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Merge remote-tracking branches 'asoc/fix/axi', 'asoc/fix/cs4265', 'asoc/fix/da732x...
[deliverable/linux.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <linux/ratelimit.h>
27 #include <linux/kthread.h>
28 #include <linux/raid/pq.h>
29 #include <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 #include "sysfs.h"
44
45 static int init_first_rw_device(struct btrfs_trans_handle *trans,
46 struct btrfs_root *root,
47 struct btrfs_device *device);
48 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
49 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
50 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
51 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
52
53 static DEFINE_MUTEX(uuid_mutex);
54 static LIST_HEAD(fs_uuids);
55
56 static void lock_chunks(struct btrfs_root *root)
57 {
58 mutex_lock(&root->fs_info->chunk_mutex);
59 }
60
61 static void unlock_chunks(struct btrfs_root *root)
62 {
63 mutex_unlock(&root->fs_info->chunk_mutex);
64 }
65
66 static struct btrfs_fs_devices *__alloc_fs_devices(void)
67 {
68 struct btrfs_fs_devices *fs_devs;
69
70 fs_devs = kzalloc(sizeof(*fs_devs), GFP_NOFS);
71 if (!fs_devs)
72 return ERR_PTR(-ENOMEM);
73
74 mutex_init(&fs_devs->device_list_mutex);
75
76 INIT_LIST_HEAD(&fs_devs->devices);
77 INIT_LIST_HEAD(&fs_devs->alloc_list);
78 INIT_LIST_HEAD(&fs_devs->list);
79
80 return fs_devs;
81 }
82
83 /**
84 * alloc_fs_devices - allocate struct btrfs_fs_devices
85 * @fsid: a pointer to UUID for this FS. If NULL a new UUID is
86 * generated.
87 *
88 * Return: a pointer to a new &struct btrfs_fs_devices on success;
89 * ERR_PTR() on error. Returned struct is not linked onto any lists and
90 * can be destroyed with kfree() right away.
91 */
92 static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid)
93 {
94 struct btrfs_fs_devices *fs_devs;
95
96 fs_devs = __alloc_fs_devices();
97 if (IS_ERR(fs_devs))
98 return fs_devs;
99
100 if (fsid)
101 memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
102 else
103 generate_random_uuid(fs_devs->fsid);
104
105 return fs_devs;
106 }
107
108 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
109 {
110 struct btrfs_device *device;
111 WARN_ON(fs_devices->opened);
112 while (!list_empty(&fs_devices->devices)) {
113 device = list_entry(fs_devices->devices.next,
114 struct btrfs_device, dev_list);
115 list_del(&device->dev_list);
116 rcu_string_free(device->name);
117 kfree(device);
118 }
119 kfree(fs_devices);
120 }
121
122 static void btrfs_kobject_uevent(struct block_device *bdev,
123 enum kobject_action action)
124 {
125 int ret;
126
127 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
128 if (ret)
129 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
130 action,
131 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
132 &disk_to_dev(bdev->bd_disk)->kobj);
133 }
134
135 void btrfs_cleanup_fs_uuids(void)
136 {
137 struct btrfs_fs_devices *fs_devices;
138
139 while (!list_empty(&fs_uuids)) {
140 fs_devices = list_entry(fs_uuids.next,
141 struct btrfs_fs_devices, list);
142 list_del(&fs_devices->list);
143 free_fs_devices(fs_devices);
144 }
145 }
146
147 static struct btrfs_device *__alloc_device(void)
148 {
149 struct btrfs_device *dev;
150
151 dev = kzalloc(sizeof(*dev), GFP_NOFS);
152 if (!dev)
153 return ERR_PTR(-ENOMEM);
154
155 INIT_LIST_HEAD(&dev->dev_list);
156 INIT_LIST_HEAD(&dev->dev_alloc_list);
157
158 spin_lock_init(&dev->io_lock);
159
160 spin_lock_init(&dev->reada_lock);
161 atomic_set(&dev->reada_in_flight, 0);
162 INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
163 INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);
164
165 return dev;
166 }
167
168 static noinline struct btrfs_device *__find_device(struct list_head *head,
169 u64 devid, u8 *uuid)
170 {
171 struct btrfs_device *dev;
172
173 list_for_each_entry(dev, head, dev_list) {
174 if (dev->devid == devid &&
175 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
176 return dev;
177 }
178 }
179 return NULL;
180 }
181
182 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
183 {
184 struct btrfs_fs_devices *fs_devices;
185
186 list_for_each_entry(fs_devices, &fs_uuids, list) {
187 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
188 return fs_devices;
189 }
190 return NULL;
191 }
192
193 static int
194 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
195 int flush, struct block_device **bdev,
196 struct buffer_head **bh)
197 {
198 int ret;
199
200 *bdev = blkdev_get_by_path(device_path, flags, holder);
201
202 if (IS_ERR(*bdev)) {
203 ret = PTR_ERR(*bdev);
204 printk(KERN_INFO "BTRFS: open %s failed\n", device_path);
205 goto error;
206 }
207
208 if (flush)
209 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
210 ret = set_blocksize(*bdev, 4096);
211 if (ret) {
212 blkdev_put(*bdev, flags);
213 goto error;
214 }
215 invalidate_bdev(*bdev);
216 *bh = btrfs_read_dev_super(*bdev);
217 if (!*bh) {
218 ret = -EINVAL;
219 blkdev_put(*bdev, flags);
220 goto error;
221 }
222
223 return 0;
224
225 error:
226 *bdev = NULL;
227 *bh = NULL;
228 return ret;
229 }
230
231 static void requeue_list(struct btrfs_pending_bios *pending_bios,
232 struct bio *head, struct bio *tail)
233 {
234
235 struct bio *old_head;
236
237 old_head = pending_bios->head;
238 pending_bios->head = head;
239 if (pending_bios->tail)
240 tail->bi_next = old_head;
241 else
242 pending_bios->tail = tail;
243 }
244
245 /*
246 * we try to collect pending bios for a device so we don't get a large
247 * number of procs sending bios down to the same device. This greatly
248 * improves the schedulers ability to collect and merge the bios.
249 *
250 * But, it also turns into a long list of bios to process and that is sure
251 * to eventually make the worker thread block. The solution here is to
252 * make some progress and then put this work struct back at the end of
253 * the list if the block device is congested. This way, multiple devices
254 * can make progress from a single worker thread.
255 */
256 static noinline void run_scheduled_bios(struct btrfs_device *device)
257 {
258 struct bio *pending;
259 struct backing_dev_info *bdi;
260 struct btrfs_fs_info *fs_info;
261 struct btrfs_pending_bios *pending_bios;
262 struct bio *tail;
263 struct bio *cur;
264 int again = 0;
265 unsigned long num_run;
266 unsigned long batch_run = 0;
267 unsigned long limit;
268 unsigned long last_waited = 0;
269 int force_reg = 0;
270 int sync_pending = 0;
271 struct blk_plug plug;
272
273 /*
274 * this function runs all the bios we've collected for
275 * a particular device. We don't want to wander off to
276 * another device without first sending all of these down.
277 * So, setup a plug here and finish it off before we return
278 */
279 blk_start_plug(&plug);
280
281 bdi = blk_get_backing_dev_info(device->bdev);
282 fs_info = device->dev_root->fs_info;
283 limit = btrfs_async_submit_limit(fs_info);
284 limit = limit * 2 / 3;
285
286 loop:
287 spin_lock(&device->io_lock);
288
289 loop_lock:
290 num_run = 0;
291
292 /* take all the bios off the list at once and process them
293 * later on (without the lock held). But, remember the
294 * tail and other pointers so the bios can be properly reinserted
295 * into the list if we hit congestion
296 */
297 if (!force_reg && device->pending_sync_bios.head) {
298 pending_bios = &device->pending_sync_bios;
299 force_reg = 1;
300 } else {
301 pending_bios = &device->pending_bios;
302 force_reg = 0;
303 }
304
305 pending = pending_bios->head;
306 tail = pending_bios->tail;
307 WARN_ON(pending && !tail);
308
309 /*
310 * if pending was null this time around, no bios need processing
311 * at all and we can stop. Otherwise it'll loop back up again
312 * and do an additional check so no bios are missed.
313 *
314 * device->running_pending is used to synchronize with the
315 * schedule_bio code.
316 */
317 if (device->pending_sync_bios.head == NULL &&
318 device->pending_bios.head == NULL) {
319 again = 0;
320 device->running_pending = 0;
321 } else {
322 again = 1;
323 device->running_pending = 1;
324 }
325
326 pending_bios->head = NULL;
327 pending_bios->tail = NULL;
328
329 spin_unlock(&device->io_lock);
330
331 while (pending) {
332
333 rmb();
334 /* we want to work on both lists, but do more bios on the
335 * sync list than the regular list
336 */
337 if ((num_run > 32 &&
338 pending_bios != &device->pending_sync_bios &&
339 device->pending_sync_bios.head) ||
340 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
341 device->pending_bios.head)) {
342 spin_lock(&device->io_lock);
343 requeue_list(pending_bios, pending, tail);
344 goto loop_lock;
345 }
346
347 cur = pending;
348 pending = pending->bi_next;
349 cur->bi_next = NULL;
350
351 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
352 waitqueue_active(&fs_info->async_submit_wait))
353 wake_up(&fs_info->async_submit_wait);
354
355 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
356
357 /*
358 * if we're doing the sync list, record that our
359 * plug has some sync requests on it
360 *
361 * If we're doing the regular list and there are
362 * sync requests sitting around, unplug before
363 * we add more
364 */
365 if (pending_bios == &device->pending_sync_bios) {
366 sync_pending = 1;
367 } else if (sync_pending) {
368 blk_finish_plug(&plug);
369 blk_start_plug(&plug);
370 sync_pending = 0;
371 }
372
373 btrfsic_submit_bio(cur->bi_rw, cur);
374 num_run++;
375 batch_run++;
376 if (need_resched())
377 cond_resched();
378
379 /*
380 * we made progress, there is more work to do and the bdi
381 * is now congested. Back off and let other work structs
382 * run instead
383 */
384 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
385 fs_info->fs_devices->open_devices > 1) {
386 struct io_context *ioc;
387
388 ioc = current->io_context;
389
390 /*
391 * the main goal here is that we don't want to
392 * block if we're going to be able to submit
393 * more requests without blocking.
394 *
395 * This code does two great things, it pokes into
396 * the elevator code from a filesystem _and_
397 * it makes assumptions about how batching works.
