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Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[mirror_ubuntu-bionic-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 <linux/semaphore.h>
30 #include <asm/div64.h>
31 #include "ctree.h"
32 #include "extent_map.h"
33 #include "disk-io.h"
34 #include "transaction.h"
35 #include "print-tree.h"
36 #include "volumes.h"
37 #include "raid56.h"
38 #include "async-thread.h"
39 #include "check-integrity.h"
40 #include "rcu-string.h"
41 #include "math.h"
42 #include "dev-replace.h"
43
44 static int init_first_rw_device(struct btrfs_trans_handle *trans,
45 struct btrfs_root *root,
46 struct btrfs_device *device);
47 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
48 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
49 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
50 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
51
52 static DEFINE_MUTEX(uuid_mutex);
53 static LIST_HEAD(fs_uuids);
54
55 static void lock_chunks(struct btrfs_root *root)
56 {
57 mutex_lock(&root->fs_info->chunk_mutex);
58 }
59
60 static void unlock_chunks(struct btrfs_root *root)
61 {
62 mutex_unlock(&root->fs_info->chunk_mutex);
63 }
64
65 static struct btrfs_fs_devices *__alloc_fs_devices(void)
66 {
67 struct btrfs_fs_devices *fs_devs;
68
69 fs_devs = kzalloc(sizeof(*fs_devs), GFP_NOFS);
70 if (!fs_devs)
71 return ERR_PTR(-ENOMEM);
72
73 mutex_init(&fs_devs->device_list_mutex);
74
75 INIT_LIST_HEAD(&fs_devs->devices);
76 INIT_LIST_HEAD(&fs_devs->alloc_list);
77 INIT_LIST_HEAD(&fs_devs->list);
78
79 return fs_devs;
80 }
81
82 /**
83 * alloc_fs_devices - allocate struct btrfs_fs_devices
84 * @fsid: a pointer to UUID for this FS. If NULL a new UUID is
85 * generated.
86 *
87 * Return: a pointer to a new &struct btrfs_fs_devices on success;
88 * ERR_PTR() on error. Returned struct is not linked onto any lists and
89 * can be destroyed with kfree() right away.
90 */
91 static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid)
92 {
93 struct btrfs_fs_devices *fs_devs;
94
95 fs_devs = __alloc_fs_devices();
96 if (IS_ERR(fs_devs))
97 return fs_devs;
98
99 if (fsid)
100 memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
101 else
102 generate_random_uuid(fs_devs->fsid);
103
104 return fs_devs;
105 }
106
107 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
108 {
109 struct btrfs_device *device;
110 WARN_ON(fs_devices->opened);
111 while (!list_empty(&fs_devices->devices)) {
112 device = list_entry(fs_devices->devices.next,
113 struct btrfs_device, dev_list);
114 list_del(&device->dev_list);
115 rcu_string_free(device->name);
116 kfree(device);
117 }
118 kfree(fs_devices);
119 }
120
121 static void btrfs_kobject_uevent(struct block_device *bdev,
122 enum kobject_action action)
123 {
124 int ret;
125
126 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
127 if (ret)
128 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
129 action,
130 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
131 &disk_to_dev(bdev->bd_disk)->kobj);
132 }
133
134 void btrfs_cleanup_fs_uuids(void)
135 {
136 struct btrfs_fs_devices *fs_devices;
137
138 while (!list_empty(&fs_uuids)) {
139 fs_devices = list_entry(fs_uuids.next,
140 struct btrfs_fs_devices, list);
141 list_del(&fs_devices->list);
142 free_fs_devices(fs_devices);
143 }
144 }
145
146 static struct btrfs_device *__alloc_device(void)
147 {
148 struct btrfs_device *dev;
149
150 dev = kzalloc(sizeof(*dev), GFP_NOFS);
151 if (!dev)
152 return ERR_PTR(-ENOMEM);
153
154 INIT_LIST_HEAD(&dev->dev_list);
155 INIT_LIST_HEAD(&dev->dev_alloc_list);
156
157 spin_lock_init(&dev->io_lock);
158
159 spin_lock_init(&dev->reada_lock);
160 atomic_set(&dev->reada_in_flight, 0);
161 INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
162 INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);
163
164 return dev;
165 }
166
167 static noinline struct btrfs_device *__find_device(struct list_head *head,
168 u64 devid, u8 *uuid)
169 {
170 struct btrfs_device *dev;
171
172 list_for_each_entry(dev, head, dev_list) {
173 if (dev->devid == devid &&
174 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
175 return dev;
176 }
177 }
178 return NULL;
179 }
180
181 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
182 {
183 struct btrfs_fs_devices *fs_devices;
184
185 list_for_each_entry(fs_devices, &fs_uuids, list) {
186 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
187 return fs_devices;
188 }
189 return NULL;
190 }
191
192 static int
193 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
194 int flush, struct block_device **bdev,
195 struct buffer_head **bh)
196 {
197 int ret;
198
199 *bdev = blkdev_get_by_path(device_path, flags, holder);
200
201 if (IS_ERR(*bdev)) {
202 ret = PTR_ERR(*bdev);
203 printk(KERN_INFO "BTRFS: open %s failed\n", device_path);
204 goto error;
205 }
206
207 if (flush)
208 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
209 ret = set_blocksize(*bdev, 4096);
210 if (ret) {
211 blkdev_put(*bdev, flags);
212 goto error;
213 }
214 invalidate_bdev(*bdev);
215 *bh = btrfs_read_dev_super(*bdev);
216 if (!*bh) {
217 ret = -EINVAL;
218 blkdev_put(*bdev, flags);
219 goto error;
220 }
221
222 return 0;
223
224 error:
225 *bdev = NULL;
226 *bh = NULL;
227 return ret;
228 }
229
230 static void requeue_list(struct btrfs_pending_bios *pending_bios,
231 struct bio *head, struct bio *tail)
232 {
233
234 struct bio *old_head;
235
236 old_head = pending_bios->head;
237 pending_bios->head = head;
238 if (pending_bios->tail)
239 tail->bi_next = old_head;
240 else
241 pending_bios->tail = tail;
242 }
243
244 /*
245 * we try to collect pending bios for a device so we don't get a large
246 * number of procs sending bios down to the same device. This greatly
247 * improves the schedulers ability to collect and merge the bios.
248 *
249 * But, it also turns into a long list of bios to process and that is sure
250 * to eventually make the worker thread block. The solution here is to
251 * make some progress and then put this work struct back at the end of
252 * the list if the block device is congested. This way, multiple devices
253 * can make progress from a single worker thread.
254 */
255 static noinline void run_scheduled_bios(struct btrfs_device *device)
256 {
257 struct bio *pending;
258 struct backing_dev_info *bdi;
259 struct btrfs_fs_info *fs_info;
260 struct btrfs_pending_bios *pending_bios;
261 struct bio *tail;
262 struct bio *cur;
263 int again = 0;
264 unsigned long num_run;
265 unsigned long batch_run = 0;
266 unsigned long limit;
267 unsigned long last_waited = 0;
268 int force_reg = 0;
269 int sync_pending = 0;
270 struct blk_plug plug;
271
272 /*
273 * this function runs all the bios we've collected for
274 * a particular device. We don't want to wander off to
275 * another device without first sending all of these down.
276 * So, setup a plug here and finish it off before we return
277 */
278 blk_start_plug(&plug);
279
280 bdi = blk_get_backing_dev_info(device->bdev);
281 fs_info = device->dev_root->fs_info;
282 limit = btrfs_async_submit_limit(fs_info);
283 limit = limit * 2 / 3;
284
285 loop:
286 spin_lock(&device->io_lock);
287
288 loop_lock:
289 num_run = 0;
290
291 /* take all the bios off the list at once and process them
292 * later on (without the lock held). But, remember the
293 * tail and other pointers so the bios can be properly reinserted
294 * into the list if we hit congestion
295 */
296 if (!force_reg && device->pending_sync_bios.head) {
297 pending_bios = &device->pending_sync_bios;
298 force_reg = 1;
299 } else {
300 pending_bios = &device->pending_bios;
301 force_reg = 0;
302 }
303
304 pending = pending_bios->head;
305 tail = pending_bios->tail;
306 WARN_ON(pending && !tail);
307
308 /*
309 * if pending was null this time around, no bios need processing
310 * at all and we can stop. Otherwise it'll loop back up again
311 * and do an additional check so no bios are missed.
312 *
313 * device->running_pending is used to synchronize with the
314 * schedule_bio code.
315 */
316 if (device->pending_sync_bios.head == NULL &&
317 device->pending_bios.head == NULL) {
318 again = 0;
319 device->running_pending = 0;
320 } else {
321 again = 1;
322 device->running_pending = 1;
323 }
324
325 pending_bios->head = NULL;
326 pending_bios->tail = NULL;
327
328 spin_unlock(&device->io_lock);
329
330 while (pending) {
331
332 rmb();
333 /* we want to work on both lists, but do more bios on the
334 * sync list than the regular list
335 */
336 if ((num_run > 32 &&
337 pending_bios != &device->pending_sync_bios &&
338 device->pending_sync_bios.head) ||
339 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
340 device->pending_bios.head)) {
341 spin_lock(&device->io_lock);
342 requeue_list(pending_bios, pending, tail);
343 goto loop_lock;
344 }
345
346 cur = pending;
347 pending = pending->bi_next;
348 cur->bi_next = NULL;
349
350 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
351 waitqueue_active(&fs_info->async_submit_wait))
352 wake_up(&fs_info->async_submit_wait);
353
354 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
355
356 /*
357 * if we're doing the sync list, record that our
358 * plug has some sync requests on it
359 *
360 * If we're doing the regular list and there are
361 * sync requests sitting around, unplug before
362 * we add more
363 */
364 if (pending_bios == &device->pending_sync_bios) {
365 sync_pending = 1;
366 } else if (sync_pending) {
367 blk_finish_plug(&plug);
368 blk_start_plug(&plug);
369 sync_pending = 0;
370 }
371
372 btrfsic_submit_bio(cur->bi_rw, cur);
373 num_run++;
374 batch_run++;
375 if (need_resched())
376 cond_resched();
377
378 /*
379 * we made progress, there is more work to do and the bdi
380 * is now congested. Back off and let other work structs
381 * run instead
382 */
383 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
384 fs_info->fs_devices->open_devices > 1) {
385 struct io_context *ioc;
386
387 ioc = current->io_context;
388
389 /*
390 * the main goal here is that we don't want to
391 * block if we're going to be able to submit
392 * more requests without blocking.
393 *
394 * This code does two great things, it pokes into
395 * the elevator code from a filesystem _and_
396 * it makes assumptions about how batching works.
397 */
398 if (ioc && ioc->nr_batch_requests > 0 &&
399 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
400 (last_waited == 0 ||
401 ioc->last_waited == last_waited)) {
402 /*
403 * we want to go through our batch of
404 * requests and stop. So, we copy out
405 * the ioc->last_waited time and test
406 * against it before looping
407 */
408 last_waited = ioc->last_waited;
409 if (need_resched())
410 cond_resched();
411 continue;
412 }
413 spin_lock(&device->io_lock);
414 requeue_list(pending_bios, pending, tail);
415 device->running_pending = 1;
416
417 spin_unlock(&device->io_lock);
418 btrfs_requeue_work(&device->work);
419 goto done;
420 }
421 /* unplug every 64 requests just for good measure */
422 if (batch_run % 64 == 0) {
423 blk_finish_plug(&plug);
424 blk_start_plug(&plug);
425 sync_pending = 0;
426 }
427 }
428
429 cond_resched();
430 if (again)
431 goto loop;
432
433 spin_lock(&device->io_lock);
434 if (device->pending_bios.head || device->pending_sync_bios.head)
435 goto loop_lock;
436 spin_unlock(&device->io_lock);
437
438 done:
439 blk_finish_plug(&plug);
440 }
441
442 static void pending_bios_fn(struct btrfs_work *work)
443 {
444 struct btrfs_device *device;
445
446 device = container_of(work, struct btrfs_device, work);
447 run_scheduled_bios(device);
448 }
449
450 static noinline int device_list_add(const char *path,
451 struct btrfs_super_block *disk_super,
452 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
453 {
454 struct btrfs_device *device;
455 struct btrfs_fs_devices *fs_devices;
456 struct rcu_string *name;
457 u64 found_transid = btrfs_super_generation(disk_super);
458
459 fs_devices = find_fsid(disk_super->fsid);
460 if (!fs_devices) {
461 fs_devices = alloc_fs_devices(disk_super->fsid);
462 if (IS_ERR(fs_devices))
463 return PTR_ERR(fs_devices);
464
465 list_add(&fs_devices->list, &fs_uuids);
466 fs_devices->latest_devid = devid;
467 fs_devices->latest_trans = found_transid;
468
469 device = NULL;
470 } else {
471 device = __find_device(&fs_devices->devices, devid,
472 disk_super->dev_item.uuid);
473 }
474 if (!device) {
475 if (fs_devices->opened)
476 return -EBUSY;
477
478 device = btrfs_alloc_device(NULL, &devid,
479 disk_super->dev_item.uuid);
480 if (IS_ERR(device)) {
481 /* we can safely leave the fs_devices entry around */
482 return PTR_ERR(device);
483 }
484
485 name = rcu_string_strdup(path, GFP_NOFS);
486 if (!name) {
487 kfree(device);
488 return -ENOMEM;
489 }
490 rcu_assign_pointer(device->name, name);
491
492 mutex_lock(&fs_devices->device_list_mutex);
493 list_add_rcu(&device->dev_list, &fs_devices->devices);
494 fs_devices->num_devices++;
495 mutex_unlock(&fs_devices->device_list_mutex);
496
497 device->fs_devices = fs_devices;
498 } else if (!device->name || strcmp(device->name->str, path)) {
499 name = rcu_string_strdup(path, GFP_NOFS);
500 if (!name)
501 return -ENOMEM;
502 rcu_string_free(device->name);
503 rcu_assign_pointer(device->name, name);
504 if (device->missing) {
505 fs_devices->missing_devices--;
506 device->missing = 0;
507 }
508 }
509
510 if (found_transid > fs_devices->latest_trans) {
511 fs_devices->latest_devid = devid;
512 fs_devices->latest_trans = found_transid;
513 }
514 *fs_devices_ret = fs_devices;
515 return 0;
516 }
517
518 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
519 {
520 struct btrfs_fs_devices *fs_devices;
521 struct btrfs_device *device;
522 struct btrfs_device *orig_dev;
523
524 fs_devices = alloc_fs_devices(orig->fsid);
525 if (IS_ERR(fs_devices))
526 return fs_devices;
527
528 fs_devices->latest_devid = orig->latest_devid;
529 fs_devices->latest_trans = orig->latest_trans;
530 fs_devices->total_devices = orig->total_devices;
531
532 /* We have held the volume lock, it is safe to get the devices. */
533 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
534 struct rcu_string *name;
535
536 device = btrfs_alloc_device(NULL, &orig_dev->devid,
537 orig_dev->uuid);
538 if (IS_ERR(device))
539 goto error;
540
541 /*
542 * This is ok to do without rcu read locked because we hold the
543 * uuid mutex so nothing we touch in here is going to disappear.
544 */
545 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
546 if (!name) {
547 kfree(device);
548 goto error;
549 }
550 rcu_assign_pointer(device->name, name);
551
552 list_add(&device->dev_list, &fs_devices->devices);
553 device->fs_devices = fs_devices;
554 fs_devices->num_devices++;
555 }
556 return fs_devices;
557 error:
558 free_fs_devices(fs_devices);
559 return ERR_PTR(-ENOMEM);
560 }
561
562 void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
563 struct btrfs_fs_devices *fs_devices, int step)
564 {
565 struct btrfs_device *device, *next;
566
567 struct block_device *latest_bdev = NULL;
568 u64 latest_devid = 0;
569 u64 latest_transid = 0;
570
571 mutex_lock(&uuid_mutex);
572 again:
573 /* This is the initialized path, it is safe to release the devices. */
574 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
575 if (device->in_fs_metadata) {
576 if (!device->is_tgtdev_for_dev_replace &&
577 (!latest_transid ||
578 device->generation > latest_transid)) {
579 latest_devid = device->devid;
580 latest_transid = device->generation;
581 latest_bdev = device->bdev;
582 }
583 continue;
584 }
585
586 if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
587 /*
588 * In the first step, keep the device which has
589 * the correct fsid and the devid that is used
590 * for the dev_replace procedure.
591 * In the second step, the dev_replace state is
592 * read from the device tree and it is known
593 * whether the procedure is really active or
594 * not, which means whether this device is
595 * used or whether it should be removed.
596 */
597 if (step == 0 || device->is_tgtdev_for_dev_replace) {
598 continue;
599 }
600 }
601 if (device->bdev) {
602 blkdev_put(device->bdev, device->mode);
603 device->bdev = NULL;
604 fs_devices->open_devices--;
605 }
606 if (device->writeable) {
607 list_del_init(&device->dev_alloc_list);
608 device->writeable = 0;
609 if (!device->is_tgtdev_for_dev_replace)
610 fs_devices->rw_devices--;
611 }
612 list_del_init(&device->dev_list);
613 fs_devices->num_devices--;
614 rcu_string_free(device->name);
615 kfree(device);
616 }
617
618 if (fs_devices->seed) {
619 fs_devices = fs_devices->seed;
620 goto again;
621 }
622
623 fs_devices->latest_bdev = latest_bdev;
624 fs_devices->latest_devid = latest_devid;
625 fs_devices->latest_trans = latest_transid;
626
627 mutex_unlock(&uuid_mutex);
628 }
629
630 static void __free_device(struct work_struct *work)
631 {
632 struct btrfs_device *device;
633
634 device = container_of(work, struct btrfs_device, rcu_work);
635
636 if (device->bdev)
637 blkdev_put(device->bdev, device->mode);
638
639 rcu_string_free(device->name);
640 kfree(device);
641 }
642
643 static void free_device(struct rcu_head *head)
644 {
645 struct btrfs_device *device;
646
647 device = container_of(head, struct btrfs_device, rcu);
648
649 INIT_WORK(&device->rcu_work, __free_device);
650 schedule_work(&device->rcu_work);
651 }
652
653 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
654 {
655 struct btrfs_device *device;
656
657 if (--fs_devices->opened > 0)
658 return 0;
659
660 mutex_lock(&fs_devices->device_list_mutex);
661 list_for_each_entry(device, &fs_devices->devices, dev_list) {
662 struct btrfs_device *new_device;
663 struct rcu_string *name;
664
665 if (device->bdev)
666 fs_devices->open_devices--;
667
668 if (device->writeable &&
669 device->devid != BTRFS_DEV_REPLACE_DEVID) {
670 list_del_init(&device->dev_alloc_list);
671 fs_devices->rw_devices--;
672 }
673
674 if (device->can_discard)
675 fs_devices->num_can_discard--;
676 if (device->missing)
677 fs_devices->missing_devices--;
678
679 new_device = btrfs_alloc_device(NULL, &device->devid,
680 device->uuid);
681 BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
682
683 /* Safe because we are under uuid_mutex */
684 if (device->name) {
685 name = rcu_string_strdup(device->name->str, GFP_NOFS);
686 BUG_ON(!name); /* -ENOMEM */
687 rcu_assign_pointer(new_device->name, name);
688 }
689
690 list_replace_rcu(&device->dev_list, &new_device->dev_list);
691 new_device->fs_devices = device->fs_devices;
692
693 call_rcu(&device->rcu, free_device);
694 }
695 mutex_unlock(&fs_devices->device_list_mutex);
696
697 WARN_ON(fs_devices->open_devices);
698 WARN_ON(fs_devices->rw_devices);
699 fs_devices->opened = 0;
700 fs_devices->seeding = 0;
701
702 return 0;
703 }
704
705 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
706 {
707 struct btrfs_fs_devices *seed_devices = NULL;
708 int ret;
709
710 mutex_lock(&uuid_mutex);
711 ret = __btrfs_close_devices(fs_devices);
712 if (!fs_devices->opened) {
713 seed_devices = fs_devices->seed;
714 fs_devices->seed = NULL;
715 }
716 mutex_unlock(&uuid_mutex);
717
718 while (seed_devices) {
719 fs_devices = seed_devices;
720 seed_devices = fs_devices->seed;
721 __btrfs_close_devices(fs_devices);
722 free_fs_devices(fs_devices);
723 }
724 /*
725 * Wait for rcu kworkers under __btrfs_close_devices
726 * to finish all blkdev_puts so device is really
727 * free when umount is done.
728 */
729 rcu_barrier();
730 return ret;
731 }
732
733 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
734 fmode_t flags, void *holder)
735 {
736 struct request_queue *q;
737 struct block_device *bdev;
738 struct list_head *head = &fs_devices->devices;
739 struct btrfs_device *device;
740 struct block_device *latest_bdev = NULL;
741 struct buffer_head *bh;
742 struct btrfs_super_block *disk_super;
743 u64 latest_devid = 0;
744 u64 latest_transid = 0;
745 u64 devid;
746 int seeding = 1;
747 int ret = 0;
748
749 flags |= FMODE_EXCL;
750
751 list_for_each_entry(device, head, dev_list) {
752 if (device->bdev)
753 continue;
754 if (!device->name)
755 continue;
756
757 /* Just open everything we can; ignore failures here */
758 if (btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
759 &bdev, &bh))
760 continue;
761
762 disk_super = (struct btrfs_super_block *)bh->b_data;
763 devid = btrfs_stack_device_id(&disk_super->dev_item);
764 if (devid != device->devid)
765 goto error_brelse;
766
767 if (memcmp(device->uuid, disk_super->dev_item.uuid,
768 BTRFS_UUID_SIZE))
769 goto error_brelse;
770
771 device->generation = btrfs_super_generation(disk_super);
772 if (!latest_transid || device->generation > latest_transid) {
773 latest_devid = devid;
774 latest_transid = device->generation;
775 latest_bdev = bdev;
776 }
777
778 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
779 device->writeable = 0;
780 } else {
781 device->writeable = !bdev_read_only(bdev);
782 seeding = 0;
783 }
784
785 q = bdev_get_queue(bdev);
786 if (blk_queue_discard(q)) {
787 device->can_discard = 1;
788 fs_devices->num_can_discard++;
789 }
790
791 device->bdev = bdev;
792 device->in_fs_metadata = 0;
793 device->mode = flags;
794
795 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
796 fs_devices->rotating = 1;
797
798 fs_devices->open_devices++;
799 if (device->writeable &&
800 device->devid != BTRFS_DEV_REPLACE_DEVID) {
801 fs_devices->rw_devices++;
802 list_add(&device->dev_alloc_list,
803 &fs_devices->alloc_list);
804 }
805 brelse(bh);
806 continue;
807
808 error_brelse:
809 brelse(bh);
810 blkdev_put(bdev, flags);
811 continue;
812 }
813 if (fs_devices->open_devices == 0) {
814 ret = -EINVAL;
815 goto out;
816 }
817 fs_devices->seeding = seeding;
818 fs_devices->opened = 1;
819 fs_devices->latest_bdev = latest_bdev;
820 fs_devices->latest_devid = latest_devid;
821 fs_devices->latest_trans = latest_transid;
822 fs_devices->total_rw_bytes = 0;
823 out:
824 return ret;
825 }
826
827 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
828 fmode_t flags, void *holder)
829 {
830 int ret;
831
832 mutex_lock(&uuid_mutex);
833 if (fs_devices->opened) {
834 fs_devices->opened++;
835 ret = 0;
836 } else {
837 ret = __btrfs_open_devices(fs_devices, flags, holder);
838 }
839 mutex_unlock(&uuid_mutex);
840 return ret;
841 }
842
843 /*
844 * Look for a btrfs signature on a device. This may be called out of the mount path
845 * and we are not allowed to call set_blocksize during the scan. The superblock
846 * is read via pagecache
847 */
848 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
849 struct btrfs_fs_devices **fs_devices_ret)
850 {
851 struct btrfs_super_block *disk_super;
852 struct block_device *bdev;
853 struct page *page;
854 void *p;
855 int ret = -EINVAL;
856 u64 devid;
857 u64 transid;
858 u64 total_devices;
859 u64 bytenr;
860 pgoff_t index;
861
862 /*
863 * we would like to check all the supers, but that would make
864 * a btrfs mount succeed after a mkfs from a different FS.
