btrfs_chunk *chunk;
5721 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
5722 ret = read_one_chunk(root, &found_key, leaf, chunk);
5723 if (ret)
5724 goto error;
5725 }
5726 path->slots[0]++;
5727 }
5728 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5729 key.objectid = 0;
5730 btrfs_release_path(path);
5731 goto again;
5732 }
5733 ret = 0;
5734 error:
5735 unlock_chunks(root);
5736 mutex_unlock(&uuid_mutex);
5737
5738 btrfs_free_path(path);
5739 return ret;
5740 }
5741
5742 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
5743 {
5744 int i;
5745
5746 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5747 btrfs_dev_stat_reset(dev, i);
5748 }
5749
5750 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
5751 {
5752 struct btrfs_key key;
5753 struct btrfs_key found_key;
5754 struct btrfs_root *dev_root = fs_info->dev_root;
5755 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5756 struct extent_buffer *eb;
5757 int slot;
5758 int ret = 0;
5759 struct btrfs_device *device;
5760 struct btrfs_path *path = NULL;
5761 int i;
5762
5763 path = btrfs_alloc_path();
5764 if (!path) {
5765 ret = -ENOMEM;
5766 goto out;
5767 }
5768
5769 mutex_lock(&fs_devices->device_list_mutex);
5770 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5771 int item_size;
5772 struct btrfs_dev_stats_item *ptr;
5773
5774 key.objectid = 0;
5775 key.type = BTRFS_DEV_STATS_KEY;
5776 key.offset = device->devid;
5777 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
5778 if (ret) {
5779 __btrfs_reset_dev_stats(device);
5780 device->dev_stats_valid = 1;
5781 btrfs_release_path(path);
5782 continue;
5783 }
5784 slot = path->slots[0];
5785 eb = path->nodes[0];
5786 btrfs_item_key_to_cpu(eb, &found_key, slot);
5787 item_size = btrfs_item_size_nr(eb, slot);
5788
5789 ptr = btrfs_item_ptr(eb, slot,
5790 struct btrfs_dev_stats_item);
5791
5792 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5793 if (item_size >= (1 + i) * sizeof(__le64))
5794 btrfs_dev_stat_set(device, i,
5795 btrfs_dev_stats_value(eb, ptr, i));
5796 else
5797 btrfs_dev_stat_reset(device, i);
5798 }
5799
5800 device->dev_stats_valid = 1;
5801 btrfs_dev_stat_print_on_load(device);
5802 btrfs_release_path(path);
5803 }
5804 mutex_unlock(&fs_devices->device_list_mutex);
5805
5806 out:
5807 btrfs_free_path(path);
5808 return ret < 0 ? ret : 0;
5809 }
5810
5811 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
5812 struct btrfs_root *dev_root,
5813 struct btrfs_device *device)
5814 {
5815 struct btrfs_path *path;
5816 struct btrfs_key key;
5817 struct extent_buffer *eb;
5818 struct btrfs_dev_stats_item *ptr;
5819 int ret;
5820 int i;
5821
5822 key.objectid = 0;
5823 key.type = BTRFS_DEV_STATS_KEY;
5824 key.offset = device->devid;
5825
5826 path = btrfs_alloc_path();
5827 BUG_ON(!path);
5828 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
5829 if (ret < 0) {
5830 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
5831 ret, rcu_str_deref(device->name));
5832 goto out;
5833 }
5834
5835 if (ret == 0 &&
5836 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
5837 /* need to delete old one and insert a new one */
5838 ret = btrfs_del_item(trans, dev_root, path);
5839 if (ret != 0) {
5840 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
5841 rcu_str_deref(device->name), ret);
5842 goto out;
5843 }
5844 ret = 1;
5845 }
5846
5847 if (ret == 1) {
5848 /* need to insert a new item */
5849 btrfs_release_path(path);
5850 ret = btrfs_insert_empty_item(trans, dev_root, path,
5851 &key, sizeof(*ptr));
5852 if (ret < 0) {
5853 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
5854 rcu_str_deref(device->name), ret);
5855 goto out;
5856 }
5857 }
5858
5859 eb = path->nodes[0];
5860 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
5861 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5862 btrfs_set_dev_stats_value(eb, ptr, i,
5863 btrfs_dev_stat_read(device, i));
5864 btrfs_mark_buffer_dirty(eb);
5865
5866 out:
5867 btrfs_free_path(path);
5868 return ret;
5869 }
5870
5871 /*
5872 * called from commit_transaction. Writes all changed device stats to disk.