398 */
399 if (ioc && ioc->nr_batch_requests > 0 &&
400 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
401 (last_waited == 0 ||
402 ioc->last_waited == last_waited)) {
403 /*
404 * we want to go through our batch of
405 * requests and stop. So, we copy out
406 * the ioc->last_waited time and test
407 * against it before looping
408 */
409 last_waited = ioc->last_waited;
410 if (need_resched())
411 cond_resched();
412 continue;
413 }
414 spin_lock(&device->io_lock);
415 requeue_list(pending_bios, pending, tail);
416 device->running_pending = 1;
417
418 spin_unlock(&device->io_lock);
419 btrfs_queue_work(fs_info->submit_workers,
420 &device->work);
421 goto done;
422 }
423 /* unplug every 64 requests just for good measure */
424 if (batch_run % 64 == 0) {
425 blk_finish_plug(&plug);
426 blk_start_plug(&plug);
427 sync_pending = 0;
428 }
429 }
430
431 cond_resched();
432 if (again)
433 goto loop;
434
435 spin_lock(&device->io_lock);
436 if (device->pending_bios.head || device->pending_sync_bios.head)
437 goto loop_lock;
438 spin_unlock(&device->io_lock);
439
440 done:
441 blk_finish_plug(&plug);
442 }
443
444 static void pending_bios_fn(struct btrfs_work *work)
445 {
446 struct btrfs_device *device;
447
448 device = container_of(work, struct btrfs_device, work);
449 run_scheduled_bios(device);
450 }
451
452 /*
453 * Add new device to list of registered devices
454 *
455 * Returns:
456 * 1 - first time device is seen
457 * 0 - device already known
458 * < 0 - error
459 */
460 static noinline int device_list_add(const char *path,
461 struct btrfs_super_block *disk_super,
462 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
463 {
464 struct btrfs_device *device;
465 struct btrfs_fs_devices *fs_devices;
466 struct rcu_string *name;
467 int ret = 0;
468 u64 found_transid = btrfs_super_generation(disk_super);
469
470 fs_devices = find_fsid(disk_super->fsid);
471 if (!fs_devices) {
472 fs_devices = alloc_fs_devices(disk_super->fsid);
473 if (IS_ERR(fs_devices))
474 return PTR_ERR(fs_devices);
475
476 list_add(&fs_devices->list, &fs_uuids);
477 fs_devices->latest_devid = devid;
478 fs_devices->latest_trans = found_transid;
479
480 device = NULL;
481 } else {
482 device = __find_device(&fs_devices->devices, devid,
483 disk_super->dev_item.uuid);
484 }
485 if (!device) {
486 if (fs_devices->opened)
487 return -EBUSY;
488
489 device = btrfs_alloc_device(NULL, &devid,
490 disk_super->dev_item.uuid);
491 if (IS_ERR(device)) {
492 /* we can safely leave the fs_devices entry around */
493 return PTR_ERR(device);
494 }
495
496 name = rcu_string_strdup(path, GFP_NOFS);
497 if (!name) {
498 kfree(device);
499 return -ENOMEM;
500 }
501 rcu_assign_pointer(device->name, name);
502
503 mutex_lock(&fs_devices->device_list_mutex);
504 list_add_rcu(&device->dev_list, &fs_devices->devices);
505 fs_devices->num_devices++;
506 mutex_unlock(&fs_devices->device_list_mutex);
507
508 ret = 1;
509 device->fs_devices = fs_devices;
510 } else if (!device->name || strcmp(device->name->str, path)) {
511 /*
512 * When FS is already mounted.
513 * 1. If you are here and if the device->name is NULL that
514 * means this device was missing at time of FS mount.
515 * 2. If you are here and if the device->name is different
516 * from 'path' that means either
517 * a. The same device disappeared and reappeared with
518 * different name. or
519 * b. The missing-disk-which-was-replaced, has
520 * reappeared now.
521 *
522 * We must allow 1 and 2a above. But 2b would be a spurious
523 * and unintentional.
524 *
525 * Further in case of 1 and 2a above, the disk at 'path'
526 * would have missed some transaction when it was away and
527 * in case of 2a the stale bdev has to be updated as well.
528 * 2b must not be allowed at all time.
529 */
530
531 /*
532 * As of now don't allow update to btrfs_fs_device through
533 * the btrfs dev scan cli, after FS has been mounted.
534 */
535 if (fs_devices->opened) {
536 return -EBUSY;
537 } else {
538 /*
539 * That is if the FS is _not_ mounted and if you
540 * are here, that means there is more than one
541 * disk with same uuid and devid.We keep the one
542 * with larger generation number or the last-in if
543 * generation are equal.
544 */
545 if (found_transid < device->generation)
546 return -EEXIST;
547 }
548
549 name = rcu_string_strdup(path, GFP_NOFS);
550 if (!name)
551 return -ENOMEM;
552 rcu_string_free(device->name);
553 rcu_assign_pointer(device->name, name);
554 if (device->missing) {
555 fs_devices->missing_devices--;
556 device->missing = 0;
557 }
558 }
559
560 /*
561 * Unmount does not free the btrfs_device struct but would zero
562 * generation along with most of the other members. So just update
563 * it back. We need it to pick the disk with largest generation
564 * (as above).
565 */
566 if (!fs_devices->opened)
567 device->generation = found_transid;
568
569 if (found_transid > fs_devices->latest_trans) {
570 fs_devices->latest_devid = devid;
571 fs_devices->latest_trans = found_transid;
572 }
573 *fs_devices_ret = fs_devices;
574
575 return ret;
576 }
577
578 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
579 {
580 struct btrfs_fs_devices *fs_devices;
581 struct btrfs_device *device;
582 struct btrfs_device *orig_dev;
583
584 fs_devices = alloc_fs_devices(orig->fsid);
585 if (IS_ERR(fs_devices))
586 return fs_devices;
587
588 fs_devices->latest_devid = orig->latest_devid;
589 fs_devices->latest_trans = orig->latest_trans;
590 fs_devices->total_devices = orig->total_devices;
591
592 /* We have held the volume lock, it is safe to get the devices. */
593 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
594 struct rcu_string *name;
595
596 device = btrfs_alloc_device(NULL, &orig_dev->devid,
597 orig_dev->uuid);
598 if (IS_ERR(device))
599 goto error;
600
601 /*
602 * This is ok to do without rcu read locked because we hold the
603 * uuid mutex so nothing we touch in here is going to disappear.
604 */
605 if (orig_dev->name) {
606 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
607 if (!name) {
608 kfree(device);
609 goto error;
610 }
611 rcu_assign_pointer(device->name, name);
612 }
613
614 list_add(&device->dev_list, &fs_devices->devices);
615 device->fs_devices = fs_devices;
616 fs_devices->num_devices++;
617 }
618 return fs_devices;
619 error:
620 free_fs_devices(fs_devices);
621 return ERR_PTR(-ENOMEM);
622 }
623
624 void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
625 struct btrfs_fs_devices *fs_devices, int step)
626 {
627 struct btrfs_device *device, *next;
628
629 struct block_device *latest_bdev = NULL;
630 u64 latest_devid = 0;
631 u64 latest_transid = 0;
632
633 mutex_lock(&uuid_mutex);
634 again:
635 /* This is the initialized path, it is safe to release the devices. */
636 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
637 if (device->in_fs_metadata) {
638 if (!device->is_tgtdev_for_dev_replace &&
639 (!latest_transid ||
640 device->generation > latest_transid)) {
641 latest_devid = device->devid;
642 latest_transid = device->generation;
643 latest_bdev = device->bdev;
644 }
645 continue;
646 }
647
648 if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
649 /*
650 * In the first step, keep the device which has
651 * the correct fsid and the devid that is used
652 * for the dev_replace procedure.
653 * In the second step, the dev_replace state is
654 * read from the device tree and it is known
655 * whether the procedure is really active or
656 * not, which means whether this device is
657 * used or whether it should be removed.
658 */
659 if (step == 0 || device->is_tgtdev_for_dev_replace) {
660 continue;
661 }
662 }
663 if (device->bdev) {
664 blkdev_put(device->bdev, device->mode);
665 device->bdev = NULL;
666 fs_devices->open_devices--;
667 }
668 if (device->writeable) {
669 list_del_init(&device->dev_alloc_list);
670 device->writeable = 0;
671 if (!device->is_tgtdev_for_dev_replace)
672 fs_devices->rw_devices--;
673 }
674 list_del_init(&device->dev_list);
675 fs_devices->num_devices--;
676 rcu_string_free(device->name);
677 kfree(device);
678 }
679
680 if (fs_devices->seed) {
681 fs_devices = fs_devices->seed;
682 goto again;
683 }
684
685 fs_devices->latest_bdev = latest_bdev;
686 fs_devices->latest_devid = latest_devid;
687 fs_devices->latest_trans = latest_transid;
688
689 mutex_unlock(&uuid_mutex);
690 }
691
692 static void __free_device(struct work_struct *work)
693 {
694 struct btrfs_device *device;
695
696 device = container_of(work, struct btrfs_device, rcu_work);
697
698 if (device->bdev)
699 blkdev_put(device->bdev, device->mode);
700
701 rcu_string_free(device->name);
702 kfree(device);
703 }
704
705 static void free_device(struct rcu_head *head)
706 {
707 struct btrfs_device *device;
708
709 device = container_of(head, struct btrfs_device, rcu);
710
711 INIT_WORK(&device->rcu_work, __free_device);
712 schedule_work(&device->rcu_work);
713 }
714
715 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
716 {
717 struct btrfs_device *device;
718
719 if (--fs_devices->opened > 0)
720 return 0;
721
722 mutex_lock(&fs_devices->device_list_mutex);
723 list_for_each_entry(device, &fs_devices->devices, dev_list) {
724 struct btrfs_device *new_device;
725 struct rcu_string *name;
726
727 if (device->bdev)
728 fs_devices->open_devices--;
729
730 if (device->writeable &&
731 device->devid != BTRFS_DEV_REPLACE_DEVID) {
732 list_del_init(&device->dev_alloc_list);
733 fs_devices->rw_devices--;
734 }
735
736 if (device->can_discard)
737 fs_devices->num_can_discard--;
738 if (device->missing)
739 fs_devices->missing_devices--;
740
741 new_device = btrfs_alloc_device(NULL, &device->devid,
742 device->uuid);
743 BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
744
745 /* Safe because we are under uuid_mutex */
746 if (device->name) {
747 name = rcu_string_strdup(device->name->str, GFP_NOFS);
748 BUG_ON(!name); /* -ENOMEM */
749 rcu_assign_pointer(new_device->name, name);
750 }
751
752 list_replace_rcu(&device->dev_list, &new_device->dev_list);
753 new_device->fs_devices = device->fs_devices;
754
755 call_rcu(&device->rcu, free_device);
756 }
757 mutex_unlock(&fs_devices->device_list_mutex);
758
759 WARN_ON(fs_devices->open_devices);
760 WARN_ON(fs_devices->rw_devices);
761 fs_devices->opened = 0;
762 fs_devices->seeding = 0;
763
764 return 0;
765 }
766
767 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
768 {
769 struct btrfs_fs_devices *seed_devices = NULL;
770 int ret;
771
772 mutex_lock(&uuid_mutex);
773 ret = __btrfs_close_devices(fs_devices);
774 if (!fs_devices->opened) {
775 seed_devices = fs_devices->seed;
776 fs_devices->seed = NULL;
777 }
778 mutex_unlock(&uuid_mutex);
779
780 while (seed_devices) {
781 fs_devices = seed_devices;
782 seed_devices = fs_devices->seed;
783 __btrfs_close_devices(fs_devices);
784 free_fs_devices(fs_devices);
785 }
786 /*
787 * Wait for rcu kworkers under __btrfs_close_devices
788 * to finish all blkdev_puts so device is really
789 * free when umount is done.