865 * So, we need to add a special mount option to scan for
866 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
867 */
868 bytenr = btrfs_sb_offset(0);
869 flags |= FMODE_EXCL;
870 mutex_lock(&uuid_mutex);
871
872 bdev = blkdev_get_by_path(path, flags, holder);
873
874 if (IS_ERR(bdev)) {
875 ret = PTR_ERR(bdev);
876 goto error;
877 }
878
879 /* make sure our super fits in the device */
880 if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
881 goto error_bdev_put;
882
883 /* make sure our super fits in the page */
884 if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
885 goto error_bdev_put;
886
887 /* make sure our super doesn't straddle pages on disk */
888 index = bytenr >> PAGE_CACHE_SHIFT;
889 if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
890 goto error_bdev_put;
891
892 /* pull in the page with our super */
893 page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
894 index, GFP_NOFS);
895
896 if (IS_ERR_OR_NULL(page))
897 goto error_bdev_put;
898
899 p = kmap(page);
900
901 /* align our pointer to the offset of the super block */
902 disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
903
904 if (btrfs_super_bytenr(disk_super) != bytenr ||
905 btrfs_super_magic(disk_super) != BTRFS_MAGIC)
906 goto error_unmap;
907
908 devid = btrfs_stack_device_id(&disk_super->dev_item);
909 transid = btrfs_super_generation(disk_super);
910 total_devices = btrfs_super_num_devices(disk_super);
911
912 if (disk_super->label[0]) {
913 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
914 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
915 printk(KERN_INFO "BTRFS: device label %s ", disk_super->label);
916 } else {
917 printk(KERN_INFO "BTRFS: device fsid %pU ", disk_super->fsid);
918 }
919
920 printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
921
922 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
923 if (!ret && fs_devices_ret)
924 (*fs_devices_ret)->total_devices = total_devices;
925
926 error_unmap:
927 kunmap(page);
928 page_cache_release(page);
929
930 error_bdev_put:
931 blkdev_put(bdev, flags);
932 error:
933 mutex_unlock(&uuid_mutex);
934 return ret;
935 }
936
937 /* helper to account the used device space in the range */
938 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
939 u64 end, u64 *length)
940 {
941 struct btrfs_key key;
942 struct btrfs_root *root = device->dev_root;
943 struct btrfs_dev_extent *dev_extent;
944 struct btrfs_path *path;
945 u64 extent_end;
946 int ret;
947 int slot;
948 struct extent_buffer *l;
949
950 *length = 0;
951
952 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
953 return 0;
954
955 path = btrfs_alloc_path();
956 if (!path)
957 return -ENOMEM;
958 path->reada = 2;
959
960 key.objectid = device->devid;
961 key.offset = start;
962 key.type = BTRFS_DEV_EXTENT_KEY;
963
964 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
965 if (ret < 0)
966 goto out;
967 if (ret > 0) {
968 ret = btrfs_previous_item(root, path, key.objectid, key.type);
969 if (ret < 0)
970 goto out;
971 }
972
973 while (1) {
974 l = path->nodes[0];
975 slot = path->slots[0];
976 if (slot >= btrfs_header_nritems(l)) {
977 ret = btrfs_next_leaf(root, path);
978 if (ret == 0)
979 continue;
980 if (ret < 0)
981 goto out;
982
983 break;
984 }
985 btrfs_item_key_to_cpu(l, &key, slot);
986
987 if (key.objectid < device->devid)
988 goto next;
989
990 if (key.objectid > device->devid)
991 break;
992
993 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
994 goto next;
995
996 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
997 extent_end = key.offset + btrfs_dev_extent_length(l,
998 dev_extent);
999 if (key.offset <= start && extent_end > end) {
1000 *length = end - start + 1;
1001 break;
1002 } else if (key.offset <= start && extent_end > start)
1003 *length += extent_end - start;
1004 else if (key.offset > start && extent_end <= end)
1005 *length += extent_end - key.offset;
1006 else if (key.offset > start && key.offset <= end) {
1007 *length += end - key.offset + 1;
1008 break;
1009 } else if (key.offset > end)
1010 break;
1011
1012 next:
1013 path->slots[0]++;
1014 }
1015 ret = 0;
1016 out:
1017 btrfs_free_path(path);
1018 return ret;
1019 }
1020
1021 static int contains_pending_extent(struct btrfs_trans_handle *trans,
1022 struct btrfs_device *device,
1023 u64 *start, u64 len)
1024 {
1025 struct extent_map *em;
1026 int ret = 0;
1027
1028 list_for_each_entry(em, &trans->transaction->pending_chunks, list) {
1029 struct map_lookup *map;
1030 int i;
1031
1032 map = (struct map_lookup *)em->bdev;
1033 for (i = 0; i < map->num_stripes; i++) {
1034 if (map->stripes[i].dev != device)
1035 continue;
1036 if (map->stripes[i].physical >= *start + len ||
1037 map->stripes[i].physical + em->orig_block_len <=
1038 *start)
1039 continue;
1040 *start = map->stripes[i].physical +
1041 em->orig_block_len;
1042 ret = 1;
1043 }
1044 }
1045
1046 return ret;
1047 }
1048
1049
1050 /*
1051 * find_free_dev_extent - find free space in the specified device
1052 * @device: the device which we search the free space in
1053 * @num_bytes: the size of the free space that we need
1054 * @start: store the start of the free space.
1055 * @len: the size of the free space. that we find, or the size of the max
1056 * free space if we don't find suitable free space
1057 *
1058 * this uses a pretty simple search, the expectation is that it is
1059 * called very infrequently and that a given device has a small number
1060 * of extents
1061 *
1062 * @start is used to store the start of the free space if we find. But if we
1063 * don't find suitable free space, it will be used to store the start position
1064 * of the max free space.
1065 *
1066 * @len is used to store the size of the free space that we find.
1067 * But if we don't find suitable free space, it is used to store the size of
1068 * the max free space.
1069 */
1070 int find_free_dev_extent(struct btrfs_trans_handle *trans,
1071 struct btrfs_device *device, u64 num_bytes,
1072 u64 *start, u64 *len)
1073 {
1074 struct btrfs_key key;
1075 struct btrfs_root *root = device->dev_root;
1076 struct btrfs_dev_extent *dev_extent;
1077 struct btrfs_path *path;
1078 u64 hole_size;
1079 u64 max_hole_start;
1080 u64 max_hole_size;
1081 u64 extent_end;
1082 u64 search_start;
1083 u64 search_end = device->total_bytes;
1084 int ret;
1085 int slot;
1086 struct extent_buffer *l;
1087
1088 /* FIXME use last free of some kind */
1089
1090 /* we don't want to overwrite the superblock on the drive,
1091 * so we make sure to start at an offset of at least 1MB
1092 */
1093 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1094
1095 path = btrfs_alloc_path();
1096 if (!path)
1097 return -ENOMEM;
1098 again:
1099 max_hole_start = search_start;
1100 max_hole_size = 0;
1101 hole_size = 0;
1102
1103 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1104 ret = -ENOSPC;
1105 goto out;
1106 }
1107
1108 path->reada = 2;
1109 path->search_commit_root = 1;
1110 path->skip_locking = 1;
1111
1112 key.objectid = device->devid;
1113 key.offset = search_start;
1114 key.type = BTRFS_DEV_EXTENT_KEY;
1115
1116 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1117 if (ret < 0)
1118 goto out;
1119 if (ret > 0) {
1120 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1121 if (ret < 0)
1122 goto out;
1123 }
1124
1125 while (1) {
1126 l = path->nodes[0];
1127 slot = path->slots[0];
1128 if (slot >= btrfs_header_nritems(l)) {
1129 ret = btrfs_next_leaf(root, path);
1130 if (ret == 0)
1131 continue;
1132 if (ret < 0)
1133 goto out;
1134
1135 break;
1136 }
1137 btrfs_item_key_to_cpu(l, &key, slot);
1138
1139 if (key.objectid < device->devid)
1140 goto next;
1141
1142 if (key.objectid > device->devid)
1143 break;
1144
1145 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1146 goto next;
1147
1148 if (key.offset > search_start) {
1149 hole_size = key.offset - search_start;
1150
1151 /*
1152 * Have to check before we set max_hole_start, otherwise
1153 * we could end up sending back this offset anyway.
1154 */
1155 if (contains_pending_extent(trans, device,
1156 &search_start,
1157 hole_size))
1158 hole_size = 0;
1159
1160 if (hole_size > max_hole_size) {
1161 max_hole_start = search_start;
1162 max_hole_size = hole_size;
1163 }
1164
1165 /*
1166 * If this free space is greater than which we need,
1167 * it must be the max free space that we have found
1168 * until now, so max_hole_start must point to the start
1169 * of this free space and the length of this free space
1170 * is stored in max_hole_size. Thus, we return
1171 * max_hole_start and max_hole_size and go back to the
1172 * caller.
1173 */
1174 if (hole_size >= num_bytes) {
1175 ret = 0;
1176 goto out;
1177 }
1178 }
1179
1180 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1181 extent_end = key.offset + btrfs_dev_extent_length(l,
1182 dev_extent);
1183 if (extent_end > search_start)
1184 search_start = extent_end;
1185 next:
1186 path->slots[0]++;
1187 cond_resched();
1188 }
1189
1190 /*
1191 * At this point, search_start should be the end of
1192 * allocated dev extents, and when shrinking the device,
1193 * search_end may be smaller than search_start.
1194 */
1195 if (search_end > search_start)
1196 hole_size = search_end - search_start;
1197
1198 if (hole_size > max_hole_size) {
1199 max_hole_start = search_start;
1200 max_hole_size = hole_size;
1201 }
1202
1203 if (contains_pending_extent(trans, device, &search_start, hole_size)) {
1204 btrfs_release_path(path);
1205 goto again;
1206 }
1207
1208 /* See above. */
1209 if (hole_size < num_bytes)
1210 ret = -ENOSPC;
1211 else
1212 ret = 0;
1213
1214 out:
1215 btrfs_free_path(path);
1216 *start = max_hole_start;
1217 if (len)
1218 *len = max_hole_size;
1219 return ret;
1220 }
1221
1222 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1223 struct btrfs_device *device,
1224 u64 start)
1225 {
1226 int ret;
1227 struct btrfs_path *path;
1228 struct btrfs_root *root = device->dev_root;
1229 struct btrfs_key key;
1230 struct btrfs_key found_key;
1231 struct extent_buffer *leaf = NULL;
1232 struct btrfs_dev_extent *extent = NULL;
1233
1234 path = btrfs_alloc_path();
1235 if (!path)
1236 return -ENOMEM;
1237
1238 key.objectid = device->devid;
1239 key.offset = start;
1240 key.type = BTRFS_DEV_EXTENT_KEY;
1241 again:
1242 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1243 if (ret > 0) {
1244 ret = btrfs_previous_item(root, path, key.objectid,
1245 BTRFS_DEV_EXTENT_KEY);
1246 if (ret)
1247 goto out;
1248 leaf = path->nodes[0];
1249 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1250 extent = btrfs_item_ptr(leaf, path->slots[0],
1251 struct btrfs_dev_extent);
1252 BUG_ON(found_key.offset > start || found_key.offset +
1253 btrfs_dev_extent_length(leaf, extent) < start);
1254 key = found_key;
1255 btrfs_release_path(path);
1256 goto again;
1257 } else if (ret == 0) {
1258 leaf = path->nodes[0];
1259 extent = btrfs_item_ptr(leaf, path->slots[0],
1260 struct btrfs_dev_extent);
1261 } else {
1262 btrfs_error(root->fs_info, ret, "Slot search failed");
1263 goto out;
1264 }
1265
1266 if (device->bytes_used > 0) {
1267 u64 len = btrfs_dev_extent_length(leaf, extent);
1268 device->bytes_used -= len;
1269 spin_lock(&root->fs_info->free_chunk_lock);
1270 root->fs_info->free_chunk_space += len;
1271 spin_unlock(&root->fs_info->free_chunk_lock);
1272 }
1273 ret = btrfs_del_item(trans, root, path);
1274 if (ret) {
1275 btrfs_error(root->fs_info, ret,
1276 "Failed to remove dev extent item");
1277 }
1278 out:
1279 btrfs_free_path(path);
1280 return ret;
1281 }
1282
1283 static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1284 struct btrfs_device *device,
1285 u64 chunk_tree, u64 chunk_objectid,
1286 u64 chunk_offset, u64 start, u64 num_bytes)
1287 {
1288 int ret;
1289 struct btrfs_path *path;
1290 struct btrfs_root *root = device->dev_root;
1291 struct btrfs_dev_extent *extent;
1292 struct extent_buffer *leaf;
1293 struct btrfs_key key;
1294
1295 WARN_ON(!device->in_fs_metadata);
1296 WARN_ON(device->is_tgtdev_for_dev_replace);
1297 path = btrfs_alloc_path();
1298 if (!path)
1299 return -ENOMEM;
1300
1301 key.objectid = device->devid;
1302 key.offset = start;
1303 key.type = BTRFS_DEV_EXTENT_KEY;
1304 ret = btrfs_insert_empty_item(trans, root, path, &key,
1305 sizeof(*extent));
1306 if (ret)
1307 goto out;
1308
1309 leaf = path->nodes[0];
1310 extent = btrfs_item_ptr(leaf, path->slots[0],
1311 struct btrfs_dev_extent);
1312 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1313 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1314 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1315
1316 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1317 btrfs_dev_extent_chunk_tree_uuid(extent), BTRFS_UUID_SIZE);
1318
1319 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1320 btrfs_mark_buffer_dirty(leaf);
1321 out:
1322 btrfs_free_path(path);
1323 return ret;
1324 }
1325
1326 static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
1327 {
1328 struct extent_map_tree *em_tree;
1329 struct extent_map *em;
1330 struct rb_node *n;
1331 u64 ret = 0;
1332
1333 em_tree = &fs_info->mapping_tree.map_tree;
1334 read_lock(&em_tree->lock);
1335 n = rb_last(&em_tree->map);
1336 if (n) {
1337 em = rb_entry(n, struct extent_map, rb_node);
1338 ret = em->start + em->len;
1339 }
1340 read_unlock(&em_tree->lock);
1341
1342 return ret;
1343 }
1344
1345 static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
1346 u64 *devid_ret)
1347 {
1348 int ret;
1349 struct btrfs_key key;
1350 struct btrfs_key found_key;
1351 struct btrfs_path *path;
1352
1353 path = btrfs_alloc_path();
1354 if (!path)
1355 return -ENOMEM;
1356
1357 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1358 key.type = BTRFS_DEV_ITEM_KEY;
1359 key.offset = (u64)-1;
1360
1361 ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
1362 if (ret < 0)
1363 goto error;
1364
1365 BUG_ON(ret == 0); /* Corruption */
1366
1367 ret = btrfs_previous_item(fs_info->chunk_root, path,
1368 BTRFS_DEV_ITEMS_OBJECTID,
1369 BTRFS_DEV_ITEM_KEY);
1370 if (ret) {
1371 *devid_ret = 1;
1372 } else {
1373 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1374 path->slots[0]);
1375 *devid_ret = found_key.offset + 1;
1376 }
1377 ret = 0;
1378 error:
1379 btrfs_free_path(path);
1380 return ret;
1381 }
1382
1383 /*
1384 * the device information is stored in the chunk root
1385 * the btrfs_device struct should be fully filled in
1386 */
1387 static int btrfs_add_device(struct btrfs_trans_handle *trans,
1388 struct btrfs_root *root,
1389 struct btrfs_device *device)
1390 {
1391 int ret;
1392 struct btrfs_path *path;
1393 struct btrfs_dev_item *dev_item;
1394 struct extent_buffer *leaf;
1395 struct btrfs_key key;
1396 unsigned long ptr;
1397
1398 root = root->fs_info->chunk_root;
1399
1400 path = btrfs_alloc_path();
1401 if (!path)
1402 return -ENOMEM;
1403
1404 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1405 key.type = BTRFS_DEV_ITEM_KEY;
1406 key.offset = device->devid;
1407
1408 ret = btrfs_insert_empty_item(trans, root, path, &key,
1409 sizeof(*dev_item));
1410 if (ret)
1411 goto out;
1412
1413 leaf = path->nodes[0];
1414 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1415
1416 btrfs_set_device_id(leaf, dev_item, device->devid);
1417 btrfs_set_device_generation(leaf, dev_item, 0);
1418 btrfs_set_device_type(leaf, dev_item, device->type);
1419 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1420 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1421 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1422 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1423 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1424 btrfs_set_device_group(leaf, dev_item, 0);
1425 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1426 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1427 btrfs_set_device_start_offset(leaf, dev_item, 0);
1428
1429 ptr = btrfs_device_uuid(dev_item);
1430 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1431 ptr = btrfs_device_fsid(dev_item);
1432 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1433 btrfs_mark_buffer_dirty(leaf);
1434
1435 ret = 0;
1436 out:
1437 btrfs_free_path(path);
1438 return ret;
1439 }
1440
1441 static int btrfs_rm_dev_item(struct btrfs_root *root,
1442 struct btrfs_device *device)
1443 {
1444 int ret;
1445 struct btrfs_path *path;
1446 struct btrfs_key key;
1447 struct btrfs_trans_handle *trans;
1448
1449 root = root->fs_info->chunk_root;
1450
1451 path = btrfs_alloc_path();
1452 if (!path)
1453 return -ENOMEM;
1454
1455 trans = btrfs_start_transaction(root, 0);
1456 if (IS_ERR(trans)) {
1457 btrfs_free_path(path);
1458 return PTR_ERR(trans);
1459 }
1460 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1461 key.type = BTRFS_DEV_ITEM_KEY;
1462 key.offset = device->devid;
1463 lock_chunks(root);
1464
1465 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1466 if (ret < 0)
1467 goto out;
1468
1469 if (ret > 0) {
1470 ret = -ENOENT;
1471 goto out;
1472 }
1473
1474 ret = btrfs_del_item(trans, root, path);
1475 if (ret)
1476 goto out;
1477 out:
1478 btrfs_free_path(path);
1479 unlock_chunks(root);
1480 btrfs_commit_transaction(trans, root);
1481 return ret;
1482 }
1483
1484 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1485 {
1486 struct btrfs_device *device;
1487 struct btrfs_device *next_device;
1488 struct block_device *bdev;
1489 struct buffer_head *bh = NULL;
1490 struct btrfs_super_block *disk_super;
1491 struct btrfs_fs_devices *cur_devices;
1492 u64 all_avail;
1493 u64 devid;
1494 u64 num_devices;
1495 u8 *dev_uuid;
1496 unsigned seq;
1497 int ret = 0;
1498 bool clear_super = false;
1499
1500 mutex_lock(&uuid_mutex);
1501
1502 do {
1503 seq = read_seqbegin(&root->fs_info->profiles_lock);
1504
1505 all_avail = root->fs_info->avail_data_alloc_bits |
1506 root->fs_info->avail_system_alloc_bits |
1507 root->fs_info->avail_metadata_alloc_bits;
1508 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
1509
1510 num_devices = root->fs_info->fs_devices->num_devices;
1511 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1512 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1513 WARN_ON(num_devices < 1);
1514 num_devices--;
1515 }
1516 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1517
1518 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1519 ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
1520 goto out;
1521 }
1522
1523 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1524 ret = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
1525 goto out;
1526 }
1527
1528 if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1529 root->fs_info->fs_devices->rw_devices <= 2) {
1530 ret = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
1531 goto out;
1532 }
1533 if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1534 root->fs_info->fs_devices->rw_devices <= 3) {
1535 ret = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
1536 goto out;
1537 }
1538
1539 if (strcmp(device_path, "missing") == 0) {
1540 struct list_head *devices;
1541 struct btrfs_device *tmp;
1542
1543 device = NULL;
1544 devices = &root->fs_info->fs_devices->devices;
1545 /*
1546 * It is safe to read the devices since the volume_mutex
1547 * is held.
1548 */
1549 list_for_each_entry(tmp, devices, dev_list) {
1550 if (tmp->in_fs_metadata &&
1551 !tmp->is_tgtdev_for_dev_replace &&
1552 !tmp->bdev) {
1553 device = tmp;
1554 break;
1555 }
1556 }
1557 bdev = NULL;
1558 bh = NULL;
1559 disk_super = NULL;
1560 if (!device) {
1561 ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
1562 goto out;
1563 }
1564 } else {
1565 ret = btrfs_get_bdev_and_sb(device_path,
1566 FMODE_WRITE | FMODE_EXCL,
1567 root->fs_info->bdev_holder, 0,
1568 &bdev, &bh);
1569 if (ret)
1570 goto out;
1571 disk_super = (struct btrfs_super_block *)bh->b_data;
1572 devid = btrfs_stack_device_id(&disk_super->dev_item);
1573 dev_uuid = disk_super->dev_item.uuid;
1574 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1575 disk_super->fsid);
1576 if (!device) {
1577 ret = -ENOENT;
1578 goto error_brelse;
1579 }
1580 }
1581
1582 if (device->is_tgtdev_for_dev_replace) {
1583 ret = BTRFS_ERROR_DEV_TGT_REPLACE;
1584 goto error_brelse;
1585 }
1586
1587 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1588 ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
1589 goto error_brelse;
1590 }
1591
1592 if (device->writeable) {
1593 lock_chunks(root);
1594 list_del_init(&device->dev_alloc_list);
1595 unlock_chunks(root);
1596 root->fs_info->fs_devices->rw_devices--;
1597 clear_super = true;
1598 }
1599
1600 mutex_unlock(&uuid_mutex);
1601 ret = btrfs_shrink_device(device, 0);
1602 mutex_lock(&uuid_mutex);
1603 if (ret)
1604 goto error_undo;
1605
1606 /*
1607 * TODO: the superblock still includes this device in its num_devices
1608 * counter although write_all_supers() is not locked out. This
1609 * could give a filesystem state which requires a degraded mount.
1610 */
1611 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1612 if (ret)
1613 goto error_undo;
1614
1615 spin_lock(&root->fs_info->free_chunk_lock);
1616 root->fs_info->free_chunk_space = device->total_bytes -
1617 device->bytes_used;
1618 spin_unlock(&root->fs_info->free_chunk_lock);
1619
1620 device->in_fs_metadata = 0;
1621 btrfs_scrub_cancel_dev(root->fs_info, device);
1622
1623 /*
1624 * the device list mutex makes sure that we don't change
1625 * the device list while someone else is writing out all
1626 * the device supers. Whoever is writing all supers, should
1627 * lock the device list mutex before getting the number of
1628 * devices in the super block (super_copy). Conversely,
1629 * whoever updates the number of devices in the super block
1630 * (super_copy) should hold the device list mutex.