5873 */
5874 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
5875 struct btrfs_fs_info *fs_info)
5876 {
5877 struct btrfs_root *dev_root = fs_info->dev_root;
5878 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5879 struct btrfs_device *device;
5880 int ret = 0;
5881
5882 mutex_lock(&fs_devices->device_list_mutex);
5883 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5884 if (!device->dev_stats_valid || !device->dev_stats_dirty)
5885 continue;
5886
5887 ret = update_dev_stat_item(trans, dev_root, device);
5888 if (!ret)
5889 device->dev_stats_dirty = 0;
5890 }
5891 mutex_unlock(&fs_devices->device_list_mutex);
5892
5893 return ret;
5894 }
5895
5896 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
5897 {
5898 btrfs_dev_stat_inc(dev, index);
5899 btrfs_dev_stat_print_on_error(dev);
5900 }
5901
5902 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
5903 {
5904 if (!dev->dev_stats_valid)
5905 return;
5906 printk_ratelimited_in_rcu(KERN_ERR
5907 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5908 rcu_str_deref(dev->name),
5909 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5910 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5911 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5912 btrfs_dev_stat_read(dev,
5913 BTRFS_DEV_STAT_CORRUPTION_ERRS),
5914 btrfs_dev_stat_read(dev,
5915 BTRFS_DEV_STAT_GENERATION_ERRS));
5916 }
5917
5918 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
5919 {
5920 int i;
5921
5922 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5923 if (btrfs_dev_stat_read(dev, i) != 0)
5924 break;
5925 if (i == BTRFS_DEV_STAT_VALUES_MAX)
5926 return; /* all values == 0, suppress message */
5927
5928 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5929 rcu_str_deref(dev->name),
5930 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5931 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5932 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5933 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
5934 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
5935 }
5936
5937 int btrfs_get_dev_stats(struct btrfs_root *root,
5938 struct btrfs_ioctl_get_dev_stats *stats)
5939 {
5940 struct btrfs_device *dev;
5941 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5942 int i;
5943
5944 mutex_lock(&fs_devices->device_list_mutex);
5945 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
5946 mutex_unlock(&fs_devices->device_list_mutex);
5947
5948 if (!dev) {
5949 printk(KERN_WARNING
5950 "btrfs: get dev_stats failed, device not found\n");
5951 return -ENODEV;
5952 } else if (!dev->dev_stats_valid) {
5953 printk(KERN_WARNING
5954 "btrfs: get dev_stats failed, not yet valid\n");
5955 return -ENODEV;
5956 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
5957 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5958 if (stats->nr_items > i)
5959 stats->values[i] =
5960 btrfs_dev_stat_read_and_reset(dev, i);
5961 else
5962 btrfs_dev_stat_reset(dev, i);
5963 }
5964 } else {
5965 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5966 if (stats->nr_items > i)
5967 stats->values[i] = btrfs_dev_stat_read(dev, i);
5968 }
5969 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
5970 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
5971 return 0;
5972 }
5973
5974 int btrfs_scratch_superblock(struct btrfs_device *device)
5975 {
5976 struct buffer_head *bh;
5977 struct btrfs_super_block *disk_super;
5978
5979 bh = btrfs_read_dev_super(device->bdev);
5980 if (!bh)
5981 return -EINVAL;
5982 disk_super = (struct btrfs_super_block *)bh->b_data;
5983
5984 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
5985 set_buffer_dirty(bh);
5986 sync_dirty_buffer(bh);
5987 brelse(bh);
5988
5989 return 0;
5990 }
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