790 */
791 rcu_barrier();
792 return ret;
793 }
794
795 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
796 fmode_t flags, void *holder)
797 {
798 struct request_queue *q;
799 struct block_device *bdev;
800 struct list_head *head = &fs_devices->devices;
801 struct btrfs_device *device;
802 struct block_device *latest_bdev = NULL;
803 struct buffer_head *bh;
804 struct btrfs_super_block *disk_super;
805 u64 latest_devid = 0;
806 u64 latest_transid = 0;
807 u64 devid;
808 int seeding = 1;
809 int ret = 0;
810
811 flags |= FMODE_EXCL;
812
813 list_for_each_entry(device, head, dev_list) {
814 if (device->bdev)
815 continue;
816 if (!device->name)
817 continue;
818
819 /* Just open everything we can; ignore failures here */
820 if (btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
821 &bdev, &bh))
822 continue;
823
824 disk_super = (struct btrfs_super_block *)bh->b_data;
825 devid = btrfs_stack_device_id(&disk_super->dev_item);
826 if (devid != device->devid)
827 goto error_brelse;
828
829 if (memcmp(device->uuid, disk_super->dev_item.uuid,
830 BTRFS_UUID_SIZE))
831 goto error_brelse;
832
833 device->generation = btrfs_super_generation(disk_super);
834 if (!latest_transid || device->generation > latest_transid) {
835 latest_devid = devid;
836 latest_transid = device->generation;
837 latest_bdev = bdev;
838 }
839
840 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
841 device->writeable = 0;
842 } else {
843 device->writeable = !bdev_read_only(bdev);
844 seeding = 0;
845 }
846
847 q = bdev_get_queue(bdev);
848 if (blk_queue_discard(q)) {
849 device->can_discard = 1;
850 fs_devices->num_can_discard++;
851 }
852
853 device->bdev = bdev;
854 device->in_fs_metadata = 0;
855 device->mode = flags;
856
857 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
858 fs_devices->rotating = 1;
859
860 fs_devices->open_devices++;
861 if (device->writeable &&
862 device->devid != BTRFS_DEV_REPLACE_DEVID) {
863 fs_devices->rw_devices++;
864 list_add(&device->dev_alloc_list,
865 &fs_devices->alloc_list);
866 }
867 brelse(bh);
868 continue;
869
870 error_brelse:
871 brelse(bh);
872 blkdev_put(bdev, flags);
873 continue;
874 }
875 if (fs_devices->open_devices == 0) {
876 ret = -EINVAL;
877 goto out;
878 }
879 fs_devices->seeding = seeding;
880 fs_devices->opened = 1;
881 fs_devices->latest_bdev = latest_bdev;
882 fs_devices->latest_devid = latest_devid;
883 fs_devices->latest_trans = latest_transid;
884 fs_devices->total_rw_bytes = 0;
885 out:
886 return ret;
887 }
888
889 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
890 fmode_t flags, void *holder)
891 {
892 int ret;
893
894 mutex_lock(&uuid_mutex);
895 if (fs_devices->opened) {
896 fs_devices->opened++;
897 ret = 0;
898 } else {
899 ret = __btrfs_open_devices(fs_devices, flags, holder);
900 }
901 mutex_unlock(&uuid_mutex);
902 return ret;
903 }
904
905 /*
906 * Look for a btrfs signature on a device. This may be called out of the mount path
907 * and we are not allowed to call set_blocksize during the scan. The superblock
908 * is read via pagecache
909 */
910 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
911 struct btrfs_fs_devices **fs_devices_ret)
912 {
913 struct btrfs_super_block *disk_super;
914 struct block_device *bdev;
915 struct page *page;
916 void *p;
917 int ret = -EINVAL;
918 u64 devid;
919 u64 transid;
920 u64 total_devices;
921 u64 bytenr;
922 pgoff_t index;
923
924 /*
925 * we would like to check all the supers, but that would make
926 * a btrfs mount succeed after a mkfs from a different FS.
927 * So, we need to add a special mount option to scan for
928 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
929 */
930 bytenr = btrfs_sb_offset(0);
931 flags |= FMODE_EXCL;
932 mutex_lock(&uuid_mutex);
933
934 bdev = blkdev_get_by_path(path, flags, holder);
935
936 if (IS_ERR(bdev)) {
937 ret = PTR_ERR(bdev);
938 goto error;
939 }
940
941 /* make sure our super fits in the device */
942 if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
943 goto error_bdev_put;
944
945 /* make sure our super fits in the page */
946 if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
947 goto error_bdev_put;
948
949 /* make sure our super doesn't straddle pages on disk */
950 index = bytenr >> PAGE_CACHE_SHIFT;
951 if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
952 goto error_bdev_put;
953
954 /* pull in the page with our super */
955 page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
956 index, GFP_NOFS);
957
958 if (IS_ERR_OR_NULL(page))
959 goto error_bdev_put;
960
961 p = kmap(page);
962
963 /* align our pointer to the offset of the super block */
964 disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
965
966 if (btrfs_super_bytenr(disk_super) != bytenr ||
967 btrfs_super_magic(disk_super) != BTRFS_MAGIC)
968 goto error_unmap;
969
970 devid = btrfs_stack_device_id(&disk_super->dev_item);
971 transid = btrfs_super_generation(disk_super);
972 total_devices = btrfs_super_num_devices(disk_super);
973
974 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
975 if (ret > 0) {
976 if (disk_super->label[0]) {
977 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
978 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
979 printk(KERN_INFO "BTRFS: device label %s ", disk_super->label);
980 } else {
981 printk(KERN_INFO "BTRFS: device fsid %pU ", disk_super->fsid);
982 }
983
984 printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
985 ret = 0;
986 }
987 if (!ret && fs_devices_ret)
988 (*fs_devices_ret)->total_devices = total_devices;
989
990 error_unmap:
991 kunmap(page);
992 page_cache_release(page);
993
994 error_bdev_put:
995 blkdev_put(bdev, flags);
996 error:
997 mutex_unlock(&uuid_mutex);
998 return ret;
999 }
1000
1001 /* helper to account the used device space in the range */
1002 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
1003 u64 end, u64 *length)
1004 {
1005 struct btrfs_key key;
1006 struct btrfs_root *root = device->dev_root;
1007 struct btrfs_dev_extent *dev_extent;
1008 struct btrfs_path *path;
1009 u64 extent_end;
1010 int ret;
1011 int slot;
1012 struct extent_buffer *l;
1013
1014 *length = 0;
1015
1016 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
1017 return 0;
1018
1019 path = btrfs_alloc_path();
1020 if (!path)
1021 return -ENOMEM;
1022 path->reada = 2;
1023
1024 key.objectid = device->devid;
1025 key.offset = start;
1026 key.type = BTRFS_DEV_EXTENT_KEY;
1027
1028 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1029 if (ret < 0)
1030 goto out;
1031 if (ret > 0) {
1032 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1033 if (ret < 0)
1034 goto out;
1035 }
1036
1037 while (1) {
1038 l = path->nodes[0];
1039 slot = path->slots[0];
1040 if (slot >= btrfs_header_nritems(l)) {
1041 ret = btrfs_next_leaf(root, path);
1042 if (ret == 0)
1043 continue;
1044 if (ret < 0)
1045 goto out;
1046
1047 break;
1048 }
1049 btrfs_item_key_to_cpu(l, &key, slot);
1050
1051 if (key.objectid < device->devid)
1052 goto next;
1053
1054 if (key.objectid > device->devid)
1055 break;
1056
1057 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1058 goto next;
1059
1060 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1061 extent_end = key.offset + btrfs_dev_extent_length(l,
1062 dev_extent);
1063 if (key.offset <= start && extent_end > end) {
1064 *length = end - start + 1;
1065 break;
1066 } else if (key.offset <= start && extent_end > start)
1067 *length += extent_end - start;
1068 else if (key.offset > start && extent_end <= end)
1069 *length += extent_end - key.offset;
1070 else if (key.offset > start && key.offset <= end) {
1071 *length += end - key.offset + 1;
1072 break;
1073 } else if (key.offset > end)
1074 break;
1075
1076 next:
1077 path->slots[0]++;
1078 }
1079 ret = 0;
1080 out:
1081 btrfs_free_path(path);
1082 return ret;
1083 }
1084
1085 static int contains_pending_extent(struct btrfs_trans_handle *trans,
1086 struct btrfs_device *device,
1087 u64 *start, u64 len)
1088 {
1089 struct extent_map *em;
1090 int ret = 0;
1091
1092 list_for_each_entry(em, &trans->transaction->pending_chunks, list) {
1093 struct map_lookup *map;
1094 int i;
1095
1096 map = (struct map_lookup *)em->bdev;
1097 for (i = 0; i < map->num_stripes; i++) {
1098 if (map->stripes[i].dev != device)
1099 continue;
1100 if (map->stripes[i].physical >= *start + len ||
1101 map->stripes[i].physical + em->orig_block_len <=
1102 *start)
1103 continue;
1104 *start = map->stripes[i].physical +
1105 em->orig_block_len;
1106 ret = 1;
1107 }
1108 }
1109
1110 return ret;
1111 }
1112
1113
1114 /*
1115 * find_free_dev_extent - find free space in the specified device
1116 * @device: the device which we search the free space in
1117 * @num_bytes: the size of the free space that we need
1118 * @start: store the start of the free space.
1119 * @len: the size of the free space. that we find, or the size of the max
1120 * free space if we don't find suitable free space
1121 *
1122 * this uses a pretty simple search, the expectation is that it is
1123 * called very infrequently and that a given device has a small number
1124 * of extents
1125 *
1126 * @start is used to store the start of the free space if we find. But if we
1127 * don't find suitable free space, it will be used to store the start position
1128 * of the max free space.
1129 *
1130 * @len is used to store the size of the free space that we find.
1131 * But if we don't find suitable free space, it is used to store the size of
1132 * the max free space.
1133 */
1134 int find_free_dev_extent(struct btrfs_trans_handle *trans,
1135 struct btrfs_device *device, u64 num_bytes,
1136 u64 *start, u64 *len)
1137 {
1138 struct btrfs_key key;
1139 struct btrfs_root *root = device->dev_root;
1140 struct btrfs_dev_extent *dev_extent;
1141 struct btrfs_path *path;
1142 u64 hole_size;
1143 u64 max_hole_start;
1144 u64 max_hole_size;
1145 u64 extent_end;
1146 u64 search_start;
1147 u64 search_end = device->total_bytes;
1148 int ret;
1149 int slot;
1150 struct extent_buffer *l;
1151
1152 /* FIXME use last free of some kind */
1153
1154 /* we don't want to overwrite the superblock on the drive,
1155 * so we make sure to start at an offset of at least 1MB
1156 */
1157 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1158
1159 path = btrfs_alloc_path();
1160 if (!path)
1161 return -ENOMEM;
1162 again:
1163 max_hole_start = search_start;
1164 max_hole_size = 0;
1165 hole_size = 0;
1166
1167 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1168 ret = -ENOSPC;
1169 goto out;
1170 }
1171
1172 path->reada = 2;
1173 path->search_commit_root = 1;
1174 path->skip_locking = 1;
1175
1176 key.objectid = device->devid;
1177 key.offset = search_start;
1178 key.type = BTRFS_DEV_EXTENT_KEY;
1179
1180 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1181 if (ret < 0)
1182 goto out;
1183 if (ret > 0) {
1184 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1185 if (ret < 0)
1186 goto out;
1187 }
1188
1189 while (1) {
1190 l = path->nodes[0];
1191 slot = path->slots[0];
1192 if (slot >= btrfs_header_nritems(l)) {
1193 ret = btrfs_next_leaf(root, path);
1194 if (ret == 0)
1195 continue;
1196 if (ret < 0)
1197 goto out;
1198
1199 break;
1200 }
1201 btrfs_item_key_to_cpu(l, &key, slot);
1202
1203 if (key.objectid < device->devid)
1204 goto next;
1205
1206 if (key.objectid > device->devid)
1207 break;
1208
1209 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1210 goto next;
1211
1212 if (key.offset > search_start) {
1213 hole_size = key.offset - search_start;
1214
1215 /*
1216 * Have to check before we set max_hole_start, otherwise
1217 * we could end up sending back this offset anyway.
1218 */
1219 if (contains_pending_extent(trans, device,
1220 &search_start,
1221 hole_size))
1222 hole_size = 0;
1223
1224 if (hole_size > max_hole_size) {
1225 max_hole_start = search_start;
1226 max_hole_size = hole_size;
1227 }
1228
1229 /*
1230 * If this free space is greater than which we need,
1231 * it must be the max free space that we have found
1232 * until now, so max_hole_start must point to the start
1233 * of this free space and the length of this free space
1234 * is stored in max_hole_size. Thus, we return
1235 * max_hole_start and max_hole_size and go back to the
1236 * caller.