1631 */
1632
1633 cur_devices = device->fs_devices;
1634 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1635 list_del_rcu(&device->dev_list);
1636
1637 device->fs_devices->num_devices--;
1638 device->fs_devices->total_devices--;
1639
1640 if (device->missing)
1641 root->fs_info->fs_devices->missing_devices--;
1642
1643 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1644 struct btrfs_device, dev_list);
1645 if (device->bdev == root->fs_info->sb->s_bdev)
1646 root->fs_info->sb->s_bdev = next_device->bdev;
1647 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1648 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1649
1650 if (device->bdev)
1651 device->fs_devices->open_devices--;
1652
1653 call_rcu(&device->rcu, free_device);
1654
1655 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1656 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1657 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1658
1659 if (cur_devices->open_devices == 0) {
1660 struct btrfs_fs_devices *fs_devices;
1661 fs_devices = root->fs_info->fs_devices;
1662 while (fs_devices) {
1663 if (fs_devices->seed == cur_devices)
1664 break;
1665 fs_devices = fs_devices->seed;
1666 }
1667 fs_devices->seed = cur_devices->seed;
1668 cur_devices->seed = NULL;
1669 lock_chunks(root);
1670 __btrfs_close_devices(cur_devices);
1671 unlock_chunks(root);
1672 free_fs_devices(cur_devices);
1673 }
1674
1675 root->fs_info->num_tolerated_disk_barrier_failures =
1676 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1677
1678 /*
1679 * at this point, the device is zero sized. We want to
1680 * remove it from the devices list and zero out the old super
1681 */
1682 if (clear_super && disk_super) {
1683 /* make sure this device isn't detected as part of
1684 * the FS anymore
1685 */
1686 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1687 set_buffer_dirty(bh);
1688 sync_dirty_buffer(bh);
1689 }
1690
1691 ret = 0;
1692
1693 /* Notify udev that device has changed */
1694 if (bdev)
1695 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1696
1697 error_brelse:
1698 brelse(bh);
1699 if (bdev)
1700 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1701 out:
1702 mutex_unlock(&uuid_mutex);
1703 return ret;
1704 error_undo:
1705 if (device->writeable) {
1706 lock_chunks(root);
1707 list_add(&device->dev_alloc_list,
1708 &root->fs_info->fs_devices->alloc_list);
1709 unlock_chunks(root);
1710 root->fs_info->fs_devices->rw_devices++;
1711 }
1712 goto error_brelse;
1713 }
1714
1715 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1716 struct btrfs_device *srcdev)
1717 {
1718 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1719
1720 list_del_rcu(&srcdev->dev_list);
1721 list_del_rcu(&srcdev->dev_alloc_list);
1722 fs_info->fs_devices->num_devices--;
1723 if (srcdev->missing) {
1724 fs_info->fs_devices->missing_devices--;
1725 fs_info->fs_devices->rw_devices++;
1726 }
1727 if (srcdev->can_discard)
1728 fs_info->fs_devices->num_can_discard--;
1729 if (srcdev->bdev) {
1730 fs_info->fs_devices->open_devices--;
1731
1732 /* zero out the old super */
1733 btrfs_scratch_superblock(srcdev);
1734 }
1735
1736 call_rcu(&srcdev->rcu, free_device);
1737 }
1738
1739 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1740 struct btrfs_device *tgtdev)
1741 {
1742 struct btrfs_device *next_device;
1743
1744 WARN_ON(!tgtdev);
1745 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1746 if (tgtdev->bdev) {
1747 btrfs_scratch_superblock(tgtdev);
1748 fs_info->fs_devices->open_devices--;
1749 }
1750 fs_info->fs_devices->num_devices--;
1751 if (tgtdev->can_discard)
1752 fs_info->fs_devices->num_can_discard++;
1753
1754 next_device = list_entry(fs_info->fs_devices->devices.next,
1755 struct btrfs_device, dev_list);
1756 if (tgtdev->bdev == fs_info->sb->s_bdev)
1757 fs_info->sb->s_bdev = next_device->bdev;
1758 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1759 fs_info->fs_devices->latest_bdev = next_device->bdev;
1760 list_del_rcu(&tgtdev->dev_list);
1761
1762 call_rcu(&tgtdev->rcu, free_device);
1763
1764 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1765 }
1766
1767 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1768 struct btrfs_device **device)
1769 {
1770 int ret = 0;
1771 struct btrfs_super_block *disk_super;
1772 u64 devid;
1773 u8 *dev_uuid;
1774 struct block_device *bdev;
1775 struct buffer_head *bh;
1776
1777 *device = NULL;
1778 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1779 root->fs_info->bdev_holder, 0, &bdev, &bh);
1780 if (ret)
1781 return ret;
1782 disk_super = (struct btrfs_super_block *)bh->b_data;
1783 devid = btrfs_stack_device_id(&disk_super->dev_item);
1784 dev_uuid = disk_super->dev_item.uuid;
1785 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1786 disk_super->fsid);
1787 brelse(bh);
1788 if (!*device)
1789 ret = -ENOENT;
1790 blkdev_put(bdev, FMODE_READ);
1791 return ret;
1792 }
1793
1794 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1795 char *device_path,
1796 struct btrfs_device **device)
1797 {
1798 *device = NULL;
1799 if (strcmp(device_path, "missing") == 0) {
1800 struct list_head *devices;
1801 struct btrfs_device *tmp;
1802
1803 devices = &root->fs_info->fs_devices->devices;
1804 /*
1805 * It is safe to read the devices since the volume_mutex
1806 * is held by the caller.
1807 */
1808 list_for_each_entry(tmp, devices, dev_list) {
1809 if (tmp->in_fs_metadata && !tmp->bdev) {
1810 *device = tmp;
1811 break;
1812 }
1813 }
1814
1815 if (!*device) {
1816 btrfs_err(root->fs_info, "no missing device found");
1817 return -ENOENT;
1818 }
1819
1820 return 0;
1821 } else {
1822 return btrfs_find_device_by_path(root, device_path, device);
1823 }
1824 }
1825
1826 /*
1827 * does all the dirty work required for changing file system's UUID.
1828 */
1829 static int btrfs_prepare_sprout(struct btrfs_root *root)
1830 {
1831 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1832 struct btrfs_fs_devices *old_devices;
1833 struct btrfs_fs_devices *seed_devices;
1834 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1835 struct btrfs_device *device;
1836 u64 super_flags;
1837
1838 BUG_ON(!mutex_is_locked(&uuid_mutex));
1839 if (!fs_devices->seeding)
1840 return -EINVAL;
1841
1842 seed_devices = __alloc_fs_devices();
1843 if (IS_ERR(seed_devices))
1844 return PTR_ERR(seed_devices);
1845
1846 old_devices = clone_fs_devices(fs_devices);
1847 if (IS_ERR(old_devices)) {
1848 kfree(seed_devices);
1849 return PTR_ERR(old_devices);
1850 }
1851
1852 list_add(&old_devices->list, &fs_uuids);
1853
1854 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1855 seed_devices->opened = 1;
1856 INIT_LIST_HEAD(&seed_devices->devices);
1857 INIT_LIST_HEAD(&seed_devices->alloc_list);
1858 mutex_init(&seed_devices->device_list_mutex);
1859
1860 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1861 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1862 synchronize_rcu);
1863
1864 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1865 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1866 device->fs_devices = seed_devices;
1867 }
1868
1869 fs_devices->seeding = 0;
1870 fs_devices->num_devices = 0;
1871 fs_devices->open_devices = 0;
1872 fs_devices->total_devices = 0;
1873 fs_devices->seed = seed_devices;
1874
1875 generate_random_uuid(fs_devices->fsid);
1876 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1877 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1878 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1879
1880 super_flags = btrfs_super_flags(disk_super) &
1881 ~BTRFS_SUPER_FLAG_SEEDING;
1882 btrfs_set_super_flags(disk_super, super_flags);
1883
1884 return 0;
1885 }
1886
1887 /*
1888 * strore the expected generation for seed devices in device items.
1889 */
1890 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1891 struct btrfs_root *root)
1892 {
1893 struct btrfs_path *path;
1894 struct extent_buffer *leaf;
1895 struct btrfs_dev_item *dev_item;
1896 struct btrfs_device *device;
1897 struct btrfs_key key;
1898 u8 fs_uuid[BTRFS_UUID_SIZE];
1899 u8 dev_uuid[BTRFS_UUID_SIZE];
1900 u64 devid;
1901 int ret;
1902
1903 path = btrfs_alloc_path();
1904 if (!path)
1905 return -ENOMEM;
1906
1907 root = root->fs_info->chunk_root;
1908 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1909 key.offset = 0;
1910 key.type = BTRFS_DEV_ITEM_KEY;
1911
1912 while (1) {
1913 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1914 if (ret < 0)
1915 goto error;
1916
1917 leaf = path->nodes[0];
1918 next_slot:
1919 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1920 ret = btrfs_next_leaf(root, path);
1921 if (ret > 0)
1922 break;
1923 if (ret < 0)
1924 goto error;
1925 leaf = path->nodes[0];
1926 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1927 btrfs_release_path(path);
1928 continue;
1929 }
1930
1931 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1932 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1933 key.type != BTRFS_DEV_ITEM_KEY)
1934 break;
1935
1936 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1937 struct btrfs_dev_item);
1938 devid = btrfs_device_id(leaf, dev_item);
1939 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
1940 BTRFS_UUID_SIZE);
1941 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
1942 BTRFS_UUID_SIZE);
1943 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1944 fs_uuid);
1945 BUG_ON(!device); /* Logic error */
1946
1947 if (device->fs_devices->seeding) {
1948 btrfs_set_device_generation(leaf, dev_item,
1949 device->generation);
1950 btrfs_mark_buffer_dirty(leaf);
1951 }
1952
1953 path->slots[0]++;
1954 goto next_slot;
1955 }
1956 ret = 0;
1957 error:
1958 btrfs_free_path(path);
1959 return ret;
1960 }
1961
1962 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1963 {
1964 struct request_queue *q;
1965 struct btrfs_trans_handle *trans;
1966 struct btrfs_device *device;
1967 struct block_device *bdev;
1968 struct list_head *devices;
1969 struct super_block *sb = root->fs_info->sb;
1970 struct rcu_string *name;
1971 u64 total_bytes;
1972 int seeding_dev = 0;
1973 int ret = 0;
1974
1975 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1976 return -EROFS;
1977
1978 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1979 root->fs_info->bdev_holder);
1980 if (IS_ERR(bdev))
1981 return PTR_ERR(bdev);
1982
1983 if (root->fs_info->fs_devices->seeding) {
1984 seeding_dev = 1;
1985 down_write(&sb->s_umount);
1986 mutex_lock(&uuid_mutex);
1987 }
1988
1989 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1990
1991 devices = &root->fs_info->fs_devices->devices;
1992
1993 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1994 list_for_each_entry(device, devices, dev_list) {
1995 if (device->bdev == bdev) {
1996 ret = -EEXIST;
1997 mutex_unlock(
1998 &root->fs_info->fs_devices->device_list_mutex);
1999 goto error;
2000 }
2001 }
2002 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2003
2004 device = btrfs_alloc_device(root->fs_info, NULL, NULL);
2005 if (IS_ERR(device)) {
2006 /* we can safely leave the fs_devices entry around */
2007 ret = PTR_ERR(device);
2008 goto error;
2009 }
2010
2011 name = rcu_string_strdup(device_path, GFP_NOFS);
2012 if (!name) {
2013 kfree(device);
2014 ret = -ENOMEM;
2015 goto error;
2016 }
2017 rcu_assign_pointer(device->name, name);
2018
2019 trans = btrfs_start_transaction(root, 0);
2020 if (IS_ERR(trans)) {
2021 rcu_string_free(device->name);
2022 kfree(device);
2023 ret = PTR_ERR(trans);
2024 goto error;
2025 }
2026
2027 lock_chunks(root);
2028
2029 q = bdev_get_queue(bdev);
2030 if (blk_queue_discard(q))
2031 device->can_discard = 1;
2032 device->writeable = 1;
2033 device->generation = trans->transid;
2034 device->io_width = root->sectorsize;
2035 device->io_align = root->sectorsize;
2036 device->sector_size = root->sectorsize;
2037 device->total_bytes = i_size_read(bdev->bd_inode);
2038 device->disk_total_bytes = device->total_bytes;
2039 device->dev_root = root->fs_info->dev_root;
2040 device->bdev = bdev;
2041 device->in_fs_metadata = 1;
2042 device->is_tgtdev_for_dev_replace = 0;
2043 device->mode = FMODE_EXCL;
2044 device->dev_stats_valid = 1;
2045 set_blocksize(device->bdev, 4096);
2046
2047 if (seeding_dev) {
2048 sb->s_flags &= ~MS_RDONLY;
2049 ret = btrfs_prepare_sprout(root);
2050 BUG_ON(ret); /* -ENOMEM */
2051 }
2052
2053 device->fs_devices = root->fs_info->fs_devices;
2054
2055 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2056 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2057 list_add(&device->dev_alloc_list,
2058 &root->fs_info->fs_devices->alloc_list);
2059 root->fs_info->fs_devices->num_devices++;
2060 root->fs_info->fs_devices->open_devices++;
2061 root->fs_info->fs_devices->rw_devices++;
2062 root->fs_info->fs_devices->total_devices++;
2063 if (device->can_discard)
2064 root->fs_info->fs_devices->num_can_discard++;
2065 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2066
2067 spin_lock(&root->fs_info->free_chunk_lock);
2068 root->fs_info->free_chunk_space += device->total_bytes;
2069 spin_unlock(&root->fs_info->free_chunk_lock);
2070
2071 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2072 root->fs_info->fs_devices->rotating = 1;
2073
2074 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2075 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2076 total_bytes + device->total_bytes);
2077
2078 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2079 btrfs_set_super_num_devices(root->fs_info->super_copy,
2080 total_bytes + 1);
2081 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2082
2083 if (seeding_dev) {
2084 ret = init_first_rw_device(trans, root, device);
2085 if (ret) {
2086 btrfs_abort_transaction(trans, root, ret);
2087 goto error_trans;
2088 }
2089 ret = btrfs_finish_sprout(trans, root);
2090 if (ret) {
2091 btrfs_abort_transaction(trans, root, ret);
2092 goto error_trans;
2093 }
2094 } else {
2095 ret = btrfs_add_device(trans, root, device);
2096 if (ret) {
2097 btrfs_abort_transaction(trans, root, ret);
2098 goto error_trans;
2099 }
2100 }
2101
2102 /*
2103 * we've got more storage, clear any full flags on the space
2104 * infos
2105 */
2106 btrfs_clear_space_info_full(root->fs_info);
2107
2108 unlock_chunks(root);
2109 root->fs_info->num_tolerated_disk_barrier_failures =
2110 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2111 ret = btrfs_commit_transaction(trans, root);
2112
2113 if (seeding_dev) {
2114 mutex_unlock(&uuid_mutex);
2115 up_write(&sb->s_umount);
2116
2117 if (ret) /* transaction commit */
2118 return ret;
2119
2120 ret = btrfs_relocate_sys_chunks(root);
2121 if (ret < 0)
2122 btrfs_error(root->fs_info, ret,
2123 "Failed to relocate sys chunks after "
2124 "device initialization. This can be fixed "
2125 "using the \"btrfs balance\" command.");
2126 trans = btrfs_attach_transaction(root);
2127 if (IS_ERR(trans)) {
2128 if (PTR_ERR(trans) == -ENOENT)
2129 return 0;
2130 return PTR_ERR(trans);
2131 }
2132 ret = btrfs_commit_transaction(trans, root);
2133 }
2134
2135 return ret;
2136
2137 error_trans:
2138 unlock_chunks(root);
2139 btrfs_end_transaction(trans, root);
2140 rcu_string_free(device->name);
2141 kfree(device);
2142 error:
2143 blkdev_put(bdev, FMODE_EXCL);
2144 if (seeding_dev) {
2145 mutex_unlock(&uuid_mutex);
2146 up_write(&sb->s_umount);
2147 }
2148 return ret;
2149 }
2150
2151 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2152 struct btrfs_device **device_out)
2153 {
2154 struct request_queue *q;
2155 struct btrfs_device *device;
2156 struct block_device *bdev;
2157 struct btrfs_fs_info *fs_info = root->fs_info;
2158 struct list_head *devices;
2159 struct rcu_string *name;
2160 u64 devid = BTRFS_DEV_REPLACE_DEVID;
2161 int ret = 0;
2162
2163 *device_out = NULL;
2164 if (fs_info->fs_devices->seeding)
2165 return -EINVAL;
2166
2167 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2168 fs_info->bdev_holder);
2169 if (IS_ERR(bdev))
2170 return PTR_ERR(bdev);
2171
2172 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2173
2174 devices = &fs_info->fs_devices->devices;
2175 list_for_each_entry(device, devices, dev_list) {
2176 if (device->bdev == bdev) {
2177 ret = -EEXIST;
2178 goto error;
2179 }
2180 }
2181
2182 device = btrfs_alloc_device(NULL, &devid, NULL);
2183 if (IS_ERR(device)) {
2184 ret = PTR_ERR(device);
2185 goto error;
2186 }
2187
2188 name = rcu_string_strdup(device_path, GFP_NOFS);
2189 if (!name) {
2190 kfree(device);
2191 ret = -ENOMEM;
2192 goto error;
2193 }
2194 rcu_assign_pointer(device->name, name);
2195
2196 q = bdev_get_queue(bdev);
2197 if (blk_queue_discard(q))
2198 device->can_discard = 1;
2199 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2200 device->writeable = 1;
2201 device->generation = 0;
2202 device->io_width = root->sectorsize;
2203 device->io_align = root->sectorsize;
2204 device->sector_size = root->sectorsize;
2205 device->total_bytes = i_size_read(bdev->bd_inode);
2206 device->disk_total_bytes = device->total_bytes;
2207 device->dev_root = fs_info->dev_root;
2208 device->bdev = bdev;
2209 device->in_fs_metadata = 1;
2210 device->is_tgtdev_for_dev_replace = 1;
2211 device->mode = FMODE_EXCL;
2212 device->dev_stats_valid = 1;
2213 set_blocksize(device->bdev, 4096);
2214 device->fs_devices = fs_info->fs_devices;
2215 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2216 fs_info->fs_devices->num_devices++;
2217 fs_info->fs_devices->open_devices++;
2218 if (device->can_discard)
2219 fs_info->fs_devices->num_can_discard++;
2220 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2221
2222 *device_out = device;
2223 return ret;
2224
2225 error:
2226 blkdev_put(bdev, FMODE_EXCL);
2227 return ret;
2228 }
2229
2230 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2231 struct btrfs_device *tgtdev)
2232 {
2233 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2234 tgtdev->io_width = fs_info->dev_root->sectorsize;
2235 tgtdev->io_align = fs_info->dev_root->sectorsize;
2236 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2237 tgtdev->dev_root = fs_info->dev_root;
2238 tgtdev->in_fs_metadata = 1;
2239 }
2240
2241 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2242 struct btrfs_device *device)
2243 {
2244 int ret;
2245 struct btrfs_path *path;
2246 struct btrfs_root *root;
2247 struct btrfs_dev_item *dev_item;
2248 struct extent_buffer *leaf;
2249 struct btrfs_key key;
2250
2251 root = device->dev_root->fs_info->chunk_root;
2252
2253 path = btrfs_alloc_path();
2254 if (!path)
2255 return -ENOMEM;
2256
2257 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2258 key.type = BTRFS_DEV_ITEM_KEY;
2259 key.offset = device->devid;
2260
2261 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2262 if (ret < 0)
2263 goto out;
2264
2265 if (ret > 0) {
2266 ret = -ENOENT;
2267 goto out;
2268 }
2269
2270 leaf = path->nodes[0];
2271 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2272
2273 btrfs_set_device_id(leaf, dev_item, device->devid);
2274 btrfs_set_device_type(leaf, dev_item, device->type);
2275 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2276 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2277 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2278 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2279 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2280 btrfs_mark_buffer_dirty(leaf);
2281
2282 out:
2283 btrfs_free_path(path);
2284 return ret;
2285 }
2286
2287 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2288 struct btrfs_device *device, u64 new_size)
2289 {
2290 struct btrfs_super_block *super_copy =
2291 device->dev_root->fs_info->super_copy;
2292 u64 old_total = btrfs_super_total_bytes(super_copy);
2293 u64 diff = new_size - device->total_bytes;
2294
2295 if (!device->writeable)
2296 return -EACCES;
2297 if (new_size <= device->total_bytes ||
2298 device->is_tgtdev_for_dev_replace)
2299 return -EINVAL;
2300
2301 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2302 device->fs_devices->total_rw_bytes += diff;
2303
2304 device->total_bytes = new_size;
2305 device->disk_total_bytes = new_size;
2306 btrfs_clear_space_info_full(device->dev_root->fs_info);
2307
2308 return btrfs_update_device(trans, device);
2309 }
2310
2311 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2312 struct btrfs_device *device, u64 new_size)
2313 {
2314 int ret;
2315 lock_chunks(device->dev_root);
2316 ret = __btrfs_grow_device(trans, device, new_size);
2317 unlock_chunks(device->dev_root);
2318 return ret;
2319 }
2320
2321 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2322 struct btrfs_root *root,
2323 u64 chunk_tree, u64 chunk_objectid,
2324 u64 chunk_offset)
2325 {
2326 int ret;
2327 struct btrfs_path *path;
2328 struct btrfs_key key;
2329
2330 root = root->fs_info->chunk_root;
2331 path = btrfs_alloc_path();
2332 if (!path)
2333 return -ENOMEM;
2334
2335 key.objectid = chunk_objectid;
2336 key.offset = chunk_offset;
2337 key.type = BTRFS_CHUNK_ITEM_KEY;
2338
2339 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2340 if (ret < 0)
2341 goto out;
2342 else if (ret > 0) { /* Logic error or corruption */
2343 btrfs_error(root->fs_info, -ENOENT,
2344 "Failed lookup while freeing chunk.");
2345 ret = -ENOENT;
2346 goto out;
2347 }
2348
2349 ret = btrfs_del_item(trans, root, path);
2350 if (ret < 0)
2351 btrfs_error(root->fs_info, ret,
2352 "Failed to delete chunk item.");
2353 out:
2354 btrfs_free_path(path);
2355 return ret;
2356 }
2357
2358 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2359 chunk_offset)
2360 {
2361 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2362 struct btrfs_disk_key *disk_key;
2363 struct btrfs_chunk *chunk;
2364 u8 *ptr;
2365 int ret = 0;
2366 u32 num_stripes;
2367 u32 array_size;
2368 u32 len = 0;
2369 u32 cur;
2370 struct btrfs_key key;
2371
2372 array_size = btrfs_super_sys_array_size(super_copy);
2373
2374 ptr = super_copy->sys_chunk_array;
2375 cur = 0;
2376
2377 while (cur < array_size) {
2378 disk_key = (struct btrfs_disk_key *)ptr;
2379 btrfs_disk_key_to_cpu(&key, disk_key);
2380
2381 len = sizeof(*disk_key);
2382
2383 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2384 chunk = (struct btrfs_chunk *)(ptr + len);
2385 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2386 len += btrfs_chunk_item_size(num_stripes);
2387 } else {
2388 ret = -EIO;
2389 break;
2390 }
2391 if (key.objectid == chunk_objectid &&
2392 key.offset == chunk_offset) {
2393 memmove(ptr, ptr + len, array_size - (cur + len));
2394 array_size -= len;
2395 btrfs_set_super_sys_array_size(super_copy, array_size);
2396 } else {
2397 ptr += len;
2398 cur += len;
2399 }
2400 }
2401 return ret;
2402 }
2403
2404 static int btrfs_relocate_chunk(struct btrfs_root *root,
2405 u64 chunk_tree, u64 chunk_objectid,
2406 u64 chunk_offset)
2407 {
2408 struct extent_map_tree *em_tree;
2409 struct btrfs_root *extent_root;
2410 struct btrfs_trans_handle *trans;
2411 struct extent_map *em;
2412 struct map_lookup *map;
2413 int ret;
2414 int i;
2415
2416 root = root->fs_info->chunk_root;
2417 extent_root = root->fs_info->extent_root;
2418 em_tree = &root->fs_info->mapping_tree.map_tree;
2419
2420 ret = btrfs_can_relocate(extent_root, chunk_offset);
2421 if (ret)
2422 return -ENOSPC;
2423
2424 /* step one, relocate all the extents inside this chunk */
2425 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2426 if (ret)
2427 return ret;
2428
2429 trans = btrfs_start_transaction(root, 0);
2430 if (IS_ERR(trans)) {
2431 ret = PTR_ERR(trans);
2432 btrfs_std_error(root->fs_info, ret);
2433 return ret;
2434 }
2435
2436 lock_chunks(root);
2437
2438 /*
2439 * step two, delete the device extents and the
2440 * chunk tree entries
2441 */
2442 read_lock(&em_tree->lock);
2443 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2444 read_unlock(&em_tree->lock);
2445
2446 BUG_ON(!em || em->start > chunk_offset ||
2447 em->start + em->len < chunk_offset);
2448 map = (struct map_lookup *)em->bdev;
2449
2450 for (i = 0; i < map->num_stripes; i++) {
2451 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2452 map->stripes[i].physical);
2453 BUG_ON(ret);
2454
2455 if (map->stripes[i].dev) {
2456 ret = btrfs_update_device(trans, map->stripes[i].dev);
2457 BUG_ON(ret);
2458 }
2459 }
2460 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2461 chunk_offset);
2462
2463 BUG_ON(ret);
2464
2465 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2466
2467 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2468 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2469 BUG_ON(ret);
2470 }
2471
2472 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2473 BUG_ON(ret);
2474
2475 write_lock(&em_tree->lock);
2476 remove_extent_mapping(em_tree, em);
2477 write_unlock(&em_tree->lock);
2478
2479 kfree(map);
2480 em->bdev = NULL;
2481
2482 /* once for the tree */
2483 free_extent_map(em);
2484 /* once for us */
2485 free_extent_map(em);
2486
2487 unlock_chunks(root);
2488 btrfs_end_transaction(trans, root);
2489 return 0;
2490 }
2491
2492 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2493 {
2494 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2495 struct btrfs_path *path;
2496 struct extent_buffer *leaf;
2497 struct btrfs_chunk *chunk;
2498 struct btrfs_key key;
2499 struct btrfs_key found_key;
2500 u64 chunk_tree = chunk_root->root_key.objectid;
2501 u64 chunk_type;
2502 bool retried = false;
2503 int failed = 0;
2504 int ret;
2505
2506 path = btrfs_alloc_path();
2507 if (!path)
2508 return -ENOMEM;
2509
2510 again:
2511 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2512 key.offset = (u64)-1;
2513 key.type = BTRFS_CHUNK_ITEM_KEY;
2514
2515 while (1) {
2516 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2517 if (ret < 0)
2518 goto error;
2519 BUG_ON(ret == 0); /* Corruption */
2520
2521 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2522 key.type);
2523 if (ret < 0)
2524 goto error;
2525 if (ret > 0)
2526 break;
2527
2528 leaf = path->nodes[0];
2529 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2530
2531 chunk = btrfs_item_ptr(leaf, path->slots[0],
2532 struct btrfs_chunk);
2533 chunk_type = btrfs_chunk_type(leaf, chunk);
2534 btrfs_release_path(path);
2535
2536 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2537 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2538 found_key.objectid,
2539 found_key.offset);
2540 if (ret == -ENOSPC)
2541 failed++;
2542 else if (ret)
2543 BUG();
2544 }
2545
2546 if (found_key.offset == 0)
2547 break;
2548 key.offset = found_key.offset - 1;
2549 }
2550 ret = 0;
2551 if (failed && !retried) {
2552 failed = 0;
2553 retried = true;
2554 goto again;
2555 } else if (WARN_ON(failed && retried)) {
2556 ret = -ENOSPC;
2557 }
2558 error:
2559 btrfs_free_path(path);
2560 return ret;
2561 }
2562
2563 static int insert_balance_item(struct btrfs_root *root,
2564 struct btrfs_balance_control *bctl)
2565 {
2566 struct btrfs_trans_handle *trans;
2567 struct btrfs_balance_item *item;
2568 struct btrfs_disk_balance_args disk_bargs;
2569 struct btrfs_path *path;
2570 struct extent_buffer *leaf;
2571 struct btrfs_key key;
2572 int ret, err;
2573
2574 path = btrfs_alloc_path();
2575 if (!path)
2576 return -ENOMEM;
2577
2578 trans = btrfs_start_transaction(root, 0);
2579 if (IS_ERR(trans)) {
2580 btrfs_free_path(path);
2581 return PTR_ERR(trans);
2582 }
2583
2584 key.objectid = BTRFS_BALANCE_OBJECTID;
2585 key.type = BTRFS_BALANCE_ITEM_KEY;
2586 key.offset = 0;
2587
2588 ret = btrfs_insert_empty_item(trans, root, path, &key,
2589 sizeof(*item));
2590 if (ret)
2591 goto out;
2592
2593 leaf = path->nodes[0];
2594 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2595
2596 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2597
2598 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2599 btrfs_set_balance_data(leaf, item, &disk_bargs);
2600 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2601 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2602 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2603 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2604
2605 btrfs_set_balance_flags(leaf, item, bctl->flags);
2606
2607 btrfs_mark_buffer_dirty(leaf);
2608 out:
2609 btrfs_free_path(path);
2610 err = btrfs_commit_transaction(trans, root);
2611 if (err && !ret)
2612 ret = err;
2613 return ret;
2614 }
2615
2616 static int del_balance_item(struct btrfs_root *root)
2617 {
2618 struct btrfs_trans_handle *trans;
2619 struct btrfs_path *path;
2620 struct btrfs_key key;
2621 int ret, err;
2622
2623 path = btrfs_alloc_path();
2624 if (!path)
2625 return -ENOMEM;
2626
2627 trans = btrfs_start_transaction(root, 0);
2628 if (IS_ERR(trans)) {
2629 btrfs_free_path(path);
2630 return PTR_ERR(trans);
2631 }
2632
2633 key.objectid = BTRFS_BALANCE_OBJECTID;
2634 key.type = BTRFS_BALANCE_ITEM_KEY;
2635 key.offset = 0;
2636
2637 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2638 if (ret < 0)
2639 goto out;
2640 if (ret > 0) {
2641 ret = -ENOENT;
2642 goto out;
2643 }
2644
2645 ret = btrfs_del_item(trans, root, path);
2646 out:
2647 btrfs_free_path(path);
2648 err = btrfs_commit_transaction(trans, root);
2649 if (err && !ret)
2650 ret = err;
2651 return ret;
2652 }
2653
2654 /*
2655 * This is a heuristic used to reduce the number of chunks balanced on
2656 * resume after balance was interrupted.