1237 */
1238 if (hole_size >= num_bytes) {
1239 ret = 0;
1240 goto out;
1241 }
1242 }
1243
1244 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1245 extent_end = key.offset + btrfs_dev_extent_length(l,
1246 dev_extent);
1247 if (extent_end > search_start)
1248 search_start = extent_end;
1249 next:
1250 path->slots[0]++;
1251 cond_resched();
1252 }
1253
1254 /*
1255 * At this point, search_start should be the end of
1256 * allocated dev extents, and when shrinking the device,
1257 * search_end may be smaller than search_start.
1258 */
1259 if (search_end > search_start)
1260 hole_size = search_end - search_start;
1261
1262 if (hole_size > max_hole_size) {
1263 max_hole_start = search_start;
1264 max_hole_size = hole_size;
1265 }
1266
1267 if (contains_pending_extent(trans, device, &search_start, hole_size)) {
1268 btrfs_release_path(path);
1269 goto again;
1270 }
1271
1272 /* See above. */
1273 if (hole_size < num_bytes)
1274 ret = -ENOSPC;
1275 else
1276 ret = 0;
1277
1278 out:
1279 btrfs_free_path(path);
1280 *start = max_hole_start;
1281 if (len)
1282 *len = max_hole_size;
1283 return ret;
1284 }
1285
1286 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1287 struct btrfs_device *device,
1288 u64 start)
1289 {
1290 int ret;
1291 struct btrfs_path *path;
1292 struct btrfs_root *root = device->dev_root;
1293 struct btrfs_key key;
1294 struct btrfs_key found_key;
1295 struct extent_buffer *leaf = NULL;
1296 struct btrfs_dev_extent *extent = NULL;
1297
1298 path = btrfs_alloc_path();
1299 if (!path)
1300 return -ENOMEM;
1301
1302 key.objectid = device->devid;
1303 key.offset = start;
1304 key.type = BTRFS_DEV_EXTENT_KEY;
1305 again:
1306 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1307 if (ret > 0) {
1308 ret = btrfs_previous_item(root, path, key.objectid,
1309 BTRFS_DEV_EXTENT_KEY);
1310 if (ret)
1311 goto out;
1312 leaf = path->nodes[0];
1313 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1314 extent = btrfs_item_ptr(leaf, path->slots[0],
1315 struct btrfs_dev_extent);
1316 BUG_ON(found_key.offset > start || found_key.offset +
1317 btrfs_dev_extent_length(leaf, extent) < start);
1318 key = found_key;
1319 btrfs_release_path(path);
1320 goto again;
1321 } else if (ret == 0) {
1322 leaf = path->nodes[0];
1323 extent = btrfs_item_ptr(leaf, path->slots[0],
1324 struct btrfs_dev_extent);
1325 } else {
1326 btrfs_error(root->fs_info, ret, "Slot search failed");
1327 goto out;
1328 }
1329
1330 if (device->bytes_used > 0) {
1331 u64 len = btrfs_dev_extent_length(leaf, extent);
1332 device->bytes_used -= len;
1333 spin_lock(&root->fs_info->free_chunk_lock);
1334 root->fs_info->free_chunk_space += len;
1335 spin_unlock(&root->fs_info->free_chunk_lock);
1336 }
1337 ret = btrfs_del_item(trans, root, path);
1338 if (ret) {
1339 btrfs_error(root->fs_info, ret,
1340 "Failed to remove dev extent item");
1341 }
1342 out:
1343 btrfs_free_path(path);
1344 return ret;
1345 }
1346
1347 static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1348 struct btrfs_device *device,
1349 u64 chunk_tree, u64 chunk_objectid,
1350 u64 chunk_offset, u64 start, u64 num_bytes)
1351 {
1352 int ret;
1353 struct btrfs_path *path;
1354 struct btrfs_root *root = device->dev_root;
1355 struct btrfs_dev_extent *extent;
1356 struct extent_buffer *leaf;
1357 struct btrfs_key key;
1358
1359 WARN_ON(!device->in_fs_metadata);
1360 WARN_ON(device->is_tgtdev_for_dev_replace);
1361 path = btrfs_alloc_path();
1362 if (!path)
1363 return -ENOMEM;
1364
1365 key.objectid = device->devid;
1366 key.offset = start;
1367 key.type = BTRFS_DEV_EXTENT_KEY;
1368 ret = btrfs_insert_empty_item(trans, root, path, &key,
1369 sizeof(*extent));
1370 if (ret)
1371 goto out;
1372
1373 leaf = path->nodes[0];
1374 extent = btrfs_item_ptr(leaf, path->slots[0],
1375 struct btrfs_dev_extent);
1376 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1377 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1378 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1379
1380 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1381 btrfs_dev_extent_chunk_tree_uuid(extent), BTRFS_UUID_SIZE);
1382
1383 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1384 btrfs_mark_buffer_dirty(leaf);
1385 out:
1386 btrfs_free_path(path);
1387 return ret;
1388 }
1389
1390 static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
1391 {
1392 struct extent_map_tree *em_tree;
1393 struct extent_map *em;
1394 struct rb_node *n;
1395 u64 ret = 0;
1396
1397 em_tree = &fs_info->mapping_tree.map_tree;
1398 read_lock(&em_tree->lock);
1399 n = rb_last(&em_tree->map);
1400 if (n) {
1401 em = rb_entry(n, struct extent_map, rb_node);
1402 ret = em->start + em->len;
1403 }
1404 read_unlock(&em_tree->lock);
1405
1406 return ret;
1407 }
1408
1409 static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
1410 u64 *devid_ret)
1411 {
1412 int ret;
1413 struct btrfs_key key;
1414 struct btrfs_key found_key;
1415 struct btrfs_path *path;
1416
1417 path = btrfs_alloc_path();
1418 if (!path)
1419 return -ENOMEM;
1420
1421 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1422 key.type = BTRFS_DEV_ITEM_KEY;
1423 key.offset = (u64)-1;
1424
1425 ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
1426 if (ret < 0)
1427 goto error;
1428
1429 BUG_ON(ret == 0); /* Corruption */
1430
1431 ret = btrfs_previous_item(fs_info->chunk_root, path,
1432 BTRFS_DEV_ITEMS_OBJECTID,
1433 BTRFS_DEV_ITEM_KEY);
1434 if (ret) {
1435 *devid_ret = 1;
1436 } else {
1437 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1438 path->slots[0]);
1439 *devid_ret = found_key.offset + 1;
1440 }
1441 ret = 0;
1442 error:
1443 btrfs_free_path(path);
1444 return ret;
1445 }
1446
1447 /*
1448 * the device information is stored in the chunk root
1449 * the btrfs_device struct should be fully filled in
1450 */
1451 static int btrfs_add_device(struct btrfs_trans_handle *trans,
1452 struct btrfs_root *root,
1453 struct btrfs_device *device)
1454 {
1455 int ret;
1456 struct btrfs_path *path;
1457 struct btrfs_dev_item *dev_item;
1458 struct extent_buffer *leaf;
1459 struct btrfs_key key;
1460 unsigned long ptr;
1461
1462 root = root->fs_info->chunk_root;
1463
1464 path = btrfs_alloc_path();
1465 if (!path)
1466 return -ENOMEM;
1467
1468 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1469 key.type = BTRFS_DEV_ITEM_KEY;
1470 key.offset = device->devid;
1471
1472 ret = btrfs_insert_empty_item(trans, root, path, &key,
1473 sizeof(*dev_item));
1474 if (ret)
1475 goto out;
1476
1477 leaf = path->nodes[0];
1478 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1479
1480 btrfs_set_device_id(leaf, dev_item, device->devid);
1481 btrfs_set_device_generation(leaf, dev_item, 0);
1482 btrfs_set_device_type(leaf, dev_item, device->type);
1483 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1484 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1485 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1486 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1487 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1488 btrfs_set_device_group(leaf, dev_item, 0);
1489 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1490 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1491 btrfs_set_device_start_offset(leaf, dev_item, 0);
1492
1493 ptr = btrfs_device_uuid(dev_item);
1494 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1495 ptr = btrfs_device_fsid(dev_item);
1496 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1497 btrfs_mark_buffer_dirty(leaf);
1498
1499 ret = 0;
1500 out:
1501 btrfs_free_path(path);
1502 return ret;
1503 }
1504
1505 /*
1506 * Function to update ctime/mtime for a given device path.
1507 * Mainly used for ctime/mtime based probe like libblkid.
1508 */
1509 static void update_dev_time(char *path_name)
1510 {
1511 struct file *filp;
1512
1513 filp = filp_open(path_name, O_RDWR, 0);
1514 if (!filp)
1515 return;
1516 file_update_time(filp);
1517 filp_close(filp, NULL);
1518 return;
1519 }
1520
1521 static int btrfs_rm_dev_item(struct btrfs_root *root,
1522 struct btrfs_device *device)
1523 {
1524 int ret;
1525 struct btrfs_path *path;
1526 struct btrfs_key key;
1527 struct btrfs_trans_handle *trans;
1528
1529 root = root->fs_info->chunk_root;
1530
1531 path = btrfs_alloc_path();
1532 if (!path)
1533 return -ENOMEM;
1534
1535 trans = btrfs_start_transaction(root, 0);
1536 if (IS_ERR(trans)) {
1537 btrfs_free_path(path);
1538 return PTR_ERR(trans);
1539 }
1540 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1541 key.type = BTRFS_DEV_ITEM_KEY;
1542 key.offset = device->devid;
1543 lock_chunks(root);
1544
1545 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1546 if (ret < 0)
1547 goto out;
1548
1549 if (ret > 0) {
1550 ret = -ENOENT;
1551 goto out;
1552 }
1553
1554 ret = btrfs_del_item(trans, root, path);
1555 if (ret)
1556 goto out;
1557 out:
1558 btrfs_free_path(path);
1559 unlock_chunks(root);
1560 btrfs_commit_transaction(trans, root);
1561 return ret;
1562 }
1563
1564 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1565 {
1566 struct btrfs_device *device;
1567 struct btrfs_device *next_device;
1568 struct block_device *bdev;
1569 struct buffer_head *bh = NULL;
1570 struct btrfs_super_block *disk_super;
1571 struct btrfs_fs_devices *cur_devices;
1572 u64 all_avail;
1573 u64 devid;
1574 u64 num_devices;
1575 u8 *dev_uuid;
1576 unsigned seq;
1577 int ret = 0;
1578 bool clear_super = false;
1579
1580 mutex_lock(&uuid_mutex);
1581
1582 do {
1583 seq = read_seqbegin(&root->fs_info->profiles_lock);
1584
1585 all_avail = root->fs_info->avail_data_alloc_bits |
1586 root->fs_info->avail_system_alloc_bits |
1587 root->fs_info->avail_metadata_alloc_bits;
1588 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
1589
1590 num_devices = root->fs_info->fs_devices->num_devices;
1591 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1592 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1593 WARN_ON(num_devices < 1);
1594 num_devices--;
1595 }
1596 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1597
1598 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1599 ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
1600 goto out;
1601 }
1602
1603 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1604 ret = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
1605 goto out;
1606 }
1607
1608 if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1609 root->fs_info->fs_devices->rw_devices <= 2) {
1610 ret = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
1611 goto out;
1612 }
1613 if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1614 root->fs_info->fs_devices->rw_devices <= 3) {
1615 ret = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
1616 goto out;
1617 }
1618
1619 if (strcmp(device_path, "missing") == 0) {
1620 struct list_head *devices;
1621 struct btrfs_device *tmp;
1622
1623 device = NULL;
1624 devices = &root->fs_info->fs_devices->devices;
1625 /*
1626 * It is safe to read the devices since the volume_mutex
1627 * is held.
1628 */
1629 list_for_each_entry(tmp, devices, dev_list) {
1630 if (tmp->in_fs_metadata &&
1631 !tmp->is_tgtdev_for_dev_replace &&
1632 !tmp->bdev) {
1633 device = tmp;
1634 break;
1635 }
1636 }
1637 bdev = NULL;
1638 bh = NULL;
1639 disk_super = NULL;
1640 if (!device) {
1641 ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
1642 goto out;
1643 }
1644 } else {
1645 ret = btrfs_get_bdev_and_sb(device_path,
1646 FMODE_WRITE | FMODE_EXCL,
1647 root->fs_info->bdev_holder, 0,
1648 &bdev, &bh);
1649 if (ret)
1650 goto out;
1651 disk_super = (struct btrfs_super_block *)bh->b_data;
1652 devid = btrfs_stack_device_id(&disk_super->dev_item);
1653 dev_uuid = disk_super->dev_item.uuid;
1654 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1655 disk_super->fsid);
1656 if (!device) {
1657 ret = -ENOENT;
1658 goto error_brelse;
1659 }
1660 }
1661
1662 if (device->is_tgtdev_for_dev_replace) {
1663 ret = BTRFS_ERROR_DEV_TGT_REPLACE;
1664 goto error_brelse;
1665 }
1666
1667 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1668 ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
1669 goto error_brelse;
1670 }
1671
1672 if (device->writeable) {
1673 lock_chunks(root);
1674 list_del_init(&device->dev_alloc_list);
1675 unlock_chunks(root);
1676 root->fs_info->fs_devices->rw_devices--;
1677 clear_super = true;
1678 }
1679
1680 mutex_unlock(&uuid_mutex);
1681 ret = btrfs_shrink_device(device, 0);
1682 mutex_lock(&uuid_mutex);
1683 if (ret)
1684 goto error_undo;
1685
1686 /*
1687 * TODO: the superblock still includes this device in its num_devices
1688 * counter although write_all_supers() is not locked out. This
1689 * could give a filesystem state which requires a degraded mount.
1690 */
1691 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1692 if (ret)
1693 goto error_undo;
1694
1695 spin_lock(&root->fs_info->free_chunk_lock);
1696 root->fs_info->free_chunk_space = device->total_bytes -
1697 device->bytes_used;
1698 spin_unlock(&root->fs_info->free_chunk_lock);
1699
1700 device->in_fs_metadata = 0;
1701 btrfs_scrub_cancel_dev(root->fs_info, device);
1702
1703 /*
1704 * the device list mutex makes sure that we don't change
1705 * the device list while someone else is writing out all
1706 * the device supers. Whoever is writing all supers, should
1707 * lock the device list mutex before getting the number of
1708 * devices in the super block (super_copy). Conversely,
1709 * whoever updates the number of devices in the super block
1710 * (super_copy) should hold the device list mutex.
1711 */
1712
1713 cur_devices = device->fs_devices;
1714 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1715 list_del_rcu(&device->dev_list);
1716
1717 device->fs_devices->num_devices--;
1718 device->fs_devices->total_devices--;
1719
1720 if (device->missing)
1721 device->fs_devices->missing_devices--;
1722
1723 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1724 struct btrfs_device, dev_list);
1725 if (device->bdev == root->fs_info->sb->s_bdev)
1726 root->fs_info->sb->s_bdev = next_device->bdev;
1727 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1728 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1729
1730 if (device->bdev) {
1731 device->fs_devices->open_devices--;
1732 /* remove sysfs entry */
1733 btrfs_kobj_rm_device(root->fs_info, device);
1734 }
1735
1736 call_rcu(&device->rcu, free_device);
1737
1738 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1739 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1740 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1741
1742 if (cur_devices->open_devices == 0) {
1743 struct btrfs_fs_devices *fs_devices;
1744 fs_devices = root->fs_info->fs_devices;
1745 while (fs_devices) {
1746 if (fs_devices->seed == cur_devices) {
1747 fs_devices->seed = cur_devices->seed;
1748 break;
1749 }
1750 fs_devices = fs_devices->seed;
1751 }
1752 cur_devices->seed = NULL;
1753 lock_chunks(root);
1754 __btrfs_close_devices(cur_devices);
1755 unlock_chunks(root);
1756 free_fs_devices(cur_devices);
1757 }
1758
1759 root->fs_info->num_tolerated_disk_barrier_failures =
1760 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1761
1762 /*
1763 * at this point, the device is zero sized. We want to
1764 * remove it from the devices list and zero out the old super
1765 */
1766 if (clear_super && disk_super) {
1767 u64 bytenr;
1768 int i;
1769
1770 /* make sure this device isn't detected as part of
1771 * the FS anymore
1772 */
1773 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1774 set_buffer_dirty(bh);
1775 sync_dirty_buffer(bh);
1776
1777 /* clear the mirror copies of super block on the disk
1778 * being removed, 0th copy is been taken care above and
1779 * the below would take of the rest
1780 */
1781 for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
1782 bytenr = btrfs_sb_offset(i);
1783 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
1784 i_size_read(bdev->bd_inode))
1785 break;
1786
1787 brelse(bh);
1788 bh = __bread(bdev, bytenr / 4096,
1789 BTRFS_SUPER_INFO_SIZE);
1790 if (!bh)
1791 continue;
1792
1793 disk_super = (struct btrfs_super_block *)bh->b_data;
1794
1795 if (btrfs_super_bytenr(disk_super) != bytenr ||
1796 btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
1797 continue;
1798 }
1799 memset(&disk_super->magic, 0,
1800 sizeof(disk_super->magic));
1801 set_buffer_dirty(bh);
1802 sync_dirty_buffer(bh);
1803 }
1804 }
1805
1806 ret = 0;
1807
1808 if (bdev) {
1809 /* Notify udev that device has changed */
1810 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1811
1812 /* Update ctime/mtime for device path for libblkid */
1813 update_dev_time(device_path);
1814 }
1815
1816 error_brelse:
1817 brelse(bh);
1818 if (bdev)
1819 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1820 out:
1821 mutex_unlock(&uuid_mutex);
1822 return ret;
1823 error_undo:
1824 if (device->writeable) {
1825 lock_chunks(root);
1826 list_add(&device->dev_alloc_list,
1827 &root->fs_info->fs_devices->alloc_list);
1828 unlock_chunks(root);
1829 root->fs_info->fs_devices->rw_devices++;
1830 }
1831 goto error_brelse;
1832 }
1833
1834 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1835 struct btrfs_device *srcdev)
1836 {
1837 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1838
1839 list_del_rcu(&srcdev->dev_list);
1840 list_del_rcu(&srcdev->dev_alloc_list);
1841 fs_info->fs_devices->num_devices--;
1842 if (srcdev->missing) {
1843 fs_info->fs_devices->missing_devices--;
1844 fs_info->fs_devices->rw_devices++;
1845 }
1846 if (srcdev->can_discard)
1847 fs_info->fs_devices->num_can_discard--;
1848 if (srcdev->bdev) {
1849 fs_info->fs_devices->open_devices--;
1850
1851 /*
1852 * zero out the old super if it is not writable
1853 * (e.g. seed device)
1854 */
1855 if (srcdev->writeable)
1856 btrfs_scratch_superblock(srcdev);
1857 }
1858
1859 call_rcu(&srcdev->rcu, free_device);
1860 }
1861
1862 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1863 struct btrfs_device *tgtdev)
1864 {
1865 struct btrfs_device *next_device;
1866
1867 WARN_ON(!tgtdev);
1868 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1869 if (tgtdev->bdev) {
1870 btrfs_scratch_superblock(tgtdev);
1871 fs_info->fs_devices->open_devices--;
1872 }
1873 fs_info->fs_devices->num_devices--;
1874 if (tgtdev->can_discard)
1875 fs_info->fs_devices->num_can_discard++;
1876
1877 next_device = list_entry(fs_info->fs_devices->devices.next,
1878 struct btrfs_device, dev_list);
1879 if (tgtdev->bdev == fs_info->sb->s_bdev)
1880 fs_info->sb->s_bdev = next_device->bdev;
1881 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1882 fs_info->fs_devices->latest_bdev = next_device->bdev;
1883 list_del_rcu(&tgtdev->dev_list);
1884
1885 call_rcu(&tgtdev->rcu, free_device);
1886
1887 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1888 }
1889
1890 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1891 struct btrfs_device **device)
1892 {
1893 int ret = 0;
1894 struct btrfs_super_block *disk_super;
1895 u64 devid;
1896 u8 *dev_uuid;
1897 struct block_device *bdev;
1898 struct buffer_head *bh;
1899
1900 *device = NULL;
1901 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1902 root->fs_info->bdev_holder, 0, &bdev, &bh);
1903 if (ret)
1904 return ret;
1905 disk_super = (struct btrfs_super_block *)bh->b_data;
1906 devid = btrfs_stack_device_id(&disk_super->dev_item);
1907 dev_uuid = disk_super->dev_item.uuid;
1908 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1909 disk_super->fsid);
1910 brelse(bh);
1911 if (!*device)
1912 ret = -ENOENT;
1913 blkdev_put(bdev, FMODE_READ);
1914 return ret;
1915 }
1916
1917 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1918 char *device_path,
1919 struct btrfs_device **device)
1920 {
1921 *device = NULL;
1922 if (strcmp(device_path, "missing") == 0) {
1923 struct list_head *devices;
1924 struct btrfs_device *tmp;
1925
1926 devices = &root->fs_info->fs_devices->devices;
1927 /*
1928 * It is safe to read the devices since the volume_mutex
1929 * is held by the caller.
1930 */
1931 list_for_each_entry(tmp, devices, dev_list) {
1932 if (tmp->in_fs_metadata && !tmp->bdev) {
1933 *device = tmp;
1934 break;
1935 }
1936 }
1937
1938 if (!*device) {
1939 btrfs_err(root->fs_info, "no missing device found");
1940 return -ENOENT;
1941 }
1942
1943 return 0;
1944 } else {
1945 return btrfs_find_device_by_path(root, device_path, device);
1946 }
1947 }
1948
1949 /*
1950 * does all the dirty work required for changing file system's UUID.
1951 */
1952 static int btrfs_prepare_sprout(struct btrfs_root *root)
1953 {
1954 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1955 struct btrfs_fs_devices *old_devices;
1956 struct btrfs_fs_devices *seed_devices;
1957 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1958 struct btrfs_device *device;
1959 u64 super_flags;
1960
1961 BUG_ON(!mutex_is_locked(&uuid_mutex));
1962 if (!fs_devices->seeding)
1963 return -EINVAL;
1964
1965 seed_devices = __alloc_fs_devices();
1966 if (IS_ERR(seed_devices))
1967 return PTR_ERR(seed_devices);
1968
1969 old_devices = clone_fs_devices(fs_devices);
1970 if (IS_ERR(old_devices)) {
1971 kfree(seed_devices);
1972 return PTR_ERR(old_devices);
1973 }
1974
1975 list_add(&old_devices->list, &fs_uuids);
1976
1977 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1978 seed_devices->opened = 1;
1979 INIT_LIST_HEAD(&seed_devices->devices);
1980 INIT_LIST_HEAD(&seed_devices->alloc_list);
1981 mutex_init(&seed_devices->device_list_mutex);
1982
1983 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1984 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1985 synchronize_rcu);
1986
1987 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1988 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1989 device->fs_devices = seed_devices;
1990 }
1991
1992 fs_devices->seeding = 0;
1993 fs_devices->num_devices = 0;
1994 fs_devices->open_devices = 0;
1995 fs_devices->missing_devices = 0;
1996 fs_devices->num_can_discard = 0;
1997 fs_devices->rotating = 0;
1998 fs_devices->seed = seed_devices;
1999
2000 generate_random_uuid(fs_devices->fsid);
2001 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
2002 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
2003 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2004
2005 super_flags = btrfs_super_flags(disk_super) &
2006 ~BTRFS_SUPER_FLAG_SEEDING;
2007 btrfs_set_super_flags(disk_super, super_flags);
2008
2009 return 0;
2010 }
2011
2012 /*
2013 * strore the expected generation for seed devices in device items.