2657 */
2658 static void update_balance_args(struct btrfs_balance_control *bctl)
2659 {
2660 /*
2661 * Turn on soft mode for chunk types that were being converted.
2662 */
2663 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2664 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2665 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2666 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2667 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2668 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2669
2670 /*
2671 * Turn on usage filter if is not already used. The idea is
2672 * that chunks that we have already balanced should be
2673 * reasonably full. Don't do it for chunks that are being
2674 * converted - that will keep us from relocating unconverted
2675 * (albeit full) chunks.
2676 */
2677 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2678 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2679 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2680 bctl->data.usage = 90;
2681 }
2682 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2683 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2684 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2685 bctl->sys.usage = 90;
2686 }
2687 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2688 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2689 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2690 bctl->meta.usage = 90;
2691 }
2692 }
2693
2694 /*
2695 * Should be called with both balance and volume mutexes held to
2696 * serialize other volume operations (add_dev/rm_dev/resize) with
2697 * restriper. Same goes for unset_balance_control.
2698 */
2699 static void set_balance_control(struct btrfs_balance_control *bctl)
2700 {
2701 struct btrfs_fs_info *fs_info = bctl->fs_info;
2702
2703 BUG_ON(fs_info->balance_ctl);
2704
2705 spin_lock(&fs_info->balance_lock);
2706 fs_info->balance_ctl = bctl;
2707 spin_unlock(&fs_info->balance_lock);
2708 }
2709
2710 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2711 {
2712 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2713
2714 BUG_ON(!fs_info->balance_ctl);
2715
2716 spin_lock(&fs_info->balance_lock);
2717 fs_info->balance_ctl = NULL;
2718 spin_unlock(&fs_info->balance_lock);
2719
2720 kfree(bctl);
2721 }
2722
2723 /*
2724 * Balance filters. Return 1 if chunk should be filtered out
2725 * (should not be balanced).
2726 */
2727 static int chunk_profiles_filter(u64 chunk_type,
2728 struct btrfs_balance_args *bargs)
2729 {
2730 chunk_type = chunk_to_extended(chunk_type) &
2731 BTRFS_EXTENDED_PROFILE_MASK;
2732
2733 if (bargs->profiles & chunk_type)
2734 return 0;
2735
2736 return 1;
2737 }
2738
2739 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2740 struct btrfs_balance_args *bargs)
2741 {
2742 struct btrfs_block_group_cache *cache;
2743 u64 chunk_used, user_thresh;
2744 int ret = 1;
2745
2746 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2747 chunk_used = btrfs_block_group_used(&cache->item);
2748
2749 if (bargs->usage == 0)
2750 user_thresh = 1;
2751 else if (bargs->usage > 100)
2752 user_thresh = cache->key.offset;
2753 else
2754 user_thresh = div_factor_fine(cache->key.offset,
2755 bargs->usage);
2756
2757 if (chunk_used < user_thresh)
2758 ret = 0;
2759
2760 btrfs_put_block_group(cache);
2761 return ret;
2762 }
2763
2764 static int chunk_devid_filter(struct extent_buffer *leaf,
2765 struct btrfs_chunk *chunk,
2766 struct btrfs_balance_args *bargs)
2767 {
2768 struct btrfs_stripe *stripe;
2769 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2770 int i;
2771
2772 for (i = 0; i < num_stripes; i++) {
2773 stripe = btrfs_stripe_nr(chunk, i);
2774 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2775 return 0;
2776 }
2777
2778 return 1;
2779 }
2780
2781 /* [pstart, pend) */
2782 static int chunk_drange_filter(struct extent_buffer *leaf,
2783 struct btrfs_chunk *chunk,
2784 u64 chunk_offset,
2785 struct btrfs_balance_args *bargs)
2786 {
2787 struct btrfs_stripe *stripe;
2788 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2789 u64 stripe_offset;
2790 u64 stripe_length;
2791 int factor;
2792 int i;
2793
2794 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2795 return 0;
2796
2797 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2798 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2799 factor = num_stripes / 2;
2800 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2801 factor = num_stripes - 1;
2802 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2803 factor = num_stripes - 2;
2804 } else {
2805 factor = num_stripes;
2806 }
2807
2808 for (i = 0; i < num_stripes; i++) {
2809 stripe = btrfs_stripe_nr(chunk, i);
2810 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2811 continue;
2812
2813 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2814 stripe_length = btrfs_chunk_length(leaf, chunk);
2815 do_div(stripe_length, factor);
2816
2817 if (stripe_offset < bargs->pend &&
2818 stripe_offset + stripe_length > bargs->pstart)
2819 return 0;
2820 }
2821
2822 return 1;
2823 }
2824
2825 /* [vstart, vend) */
2826 static int chunk_vrange_filter(struct extent_buffer *leaf,
2827 struct btrfs_chunk *chunk,
2828 u64 chunk_offset,
2829 struct btrfs_balance_args *bargs)
2830 {
2831 if (chunk_offset < bargs->vend &&
2832 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2833 /* at least part of the chunk is inside this vrange */
2834 return 0;
2835
2836 return 1;
2837 }
2838
2839 static int chunk_soft_convert_filter(u64 chunk_type,
2840 struct btrfs_balance_args *bargs)
2841 {
2842 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2843 return 0;
2844
2845 chunk_type = chunk_to_extended(chunk_type) &
2846 BTRFS_EXTENDED_PROFILE_MASK;
2847
2848 if (bargs->target == chunk_type)
2849 return 1;
2850
2851 return 0;
2852 }
2853
2854 static int should_balance_chunk(struct btrfs_root *root,
2855 struct extent_buffer *leaf,
2856 struct btrfs_chunk *chunk, u64 chunk_offset)
2857 {
2858 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2859 struct btrfs_balance_args *bargs = NULL;
2860 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2861
2862 /* type filter */
2863 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2864 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2865 return 0;
2866 }
2867
2868 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2869 bargs = &bctl->data;
2870 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2871 bargs = &bctl->sys;
2872 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2873 bargs = &bctl->meta;
2874
2875 /* profiles filter */
2876 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2877 chunk_profiles_filter(chunk_type, bargs)) {
2878 return 0;
2879 }
2880
2881 /* usage filter */
2882 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2883 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2884 return 0;
2885 }
2886
2887 /* devid filter */
2888 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2889 chunk_devid_filter(leaf, chunk, bargs)) {
2890 return 0;
2891 }
2892
2893 /* drange filter, makes sense only with devid filter */
2894 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2895 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2896 return 0;
2897 }
2898
2899 /* vrange filter */
2900 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2901 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2902 return 0;
2903 }
2904
2905 /* soft profile changing mode */
2906 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2907 chunk_soft_convert_filter(chunk_type, bargs)) {
2908 return 0;
2909 }
2910
2911 return 1;
2912 }
2913
2914 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2915 {
2916 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2917 struct btrfs_root *chunk_root = fs_info->chunk_root;
2918 struct btrfs_root *dev_root = fs_info->dev_root;
2919 struct list_head *devices;
2920 struct btrfs_device *device;
2921 u64 old_size;
2922 u64 size_to_free;
2923 struct btrfs_chunk *chunk;
2924 struct btrfs_path *path;
2925 struct btrfs_key key;
2926 struct btrfs_key found_key;
2927 struct btrfs_trans_handle *trans;
2928 struct extent_buffer *leaf;
2929 int slot;
2930 int ret;
2931 int enospc_errors = 0;
2932 bool counting = true;
2933
2934 /* step one make some room on all the devices */
2935 devices = &fs_info->fs_devices->devices;
2936 list_for_each_entry(device, devices, dev_list) {
2937 old_size = device->total_bytes;
2938 size_to_free = div_factor(old_size, 1);
2939 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2940 if (!device->writeable ||
2941 device->total_bytes - device->bytes_used > size_to_free ||
2942 device->is_tgtdev_for_dev_replace)
2943 continue;
2944
2945 ret = btrfs_shrink_device(device, old_size - size_to_free);
2946 if (ret == -ENOSPC)
2947 break;
2948 BUG_ON(ret);
2949
2950 trans = btrfs_start_transaction(dev_root, 0);
2951 BUG_ON(IS_ERR(trans));
2952
2953 ret = btrfs_grow_device(trans, device, old_size);
2954 BUG_ON(ret);
2955
2956 btrfs_end_transaction(trans, dev_root);
2957 }
2958
2959 /* step two, relocate all the chunks */
2960 path = btrfs_alloc_path();
2961 if (!path) {
2962 ret = -ENOMEM;
2963 goto error;
2964 }
2965
2966 /* zero out stat counters */
2967 spin_lock(&fs_info->balance_lock);
2968 memset(&bctl->stat, 0, sizeof(bctl->stat));
2969 spin_unlock(&fs_info->balance_lock);
2970 again:
2971 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2972 key.offset = (u64)-1;
2973 key.type = BTRFS_CHUNK_ITEM_KEY;
2974
2975 while (1) {
2976 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2977 atomic_read(&fs_info->balance_cancel_req)) {
2978 ret = -ECANCELED;
2979 goto error;
2980 }
2981
2982 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2983 if (ret < 0)
2984 goto error;
2985
2986 /*
2987 * this shouldn't happen, it means the last relocate
2988 * failed
2989 */
2990 if (ret == 0)
2991 BUG(); /* FIXME break ? */
2992
2993 ret = btrfs_previous_item(chunk_root, path, 0,
2994 BTRFS_CHUNK_ITEM_KEY);
2995 if (ret) {
2996 ret = 0;
2997 break;
2998 }
2999
3000 leaf = path->nodes[0];
3001 slot = path->slots[0];
3002 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3003
3004 if (found_key.objectid != key.objectid)
3005 break;
3006
3007 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3008
3009 if (!counting) {
3010 spin_lock(&fs_info->balance_lock);
3011 bctl->stat.considered++;
3012 spin_unlock(&fs_info->balance_lock);
3013 }
3014
3015 ret = should_balance_chunk(chunk_root, leaf, chunk,
3016 found_key.offset);
3017 btrfs_release_path(path);
3018 if (!ret)
3019 goto loop;
3020
3021 if (counting) {
3022 spin_lock(&fs_info->balance_lock);
3023 bctl->stat.expected++;
3024 spin_unlock(&fs_info->balance_lock);
3025 goto loop;
3026 }
3027
3028 ret = btrfs_relocate_chunk(chunk_root,
3029 chunk_root->root_key.objectid,
3030 found_key.objectid,
3031 found_key.offset);
3032 if (ret && ret != -ENOSPC)
3033 goto error;
3034 if (ret == -ENOSPC) {
3035 enospc_errors++;
3036 } else {
3037 spin_lock(&fs_info->balance_lock);
3038 bctl->stat.completed++;
3039 spin_unlock(&fs_info->balance_lock);
3040 }
3041 loop:
3042 if (found_key.offset == 0)
3043 break;
3044 key.offset = found_key.offset - 1;
3045 }
3046
3047 if (counting) {
3048 btrfs_release_path(path);
3049 counting = false;
3050 goto again;
3051 }
3052 error:
3053 btrfs_free_path(path);
3054 if (enospc_errors) {
3055 btrfs_info(fs_info, "%d enospc errors during balance",
3056 enospc_errors);
3057 if (!ret)
3058 ret = -ENOSPC;
3059 }
3060
3061 return ret;
3062 }
3063
3064 /**
3065 * alloc_profile_is_valid - see if a given profile is valid and reduced
3066 * @flags: profile to validate
3067 * @extended: if true @flags is treated as an extended profile
3068 */
3069 static int alloc_profile_is_valid(u64 flags, int extended)
3070 {
3071 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3072 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3073
3074 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3075
3076 /* 1) check that all other bits are zeroed */
3077 if (flags & ~mask)
3078 return 0;
3079
3080 /* 2) see if profile is reduced */
3081 if (flags == 0)
3082 return !extended; /* "0" is valid for usual profiles */
3083
3084 /* true if exactly one bit set */
3085 return (flags & (flags - 1)) == 0;
3086 }
3087
3088 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3089 {
3090 /* cancel requested || normal exit path */
3091 return atomic_read(&fs_info->balance_cancel_req) ||
3092 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3093 atomic_read(&fs_info->balance_cancel_req) == 0);
3094 }
3095
3096 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3097 {
3098 int ret;
3099
3100 unset_balance_control(fs_info);
3101 ret = del_balance_item(fs_info->tree_root);
3102 if (ret)
3103 btrfs_std_error(fs_info, ret);
3104
3105 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3106 }
3107
3108 /*
3109 * Should be called with both balance and volume mutexes held
3110 */
3111 int btrfs_balance(struct btrfs_balance_control *bctl,
3112 struct btrfs_ioctl_balance_args *bargs)
3113 {
3114 struct btrfs_fs_info *fs_info = bctl->fs_info;
3115 u64 allowed;
3116 int mixed = 0;
3117 int ret;
3118 u64 num_devices;
3119 unsigned seq;
3120
3121 if (btrfs_fs_closing(fs_info) ||
3122 atomic_read(&fs_info->balance_pause_req) ||
3123 atomic_read(&fs_info->balance_cancel_req)) {
3124 ret = -EINVAL;
3125 goto out;
3126 }
3127
3128 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3129 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3130 mixed = 1;
3131
3132 /*
3133 * In case of mixed groups both data and meta should be picked,
3134 * and identical options should be given for both of them.