2014 */
2015 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
2016 struct btrfs_root *root)
2017 {
2018 struct btrfs_path *path;
2019 struct extent_buffer *leaf;
2020 struct btrfs_dev_item *dev_item;
2021 struct btrfs_device *device;
2022 struct btrfs_key key;
2023 u8 fs_uuid[BTRFS_UUID_SIZE];
2024 u8 dev_uuid[BTRFS_UUID_SIZE];
2025 u64 devid;
2026 int ret;
2027
2028 path = btrfs_alloc_path();
2029 if (!path)
2030 return -ENOMEM;
2031
2032 root = root->fs_info->chunk_root;
2033 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2034 key.offset = 0;
2035 key.type = BTRFS_DEV_ITEM_KEY;
2036
2037 while (1) {
2038 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2039 if (ret < 0)
2040 goto error;
2041
2042 leaf = path->nodes[0];
2043 next_slot:
2044 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
2045 ret = btrfs_next_leaf(root, path);
2046 if (ret > 0)
2047 break;
2048 if (ret < 0)
2049 goto error;
2050 leaf = path->nodes[0];
2051 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2052 btrfs_release_path(path);
2053 continue;
2054 }
2055
2056 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
2057 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
2058 key.type != BTRFS_DEV_ITEM_KEY)
2059 break;
2060
2061 dev_item = btrfs_item_ptr(leaf, path->slots[0],
2062 struct btrfs_dev_item);
2063 devid = btrfs_device_id(leaf, dev_item);
2064 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
2065 BTRFS_UUID_SIZE);
2066 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
2067 BTRFS_UUID_SIZE);
2068 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
2069 fs_uuid);
2070 BUG_ON(!device); /* Logic error */
2071
2072 if (device->fs_devices->seeding) {
2073 btrfs_set_device_generation(leaf, dev_item,
2074 device->generation);
2075 btrfs_mark_buffer_dirty(leaf);
2076 }
2077
2078 path->slots[0]++;
2079 goto next_slot;
2080 }
2081 ret = 0;
2082 error:
2083 btrfs_free_path(path);
2084 return ret;
2085 }
2086
2087 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
2088 {
2089 struct request_queue *q;
2090 struct btrfs_trans_handle *trans;
2091 struct btrfs_device *device;
2092 struct block_device *bdev;
2093 struct list_head *devices;
2094 struct super_block *sb = root->fs_info->sb;
2095 struct rcu_string *name;
2096 u64 total_bytes;
2097 int seeding_dev = 0;
2098 int ret = 0;
2099
2100 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
2101 return -EROFS;
2102
2103 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2104 root->fs_info->bdev_holder);
2105 if (IS_ERR(bdev))
2106 return PTR_ERR(bdev);
2107
2108 if (root->fs_info->fs_devices->seeding) {
2109 seeding_dev = 1;
2110 down_write(&sb->s_umount);
2111 mutex_lock(&uuid_mutex);
2112 }
2113
2114 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2115
2116 devices = &root->fs_info->fs_devices->devices;
2117
2118 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2119 list_for_each_entry(device, devices, dev_list) {
2120 if (device->bdev == bdev) {
2121 ret = -EEXIST;
2122 mutex_unlock(
2123 &root->fs_info->fs_devices->device_list_mutex);
2124 goto error;
2125 }
2126 }
2127 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2128
2129 device = btrfs_alloc_device(root->fs_info, NULL, NULL);
2130 if (IS_ERR(device)) {
2131 /* we can safely leave the fs_devices entry around */
2132 ret = PTR_ERR(device);
2133 goto error;
2134 }
2135
2136 name = rcu_string_strdup(device_path, GFP_NOFS);
2137 if (!name) {
2138 kfree(device);
2139 ret = -ENOMEM;
2140 goto error;
2141 }
2142 rcu_assign_pointer(device->name, name);
2143
2144 trans = btrfs_start_transaction(root, 0);
2145 if (IS_ERR(trans)) {
2146 rcu_string_free(device->name);
2147 kfree(device);
2148 ret = PTR_ERR(trans);
2149 goto error;
2150 }
2151
2152 lock_chunks(root);
2153
2154 q = bdev_get_queue(bdev);
2155 if (blk_queue_discard(q))
2156 device->can_discard = 1;
2157 device->writeable = 1;
2158 device->generation = trans->transid;
2159 device->io_width = root->sectorsize;
2160 device->io_align = root->sectorsize;
2161 device->sector_size = root->sectorsize;
2162 device->total_bytes = i_size_read(bdev->bd_inode);
2163 device->disk_total_bytes = device->total_bytes;
2164 device->dev_root = root->fs_info->dev_root;
2165 device->bdev = bdev;
2166 device->in_fs_metadata = 1;
2167 device->is_tgtdev_for_dev_replace = 0;
2168 device->mode = FMODE_EXCL;
2169 device->dev_stats_valid = 1;
2170 set_blocksize(device->bdev, 4096);
2171
2172 if (seeding_dev) {
2173 sb->s_flags &= ~MS_RDONLY;
2174 ret = btrfs_prepare_sprout(root);
2175 BUG_ON(ret); /* -ENOMEM */
2176 }
2177
2178 device->fs_devices = root->fs_info->fs_devices;
2179
2180 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2181 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2182 list_add(&device->dev_alloc_list,
2183 &root->fs_info->fs_devices->alloc_list);
2184 root->fs_info->fs_devices->num_devices++;
2185 root->fs_info->fs_devices->open_devices++;
2186 root->fs_info->fs_devices->rw_devices++;
2187 root->fs_info->fs_devices->total_devices++;
2188 if (device->can_discard)
2189 root->fs_info->fs_devices->num_can_discard++;
2190 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2191
2192 spin_lock(&root->fs_info->free_chunk_lock);
2193 root->fs_info->free_chunk_space += device->total_bytes;
2194 spin_unlock(&root->fs_info->free_chunk_lock);
2195
2196 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2197 root->fs_info->fs_devices->rotating = 1;
2198
2199 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2200 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2201 total_bytes + device->total_bytes);
2202
2203 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2204 btrfs_set_super_num_devices(root->fs_info->super_copy,
2205 total_bytes + 1);
2206
2207 /* add sysfs device entry */
2208 btrfs_kobj_add_device(root->fs_info, device);
2209
2210 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2211
2212 if (seeding_dev) {
2213 char fsid_buf[BTRFS_UUID_UNPARSED_SIZE];
2214 ret = init_first_rw_device(trans, root, device);
2215 if (ret) {
2216 btrfs_abort_transaction(trans, root, ret);
2217 goto error_trans;
2218 }
2219 ret = btrfs_finish_sprout(trans, root);
2220 if (ret) {
2221 btrfs_abort_transaction(trans, root, ret);
2222 goto error_trans;
2223 }
2224
2225 /* Sprouting would change fsid of the mounted root,
2226 * so rename the fsid on the sysfs
2227 */
2228 snprintf(fsid_buf, BTRFS_UUID_UNPARSED_SIZE, "%pU",
2229 root->fs_info->fsid);
2230 if (kobject_rename(&root->fs_info->super_kobj, fsid_buf))
2231 goto error_trans;
2232 } else {
2233 ret = btrfs_add_device(trans, root, device);
2234 if (ret) {
2235 btrfs_abort_transaction(trans, root, ret);
2236 goto error_trans;
2237 }
2238 }
2239
2240 /*
2241 * we've got more storage, clear any full flags on the space
2242 * infos
2243 */
2244 btrfs_clear_space_info_full(root->fs_info);
2245
2246 unlock_chunks(root);
2247 root->fs_info->num_tolerated_disk_barrier_failures =
2248 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2249 ret = btrfs_commit_transaction(trans, root);
2250
2251 if (seeding_dev) {
2252 mutex_unlock(&uuid_mutex);
2253 up_write(&sb->s_umount);
2254
2255 if (ret) /* transaction commit */
2256 return ret;
2257
2258 ret = btrfs_relocate_sys_chunks(root);
2259 if (ret < 0)
2260 btrfs_error(root->fs_info, ret,
2261 "Failed to relocate sys chunks after "
2262 "device initialization. This can be fixed "
2263 "using the \"btrfs balance\" command.");
2264 trans = btrfs_attach_transaction(root);
2265 if (IS_ERR(trans)) {
2266 if (PTR_ERR(trans) == -ENOENT)
2267 return 0;
2268 return PTR_ERR(trans);
2269 }
2270 ret = btrfs_commit_transaction(trans, root);
2271 }
2272
2273 /* Update ctime/mtime for libblkid */
2274 update_dev_time(device_path);
2275 return ret;
2276
2277 error_trans:
2278 unlock_chunks(root);
2279 btrfs_end_transaction(trans, root);
2280 rcu_string_free(device->name);
2281 btrfs_kobj_rm_device(root->fs_info, device);
2282 kfree(device);
2283 error:
2284 blkdev_put(bdev, FMODE_EXCL);
2285 if (seeding_dev) {
2286 mutex_unlock(&uuid_mutex);
2287 up_write(&sb->s_umount);
2288 }
2289 return ret;
2290 }
2291
2292 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2293 struct btrfs_device **device_out)
2294 {
2295 struct request_queue *q;
2296 struct btrfs_device *device;
2297 struct block_device *bdev;
2298 struct btrfs_fs_info *fs_info = root->fs_info;
2299 struct list_head *devices;
2300 struct rcu_string *name;
2301 u64 devid = BTRFS_DEV_REPLACE_DEVID;
2302 int ret = 0;
2303
2304 *device_out = NULL;
2305 if (fs_info->fs_devices->seeding)
2306 return -EINVAL;
2307
2308 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2309 fs_info->bdev_holder);
2310 if (IS_ERR(bdev))
2311 return PTR_ERR(bdev);
2312
2313 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2314
2315 devices = &fs_info->fs_devices->devices;
2316 list_for_each_entry(device, devices, dev_list) {
2317 if (device->bdev == bdev) {
2318 ret = -EEXIST;
2319 goto error;
2320 }
2321 }
2322
2323 device = btrfs_alloc_device(NULL, &devid, NULL);
2324 if (IS_ERR(device)) {
2325 ret = PTR_ERR(device);
2326 goto error;
2327 }
2328
2329 name = rcu_string_strdup(device_path, GFP_NOFS);
2330 if (!name) {
2331 kfree(device);
2332 ret = -ENOMEM;
2333 goto error;
2334 }
2335 rcu_assign_pointer(device->name, name);
2336
2337 q = bdev_get_queue(bdev);
2338 if (blk_queue_discard(q))
2339 device->can_discard = 1;
2340 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2341 device->writeable = 1;
2342 device->generation = 0;
2343 device->io_width = root->sectorsize;
2344 device->io_align = root->sectorsize;
2345 device->sector_size = root->sectorsize;
2346 device->total_bytes = i_size_read(bdev->bd_inode);
2347 device->disk_total_bytes = device->total_bytes;
2348 device->dev_root = fs_info->dev_root;
2349 device->bdev = bdev;
2350 device->in_fs_metadata = 1;
2351 device->is_tgtdev_for_dev_replace = 1;
2352 device->mode = FMODE_EXCL;
2353 device->dev_stats_valid = 1;
2354 set_blocksize(device->bdev, 4096);
2355 device->fs_devices = fs_info->fs_devices;
2356 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2357 fs_info->fs_devices->num_devices++;
2358 fs_info->fs_devices->open_devices++;
2359 if (device->can_discard)
2360 fs_info->fs_devices->num_can_discard++;
2361 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2362
2363 *device_out = device;
2364 return ret;
2365
2366 error:
2367 blkdev_put(bdev, FMODE_EXCL);
2368 return ret;
2369 }
2370
2371 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2372 struct btrfs_device *tgtdev)
2373 {
2374 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2375 tgtdev->io_width = fs_info->dev_root->sectorsize;
2376 tgtdev->io_align = fs_info->dev_root->sectorsize;
2377 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2378 tgtdev->dev_root = fs_info->dev_root;
2379 tgtdev->in_fs_metadata = 1;
2380 }
2381
2382 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2383 struct btrfs_device *device)
2384 {
2385 int ret;
2386 struct btrfs_path *path;
2387 struct btrfs_root *root;
2388 struct btrfs_dev_item *dev_item;
2389 struct extent_buffer *leaf;
2390 struct btrfs_key key;
2391
2392 root = device->dev_root->fs_info->chunk_root;
2393
2394 path = btrfs_alloc_path();
2395 if (!path)
2396 return -ENOMEM;
2397
2398 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2399 key.type = BTRFS_DEV_ITEM_KEY;
2400 key.offset = device->devid;
2401
2402 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2403 if (ret < 0)
2404 goto out;
2405
2406 if (ret > 0) {
2407 ret = -ENOENT;
2408 goto out;
2409 }
2410
2411 leaf = path->nodes[0];
2412 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2413
2414 btrfs_set_device_id(leaf, dev_item, device->devid);
2415 btrfs_set_device_type(leaf, dev_item, device->type);
2416 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2417 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2418 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2419 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2420 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2421 btrfs_mark_buffer_dirty(leaf);
2422
2423 out:
2424 btrfs_free_path(path);
2425 return ret;
2426 }
2427
2428 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2429 struct btrfs_device *device, u64 new_size)
2430 {
2431 struct btrfs_super_block *super_copy =
2432 device->dev_root->fs_info->super_copy;
2433 u64 old_total = btrfs_super_total_bytes(super_copy);
2434 u64 diff = new_size - device->total_bytes;
2435
2436 if (!device->writeable)
2437 return -EACCES;
2438 if (new_size <= device->total_bytes ||
2439 device->is_tgtdev_for_dev_replace)
2440 return -EINVAL;
2441
2442 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2443 device->fs_devices->total_rw_bytes += diff;
2444
2445 device->total_bytes = new_size;
2446 device->disk_total_bytes = new_size;
2447 btrfs_clear_space_info_full(device->dev_root->fs_info);
2448
2449 return btrfs_update_device(trans, device);
2450 }
2451
2452 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2453 struct btrfs_device *device, u64 new_size)
2454 {
2455 int ret;
2456 lock_chunks(device->dev_root);
2457 ret = __btrfs_grow_device(trans, device, new_size);
2458 unlock_chunks(device->dev_root);
2459 return ret;
2460 }
2461
2462 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2463 struct btrfs_root *root,
2464 u64 chunk_tree, u64 chunk_objectid,
2465 u64 chunk_offset)
2466 {
2467 int ret;
2468 struct btrfs_path *path;
2469 struct btrfs_key key;
2470
2471 root = root->fs_info->chunk_root;
2472 path = btrfs_alloc_path();
2473 if (!path)
2474 return -ENOMEM;
2475
2476 key.objectid = chunk_objectid;
2477 key.offset = chunk_offset;
2478 key.type = BTRFS_CHUNK_ITEM_KEY;
2479
2480 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2481 if (ret < 0)
2482 goto out;
2483 else if (ret > 0) { /* Logic error or corruption */
2484 btrfs_error(root->fs_info, -ENOENT,
2485 "Failed lookup while freeing chunk.");
2486 ret = -ENOENT;
2487 goto out;
2488 }
2489
2490 ret = btrfs_del_item(trans, root, path);
2491 if (ret < 0)
2492 btrfs_error(root->fs_info, ret,
2493 "Failed to delete chunk item.");
2494 out:
2495 btrfs_free_path(path);
2496 return ret;
2497 }
2498
2499 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2500 chunk_offset)
2501 {
2502 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2503 struct btrfs_disk_key *disk_key;
2504 struct btrfs_chunk *chunk;
2505 u8 *ptr;
2506 int ret = 0;
2507 u32 num_stripes;
2508 u32 array_size;
2509 u32 len = 0;
2510 u32 cur;
2511 struct btrfs_key key;
2512
2513 array_size = btrfs_super_sys_array_size(super_copy);
2514
2515 ptr = super_copy->sys_chunk_array;
2516 cur = 0;
2517
2518 while (cur < array_size) {
2519 disk_key = (struct btrfs_disk_key *)ptr;
2520 btrfs_disk_key_to_cpu(&key, disk_key);
2521
2522 len = sizeof(*disk_key);
2523
2524 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2525 chunk = (struct btrfs_chunk *)(ptr + len);
2526 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2527 len += btrfs_chunk_item_size(num_stripes);
2528 } else {
2529 ret = -EIO;
2530 break;
2531 }
2532 if (key.objectid == chunk_objectid &&
2533 key.offset == chunk_offset) {
2534 memmove(ptr, ptr + len, array_size - (cur + len));
2535 array_size -= len;
2536 btrfs_set_super_sys_array_size(super_copy, array_size);
2537 } else {
2538 ptr += len;
2539 cur += len;
2540 }
2541 }
2542 return ret;
2543 }
2544
2545 static int btrfs_relocate_chunk(struct btrfs_root *root,
2546 u64 chunk_tree, u64 chunk_objectid,
2547 u64 chunk_offset)
2548 {
2549 struct extent_map_tree *em_tree;
2550 struct btrfs_root *extent_root;
2551 struct btrfs_trans_handle *trans;
2552 struct extent_map *em;
2553 struct map_lookup *map;
2554 int ret;
2555 int i;
2556
2557 root = root->fs_info->chunk_root;
2558 extent_root = root->fs_info->extent_root;
2559 em_tree = &root->fs_info->mapping_tree.map_tree;
2560
2561 ret = btrfs_can_relocate(extent_root, chunk_offset);
2562 if (ret)
2563 return -ENOSPC;
2564
2565 /* step one, relocate all the extents inside this chunk */
2566 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2567 if (ret)
2568 return ret;
2569
2570 trans = btrfs_start_transaction(root, 0);
2571 if (IS_ERR(trans)) {
2572 ret = PTR_ERR(trans);
2573 btrfs_std_error(root->fs_info, ret);
2574 return ret;
2575 }
2576
2577 lock_chunks(root);
2578
2579 /*
2580 * step two, delete the device extents and the
2581 * chunk tree entries
2582 */
2583 read_lock(&em_tree->lock);
2584 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2585 read_unlock(&em_tree->lock);
2586
2587 BUG_ON(!em || em->start > chunk_offset ||
2588 em->start + em->len < chunk_offset);
2589 map = (struct map_lookup *)em->bdev;
2590
2591 for (i = 0; i < map->num_stripes; i++) {
2592 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2593 map->stripes[i].physical);
2594 BUG_ON(ret);
2595
2596 if (map->stripes[i].dev) {
2597 ret = btrfs_update_device(trans, map->stripes[i].dev);
2598 BUG_ON(ret);
2599 }
2600 }
2601 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2602 chunk_offset);
2603
2604 BUG_ON(ret);
2605
2606 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2607
2608 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2609 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2610 BUG_ON(ret);
2611 }
2612
2613 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2614 BUG_ON(ret);
2615
2616 write_lock(&em_tree->lock);
2617 remove_extent_mapping(em_tree, em);
2618 write_unlock(&em_tree->lock);
2619
2620 /* once for the tree */
2621 free_extent_map(em);
2622 /* once for us */
2623 free_extent_map(em);
2624
2625 unlock_chunks(root);
2626 btrfs_end_transaction(trans, root);
2627 return 0;
2628 }
2629
2630 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2631 {
2632 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2633 struct btrfs_path *path;
2634 struct extent_buffer *leaf;
2635 struct btrfs_chunk *chunk;
2636 struct btrfs_key key;
2637 struct btrfs_key found_key;
2638 u64 chunk_tree = chunk_root->root_key.objectid;
2639 u64 chunk_type;
2640 bool retried = false;
2641 int failed = 0;
2642 int ret;
2643
2644 path = btrfs_alloc_path();
2645 if (!path)
2646 return -ENOMEM;
2647
2648 again:
2649 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2650 key.offset = (u64)-1;
2651 key.type = BTRFS_CHUNK_ITEM_KEY;
2652
2653 while (1) {
2654 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2655 if (ret < 0)
2656 goto error;
2657 BUG_ON(ret == 0); /* Corruption */
2658
2659 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2660 key.type);
2661 if (ret < 0)
2662 goto error;
2663 if (ret > 0)
2664 break;
2665
2666 leaf = path->nodes[0];
2667 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2668
2669 chunk = btrfs_item_ptr(leaf, path->slots[0],
2670 struct btrfs_chunk);
2671 chunk_type = btrfs_chunk_type(leaf, chunk);
2672 btrfs_release_path(path);
2673
2674 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2675 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2676 found_key.objectid,
2677 found_key.offset);
2678 if (ret == -ENOSPC)
2679 failed++;
2680 else if (ret)
2681 BUG();
2682 }
2683
2684 if (found_key.offset == 0)
2685 break;
2686 key.offset = found_key.offset - 1;
2687 }
2688 ret = 0;
2689 if (failed && !retried) {
2690 failed = 0;
2691 retried = true;
2692 goto again;
2693 } else if (WARN_ON(failed && retried)) {
2694 ret = -ENOSPC;
2695 }
2696 error:
2697 btrfs_free_path(path);
2698 return ret;
2699 }
2700
2701 static int insert_balance_item(struct btrfs_root *root,
2702 struct btrfs_balance_control *bctl)
2703 {
2704 struct btrfs_trans_handle *trans;
2705 struct btrfs_balance_item *item;
2706 struct btrfs_disk_balance_args disk_bargs;
2707 struct btrfs_path *path;
2708 struct extent_buffer *leaf;
2709 struct btrfs_key key;
2710 int ret, err;
2711
2712 path = btrfs_alloc_path();
2713 if (!path)
2714 return -ENOMEM;
2715
2716 trans = btrfs_start_transaction(root, 0);
2717 if (IS_ERR(trans)) {
2718 btrfs_free_path(path);
2719 return PTR_ERR(trans);
2720 }
2721
2722 key.objectid = BTRFS_BALANCE_OBJECTID;
2723 key.type = BTRFS_BALANCE_ITEM_KEY;
2724 key.offset = 0;
2725
2726 ret = btrfs_insert_empty_item(trans, root, path, &key,
2727 sizeof(*item));
2728 if (ret)
2729 goto out;
2730
2731 leaf = path->nodes[0];
2732 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2733
2734 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2735
2736 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2737 btrfs_set_balance_data(leaf, item, &disk_bargs);
2738 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2739 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2740 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2741 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2742
2743 btrfs_set_balance_flags(leaf, item, bctl->flags);
2744
2745 btrfs_mark_buffer_dirty(leaf);
2746 out:
2747 btrfs_free_path(path);
2748 err = btrfs_commit_transaction(trans, root);
2749 if (err && !ret)
2750 ret = err;
2751 return ret;
2752 }
2753
2754 static int del_balance_item(struct btrfs_root *root)
2755 {
2756 struct btrfs_trans_handle *trans;
2757 struct btrfs_path *path;
2758 struct btrfs_key key;
2759 int ret, err;
2760
2761 path = btrfs_alloc_path();
2762 if (!path)
2763 return -ENOMEM;
2764
2765 trans = btrfs_start_transaction(root, 0);
2766 if (IS_ERR(trans)) {
2767 btrfs_free_path(path);
2768 return PTR_ERR(trans);
2769 }
2770
2771 key.objectid = BTRFS_BALANCE_OBJECTID;
2772 key.type = BTRFS_BALANCE_ITEM_KEY;
2773 key.offset = 0;
2774
2775 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2776 if (ret < 0)
2777 goto out;
2778 if (ret > 0) {
2779 ret = -ENOENT;
2780 goto out;
2781 }
2782
2783 ret = btrfs_del_item(trans, root, path);
2784 out:
2785 btrfs_free_path(path);
2786 err = btrfs_commit_transaction(trans, root);
2787 if (err && !ret)
2788 ret = err;
2789 return ret;
2790 }
2791
2792 /*
2793 * This is a heuristic used to reduce the number of chunks balanced on
2794 * resume after balance was interrupted.