3135 */
3136 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3137 if (mixed && (bctl->flags & allowed)) {
3138 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3139 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3140 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3141 btrfs_err(fs_info, "with mixed groups data and "
3142 "metadata balance options must be the same");
3143 ret = -EINVAL;
3144 goto out;
3145 }
3146 }
3147
3148 num_devices = fs_info->fs_devices->num_devices;
3149 btrfs_dev_replace_lock(&fs_info->dev_replace);
3150 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3151 BUG_ON(num_devices < 1);
3152 num_devices--;
3153 }
3154 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3155 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3156 if (num_devices == 1)
3157 allowed |= BTRFS_BLOCK_GROUP_DUP;
3158 else if (num_devices > 1)
3159 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3160 if (num_devices > 2)
3161 allowed |= BTRFS_BLOCK_GROUP_RAID5;
3162 if (num_devices > 3)
3163 allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
3164 BTRFS_BLOCK_GROUP_RAID6);
3165 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3166 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3167 (bctl->data.target & ~allowed))) {
3168 btrfs_err(fs_info, "unable to start balance with target "
3169 "data profile %llu",
3170 bctl->data.target);
3171 ret = -EINVAL;
3172 goto out;
3173 }
3174 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3175 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3176 (bctl->meta.target & ~allowed))) {
3177 btrfs_err(fs_info,
3178 "unable to start balance with target metadata profile %llu",
3179 bctl->meta.target);
3180 ret = -EINVAL;
3181 goto out;
3182 }
3183 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3184 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3185 (bctl->sys.target & ~allowed))) {
3186 btrfs_err(fs_info,
3187 "unable to start balance with target system profile %llu",
3188 bctl->sys.target);
3189 ret = -EINVAL;
3190 goto out;
3191 }
3192
3193 /* allow dup'ed data chunks only in mixed mode */
3194 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3195 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3196 btrfs_err(fs_info, "dup for data is not allowed");
3197 ret = -EINVAL;
3198 goto out;
3199 }
3200
3201 /* allow to reduce meta or sys integrity only if force set */
3202 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3203 BTRFS_BLOCK_GROUP_RAID10 |
3204 BTRFS_BLOCK_GROUP_RAID5 |
3205 BTRFS_BLOCK_GROUP_RAID6;
3206 do {
3207 seq = read_seqbegin(&fs_info->profiles_lock);
3208
3209 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3210 (fs_info->avail_system_alloc_bits & allowed) &&
3211 !(bctl->sys.target & allowed)) ||
3212 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3213 (fs_info->avail_metadata_alloc_bits & allowed) &&
3214 !(bctl->meta.target & allowed))) {
3215 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3216 btrfs_info(fs_info, "force reducing metadata integrity");
3217 } else {
3218 btrfs_err(fs_info, "balance will reduce metadata "
3219 "integrity, use force if you want this");
3220 ret = -EINVAL;
3221 goto out;
3222 }
3223 }
3224 } while (read_seqretry(&fs_info->profiles_lock, seq));
3225
3226 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3227 int num_tolerated_disk_barrier_failures;
3228 u64 target = bctl->sys.target;
3229
3230 num_tolerated_disk_barrier_failures =
3231 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3232 if (num_tolerated_disk_barrier_failures > 0 &&
3233 (target &
3234 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3235 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3236 num_tolerated_disk_barrier_failures = 0;
3237 else if (num_tolerated_disk_barrier_failures > 1 &&
3238 (target &
3239 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3240 num_tolerated_disk_barrier_failures = 1;
3241
3242 fs_info->num_tolerated_disk_barrier_failures =
3243 num_tolerated_disk_barrier_failures;
3244 }
3245
3246 ret = insert_balance_item(fs_info->tree_root, bctl);
3247 if (ret && ret != -EEXIST)
3248 goto out;
3249
3250 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3251 BUG_ON(ret == -EEXIST);
3252 set_balance_control(bctl);
3253 } else {
3254 BUG_ON(ret != -EEXIST);
3255 spin_lock(&fs_info->balance_lock);
3256 update_balance_args(bctl);
3257 spin_unlock(&fs_info->balance_lock);
3258 }
3259
3260 atomic_inc(&fs_info->balance_running);
3261 mutex_unlock(&fs_info->balance_mutex);
3262
3263 ret = __btrfs_balance(fs_info);
3264
3265 mutex_lock(&fs_info->balance_mutex);
3266 atomic_dec(&fs_info->balance_running);
3267
3268 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3269 fs_info->num_tolerated_disk_barrier_failures =
3270 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3271 }
3272
3273 if (bargs) {
3274 memset(bargs, 0, sizeof(*bargs));
3275 update_ioctl_balance_args(fs_info, 0, bargs);
3276 }
3277
3278 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3279 balance_need_close(fs_info)) {
3280 __cancel_balance(fs_info);
3281 }
3282
3283 wake_up(&fs_info->balance_wait_q);
3284
3285 return ret;
3286 out:
3287 if (bctl->flags & BTRFS_BALANCE_RESUME)
3288 __cancel_balance(fs_info);
3289 else {
3290 kfree(bctl);
3291 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3292 }
3293 return ret;
3294 }
3295
3296 static int balance_kthread(void *data)
3297 {
3298 struct btrfs_fs_info *fs_info = data;
3299 int ret = 0;
3300
3301 mutex_lock(&fs_info->volume_mutex);
3302 mutex_lock(&fs_info->balance_mutex);
3303
3304 if (fs_info->balance_ctl) {
3305 btrfs_info(fs_info, "continuing balance");
3306 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3307 }
3308
3309 mutex_unlock(&fs_info->balance_mutex);
3310 mutex_unlock(&fs_info->volume_mutex);
3311
3312 return ret;
3313 }
3314
3315 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3316 {
3317 struct task_struct *tsk;
3318
3319 spin_lock(&fs_info->balance_lock);
3320 if (!fs_info->balance_ctl) {
3321 spin_unlock(&fs_info->balance_lock);
3322 return 0;
3323 }
3324 spin_unlock(&fs_info->balance_lock);
3325
3326 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3327 btrfs_info(fs_info, "force skipping balance");
3328 return 0;
3329 }
3330
3331 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3332 return PTR_ERR_OR_ZERO(tsk);
3333 }
3334
3335 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3336 {
3337 struct btrfs_balance_control *bctl;
3338 struct btrfs_balance_item *item;
3339 struct btrfs_disk_balance_args disk_bargs;
3340 struct btrfs_path *path;
3341 struct extent_buffer *leaf;
3342 struct btrfs_key key;
3343 int ret;
3344
3345 path = btrfs_alloc_path();
3346 if (!path)
3347 return -ENOMEM;
3348
3349 key.objectid = BTRFS_BALANCE_OBJECTID;
3350 key.type = BTRFS_BALANCE_ITEM_KEY;
3351 key.offset = 0;
3352
3353 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3354 if (ret < 0)
3355 goto out;
3356 if (ret > 0) { /* ret = -ENOENT; */
3357 ret = 0;
3358 goto out;
3359 }
3360
3361 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3362 if (!bctl) {
3363 ret = -ENOMEM;
3364 goto out;
3365 }
3366
3367 leaf = path->nodes[0];
3368 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3369
3370 bctl->fs_info = fs_info;
3371 bctl->flags = btrfs_balance_flags(leaf, item);
3372 bctl->flags |= BTRFS_BALANCE_RESUME;
3373
3374 btrfs_balance_data(leaf, item, &disk_bargs);
3375 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3376 btrfs_balance_meta(leaf, item, &disk_bargs);
3377 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3378 btrfs_balance_sys(leaf, item, &disk_bargs);
3379 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3380
3381 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3382
3383 mutex_lock(&fs_info->volume_mutex);
3384 mutex_lock(&fs_info->balance_mutex);
3385
3386 set_balance_control(bctl);
3387
3388 mutex_unlock(&fs_info->balance_mutex);
3389 mutex_unlock(&fs_info->volume_mutex);
3390 out:
3391 btrfs_free_path(path);
3392 return ret;
3393 }
3394
3395 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3396 {
3397 int ret = 0;
3398
3399 mutex_lock(&fs_info->balance_mutex);
3400 if (!fs_info->balance_ctl) {
3401 mutex_unlock(&fs_info->balance_mutex);
3402 return -ENOTCONN;
3403 }
3404
3405 if (atomic_read(&fs_info->balance_running)) {
3406 atomic_inc(&fs_info->balance_pause_req);
3407 mutex_unlock(&fs_info->balance_mutex);
3408
3409 wait_event(fs_info->balance_wait_q,
3410 atomic_read(&fs_info->balance_running) == 0);
3411
3412 mutex_lock(&fs_info->balance_mutex);
3413 /* we are good with balance_ctl ripped off from under us */
3414 BUG_ON(atomic_read(&fs_info->balance_running));
3415 atomic_dec(&fs_info->balance_pause_req);
3416 } else {
3417 ret = -ENOTCONN;
3418 }
3419
3420 mutex_unlock(&fs_info->balance_mutex);
3421 return ret;
3422 }
3423
3424 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3425 {
3426 if (fs_info->sb->s_flags & MS_RDONLY)
3427 return -EROFS;
3428
3429 mutex_lock(&fs_info->balance_mutex);
3430 if (!fs_info->balance_ctl) {
3431 mutex_unlock(&fs_info->balance_mutex);
3432 return -ENOTCONN;
3433 }
3434
3435 atomic_inc(&fs_info->balance_cancel_req);
3436 /*
3437 * if we are running just wait and return, balance item is
3438 * deleted in btrfs_balance in this case
3439 */
3440 if (atomic_read(&fs_info->balance_running)) {
3441 mutex_unlock(&fs_info->balance_mutex);
3442 wait_event(fs_info->balance_wait_q,
3443 atomic_read(&fs_info->balance_running) == 0);
3444 mutex_lock(&fs_info->balance_mutex);
3445 } else {
3446 /* __cancel_balance needs volume_mutex */
3447 mutex_unlock(&fs_info->balance_mutex);
3448 mutex_lock(&fs_info->volume_mutex);
3449 mutex_lock(&fs_info->balance_mutex);
3450
3451 if (fs_info->balance_ctl)
3452 __cancel_balance(fs_info);
3453
3454 mutex_unlock(&fs_info->volume_mutex);
3455 }
3456
3457 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3458 atomic_dec(&fs_info->balance_cancel_req);
3459 mutex_unlock(&fs_info->balance_mutex);
3460 return 0;
3461 }
3462
3463 static int btrfs_uuid_scan_kthread(void *data)
3464 {
3465 struct btrfs_fs_info *fs_info = data;
3466 struct btrfs_root *root = fs_info->tree_root;
3467 struct btrfs_key key;
3468 struct btrfs_key max_key;
3469 struct btrfs_path *path = NULL;
3470 int ret = 0;
3471 struct extent_buffer *eb;
3472 int slot;
3473 struct btrfs_root_item root_item;
3474 u32 item_size;
3475 struct btrfs_trans_handle *trans = NULL;
3476
3477 path = btrfs_alloc_path();
3478 if (!path) {
3479 ret = -ENOMEM;
3480 goto out;
3481 }
3482
3483 key.objectid = 0;
3484 key.type = BTRFS_ROOT_ITEM_KEY;
3485 key.offset = 0;
3486
3487 max_key.objectid = (u64)-1;
3488 max_key.type = BTRFS_ROOT_ITEM_KEY;
3489 max_key.offset = (u64)-1;
3490
3491 path->keep_locks = 1;
3492
3493 while (1) {
3494 ret = btrfs_search_forward(root, &key, path, 0);
3495 if (ret) {
3496 if (ret > 0)
3497 ret = 0;
3498 break;
3499 }
3500
3501 if (key.type != BTRFS_ROOT_ITEM_KEY ||
3502 (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
3503 key.objectid != BTRFS_FS_TREE_OBJECTID) ||
3504 key.objectid > BTRFS_LAST_FREE_OBJECTID)
3505 goto skip;
3506
3507 eb = path->nodes[0];
3508 slot = path->slots[0];
3509 item_size = btrfs_item_size_nr(eb, slot);
3510 if (item_size < sizeof(root_item))
3511 goto skip;
3512
3513 read_extent_buffer(eb, &root_item,
3514 btrfs_item_ptr_offset(eb, slot),
3515 (int)sizeof(root_item));
3516 if (btrfs_root_refs(&root_item) == 0)
3517 goto skip;
3518
3519 if (!btrfs_is_empty_uuid(root_item.uuid) ||
3520 !btrfs_is_empty_uuid(root_item.received_uuid)) {
3521 if (trans)
3522 goto update_tree;
3523
3524 btrfs_release_path(path);
3525 /*
3526 * 1 - subvol uuid item
3527 * 1 - received_subvol uuid item
3528 */
3529 trans = btrfs_start_transaction(fs_info->uuid_root, 2);
3530 if (IS_ERR(trans)) {
3531 ret = PTR_ERR(trans);
3532 break;
3533 }
3534 continue;
3535 } else {
3536 goto skip;
3537 }
3538 update_tree:
3539 if (!btrfs_is_empty_uuid(root_item.uuid)) {
3540 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3541 root_item.uuid,
3542 BTRFS_UUID_KEY_SUBVOL,
3543 key.objectid);
3544 if (ret < 0) {
3545 btrfs_warn(fs_info, "uuid_tree_add failed %d",
3546 ret);
3547 break;
3548 }
3549 }
3550
3551 if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
3552 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3553 root_item.received_uuid,
3554 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
3555 key.objectid);
3556 if (ret < 0) {
3557 btrfs_warn(fs_info, "uuid_tree_add failed %d",
3558 ret);
3559 break;
3560 }
3561 }
3562
3563 skip:
3564 if (trans) {
3565 ret = btrfs_end_transaction(trans, fs_info->uuid_root);
3566 trans = NULL;
3567 if (ret)
3568 break;
3569 }
3570
3571 btrfs_release_path(path);
3572 if (key.offset < (u64)-1) {
3573 key.offset++;
3574 } else if (key.type < BTRFS_ROOT_ITEM_KEY) {
3575 key.offset = 0;
3576 key.type = BTRFS_ROOT_ITEM_KEY;
3577 } else if (key.objectid < (u64)-1) {
3578 key.offset = 0;
3579 key.type = BTRFS_ROOT_ITEM_KEY;
3580 key.objectid++;
3581 } else {
3582 break;
3583 }
3584 cond_resched();
3585 }
3586
3587 out:
3588 btrfs_free_path(path);
3589 if (trans && !IS_ERR(trans))
3590 btrfs_end_transaction(trans, fs_info->uuid_root);
3591 if (ret)
3592 btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
3593 else
3594 fs_info->update_uuid_tree_gen = 1;
3595 up(&fs_info->uuid_tree_rescan_sem);
3596 return 0;
3597 }
3598
3599 /*
3600 * Callback for btrfs_uuid_tree_iterate().
3601 * returns:
3602 * 0 check succeeded, the entry is not outdated.
3603 * < 0 if an error occured.
3604 * > 0 if the check failed, which means the caller shall remove the entry.
3605 */
3606 static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
3607 u8 *uuid, u8 type, u64 subid)
3608 {
3609 struct btrfs_key key;
3610 int ret = 0;
3611 struct btrfs_root *subvol_root;
3612
3613 if (type != BTRFS_UUID_KEY_SUBVOL &&
3614 type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
3615 goto out;
3616
3617 key.objectid = subid;
3618 key.type = BTRFS_ROOT_ITEM_KEY;
3619 key.offset = (u64)-1;
3620 subvol_root = btrfs_read_fs_root_no_name(fs_info, &key);
3621 if (IS_ERR(subvol_root)) {
3622 ret = PTR_ERR(subvol_root);
3623 if (ret == -ENOENT)
3624 ret = 1;
3625 goto out;
3626 }
3627
3628 switch (type) {
3629 case BTRFS_UUID_KEY_SUBVOL:
3630 if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
3631 ret = 1;
3632 break;
3633 case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
3634 if (memcmp(uuid, subvol_root->root_item.received_uuid,
3635 BTRFS_UUID_SIZE))
3636 ret = 1;
3637 break;
3638 }
3639
3640 out:
3641 return ret;
3642 }
3643
3644 static int btrfs_uuid_rescan_kthread(void *data)
3645 {
3646 struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
3647 int ret;
3648
3649 /*
3650 * 1st step is to iterate through the existing UUID tree and
3651 * to delete all entries that contain outdated data.
3652 * 2nd step is to add all missing entries to the UUID tree.
3653 */
3654 ret = btrfs_uuid_tree_iterate(fs_info, btrfs_check_uuid_tree_entry);
3655 if (ret < 0) {
3656 btrfs_warn(fs_info, "iterating uuid_tree failed %d", ret);
3657 up(&fs_info->uuid_tree_rescan_sem);
3658 return ret;
3659 }
3660 return btrfs_uuid_scan_kthread(data);
3661 }
3662
3663 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
3664 {
3665 struct btrfs_trans_handle *trans;
3666 struct btrfs_root *tree_root = fs_info->tree_root;
3667 struct btrfs_root *uuid_root;
3668 struct task_struct *task;
3669 int ret;
3670
3671 /*
3672 * 1 - root node
3673 * 1 - root item
3674 */
3675 trans = btrfs_start_transaction(tree_root, 2);
3676 if (IS_ERR(trans))
3677 return PTR_ERR(trans);
3678
3679 uuid_root = btrfs_create_tree(trans, fs_info,
3680 BTRFS_UUID_TREE_OBJECTID);
3681 if (IS_ERR(uuid_root)) {
3682 btrfs_abort_transaction(trans, tree_root,
3683 PTR_ERR(uuid_root));
3684 return PTR_ERR(uuid_root);
3685 }
3686
3687 fs_info->uuid_root = uuid_root;
3688
3689 ret = btrfs_commit_transaction(trans, tree_root);
3690 if (ret)
3691 return ret;
3692
3693 down(&fs_info->uuid_tree_rescan_sem);
3694 task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
3695 if (IS_ERR(task)) {
3696 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3697 btrfs_warn(fs_info, "failed to start uuid_scan task");
3698 up(&fs_info->uuid_tree_rescan_sem);
3699 return PTR_ERR(task);
3700 }
3701
3702 return 0;
3703 }
3704
3705 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3706 {
3707 struct task_struct *task;
3708
3709 down(&fs_info->uuid_tree_rescan_sem);
3710 task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3711 if (IS_ERR(task)) {
3712 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3713 btrfs_warn(fs_info, "failed to start uuid_rescan task");
3714 up(&fs_info->uuid_tree_rescan_sem);
3715 return PTR_ERR(task);
3716 }
3717
3718 return 0;
3719 }
3720
3721 /*
3722 * shrinking a device means finding all of the device extents past
3723 * the new size, and then following the back refs to the chunks.
3724 * The chunk relocation code actually frees the device extent
3725 */
3726 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3727 {
3728 struct btrfs_trans_handle *trans;
3729 struct btrfs_root *root = device->dev_root;
3730 struct btrfs_dev_extent *dev_extent = NULL;
3731 struct btrfs_path *path;
3732 u64 length;
3733 u64 chunk_tree;
3734 u64 chunk_objectid;
3735 u64 chunk_offset;
3736 int ret;
3737 int slot;
3738 int failed = 0;
3739 bool retried = false;
3740 struct extent_buffer *l;
3741 struct btrfs_key key;
3742 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3743 u64 old_total = btrfs_super_total_bytes(super_copy);
3744 u64 old_size = device->total_bytes;
3745 u64 diff = device->total_bytes - new_size;
3746
3747 if (device->is_tgtdev_for_dev_replace)
3748 return -EINVAL;
3749
3750 path = btrfs_alloc_path();
3751 if (!path)
3752 return -ENOMEM;
3753
3754 path->reada = 2;
3755
3756 lock_chunks(root);
3757
3758 device->total_bytes = new_size;
3759 if (device->writeable) {
3760 device->fs_devices->total_rw_bytes -= diff;
3761 spin_lock(&root->fs_info->free_chunk_lock);
3762 root->fs_info->free_chunk_space -= diff;
3763 spin_unlock(&root->fs_info->free_chunk_lock);
3764 }
3765 unlock_chunks(root);
3766
3767 again:
3768 key.objectid = device->devid;
3769 key.offset = (u64)-1;
3770 key.type = BTRFS_DEV_EXTENT_KEY;
3771
3772 do {
3773 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3774 if (ret < 0)
3775 goto done;
3776
3777 ret = btrfs_previous_item(root, path, 0, key.type);
3778 if (ret < 0)
3779 goto done;
3780 if (ret) {
3781 ret = 0;
3782 btrfs_release_path(path);
3783 break;
3784 }
3785
3786 l = path->nodes[0];
3787 slot = path->slots[0];
3788 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3789
3790 if (key.objectid != device->devid) {
3791 btrfs_release_path(path);
3792 break;
3793 }
3794
3795 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3796 length = btrfs_dev_extent_length(l, dev_extent);
3797
3798 if (key.offset + length <= new_size) {
3799 btrfs_release_path(path);
3800 break;
3801 }
3802
3803 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3804 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3805 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3806 btrfs_release_path(path);
3807
3808 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3809 chunk_offset);
3810 if (ret && ret != -ENOSPC)
3811 goto done;
3812 if (ret == -ENOSPC)
3813 failed++;
3814 } while (key.offset-- > 0);
3815
3816 if (failed && !retried) {
3817 failed = 0;
3818 retried = true;
3819 goto again;
3820 } else if (failed && retried) {
3821 ret = -ENOSPC;
3822 lock_chunks(root);
3823
3824 device->total_bytes = old_size;
3825 if (device->writeable)
3826 device->fs_devices->total_rw_bytes += diff;
3827 spin_lock(&root->fs_info->free_chunk_lock);
3828 root->fs_info->free_chunk_space += diff;
3829 spin_unlock(&root->fs_info->free_chunk_lock);
3830 unlock_chunks(root);
3831 goto done;
3832 }
3833
3834 /* Shrinking succeeded, else we would be at "done". */
3835 trans = btrfs_start_transaction(root, 0);
3836 if (IS_ERR(trans)) {
3837 ret = PTR_ERR(trans);
3838 goto done;
3839 }
3840
3841 lock_chunks(root);
3842
3843 device->disk_total_bytes = new_size;
3844 /* Now btrfs_update_device() will change the on-disk size. */
3845 ret = btrfs_update_device(trans, device);
3846 if (ret) {
3847 unlock_chunks(root);
3848 btrfs_end_transaction(trans, root);
3849 goto done;
3850 }
3851 WARN_ON(diff > old_total);
3852 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3853 unlock_chunks(root);
3854 btrfs_end_transaction(trans, root);
3855 done:
3856 btrfs_free_path(path);
3857 return ret;
3858 }
3859
3860 static int btrfs_add_system_chunk(struct btrfs_root *root,
3861 struct btrfs_key *key,
3862 struct btrfs_chunk *chunk, int item_size)
3863 {
3864 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3865 struct btrfs_disk_key disk_key;
3866 u32 array_size;
3867 u8 *ptr;
3868
3869 array_size = btrfs_super_sys_array_size(super_copy);
3870 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3871 return -EFBIG;
3872
3873 ptr = super_copy->sys_chunk_array + array_size;
3874 btrfs_cpu_key_to_disk(&disk_key, key);
3875 memcpy(ptr, &disk_key, sizeof(disk_key));
3876 ptr += sizeof(disk_key);
3877 memcpy(ptr, chunk, item_size);
3878 item_size += sizeof(disk_key);
3879 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3880 return 0;
3881 }
3882
3883 /*
3884 * sort the devices in descending order by max_avail, total_avail
3885 */
3886 static int btrfs_cmp_device_info(const void *a, const void *b)
3887 {
3888 const struct btrfs_device_info *di_a = a;
3889 const struct btrfs_device_info *di_b = b;
3890
3891 if (di_a->max_avail > di_b->max_avail)
3892 return -1;
3893 if (di_a->max_avail < di_b->max_avail)
3894 return 1;
3895 if (di_a->total_avail > di_b->total_avail)
3896 return -1;
3897 if (di_a->total_avail < di_b->total_avail)
3898 return 1;
3899 return 0;
3900 }
3901
3902 static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3903 [BTRFS_RAID_RAID10] = {
3904 .sub_stripes = 2,
3905 .dev_stripes = 1,
3906 .devs_max = 0, /* 0 == as many as possible */
3907 .devs_min = 4,
3908 .devs_increment = 2,
3909 .ncopies = 2,
3910 },
3911 [BTRFS_RAID_RAID1] = {
3912 .sub_stripes = 1,
3913 .dev_stripes = 1,
3914 .devs_max = 2,
3915 .devs_min = 2,
3916 .devs_increment = 2,
3917 .ncopies = 2,
3918 },
3919 [BTRFS_RAID_DUP] = {
3920 .sub_stripes = 1,
3921 .dev_stripes = 2,
3922 .devs_max = 1,
3923 .devs_min = 1,
3924 .devs_increment = 1,
3925 .ncopies = 2,
3926 },
3927 [BTRFS_RAID_RAID0] = {
3928 .sub_stripes = 1,
3929 .dev_stripes = 1,
3930 .devs_max = 0,
3931 .devs_min = 2,
3932 .devs_increment = 1,
3933 .ncopies = 1,
3934 },
3935 [BTRFS_RAID_SINGLE] = {
3936 .sub_stripes = 1,
3937 .dev_stripes = 1,
3938 .devs_max = 1,
3939 .devs_min = 1,
3940 .devs_increment = 1,
3941 .ncopies = 1,
3942 },
3943 [BTRFS_RAID_RAID5] = {
3944 .sub_stripes = 1,
3945 .dev_stripes = 1,
3946 .devs_max = 0,
3947 .devs_min = 2,
3948 .devs_increment = 1,
3949 .ncopies = 2,
3950 },
3951 [BTRFS_RAID_RAID6] = {
3952 .sub_stripes = 1,
3953 .dev_stripes = 1,
3954 .devs_max = 0,
3955 .devs_min = 3,
3956 .devs_increment = 1,
3957 .ncopies = 3,
3958 },
3959 };
3960
3961 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3962 {
3963 /* TODO allow them to set a preferred stripe size */
3964 return 64 * 1024;
3965 }
3966
3967 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3968 {
3969 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3970 return;
3971
3972 btrfs_set_fs_incompat(info, RAID56);
3973 }
3974
3975 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3976 struct btrfs_root *extent_root, u64 start,
3977 u64 type)
3978 {
3979 struct btrfs_fs_info *info = extent_root->fs_info;
3980 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3981 struct list_head *cur;
3982 struct map_lookup *map = NULL;
3983 struct extent_map_tree *em_tree;
3984 struct extent_map *em;
3985 struct btrfs_device_info *devices_info = NULL;
3986 u64 total_avail;
3987 int num_stripes; /* total number of stripes to allocate */
3988 int data_stripes; /* number of stripes that count for
3989 block group size */
3990 int sub_stripes; /* sub_stripes info for map */
3991 int dev_stripes; /* stripes per dev */
3992 int devs_max; /* max devs to use */
3993 int devs_min; /* min devs needed */
3994 int devs_increment; /* ndevs has to be a multiple of this */
3995 int ncopies; /* how many copies to data has */
3996 int ret;
3997 u64 max_stripe_size;
3998 u64 max_chunk_size;
3999 u64 stripe_size;
4000 u64 num_bytes;
4001 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
4002 int ndevs;
4003 int i;
4004 int j;
4005 int index;
4006
4007 BUG_ON(!alloc_profile_is_valid(type, 0));
4008
4009 if (list_empty(&fs_devices->alloc_list))
4010 return -ENOSPC;
4011
4012 index = __get_raid_index(type);
4013
4014 sub_stripes = btrfs_raid_array[index].sub_stripes;
4015 dev_stripes = btrfs_raid_array[index].dev_stripes;
4016 devs_max = btrfs_raid_array[index].devs_max;
4017 devs_min = btrfs_raid_array[index].devs_min;
4018 devs_increment = btrfs_raid_array[index].devs_increment;
4019 ncopies = btrfs_raid_array[index].ncopies;
4020
4021 if (type & BTRFS_BLOCK_GROUP_DATA) {
4022 max_stripe_size = 1024 * 1024 * 1024;
4023 max_chunk_size = 10 * max_stripe_size;
4024 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
4025 /* for larger filesystems, use larger metadata chunks */
4026 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
4027 max_stripe_size = 1024 * 1024 * 1024;
4028 else
4029 max_stripe_size = 256 * 1024 * 1024;
4030 max_chunk_size = max_stripe_size;
4031 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
4032 max_stripe_size = 32 * 1024 * 1024;
4033 max_chunk_size = 2 * max_stripe_size;
4034 } else {
4035 btrfs_err(info, "invalid chunk type 0x%llx requested\n",
4036 type);
4037 BUG_ON(1);
4038 }
4039
4040 /* we don't want a chunk larger than 10% of writeable space */
4041 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
4042 max_chunk_size);
4043
4044 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
4045 GFP_NOFS);
4046 if (!devices_info)
4047 return -ENOMEM;
4048
4049 cur = fs_devices->alloc_list.next;
4050
4051 /*
4052 * in the first pass through the devices list, we gather information
4053 * about the available holes on each device.
4054 */
4055 ndevs = 0;
4056 while (cur != &fs_devices->alloc_list) {
4057 struct btrfs_device *device;
4058 u64 max_avail;
4059 u64 dev_offset;
4060
4061 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
4062
4063 cur = cur->next;
4064
4065 if (!device->writeable) {
4066 WARN(1, KERN_ERR
4067 "BTRFS: read-only device in alloc_list\n");
4068 continue;
4069 }
4070
4071 if (!device->in_fs_metadata ||
4072 device->is_tgtdev_for_dev_replace)
4073 continue;
4074
4075 if (device->total_bytes > device->bytes_used)
4076 total_avail = device->total_bytes - device->bytes_used;
4077 else
4078 total_avail = 0;
4079
4080 /* If there is no space on this device, skip it. */
4081 if (total_avail == 0)
4082 continue;
4083
4084 ret = find_free_dev_extent(trans, device,
4085 max_stripe_size * dev_stripes,
4086 &dev_offset, &max_avail);
4087 if (ret && ret != -ENOSPC)
4088 goto error;
4089
4090 if (ret == 0)
4091 max_avail = max_stripe_size * dev_stripes;
4092
4093 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
4094 continue;
4095
4096 if (ndevs == fs_devices->rw_devices) {
4097 WARN(1, "%s: found more than %llu devices\n",
4098 __func__, fs_devices->rw_devices);
4099 break;
4100 }
4101 devices_info[ndevs].dev_offset = dev_offset;
4102 devices_info[ndevs].max_avail = max_avail;
4103 devices_info[ndevs].total_avail = total_avail;
4104 devices_info[ndevs].dev = device;
4105 ++ndevs;
4106 }
4107
4108 /*
4109 * now sort the devices by hole size / available space
4110 */
4111 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
4112 btrfs_cmp_device_info, NULL);
4113
4114 /* round down to number of usable stripes */
4115 ndevs -= ndevs % devs_increment;
4116
4117 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
4118 ret = -ENOSPC;
4119 goto error;
4120 }
4121
4122 if (devs_max && ndevs > devs_max)
4123 ndevs = devs_max;
4124 /*
4125 * the primary goal is to maximize the number of stripes, so use as many
4126 * devices as possible, even if the stripes are not maximum sized.
4127 */
4128 stripe_size = devices_info[ndevs-1].max_avail;
4129 num_stripes = ndevs * dev_stripes;
4130
4131 /*
4132 * this will have to be fixed for RAID1 and RAID10 over
4133 * more drives
4134 */
4135 data_stripes = num_stripes / ncopies;
4136
4137 if (type & BTRFS_BLOCK_GROUP_RAID5) {
4138 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
4139 btrfs_super_stripesize(info->super_copy));
4140 data_stripes = num_stripes - 1;
4141 }
4142 if (type & BTRFS_BLOCK_GROUP_RAID6) {
4143 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
4144 btrfs_super_stripesize(info->super_copy));
4145 data_stripes = num_stripes - 2;
4146 }
4147
4148 /*
4149 * Use the number of data stripes to figure out how big this chunk
4150 * is really going to be in terms of logical address space,
4151 * and compare that answer with the max chunk size
4152 */
4153 if (stripe_size * data_stripes > max_chunk_size) {
4154 u64 mask = (1ULL << 24) - 1;
4155 stripe_size = max_chunk_size;
4156 do_div(stripe_size, data_stripes);
4157
4158 /* bump the answer up to a 16MB boundary */
4159 stripe_size = (stripe_size + mask) & ~mask;
4160
4161 /* but don't go higher than the limits we found
4162 * while searching for free extents
4163 */
4164 if (stripe_size > devices_info[ndevs-1].max_avail)
4165 stripe_size = devices_info[ndevs-1].max_avail;
4166 }
4167
4168 do_div(stripe_size, dev_stripes);
4169
4170 /* align to BTRFS_STRIPE_LEN */
4171 do_div(stripe_size, raid_stripe_len);
4172 stripe_size *= raid_stripe_len;
4173
4174 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4175 if (!map) {
4176 ret = -ENOMEM;
4177 goto error;
4178 }
4179 map->num_stripes = num_stripes;
4180
4181 for (i = 0; i < ndevs; ++i) {
4182 for (j = 0; j < dev_stripes; ++j) {
4183 int s = i * dev_stripes + j;
4184 map->stripes[s].dev = devices_info[i].dev;
4185 map->stripes[s].physical = devices_info[i].dev_offset +
4186 j * stripe_size;
4187 }
4188 }
4189 map->sector_size = extent_root->sectorsize;
4190 map->stripe_len = raid_stripe_len;
4191 map->io_align = raid_stripe_len;
4192 map->io_width = raid_stripe_len;
4193 map->type = type;
4194 map->sub_stripes = sub_stripes;
4195
4196 num_bytes = stripe_size * data_stripes;
4197
4198 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
4199
4200 em = alloc_extent_map();
4201 if (!em) {
4202 ret = -ENOMEM;
4203 goto error;
4204 }
4205 em->bdev = (struct block_device *)map;
4206 em->start = start;
4207 em->len = num_bytes;
4208 em->block_start = 0;
4209 em->block_len = em->len;
4210 em->orig_block_len = stripe_size;
4211
4212 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4213 write_lock(&em_tree->lock);
4214 ret = add_extent_mapping(em_tree, em, 0);
4215 if (!ret) {
4216 list_add_tail(&em->list, &trans->transaction->pending_chunks);
4217 atomic_inc(&em->refs);
4218 }
4219 write_unlock(&em_tree->lock);
4220 if (ret) {
4221 free_extent_map(em);
4222 goto error;
4223 }
4224
4225 ret = btrfs_make_block_group(trans, extent_root, 0, type,
4226 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4227 start, num_bytes);
4228 if (ret)
4229 goto error_del_extent;
4230
4231 free_extent_map(em);
4232 check_raid56_incompat_flag(extent_root->fs_info, type);
4233
4234 kfree(devices_info);
4235 return 0;
4236
4237 error_del_extent:
4238 write_lock(&em_tree->lock);
4239 remove_extent_mapping(em_tree, em);
4240 write_unlock(&em_tree->lock);
4241
4242 /* One for our allocation */
4243 free_extent_map(em);
4244 /* One for the tree reference */
4245 free_extent_map(em);
4246 error:
4247 kfree(map);
4248 kfree(devices_info);
4249 return ret;
4250 }
4251
4252 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
4253 struct btrfs_root *extent_root,
4254 u64 chunk_offset, u64 chunk_size)
4255 {
4256 struct btrfs_key key;
4257 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4258 struct btrfs_device *device;
4259 struct btrfs_chunk *chunk;
4260 struct btrfs_stripe *stripe;
4261 struct extent_map_tree *em_tree;
4262 struct extent_map *em;
4263 struct map_lookup *map;
4264 size_t item_size;
4265 u64 dev_offset;
4266 u64 stripe_size;
4267 int i = 0;
4268 int ret;
4269
4270 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4271 read_lock(&em_tree->lock);
4272 em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
4273 read_unlock(&em_tree->lock);
4274
4275 if (!em) {
4276 btrfs_crit(extent_root->fs_info, "unable to find logical "
4277 "%Lu len %Lu", chunk_offset, chunk_size);
4278 return -EINVAL;
4279 }
4280
4281 if (em->start != chunk_offset || em->len != chunk_size) {
4282 btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
4283 " %Lu-%Lu, found %Lu-%Lu\n", chunk_offset,
4284 chunk_size, em->start, em->len);
4285 free_extent_map(em);
4286 return -EINVAL;
4287 }
4288
4289 map = (struct map_lookup *)em->bdev;
4290 item_size = btrfs_chunk_item_size(map->num_stripes);
4291 stripe_size = em->orig_block_len;
4292
4293 chunk = kzalloc(item_size, GFP_NOFS);
4294 if (!chunk) {
4295 ret = -ENOMEM;
4296 goto out;
4297 }
4298
4299 for (i = 0; i < map->num_stripes; i++) {
4300 device = map->stripes[i].dev;
4301 dev_offset = map->stripes[i].physical;
4302
4303 device->bytes_used += stripe_size;
4304 ret = btrfs_update_device(trans, device);
4305 if (ret)
4306 goto out;
4307 ret = btrfs_alloc_dev_extent(trans, device,
4308 chunk_root->root_key.objectid,
4309 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4310 chunk_offset, dev_offset,
4311 stripe_size);
4312 if (ret)
4313 goto out;
4314 }
4315
4316 spin_lock(&extent_root->fs_info->free_chunk_lock);
4317 extent_root->fs_info->free_chunk_space -= (stripe_size *
4318 map->num_stripes);
4319 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4320
4321 stripe = &chunk->stripe;
4322 for (i = 0; i < map->num_stripes; i++) {
4323 device = map->stripes[i].dev;
4324 dev_offset = map->stripes[i].physical;
4325
4326 btrfs_set_stack_stripe_devid(stripe, device->devid);
4327 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4328 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4329 stripe++;
4330 }
4331
4332 btrfs_set_stack_chunk_length(chunk, chunk_size);
4333 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4334 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4335 btrfs_set_stack_chunk_type(chunk, map->type);
4336 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4337 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4338 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4339 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4340 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4341
4342 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4343 key.type = BTRFS_CHUNK_ITEM_KEY;
4344 key.offset = chunk_offset;
4345
4346 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4347 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4348 /*
4349 * TODO: Cleanup of inserted chunk root in case of
4350 * failure.
4351 */
4352 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4353 item_size);
4354 }
4355
4356 out:
4357 kfree(chunk);
4358 free_extent_map(em);
4359 return ret;
4360 }
4361
4362 /*
4363 * Chunk allocation falls into two parts. The first part does works
4364 * that make the new allocated chunk useable, but not do any operation
4365 * that modifies the chunk tree. The second part does the works that
4366 * require modifying the chunk tree. This division is important for the
4367 * bootstrap process of adding storage to a seed btrfs.
4368 */
4369 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4370 struct btrfs_root *extent_root, u64 type)
4371 {
4372 u64 chunk_offset;
4373
4374 chunk_offset = find_next_chunk(extent_root->fs_info);
4375 return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
4376 }
4377
4378 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4379 struct btrfs_root *root,
4380 struct btrfs_device *device)
4381 {
4382 u64 chunk_offset;
4383 u64 sys_chunk_offset;
4384 u64 alloc_profile;
4385 struct btrfs_fs_info *fs_info = root->fs_info;
4386 struct btrfs_root *extent_root = fs_info->extent_root;
4387 int ret;
4388
4389 chunk_offset = find_next_chunk(fs_info);
4390 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4391 ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
4392 alloc_profile);
4393 if (ret)
4394 return ret;
4395
4396 sys_chunk_offset = find_next_chunk(root->fs_info);
4397 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4398 ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
4399 alloc_profile);
4400 if (ret) {
4401 btrfs_abort_transaction(trans, root, ret);
4402 goto out;
4403 }
4404
4405 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4406 if (ret)
4407 btrfs_abort_transaction(trans, root, ret);
4408 out:
4409 return ret;
4410 }
4411
4412 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4413 {
4414 struct extent_map *em;
4415 struct map_lookup *map;
4416 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4417 int readonly = 0;
4418 int i;
4419
4420 read_lock(&map_tree->map_tree.lock);
4421 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4422 read_unlock(&map_tree->map_tree.lock);
4423 if (!em)
4424 return 1;
4425
4426 if (btrfs_test_opt(root, DEGRADED)) {
4427 free_extent_map(em);
4428 return 0;
4429 }
4430
4431 map = (struct map_lookup *)em->bdev;
4432 for (i = 0; i < map->num_stripes; i++) {
4433 if (!map->stripes[i].dev->writeable) {
4434 readonly = 1;
4435 break;
4436 }
4437 }
4438 free_extent_map(em);
4439 return readonly;
4440 }
4441
4442 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4443 {
4444 extent_map_tree_init(&tree->map_tree);
4445 }
4446
4447 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4448 {
4449 struct extent_map *em;
4450
4451 while (1) {
4452 write_lock(&tree->map_tree.lock);
4453 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4454 if (em)
4455 remove_extent_mapping(&tree->map_tree, em);
4456 write_unlock(&tree->map_tree.lock);
4457 if (!em)
4458 break;
4459 kfree(em->bdev);
4460 /* once for us */
4461 free_extent_map(em);
4462 /* once for the tree */
4463 free_extent_map(em);
4464 }
4465 }
4466
4467 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4468 {
4469 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4470 struct extent_map *em;
4471 struct map_lookup *map;
4472 struct extent_map_tree *em_tree = &map_tree->map_tree;
4473 int ret;
4474
4475 read_lock(&em_tree->lock);
4476 em = lookup_extent_mapping(em_tree, logical, len);
4477 read_unlock(&em_tree->lock);
4478
4479 /*
4480 * We could return errors for these cases, but that could get ugly and
4481 * we'd probably do the same thing which is just not do anything else
4482 * and exit, so return 1 so the callers don't try to use other copies.
4483 */
4484 if (!em) {
4485 btrfs_crit(fs_info, "No mapping for %Lu-%Lu\n", logical,
4486 logical+len);
4487 return 1;
4488 }
4489
4490 if (em->start > logical || em->start + em->len < logical) {
4491 btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got "
4492 "%Lu-%Lu\n", logical, logical+len, em->start,
4493 em->start + em->len);
4494 free_extent_map(em);
4495 return 1;
4496 }
4497
4498 map = (struct map_lookup *)em->bdev;
4499 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4500 ret = map->num_stripes;
4501 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4502 ret = map->sub_stripes;
4503 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4504 ret = 2;
4505 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4506 ret = 3;
4507 else
4508 ret = 1;
4509 free_extent_map(em);
4510
4511 btrfs_dev_replace_lock(&fs_info->dev_replace);
4512 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4513 ret++;
4514 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4515
4516 return ret;
4517 }
4518
4519 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4520 struct btrfs_mapping_tree *map_tree,
4521 u64 logical)
4522 {
4523 struct extent_map *em;
4524 struct map_lookup *map;
4525 struct extent_map_tree *em_tree = &map_tree->map_tree;
4526 unsigned long len = root->sectorsize;
4527
4528 read_lock(&em_tree->lock);
4529 em = lookup_extent_mapping(em_tree, logical, len);
4530 read_unlock(&em_tree->lock);
4531 BUG_ON(!em);
4532
4533 BUG_ON(em->start > logical || em->start + em->len < logical);
4534 map = (struct map_lookup *)em->bdev;
4535 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4536 BTRFS_BLOCK_GROUP_RAID6)) {
4537 len = map->stripe_len * nr_data_stripes(map);
4538 }
4539 free_extent_map(em);
4540 return len;
4541 }
4542
4543 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4544 u64 logical, u64 len, int mirror_num)
4545 {
4546 struct extent_map *em;
4547 struct map_lookup *map;
4548 struct extent_map_tree *em_tree = &map_tree->map_tree;
4549 int ret = 0;
4550
4551 read_lock(&em_tree->lock);
4552 em = lookup_extent_mapping(em_tree, logical, len);
4553 read_unlock(&em_tree->lock);
4554 BUG_ON(!em);
4555
4556 BUG_ON(em->start > logical || em->start + em->len < logical);
4557 map = (struct map_lookup *)em->bdev;
4558 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4559 BTRFS_BLOCK_GROUP_RAID6))
4560 ret = 1;
4561 free_extent_map(em);
4562 return ret;
4563 }
4564
4565 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4566 struct map_lookup *map, int first, int num,
4567 int optimal, int dev_replace_is_ongoing)
4568 {
4569 int i;
4570 int tolerance;
4571 struct btrfs_device *srcdev;
4572
4573 if (dev_replace_is_ongoing &&
4574 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4575 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4576 srcdev = fs_info->dev_replace.srcdev;
4577 else
4578 srcdev = NULL;
4579
4580 /*
4581 * try to avoid the drive that is the source drive for a
4582 * dev-replace procedure, only choose it if no other non-missing
4583 * mirror is available
4584 */
4585 for (tolerance = 0; tolerance < 2; tolerance++) {
4586 if (map->stripes[optimal].dev->bdev &&
4587 (tolerance || map->stripes[optimal].dev != srcdev))
4588 return optimal;
4589 for (i = first; i < first + num; i++) {
4590 if (map->stripes[i].dev->bdev &&
4591 (tolerance || map->stripes[i].dev != srcdev))
4592 return i;
4593 }
4594 }
4595
4596 /* we couldn't find one that doesn't fail. Just return something
4597 * and the io error handling code will clean up eventually
4598 */
4599 return optimal;
4600 }
4601
4602 static inline int parity_smaller(u64 a, u64 b)
4603 {
4604 return a > b;
4605 }
4606
4607 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4608 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4609 {
4610 struct btrfs_bio_stripe s;
4611 int i;
4612 u64 l;
4613 int again = 1;
4614
4615 while (again) {
4616 again = 0;
4617 for (i = 0; i < bbio->num_stripes - 1; i++) {
4618 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4619 s = bbio->stripes[i];
4620 l = raid_map[i];
4621 bbio->stripes[i] = bbio->stripes[i+1];
4622 raid_map[i] = raid_map[i+1];
4623 bbio->stripes[i+1] = s;
4624 raid_map[i+1] = l;
4625 again = 1;
4626 }
4627 }
4628 }
4629 }
4630
4631 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4632 u64 logical, u64 *length,
4633 struct btrfs_bio **bbio_ret,
4634 int mirror_num, u64 **raid_map_ret)
4635 {
4636 struct extent_map *em;
4637 struct map_lookup *map;
4638 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4639 struct extent_map_tree *em_tree = &map_tree->map_tree;
4640 u64 offset;
4641 u64 stripe_offset;
4642 u64 stripe_end_offset;
4643 u64 stripe_nr;
4644 u64 stripe_nr_orig;
4645 u64 stripe_nr_end;
4646 u64 stripe_len;
4647 u64 *raid_map = NULL;
4648 int stripe_index;
4649 int i;
4650 int ret = 0;
4651 int num_stripes;
4652 int max_errors = 0;
4653 struct btrfs_bio *bbio = NULL;
4654 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4655 int dev_replace_is_ongoing = 0;
4656 int num_alloc_stripes;
4657 int patch_the_first_stripe_for_dev_replace = 0;
4658 u64 physical_to_patch_in_first_stripe = 0;
4659 u64 raid56_full_stripe_start = (u64)-1;
4660
4661 read_lock(&em_tree->lock);
4662 em = lookup_extent_mapping(em_tree, logical, *length);
4663 read_unlock(&em_tree->lock);
4664
4665 if (!em) {
4666 btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4667 logical, *length);
4668 return -EINVAL;
4669 }
4670
4671 if (em->start > logical || em->start + em->len < logical) {
4672 btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4673 "found %Lu-%Lu\n", logical, em->start,
4674 em->start + em->len);
4675 free_extent_map(em);
4676 return -EINVAL;
4677 }
4678
4679 map = (struct map_lookup *)em->bdev;
4680 offset = logical - em->start;
4681
4682 stripe_len = map->stripe_len;
4683 stripe_nr = offset;
4684 /*
4685 * stripe_nr counts the total number of stripes we have to stride
4686 * to get to this block
4687 */
4688 do_div(stripe_nr, stripe_len);
4689
4690 stripe_offset = stripe_nr * stripe_len;
4691 BUG_ON(offset < stripe_offset);
4692
4693 /* stripe_offset is the offset of this block in its stripe*/
4694 stripe_offset = offset - stripe_offset;
4695
4696 /* if we're here for raid56, we need to know the stripe aligned start */
4697 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4698 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4699 raid56_full_stripe_start = offset;
4700
4701 /* allow a write of a full stripe, but make sure we don't
4702 * allow straddling of stripes
4703 */
4704 do_div(raid56_full_stripe_start, full_stripe_len);
4705 raid56_full_stripe_start *= full_stripe_len;
4706 }
4707
4708 if (rw & REQ_DISCARD) {
4709 /* we don't discard raid56 yet */
4710 if (map->type &
4711 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4712 ret = -EOPNOTSUPP;
4713 goto out;
4714 }
4715 *length = min_t(u64, em->len - offset, *length);
4716 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4717 u64 max_len;
4718 /* For writes to RAID[56], allow a full stripeset across all disks.
4719 For other RAID types and for RAID[56] reads, just allow a single
4720 stripe (on a single disk). */
4721 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4722 (rw & REQ_WRITE)) {
4723 max_len = stripe_len * nr_data_stripes(map) -
4724 (offset - raid56_full_stripe_start);
4725 } else {
4726 /* we limit the length of each bio to what fits in a stripe */
4727 max_len = stripe_len - stripe_offset;
4728 }
4729 *length = min_t(u64, em->len - offset, max_len);
4730 } else {
4731 *length = em->len - offset;
4732 }
4733
4734 /* This is for when we're called from btrfs_merge_bio_hook() and all
4735 it cares about is the length */
4736 if (!bbio_ret)
4737 goto out;
4738
4739 btrfs_dev_replace_lock(dev_replace);
4740 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4741 if (!dev_replace_is_ongoing)
4742 btrfs_dev_replace_unlock(dev_replace);
4743
4744 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4745 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4746 dev_replace->tgtdev != NULL) {
4747 /*
4748 * in dev-replace case, for repair case (that's the only
4749 * case where the mirror is selected explicitly when
4750 * calling btrfs_map_block), blocks left of the left cursor
4751 * can also be read from the target drive.
4752 * For REQ_GET_READ_MIRRORS, the target drive is added as
4753 * the last one to the array of stripes. For READ, it also
4754 * needs to be supported using the same mirror number.
4755 * If the requested block is not left of the left cursor,
4756 * EIO is returned. This can happen because btrfs_num_copies()
4757 * returns one more in the dev-replace case.
4758 */
4759 u64 tmp_length = *length;
4760 struct btrfs_bio *tmp_bbio = NULL;
4761 int tmp_num_stripes;
4762 u64 srcdev_devid = dev_replace->srcdev->devid;
4763 int index_srcdev = 0;
4764 int found = 0;
4765 u64 physical_of_found = 0;
4766
4767 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4768 logical, &tmp_length, &tmp_bbio, 0, NULL);
4769 if (ret) {
4770 WARN_ON(tmp_bbio != NULL);
4771 goto out;
4772 }
4773
4774 tmp_num_stripes = tmp_bbio->num_stripes;
4775 if (mirror_num > tmp_num_stripes) {
4776 /*
4777 * REQ_GET_READ_MIRRORS does not contain this
4778 * mirror, that means that the requested area
4779 * is not left of the left cursor
4780 */
4781 ret = -EIO;
4782 kfree(tmp_bbio);
4783 goto out;
4784 }
4785
4786 /*
4787 * process the rest of the function using the mirror_num
4788 * of the source drive. Therefore look it up first.
4789 * At the end, patch the device pointer to the one of the
4790 * target drive.
4791 */
4792 for (i = 0; i < tmp_num_stripes; i++) {
4793 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4794 /*
4795 * In case of DUP, in order to keep it
4796 * simple, only add the mirror with the
4797 * lowest physical address
4798 */
4799 if (found &&
4800 physical_of_found <=
4801 tmp_bbio->stripes[i].physical)
4802 continue;
4803 index_srcdev = i;
4804 found = 1;
4805 physical_of_found =
4806 tmp_bbio->stripes[i].physical;
4807 }
4808 }
4809
4810 if (found) {
4811 mirror_num = index_srcdev + 1;
4812 patch_the_first_stripe_for_dev_replace = 1;
4813 physical_to_patch_in_first_stripe = physical_of_found;
4814 } else {
4815 WARN_ON(1);
4816 ret = -EIO;
4817 kfree(tmp_bbio);
4818 goto out;
4819 }
4820
4821 kfree(tmp_bbio);
4822 } else if (mirror_num > map->num_stripes) {
4823 mirror_num = 0;
4824 }
4825
4826 num_stripes = 1;
4827 stripe_index = 0;
4828 stripe_nr_orig = stripe_nr;
4829 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
4830 do_div(stripe_nr_end, map->stripe_len);
4831 stripe_end_offset = stripe_nr_end * map->stripe_len -
4832 (offset + *length);
4833
4834 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4835 if (rw & REQ_DISCARD)
4836 num_stripes = min_t(u64, map->num_stripes,
4837 stripe_nr_end - stripe_nr_orig);
4838 stripe_index = do_div(stripe_nr, map->num_stripes);
4839 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4840 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4841 num_stripes = map->num_stripes;
4842 else if (mirror_num)
4843 stripe_index = mirror_num - 1;
4844 else {
4845 stripe_index = find_live_mirror(fs_info, map, 0,
4846 map->num_stripes,
4847 current->pid % map->num_stripes,
4848 dev_replace_is_ongoing);
4849 mirror_num = stripe_index + 1;
4850 }
4851
4852 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4853 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4854 num_stripes = map->num_stripes;
4855 } else if (mirror_num) {
4856 stripe_index = mirror_num - 1;
4857 } else {
4858 mirror_num = 1;
4859 }
4860
4861 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4862 int factor = map->num_stripes / map->sub_stripes;
4863
4864 stripe_index = do_div(stripe_nr, factor);
4865 stripe_index *= map->sub_stripes;
4866
4867 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4868 num_stripes = map->sub_stripes;
4869 else if (rw & REQ_DISCARD)
4870 num_stripes = min_t(u64, map->sub_stripes *
4871 (stripe_nr_end - stripe_nr_orig),
4872 map->num_stripes);
4873 else if (mirror_num)
4874 stripe_index += mirror_num - 1;
4875 else {
4876 int old_stripe_index = stripe_index;
4877 stripe_index = find_live_mirror(fs_info, map,
4878 stripe_index,
4879 map->sub_stripes, stripe_index +
4880 current->pid % map->sub_stripes,
4881 dev_replace_is_ongoing);
4882 mirror_num = stripe_index - old_stripe_index + 1;
4883 }
4884
4885 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4886 BTRFS_BLOCK_GROUP_RAID6)) {
4887 u64 tmp;
4888
4889 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4890 && raid_map_ret) {
4891 int i, rot;
4892
4893 /* push stripe_nr back to the start of the full stripe */
4894 stripe_nr = raid56_full_stripe_start;
4895 do_div(stripe_nr, stripe_len);
4896
4897 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4898
4899 /* RAID[56] write or recovery. Return all stripes */
4900 num_stripes = map->num_stripes;
4901 max_errors = nr_parity_stripes(map);
4902
4903 raid_map = kmalloc_array(num_stripes, sizeof(u64),
4904 GFP_NOFS);
4905 if (!raid_map) {
4906 ret = -ENOMEM;
4907 goto out;
4908 }
4909
4910 /* Work out the disk rotation on this stripe-set */
4911 tmp = stripe_nr;
4912 rot = do_div(tmp, num_stripes);
4913
4914 /* Fill in the logical address of each stripe */
4915 tmp = stripe_nr * nr_data_stripes(map);
4916 for (i = 0; i < nr_data_stripes(map); i++)
4917 raid_map[(i+rot) % num_stripes] =
4918 em->start + (tmp + i) * map->stripe_len;
4919
4920 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4921 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4922 raid_map[(i+rot+1) % num_stripes] =
4923 RAID6_Q_STRIPE;
4924
4925 *length = map->stripe_len;
4926 stripe_index = 0;
4927 stripe_offset = 0;
4928 } else {
4929 /*
4930 * Mirror #0 or #1 means the original data block.
4931 * Mirror #2 is RAID5 parity block.
4932 * Mirror #3 is RAID6 Q block.
4933 */
4934 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4935 if (mirror_num > 1)
4936 stripe_index = nr_data_stripes(map) +
4937 mirror_num - 2;
4938
4939 /* We distribute the parity blocks across stripes */
4940 tmp = stripe_nr + stripe_index;
4941 stripe_index = do_div(tmp, map->num_stripes);
4942 }
4943 } else {
4944 /*
4945 * after this do_div call, stripe_nr is the number of stripes
4946 * on this device we have to walk to find the data, and
4947 * stripe_index is the number of our device in the stripe array
4948 */
4949 stripe_index = do_div(stripe_nr, map->num_stripes);
4950 mirror_num = stripe_index + 1;
4951 }
4952 BUG_ON(stripe_index >= map->num_stripes);
4953
4954 num_alloc_stripes = num_stripes;
4955 if (dev_replace_is_ongoing) {
4956 if (rw & (REQ_WRITE | REQ_DISCARD))
4957 num_alloc_stripes <<= 1;
4958 if (rw & REQ_GET_READ_MIRRORS)
4959 num_alloc_stripes++;
4960 }
4961 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4962 if (!bbio) {
4963 kfree(raid_map);
4964 ret = -ENOMEM;
4965 goto out;
4966 }
4967 atomic_set(&bbio->error, 0);
4968
4969 if (rw & REQ_DISCARD) {
4970 int factor = 0;
4971 int sub_stripes = 0;
4972 u64 stripes_per_dev = 0;
4973 u32 remaining_stripes = 0;
4974 u32 last_stripe = 0;
4975
4976 if (map->type &
4977 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4978 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4979 sub_stripes = 1;
4980 else
4981 sub_stripes = map->sub_stripes;
4982
4983 factor = map->num_stripes / sub_stripes;
4984 stripes_per_dev = div_u64_rem(stripe_nr_end -
4985 stripe_nr_orig,
4986 factor,
4987 &remaining_stripes);
4988 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4989 last_stripe *= sub_stripes;
4990 }
4991
4992 for (i = 0; i < num_stripes; i++) {
4993 bbio->stripes[i].physical =
4994 map->stripes[stripe_index].physical +
4995 stripe_offset + stripe_nr * map->stripe_len;
4996 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4997
4998 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4999 BTRFS_BLOCK_GROUP_RAID10)) {
5000 bbio->stripes[i].length = stripes_per_dev *
5001 map->stripe_len;
5002
5003 if (i / sub_stripes < remaining_stripes)
5004 bbio->stripes[i].length +=
5005 map->stripe_len;
5006
5007 /*
5008 * Special for the first stripe and
5009 * the last stripe:
5010 *
5011 * |-------|...|-------|
5012 * |----------|
5013 * off end_off
5014 */
5015 if (i < sub_stripes)
5016 bbio->stripes[i].length -=
5017 stripe_offset;
5018
5019 if (stripe_index >= last_stripe &&
5020 stripe_index <= (last_stripe +
5021 sub_stripes - 1))
5022 bbio->stripes[i].length -=
5023 stripe_end_offset;
5024
5025 if (i == sub_stripes - 1)
5026 stripe_offset = 0;
5027 } else
5028 bbio->stripes[i].length = *length;
5029
5030 stripe_index++;
5031 if (stripe_index == map->num_stripes) {
5032 /* This could only happen for RAID0/10 */
5033 stripe_index = 0;
5034 stripe_nr++;
5035 }
5036 }
5037 } else {
5038 for (i = 0; i < num_stripes; i++) {
5039 bbio->stripes[i].physical =
5040 map->stripes[stripe_index].physical +
5041 stripe_offset +
5042 stripe_nr * map->stripe_len;
5043 bbio->stripes[i].dev =
5044 map->stripes[stripe_index].dev;
5045 stripe_index++;
5046 }
5047 }
5048
5049 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
5050 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
5051 BTRFS_BLOCK_GROUP_RAID10 |
5052 BTRFS_BLOCK_GROUP_RAID5 |
5053 BTRFS_BLOCK_GROUP_DUP)) {
5054 max_errors = 1;
5055 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
5056 max_errors = 2;
5057 }
5058 }
5059
5060 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
5061 dev_replace->tgtdev != NULL) {
5062 int index_where_to_add;
5063 u64 srcdev_devid = dev_replace->srcdev->devid;
5064
5065 /*
5066 * duplicate the write operations while the dev replace
5067 * procedure is running. Since the copying of the old disk
5068 * to the new disk takes place at run time while the
5069 * filesystem is mounted writable, the regular write
5070 * operations to the old disk have to be duplicated to go
5071 * to the new disk as well.
5072 * Note that device->missing is handled by the caller, and
5073 * that the write to the old disk is already set up in the
5074 * stripes array.
5075 */
5076 index_where_to_add = num_stripes;
5077 for (i = 0; i < num_stripes; i++) {
5078 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5079 /* write to new disk, too */
5080 struct btrfs_bio_stripe *new =
5081 bbio->stripes + index_where_to_add;
5082 struct btrfs_bio_stripe *old =
5083 bbio->stripes + i;
5084
5085 new->physical = old->physical;
5086 new->length = old->length;
5087 new->dev = dev_replace->tgtdev;
5088 index_where_to_add++;
5089 max_errors++;
5090 }
5091 }
5092 num_stripes = index_where_to_add;
5093 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
5094 dev_replace->tgtdev != NULL) {
5095 u64 srcdev_devid = dev_replace->srcdev->devid;
5096 int index_srcdev = 0;
5097 int found = 0;
5098 u64 physical_of_found = 0;
5099
5100 /*
5101 * During the dev-replace procedure, the target drive can
5102 * also be used to read data in case it is needed to repair
5103 * a corrupt block elsewhere. This is possible if the
5104 * requested area is left of the left cursor. In this area,
5105 * the target drive is a full copy of the source drive.
5106 */
5107 for (i = 0; i < num_stripes; i++) {
5108 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5109 /*
5110 * In case of DUP, in order to keep it
5111 * simple, only add the mirror with the
5112 * lowest physical address
5113 */
5114 if (found &&
5115 physical_of_found <=
5116 bbio->stripes[i].physical)
5117 continue;
5118 index_srcdev = i;
5119 found = 1;
5120 physical_of_found = bbio->stripes[i].physical;
5121 }
5122 }
5123 if (found) {
5124 u64 length = map->stripe_len;
5125
5126 if (physical_of_found + length <=
5127 dev_replace->cursor_left) {
5128 struct btrfs_bio_stripe *tgtdev_stripe =
5129 bbio->stripes + num_stripes;
5130
5131 tgtdev_stripe->physical = physical_of_found;
5132 tgtdev_stripe->length =
5133 bbio->stripes[index_srcdev].length;
5134 tgtdev_stripe->dev = dev_replace->tgtdev;
5135
5136 num_stripes++;
5137 }
5138 }
5139 }
5140
5141 *bbio_ret = bbio;
5142 bbio->num_stripes = num_stripes;
5143 bbio->max_errors = max_errors;
5144 bbio->mirror_num = mirror_num;
5145
5146 /*
5147 * this is the case that REQ_READ && dev_replace_is_ongoing &&
5148 * mirror_num == num_stripes + 1 && dev_replace target drive is
5149 * available as a mirror
5150 */
5151 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
5152 WARN_ON(num_stripes > 1);
5153 bbio->stripes[0].dev = dev_replace->tgtdev;
5154 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
5155 bbio->mirror_num = map->num_stripes + 1;
5156 }
5157 if (raid_map) {
5158 sort_parity_stripes(bbio, raid_map);
5159 *raid_map_ret = raid_map;
5160 }
5161 out:
5162 if (dev_replace_is_ongoing)
5163 btrfs_dev_replace_unlock(dev_replace);
5164 free_extent_map(em);
5165 return ret;
5166 }
5167
5168 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
5169 u64 logical, u64 *length,
5170 struct btrfs_bio **bbio_ret, int mirror_num)
5171 {
5172 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
5173 mirror_num, NULL);
5174 }
5175
5176 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
5177 u64 chunk_start, u64 physical, u64 devid,
5178 u64 **logical, int *naddrs, int *stripe_len)
5179 {
5180 struct extent_map_tree *em_tree = &map_tree->map_tree;
5181 struct extent_map *em;
5182 struct map_lookup *map;
5183 u64 *buf;
5184 u64 bytenr;
5185 u64 length;
5186 u64 stripe_nr;
5187 u64 rmap_len;
5188 int i, j, nr = 0;
5189
5190 read_lock(&em_tree->lock);
5191 em = lookup_extent_mapping(em_tree, chunk_start, 1);
5192 read_unlock(&em_tree->lock);
5193
5194 if (!em) {
5195 printk(KERN_ERR "BTRFS: couldn't find em for chunk %Lu\n",
5196 chunk_start);
5197 return -EIO;
5198 }
5199
5200 if (em->start != chunk_start) {
5201 printk(KERN_ERR "BTRFS: bad chunk start, em=%Lu, wanted=%Lu\n",
5202 em->start, chunk_start);
5203 free_extent_map(em);
5204 return -EIO;
5205 }
5206 map = (struct map_lookup *)em->bdev;
5207
5208 length = em->len;
5209 rmap_len = map->stripe_len;
5210
5211 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
5212 do_div(length, map->num_stripes / map->sub_stripes);
5213 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
5214 do_div(length, map->num_stripes);
5215 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
5216 BTRFS_BLOCK_GROUP_RAID6)) {
5217 do_div(length, nr_data_stripes(map));
5218 rmap_len = map->stripe_len * nr_data_stripes(map);
5219 }
5220
5221 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
5222 BUG_ON(!buf); /* -ENOMEM */
5223
5224 for (i = 0; i < map->num_stripes; i++) {
5225 if (devid && map->stripes[i].dev->devid != devid)
5226 continue;
5227 if (map->stripes[i].physical > physical ||
5228 map->stripes[i].physical + length <= physical)
5229 continue;
5230
5231 stripe_nr = physical - map->stripes[i].physical;
5232 do_div(stripe_nr, map->stripe_len);
5233
5234 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
5235 stripe_nr = stripe_nr * map->num_stripes + i;
5236 do_div(stripe_nr, map->sub_stripes);
5237 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
5238 stripe_nr = stripe_nr * map->num_stripes + i;
5239 } /* else if RAID[56], multiply by nr_data_stripes().
5240 * Alternatively, just use rmap_len below instead of
5241 * map->stripe_len */
5242
5243 bytenr = chunk_start + stripe_nr * rmap_len;
5244 WARN_ON(nr >= map->num_stripes);
5245 for (j = 0; j < nr; j++) {
5246 if (buf[j] == bytenr)
5247 break;
5248 }
5249 if (j == nr) {
5250 WARN_ON(nr >= map->num_stripes);
5251 buf[nr++] = bytenr;
5252 }
5253 }
5254
5255 *logical = buf;
5256 *naddrs = nr;
5257 *stripe_len = rmap_len;
5258
5259 free_extent_map(em);
5260 return 0;
5261 }
5262
5263 static void btrfs_end_bio(struct bio *bio, int err)
5264 {
5265 struct btrfs_bio *bbio = bio->bi_private;
5266 int is_orig_bio = 0;
5267
5268 if (err) {
5269 atomic_inc(&bbio->error);
5270 if (err == -EIO || err == -EREMOTEIO) {
5271 unsigned int stripe_index =
5272 btrfs_io_bio(bio)->stripe_index;
5273 struct btrfs_device *dev;
5274
5275 BUG_ON(stripe_index >= bbio->num_stripes);
5276 dev = bbio->stripes[stripe_index].dev;
5277 if (dev->bdev) {
5278 if (bio->bi_rw & WRITE)
5279 btrfs_dev_stat_inc(dev,
5280 BTRFS_DEV_STAT_WRITE_ERRS);
5281 else
5282 btrfs_dev_stat_inc(dev,
5283 BTRFS_DEV_STAT_READ_ERRS);
5284 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5285 btrfs_dev_stat_inc(dev,
5286 BTRFS_DEV_STAT_FLUSH_ERRS);
5287 btrfs_dev_stat_print_on_error(dev);
5288 }
5289 }
5290 }
5291
5292 if (bio == bbio->orig_bio)
5293 is_orig_bio = 1;
5294
5295 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5296 if (!is_orig_bio) {
5297 bio_put(bio);
5298 bio = bbio->orig_bio;
5299 }
5300
5301 /*
5302 * We have original bio now. So increment bi_remaining to
5303 * account for it in endio
5304 */
5305 atomic_inc(&bio->bi_remaining);
5306
5307 bio->bi_private = bbio->private;
5308 bio->bi_end_io = bbio->end_io;
5309 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5310 /* only send an error to the higher layers if it is
5311 * beyond the tolerance of the btrfs bio
5312 */
5313 if (atomic_read(&bbio->error) > bbio->max_errors) {
5314 err = -EIO;
5315 } else {
5316 /*
5317 * this bio is actually up to date, we didn't
5318 * go over the max number of errors
5319 */
5320 set_bit(BIO_UPTODATE, &bio->bi_flags);
5321 err = 0;
5322 }
5323 kfree(bbio);
5324
5325 bio_endio(bio, err);
5326 } else if (!is_orig_bio) {
5327 bio_put(bio);
5328 }
5329 }
5330
5331 struct async_sched {
5332 struct bio *bio;
5333 int rw;
5334 struct btrfs_fs_info *info;
5335 struct btrfs_work work;
5336 };
5337
5338 /*
5339 * see run_scheduled_bios for a description of why bios are collected for
5340 * async submit.
5341 *
5342 * This will add one bio to the pending list for a device and make sure
5343 * the work struct is scheduled.
5344 */
5345 static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5346 struct btrfs_device *device,
5347 int rw, struct bio *bio)
5348 {
5349 int should_queue = 1;
5350 struct btrfs_pending_bios *pending_bios;
5351
5352 if (device->missing || !device->bdev) {
5353 bio_endio(bio, -EIO);
5354 return;
5355 }
5356
5357 /* don't bother with additional async steps for reads, right now */
5358 if (!(rw & REQ_WRITE)) {
5359 bio_get(bio);
5360 btrfsic_submit_bio(rw, bio);
5361 bio_put(bio);
5362 return;
5363 }
5364
5365 /*
5366 * nr_async_bios allows us to reliably return congestion to the
5367 * higher layers. Otherwise, the async bio makes it appear we have
5368 * made progress against dirty pages when we've really just put it
5369 * on a queue for later
5370 */
5371 atomic_inc(&root->fs_info->nr_async_bios);
5372 WARN_ON(bio->bi_next);
5373 bio->bi_next = NULL;
5374 bio->bi_rw |= rw;
5375
5376 spin_lock(&device->io_lock);
5377 if (bio->bi_rw & REQ_SYNC)
5378 pending_bios = &device->pending_sync_bios;
5379 else
5380 pending_bios = &device->pending_bios;
5381
5382 if (pending_bios->tail)
5383 pending_bios->tail->bi_next = bio;
5384
5385 pending_bios->tail = bio;
5386 if (!pending_bios->head)
5387 pending_bios->head = bio;
5388 if (device->running_pending)
5389 should_queue = 0;
5390
5391 spin_unlock(&device->io_lock);
5392
5393 if (should_queue)
5394 btrfs_queue_worker(&root->fs_info->submit_workers,
5395 &device->work);
5396 }
5397
5398 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5399 sector_t sector)
5400 {
5401 struct bio_vec *prev;
5402 struct request_queue *q = bdev_get_queue(bdev);
5403 unsigned int max_sectors = queue_max_sectors(q);
5404 struct bvec_merge_data bvm = {
5405 .bi_bdev = bdev,
5406 .bi_sector = sector,
5407 .bi_rw = bio->bi_rw,
5408 };
5409
5410 if (WARN_ON(bio->bi_vcnt == 0))
5411 return 1;
5412
5413 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5414 if (bio_sectors(bio) > max_sectors)
5415 return 0;
5416
5417 if (!q->merge_bvec_fn)
5418 return 1;
5419
5420 bvm.bi_size = bio->bi_iter.bi_size - prev->bv_len;
5421 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5422 return 0;
5423 return 1;
5424 }
5425
5426 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5427 struct bio *bio, u64 physical, int dev_nr,
5428 int rw, int async)
5429 {
5430 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5431
5432 bio->bi_private = bbio;
5433 btrfs_io_bio(bio)->stripe_index = dev_nr;
5434 bio->bi_end_io = btrfs_end_bio;
5435 bio->bi_iter.bi_sector = physical >> 9;
5436 #ifdef DEBUG
5437 {
5438 struct rcu_string *name;
5439
5440 rcu_read_lock();
5441 name = rcu_dereference(dev->name);
5442 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5443 "(%s id %llu), size=%u\n", rw,
5444 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5445 name->str, dev->devid, bio->bi_size);
5446 rcu_read_unlock();
5447 }
5448 #endif
5449 bio->bi_bdev = dev->bdev;
5450 if (async)
5451 btrfs_schedule_bio(root, dev, rw, bio);
5452 else
5453 btrfsic_submit_bio(rw, bio);
5454 }
5455
5456 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5457 struct bio *first_bio, struct btrfs_device *dev,
5458 int dev_nr, int rw, int async)
5459 {
5460 struct bio_vec *bvec = first_bio->bi_io_vec;
5461 struct bio *bio;
5462 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5463 u64 physical = bbio->stripes[dev_nr].physical;
5464
5465 again:
5466 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5467 if (!bio)
5468 return -ENOMEM;
5469
5470 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5471 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5472 bvec->bv_offset) < bvec->bv_len) {
5473 u64 len = bio->bi_iter.bi_size;
5474
5475 atomic_inc(&bbio->stripes_pending);
5476 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5477 rw, async);
5478 physical += len;
5479 goto again;
5480 }
5481 bvec++;
5482 }
5483
5484 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5485 return 0;
5486 }
5487
5488 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5489 {
5490 atomic_inc(&bbio->error);
5491 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5492 bio->bi_private = bbio->private;
5493 bio->bi_end_io = bbio->end_io;
5494 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5495 bio->bi_iter.bi_sector = logical >> 9;
5496 kfree(bbio);
5497 bio_endio(bio, -EIO);
5498 }
5499 }
5500
5501 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5502 int mirror_num, int async_submit)
5503 {
5504 struct btrfs_device *dev;
5505 struct bio *first_bio = bio;
5506 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
5507 u64 length = 0;
5508 u64 map_length;
5509 u64 *raid_map = NULL;
5510 int ret;
5511 int dev_nr = 0;
5512 int total_devs = 1;
5513 struct btrfs_bio *bbio = NULL;
5514
5515 length = bio->bi_iter.bi_size;
5516 map_length = length;
5517
5518 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5519 mirror_num, &raid_map);
5520 if (ret) /* -ENOMEM */
5521 return ret;
5522
5523 total_devs = bbio->num_stripes;
5524 bbio->orig_bio = first_bio;
5525 bbio->private = first_bio->bi_private;
5526 bbio->end_io = first_bio->bi_end_io;
5527 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5528
5529 if (raid_map) {
5530 /* In this case, map_length has been set to the length of
5531 a single stripe; not the whole write */
5532 if (rw & WRITE) {
5533 return raid56_parity_write(root, bio, bbio,
5534 raid_map, map_length);
5535 } else {
5536 return raid56_parity_recover(root, bio, bbio,
5537 raid_map, map_length,
5538 mirror_num);
5539 }
5540 }
5541
5542 if (map_length < length) {
5543 btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5544 logical, length, map_length);
5545 BUG();
5546 }
5547
5548 while (dev_nr < total_devs) {
5549 dev = bbio->stripes[dev_nr].dev;
5550 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5551 bbio_error(bbio, first_bio, logical);
5552 dev_nr++;
5553 continue;
5554 }
5555
5556 /*
5557 * Check and see if we're ok with this bio based on it's size
5558 * and offset with the given device.
5559 */
5560 if (!bio_size_ok(dev->bdev, first_bio,
5561 bbio->stripes[dev_nr].physical >> 9)) {
5562 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5563 dev_nr, rw, async_submit);
5564 BUG_ON(ret);
5565 dev_nr++;
5566 continue;
5567 }
5568
5569 if (dev_nr < total_devs - 1) {
5570 bio = btrfs_bio_clone(first_bio, GFP_NOFS);
5571 BUG_ON(!bio); /* -ENOMEM */
5572 } else {
5573 bio = first_bio;
5574 }
5575
5576 submit_stripe_bio(root, bbio, bio,
5577 bbio->stripes[dev_nr].physical, dev_nr, rw,
5578 async_submit);
5579 dev_nr++;
5580 }
5581 return 0;
5582 }
5583
5584 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5585 u8 *uuid, u8 *fsid)
5586 {
5587 struct btrfs_device *device;
5588 struct btrfs_fs_devices *cur_devices;
5589
5590 cur_devices = fs_info->fs_devices;
5591 while (cur_devices) {
5592 if (!fsid ||
5593 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5594 device = __find_device(&cur_devices->devices,
5595 devid, uuid);
5596 if (device)
5597 return device;
5598 }
5599 cur_devices = cur_devices->seed;
5600 }
5601 return NULL;
5602 }
5603
5604 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5605 u64 devid, u8 *dev_uuid)
5606 {
5607 struct btrfs_device *device;
5608 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5609
5610 device = btrfs_alloc_device(NULL, &devid, dev_uuid);
5611 if (IS_ERR(device))
5612 return NULL;
5613
5614 list_add(&device->dev_list, &fs_devices->devices);
5615 device->fs_devices = fs_devices;
5616 fs_devices->num_devices++;
5617
5618 device->missing = 1;
5619 fs_devices->missing_devices++;
5620
5621 return device;
5622 }
5623
5624 /**
5625 * btrfs_alloc_device - allocate struct btrfs_device
5626 * @fs_info: used only for generating a new devid, can be NULL if
5627 * devid is provided (i.e. @devid != NULL).
5628 * @devid: a pointer to devid for this device. If NULL a new devid
5629 * is generated.
5630 * @uuid: a pointer to UUID for this device. If NULL a new UUID
5631 * is generated.
5632 *
5633 * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
5634 * on error. Returned struct is not linked onto any lists and can be
5635 * destroyed with kfree() right away.
5636 */
5637 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
5638 const u64 *devid,
5639 const u8 *uuid)
5640 {
5641 struct btrfs_device *dev;
5642 u64 tmp;
5643
5644 if (WARN_ON(!devid && !fs_info))
5645 return ERR_PTR(-EINVAL);
5646
5647 dev = __alloc_device();
5648 if (IS_ERR(dev))
5649 return dev;
5650
5651 if (devid)
5652 tmp = *devid;
5653 else {
5654 int ret;
5655
5656 ret = find_next_devid(fs_info, &tmp);
5657 if (ret) {
5658 kfree(dev);
5659 return ERR_PTR(ret);
5660 }
5661 }
5662 dev->devid = tmp;
5663
5664 if (uuid)
5665 memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
5666 else
5667 generate_random_uuid(dev->uuid);
5668
5669 dev->work.func = pending_bios_fn;
5670
5671 return dev;
5672 }
5673
5674 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5675 struct extent_buffer *leaf,
5676 struct btrfs_chunk *chunk)
5677 {
5678 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5679 struct map_lookup *map;
5680 struct extent_map *em;
5681 u64 logical;
5682 u64 length;
5683 u64 devid;
5684 u8 uuid[BTRFS_UUID_SIZE];
5685 int num_stripes;
5686 int ret;
5687 int i;
5688
5689 logical = key->offset;
5690 length = btrfs_chunk_length(leaf, chunk);
5691
5692 read_lock(&map_tree->map_tree.lock);
5693 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5694 read_unlock(&map_tree->map_tree.lock);
5695
5696 /* already mapped? */
5697 if (em && em->start <= logical && em->start + em->len > logical) {
5698 free_extent_map(em);
5699 return 0;
5700 } else if (em) {
5701 free_extent_map(em);
5702 }
5703
5704 em = alloc_extent_map();
5705 if (!em)
5706 return -ENOMEM;
5707 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5708 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5709 if (!map) {
5710 free_extent_map(em);
5711 return -ENOMEM;
5712 }
5713
5714 em->bdev = (struct block_device *)map;
5715 em->start = logical;
5716 em->len = length;
5717 em->orig_start = 0;
5718 em->block_start = 0;
5719 em->block_len = em->len;
5720
5721 map->num_stripes = num_stripes;
5722 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5723 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5724 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5725 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5726 map->type = btrfs_chunk_type(leaf, chunk);
5727 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5728 for (i = 0; i < num_stripes; i++) {
5729 map->stripes[i].physical =
5730 btrfs_stripe_offset_nr(leaf, chunk, i);
5731 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5732 read_extent_buffer(leaf, uuid, (unsigned long)
5733 btrfs_stripe_dev_uuid_nr(chunk, i),
5734 BTRFS_UUID_SIZE);
5735 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5736 uuid, NULL);
5737 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5738 kfree(map);
5739 free_extent_map(em);
5740 return -EIO;
5741 }
5742 if (!map->stripes[i].dev) {
5743 map->stripes[i].dev =
5744 add_missing_dev(root, devid, uuid);
5745 if (!map->stripes[i].dev) {
5746 kfree(map);
5747 free_extent_map(em);
5748 return -EIO;
5749 }
5750 }
5751 map->stripes[i].dev->in_fs_metadata = 1;
5752 }
5753
5754 write_lock(&map_tree->map_tree.lock);
5755 ret = add_extent_mapping(&map_tree->map_tree, em, 0);
5756 write_unlock(&map_tree->map_tree.lock);
5757 BUG_ON(ret); /* Tree corruption */
5758 free_extent_map(em);
5759
5760 return 0;
5761 }
5762
5763 static void fill_device_from_item(struct extent_buffer *leaf,
5764 struct btrfs_dev_item *dev_item,
5765 struct btrfs_device *device)
5766 {
5767 unsigned long ptr;
5768
5769 device->devid = btrfs_device_id(leaf, dev_item);
5770 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5771 device->total_bytes = device->disk_total_bytes;
5772 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5773 device->type = btrfs_device_type(leaf, dev_item);
5774 device->io_align = btrfs_device_io_align(leaf, dev_item);
5775 device->io_width = btrfs_device_io_width(leaf, dev_item);
5776 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5777 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5778 device->is_tgtdev_for_dev_replace = 0;
5779
5780 ptr = btrfs_device_uuid(dev_item);
5781 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5782 }
5783
5784 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5785 {
5786 struct btrfs_fs_devices *fs_devices;
5787 int ret;
5788
5789 BUG_ON(!mutex_is_locked(&uuid_mutex));
5790
5791 fs_devices = root->fs_info->fs_devices->seed;
5792 while (fs_devices) {
5793 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5794 ret = 0;
5795 goto out;
5796 }
5797 fs_devices = fs_devices->seed;
5798 }
5799
5800 fs_devices = find_fsid(fsid);
5801 if (!fs_devices) {
5802 ret = -ENOENT;
5803 goto out;
5804 }
5805
5806 fs_devices = clone_fs_devices(fs_devices);
5807 if (IS_ERR(fs_devices)) {
5808 ret = PTR_ERR(fs_devices);
5809 goto out;
5810 }
5811
5812 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5813 root->fs_info->bdev_holder);
5814 if (ret) {
5815 free_fs_devices(fs_devices);
5816 goto out;
5817 }
5818
5819 if (!fs_devices->seeding) {
5820 __btrfs_close_devices(fs_devices);
5821 free_fs_devices(fs_devices);
5822 ret = -EINVAL;
5823 goto out;
5824 }
5825
5826 fs_devices->seed = root->fs_info->fs_devices->seed;
5827 root->fs_info->fs_devices->seed = fs_devices;
5828 out:
5829 return ret;
5830 }
5831
5832 static int read_one_dev(struct btrfs_root *root,
5833 struct extent_buffer *leaf,
5834 struct btrfs_dev_item *dev_item)
5835 {
5836 struct btrfs_device *device;
5837 u64 devid;
5838 int ret;
5839 u8 fs_uuid[BTRFS_UUID_SIZE];
5840 u8 dev_uuid[BTRFS_UUID_SIZE];
5841
5842 devid = btrfs_device_id(leaf, dev_item);
5843 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
5844 BTRFS_UUID_SIZE);
5845 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
5846 BTRFS_UUID_SIZE);
5847
5848 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5849 ret = open_seed_devices(root, fs_uuid);
5850 if (ret && !btrfs_test_opt(root, DEGRADED))
5851 return ret;
5852 }
5853
5854 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5855 if (!device || !device->bdev) {
5856 if (!btrfs_test_opt(root, DEGRADED))
5857 return -EIO;
5858
5859 if (!device) {
5860 btrfs_warn(root->fs_info, "devid %llu missing", devid);
5861 device = add_missing_dev(root, devid, dev_uuid);
5862 if (!device)
5863 return -ENOMEM;
5864 } else if (!device->missing) {
5865 /*
5866 * this happens when a device that was properly setup
5867 * in the device info lists suddenly goes bad.
5868 * device->bdev is NULL, and so we have to set
5869 * device->missing to one here
5870 */
5871 root->fs_info->fs_devices->missing_devices++;
5872 device->missing = 1;
5873 }
5874 }
5875
5876 if (device->fs_devices != root->fs_info->fs_devices) {
5877 BUG_ON(device->writeable);
5878 if (device->generation !=
5879 btrfs_device_generation(leaf, dev_item))
5880 return -EINVAL;
5881 }
5882
5883 fill_device_from_item(leaf, dev_item, device);
5884 device->in_fs_metadata = 1;
5885 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5886 device->fs_devices->total_rw_bytes += device->total_bytes;
5887 spin_lock(&root->fs_info->free_chunk_lock);
5888 root->fs_info->free_chunk_space += device->total_bytes -
5889 device->bytes_used;
5890 spin_unlock(&root->fs_info->free_chunk_lock);
5891 }
5892 ret = 0;
5893 return ret;
5894 }
5895
5896 int btrfs_read_sys_array(struct btrfs_root *root)
5897 {
5898 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5899 struct extent_buffer *sb;
5900 struct btrfs_disk_key *disk_key;
5901 struct btrfs_chunk *chunk;
5902 u8 *ptr;
5903 unsigned long sb_ptr;
5904 int ret = 0;
5905 u32 num_stripes;
5906 u32 array_size;
5907 u32 len = 0;
5908 u32 cur;
5909 struct btrfs_key key;
5910
5911 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5912 BTRFS_SUPER_INFO_SIZE);
5913 if (!sb)
5914 return -ENOMEM;
5915 btrfs_set_buffer_uptodate(sb);
5916 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5917 /*
5918 * The sb extent buffer is artifical and just used to read the system array.
5919 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5920 * pages up-to-date when the page is larger: extent does not cover the
5921 * whole page and consequently check_page_uptodate does not find all
5922 * the page's extents up-to-date (the hole beyond sb),
5923 * write_extent_buffer then triggers a WARN_ON.
5924 *
5925 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5926 * but sb spans only this function. Add an explicit SetPageUptodate call
5927 * to silence the warning eg. on PowerPC 64.
5928 */
5929 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5930 SetPageUptodate(sb->pages[0]);
5931
5932 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5933 array_size = btrfs_super_sys_array_size(super_copy);
5934
5935 ptr = super_copy->sys_chunk_array;
5936 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5937 cur = 0;
5938
5939 while (cur < array_size) {
5940 disk_key = (struct btrfs_disk_key *)ptr;
5941 btrfs_disk_key_to_cpu(&key, disk_key);
5942
5943 len = sizeof(*disk_key); ptr += len;
5944 sb_ptr += len;
5945 cur += len;
5946
5947 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5948 chunk = (struct btrfs_chunk *)sb_ptr;
5949 ret = read_one_chunk(root, &key, sb, chunk);
5950 if (ret)
5951 break;
5952 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5953 len = btrfs_chunk_item_size(num_stripes);
5954 } else {
5955 ret = -EIO;
5956 break;
5957 }
5958 ptr += len;
5959 sb_ptr += len;
5960 cur += len;
5961 }
5962 free_extent_buffer(sb);
5963 return ret;
5964 }
5965
5966 int btrfs_read_chunk_tree(struct btrfs_root *root)
5967 {
5968 struct btrfs_path *path;
5969 struct extent_buffer *leaf;
5970 struct btrfs_key key;
5971 struct btrfs_key found_key;
5972 int ret;
5973 int slot;
5974
5975 root = root->fs_info->chunk_root;
5976
5977 path = btrfs_alloc_path();
5978 if (!path)
5979 return -ENOMEM;
5980
5981 mutex_lock(&uuid_mutex);
5982 lock_chunks(root);
5983
5984 /*
5985 * Read all device items, and then all the chunk items. All
5986 * device items are found before any chunk item (their object id
5987 * is smaller than the lowest possible object id for a chunk
5988 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
5989 */
5990 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5991 key.offset = 0;
5992 key.type = 0;
5993 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5994 if (ret < 0)
5995 goto error;
5996 while (1) {
5997 leaf = path->nodes[0];
5998 slot = path->slots[0];
5999 if (slot >= btrfs_header_nritems(leaf)) {
6000 ret = btrfs_next_leaf(root, path);
6001 if (ret == 0)
6002 continue;
6003 if (ret < 0)
6004 goto error;
6005 break;
6006 }
6007 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6008 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
6009 struct btrfs_dev_item *dev_item;
6010 dev_item = btrfs_item_ptr(leaf, slot,
6011 struct btrfs_dev_item);
6012 ret = read_one_dev(root, leaf, dev_item);
6013 if (ret)
6014 goto error;
6015 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
6016 struct btrfs_chunk *chunk;
6017 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
6018 ret = read_one_chunk(root, &found_key, leaf, chunk);
6019 if (ret)
6020 goto error;
6021 }
6022 path->slots[0]++;
6023 }
6024 ret = 0;
6025 error:
6026 unlock_chunks(root);
6027 mutex_unlock(&uuid_mutex);
6028
6029 btrfs_free_path(path);
6030 return ret;
6031 }
6032
6033 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
6034 {
6035 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6036 struct btrfs_device *device;
6037
6038 mutex_lock(&fs_devices->device_list_mutex);
6039 list_for_each_entry(device, &fs_devices->devices, dev_list)
6040 device->dev_root = fs_info->dev_root;
6041 mutex_unlock(&fs_devices->device_list_mutex);
6042 }
6043
6044 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
6045 {
6046 int i;
6047
6048 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6049 btrfs_dev_stat_reset(dev, i);
6050 }
6051
6052 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
6053 {
6054 struct btrfs_key key;
6055 struct btrfs_key found_key;
6056 struct btrfs_root *dev_root = fs_info->dev_root;
6057 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6058 struct extent_buffer *eb;
6059 int slot;
6060 int ret = 0;
6061 struct btrfs_device *device;
6062 struct btrfs_path *path = NULL;
6063 int i;
6064
6065 path = btrfs_alloc_path();
6066 if (!path) {
6067 ret = -ENOMEM;
6068 goto out;
6069 }
6070
6071 mutex_lock(&fs_devices->device_list_mutex);
6072 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6073 int item_size;
6074 struct btrfs_dev_stats_item *ptr;
6075
6076 key.objectid = 0;
6077 key.type = BTRFS_DEV_STATS_KEY;
6078 key.offset = device->devid;
6079 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
6080 if (ret) {
6081 __btrfs_reset_dev_stats(device);
6082 device->dev_stats_valid = 1;
6083 btrfs_release_path(path);
6084 continue;
6085 }
6086 slot = path->slots[0];
6087 eb = path->nodes[0];
6088 btrfs_item_key_to_cpu(eb, &found_key, slot);
6089 item_size = btrfs_item_size_nr(eb, slot);
6090
6091 ptr = btrfs_item_ptr(eb, slot,
6092 struct btrfs_dev_stats_item);
6093
6094 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6095 if (item_size >= (1 + i) * sizeof(__le64))
6096 btrfs_dev_stat_set(device, i,
6097 btrfs_dev_stats_value(eb, ptr, i));
6098 else
6099 btrfs_dev_stat_reset(device, i);
6100 }
6101
6102 device->dev_stats_valid = 1;
6103 btrfs_dev_stat_print_on_load(device);
6104 btrfs_release_path(path);
6105 }
6106 mutex_unlock(&fs_devices->device_list_mutex);
6107
6108 out:
6109 btrfs_free_path(path);
6110 return ret < 0 ? ret : 0;
6111 }
6112
6113 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
6114 struct btrfs_root *dev_root,
6115 struct btrfs_device *device)
6116 {
6117 struct btrfs_path *path;
6118 struct btrfs_key key;
6119 struct extent_buffer *eb;
6120 struct btrfs_dev_stats_item *ptr;
6121 int ret;
6122 int i;
6123
6124 key.objectid = 0;
6125 key.type = BTRFS_DEV_STATS_KEY;
6126 key.offset = device->devid;
6127
6128 path = btrfs_alloc_path();
6129 BUG_ON(!path);
6130 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
6131 if (ret < 0) {
6132 printk_in_rcu(KERN_WARNING "BTRFS: "
6133 "error %d while searching for dev_stats item for device %s!\n",
6134 ret, rcu_str_deref(device->name));
6135 goto out;
6136 }
6137
6138 if (ret == 0 &&
6139 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
6140 /* need to delete old one and insert a new one */
6141 ret = btrfs_del_item(trans, dev_root, path);
6142 if (ret != 0) {
6143 printk_in_rcu(KERN_WARNING "BTRFS: "
6144 "delete too small dev_stats item for device %s failed %d!\n",
6145 rcu_str_deref(device->name), ret);
6146 goto out;
6147 }
6148 ret = 1;
6149 }
6150
6151 if (ret == 1) {
6152 /* need to insert a new item */
6153 btrfs_release_path(path);
6154 ret = btrfs_insert_empty_item(trans, dev_root, path,
6155 &key, sizeof(*ptr));
6156 if (ret < 0) {
6157 printk_in_rcu(KERN_WARNING "BTRFS: "
6158 "insert dev_stats item for device %s failed %d!\n",
6159 rcu_str_deref(device->name), ret);
6160 goto out;
6161 }
6162 }
6163
6164 eb = path->nodes[0];
6165 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
6166 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6167 btrfs_set_dev_stats_value(eb, ptr, i,
6168 btrfs_dev_stat_read(device, i));
6169 btrfs_mark_buffer_dirty(eb);
6170
6171 out:
6172 btrfs_free_path(path);
6173 return ret;
6174 }
6175
6176 /*
6177 * called from commit_transaction. Writes all changed device stats to disk.
6178 */
6179 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
6180 struct btrfs_fs_info *fs_info)
6181 {
6182 struct btrfs_root *dev_root = fs_info->dev_root;
6183 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6184 struct btrfs_device *device;
6185 int ret = 0;
6186
6187 mutex_lock(&fs_devices->device_list_mutex);
6188 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6189 if (!device->dev_stats_valid || !device->dev_stats_dirty)
6190 continue;
6191
6192 ret = update_dev_stat_item(trans, dev_root, device);
6193 if (!ret)
6194 device->dev_stats_dirty = 0;
6195 }
6196 mutex_unlock(&fs_devices->device_list_mutex);
6197
6198 return ret;
6199 }
6200
6201 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
6202 {
6203 btrfs_dev_stat_inc(dev, index);
6204 btrfs_dev_stat_print_on_error(dev);
6205 }
6206
6207 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
6208 {
6209 if (!dev->dev_stats_valid)
6210 return;
6211 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
6212 "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6213 rcu_str_deref(dev->name),
6214 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6215 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6216 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6217 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6218 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6219 }
6220
6221 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
6222 {
6223 int i;
6224
6225 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6226 if (btrfs_dev_stat_read(dev, i) != 0)
6227 break;
6228 if (i == BTRFS_DEV_STAT_VALUES_MAX)
6229 return; /* all values == 0, suppress message */
6230
6231 printk_in_rcu(KERN_INFO "BTRFS: "
6232 "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6233 rcu_str_deref(dev->name),
6234 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6235 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6236 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6237 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6238 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6239 }
6240
6241 int btrfs_get_dev_stats(struct btrfs_root *root,
6242 struct btrfs_ioctl_get_dev_stats *stats)
6243 {
6244 struct btrfs_device *dev;
6245 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6246 int i;
6247
6248 mutex_lock(&fs_devices->device_list_mutex);
6249 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
6250 mutex_unlock(&fs_devices->device_list_mutex);
6251
6252 if (!dev) {
6253 btrfs_warn(root->fs_info, "get dev_stats failed, device not found");
6254 return -ENODEV;
6255 } else if (!dev->dev_stats_valid) {
6256 btrfs_warn(root->fs_info, "get dev_stats failed, not yet valid");
6257 return -ENODEV;
6258 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
6259 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6260 if (stats->nr_items > i)
6261 stats->values[i] =
6262 btrfs_dev_stat_read_and_reset(dev, i);
6263 else
6264 btrfs_dev_stat_reset(dev, i);
6265 }
6266 } else {
6267 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6268 if (stats->nr_items > i)
6269 stats->values[i] = btrfs_dev_stat_read(dev, i);
6270 }
6271 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
6272 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
6273 return 0;
6274 }
6275
6276 int btrfs_scratch_superblock(struct btrfs_device *device)
6277 {
6278 struct buffer_head *bh;
6279 struct btrfs_super_block *disk_super;
6280
6281 bh = btrfs_read_dev_super(device->bdev);
6282 if (!bh)
6283 return -EINVAL;
6284 disk_super = (struct btrfs_super_block *)bh->b_data;
6285
6286 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
6287 set_buffer_dirty(bh);
6288 sync_dirty_buffer(bh);
6289 brelse(bh);
6290
6291 return 0;
6292 }
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