2795 */
2796 static void update_balance_args(struct btrfs_balance_control *bctl)
2797 {
2798 /*
2799 * Turn on soft mode for chunk types that were being converted.
2800 */
2801 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2802 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2803 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2804 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2805 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2806 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2807
2808 /*
2809 * Turn on usage filter if is not already used. The idea is
2810 * that chunks that we have already balanced should be
2811 * reasonably full. Don't do it for chunks that are being
2812 * converted - that will keep us from relocating unconverted
2813 * (albeit full) chunks.
2814 */
2815 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2816 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2817 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2818 bctl->data.usage = 90;
2819 }
2820 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2821 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2822 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2823 bctl->sys.usage = 90;
2824 }
2825 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2826 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2827 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2828 bctl->meta.usage = 90;
2829 }
2830 }
2831
2832 /*
2833 * Should be called with both balance and volume mutexes held to
2834 * serialize other volume operations (add_dev/rm_dev/resize) with
2835 * restriper. Same goes for unset_balance_control.
2836 */
2837 static void set_balance_control(struct btrfs_balance_control *bctl)
2838 {
2839 struct btrfs_fs_info *fs_info = bctl->fs_info;
2840
2841 BUG_ON(fs_info->balance_ctl);
2842
2843 spin_lock(&fs_info->balance_lock);
2844 fs_info->balance_ctl = bctl;
2845 spin_unlock(&fs_info->balance_lock);
2846 }
2847
2848 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2849 {
2850 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2851
2852 BUG_ON(!fs_info->balance_ctl);
2853
2854 spin_lock(&fs_info->balance_lock);
2855 fs_info->balance_ctl = NULL;
2856 spin_unlock(&fs_info->balance_lock);
2857
2858 kfree(bctl);
2859 }
2860
2861 /*
2862 * Balance filters. Return 1 if chunk should be filtered out
2863 * (should not be balanced).
2864 */
2865 static int chunk_profiles_filter(u64 chunk_type,
2866 struct btrfs_balance_args *bargs)
2867 {
2868 chunk_type = chunk_to_extended(chunk_type) &
2869 BTRFS_EXTENDED_PROFILE_MASK;
2870
2871 if (bargs->profiles & chunk_type)
2872 return 0;
2873
2874 return 1;
2875 }
2876
2877 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2878 struct btrfs_balance_args *bargs)
2879 {
2880 struct btrfs_block_group_cache *cache;
2881 u64 chunk_used, user_thresh;
2882 int ret = 1;
2883
2884 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2885 chunk_used = btrfs_block_group_used(&cache->item);
2886
2887 if (bargs->usage == 0)
2888 user_thresh = 1;
2889 else if (bargs->usage > 100)
2890 user_thresh = cache->key.offset;
2891 else
2892 user_thresh = div_factor_fine(cache->key.offset,
2893 bargs->usage);
2894
2895 if (chunk_used < user_thresh)
2896 ret = 0;
2897
2898 btrfs_put_block_group(cache);
2899 return ret;
2900 }
2901
2902 static int chunk_devid_filter(struct extent_buffer *leaf,
2903 struct btrfs_chunk *chunk,
2904 struct btrfs_balance_args *bargs)
2905 {
2906 struct btrfs_stripe *stripe;
2907 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2908 int i;
2909
2910 for (i = 0; i < num_stripes; i++) {
2911 stripe = btrfs_stripe_nr(chunk, i);
2912 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2913 return 0;
2914 }
2915
2916 return 1;
2917 }
2918
2919 /* [pstart, pend) */
2920 static int chunk_drange_filter(struct extent_buffer *leaf,
2921 struct btrfs_chunk *chunk,
2922 u64 chunk_offset,
2923 struct btrfs_balance_args *bargs)
2924 {
2925 struct btrfs_stripe *stripe;
2926 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2927 u64 stripe_offset;
2928 u64 stripe_length;
2929 int factor;
2930 int i;
2931
2932 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2933 return 0;
2934
2935 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2936 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2937 factor = num_stripes / 2;
2938 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2939 factor = num_stripes - 1;
2940 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2941 factor = num_stripes - 2;
2942 } else {
2943 factor = num_stripes;
2944 }
2945
2946 for (i = 0; i < num_stripes; i++) {
2947 stripe = btrfs_stripe_nr(chunk, i);
2948 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2949 continue;
2950
2951 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2952 stripe_length = btrfs_chunk_length(leaf, chunk);
2953 do_div(stripe_length, factor);
2954
2955 if (stripe_offset < bargs->pend &&
2956 stripe_offset + stripe_length > bargs->pstart)
2957 return 0;
2958 }
2959
2960 return 1;
2961 }
2962
2963 /* [vstart, vend) */
2964 static int chunk_vrange_filter(struct extent_buffer *leaf,
2965 struct btrfs_chunk *chunk,
2966 u64 chunk_offset,
2967 struct btrfs_balance_args *bargs)
2968 {
2969 if (chunk_offset < bargs->vend &&
2970 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2971 /* at least part of the chunk is inside this vrange */
2972 return 0;
2973
2974 return 1;
2975 }
2976
2977 static int chunk_soft_convert_filter(u64 chunk_type,
2978 struct btrfs_balance_args *bargs)
2979 {
2980 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2981 return 0;
2982
2983 chunk_type = chunk_to_extended(chunk_type) &
2984 BTRFS_EXTENDED_PROFILE_MASK;
2985
2986 if (bargs->target == chunk_type)
2987 return 1;
2988
2989 return 0;
2990 }
2991
2992 static int should_balance_chunk(struct btrfs_root *root,
2993 struct extent_buffer *leaf,
2994 struct btrfs_chunk *chunk, u64 chunk_offset)
2995 {
2996 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2997 struct btrfs_balance_args *bargs = NULL;
2998 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2999
3000 /* type filter */
3001 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
3002 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
3003 return 0;
3004 }
3005
3006 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
3007 bargs = &bctl->data;
3008 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
3009 bargs = &bctl->sys;
3010 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
3011 bargs = &bctl->meta;
3012
3013 /* profiles filter */
3014 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
3015 chunk_profiles_filter(chunk_type, bargs)) {
3016 return 0;
3017 }
3018
3019 /* usage filter */
3020 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
3021 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
3022 return 0;
3023 }
3024
3025 /* devid filter */
3026 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
3027 chunk_devid_filter(leaf, chunk, bargs)) {
3028 return 0;
3029 }
3030
3031 /* drange filter, makes sense only with devid filter */
3032 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
3033 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
3034 return 0;
3035 }
3036
3037 /* vrange filter */
3038 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
3039 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
3040 return 0;
3041 }
3042
3043 /* soft profile changing mode */
3044 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
3045 chunk_soft_convert_filter(chunk_type, bargs)) {
3046 return 0;
3047 }
3048
3049 /*
3050 * limited by count, must be the last filter
3051 */
3052 if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) {
3053 if (bargs->limit == 0)
3054 return 0;
3055 else
3056 bargs->limit--;
3057 }
3058
3059 return 1;
3060 }
3061
3062 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
3063 {
3064 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
3065 struct btrfs_root *chunk_root = fs_info->chunk_root;
3066 struct btrfs_root *dev_root = fs_info->dev_root;
3067 struct list_head *devices;
3068 struct btrfs_device *device;
3069 u64 old_size;
3070 u64 size_to_free;
3071 struct btrfs_chunk *chunk;
3072 struct btrfs_path *path;
3073 struct btrfs_key key;
3074 struct btrfs_key found_key;
3075 struct btrfs_trans_handle *trans;
3076 struct extent_buffer *leaf;
3077 int slot;
3078 int ret;
3079 int enospc_errors = 0;
3080 bool counting = true;
3081 u64 limit_data = bctl->data.limit;
3082 u64 limit_meta = bctl->meta.limit;
3083 u64 limit_sys = bctl->sys.limit;
3084
3085 /* step one make some room on all the devices */
3086 devices = &fs_info->fs_devices->devices;
3087 list_for_each_entry(device, devices, dev_list) {
3088 old_size = device->total_bytes;
3089 size_to_free = div_factor(old_size, 1);
3090 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
3091 if (!device->writeable ||
3092 device->total_bytes - device->bytes_used > size_to_free ||
3093 device->is_tgtdev_for_dev_replace)
3094 continue;
3095
3096 ret = btrfs_shrink_device(device, old_size - size_to_free);
3097 if (ret == -ENOSPC)
3098 break;
3099 BUG_ON(ret);
3100
3101 trans = btrfs_start_transaction(dev_root, 0);
3102 BUG_ON(IS_ERR(trans));
3103
3104 ret = btrfs_grow_device(trans, device, old_size);
3105 BUG_ON(ret);
3106
3107 btrfs_end_transaction(trans, dev_root);
3108 }
3109
3110 /* step two, relocate all the chunks */
3111 path = btrfs_alloc_path();
3112 if (!path) {
3113 ret = -ENOMEM;
3114 goto error;
3115 }
3116
3117 /* zero out stat counters */
3118 spin_lock(&fs_info->balance_lock);
3119 memset(&bctl->stat, 0, sizeof(bctl->stat));
3120 spin_unlock(&fs_info->balance_lock);
3121 again:
3122 if (!counting) {
3123 bctl->data.limit = limit_data;
3124 bctl->meta.limit = limit_meta;
3125 bctl->sys.limit = limit_sys;
3126 }
3127 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3128 key.offset = (u64)-1;
3129 key.type = BTRFS_CHUNK_ITEM_KEY;
3130
3131 while (1) {
3132 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
3133 atomic_read(&fs_info->balance_cancel_req)) {
3134 ret = -ECANCELED;
3135 goto error;
3136 }
3137
3138 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
3139 if (ret < 0)
3140 goto error;
3141
3142 /*
3143 * this shouldn't happen, it means the last relocate
3144 * failed
3145 */
3146 if (ret == 0)
3147 BUG(); /* FIXME break ? */
3148
3149 ret = btrfs_previous_item(chunk_root, path, 0,
3150 BTRFS_CHUNK_ITEM_KEY);
3151 if (ret) {
3152 ret = 0;
3153 break;
3154 }
3155
3156 leaf = path->nodes[0];
3157 slot = path->slots[0];
3158 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3159
3160 if (found_key.objectid != key.objectid)
3161 break;
3162
3163 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3164
3165 if (!counting) {
3166 spin_lock(&fs_info->balance_lock);
3167 bctl->stat.considered++;
3168 spin_unlock(&fs_info->balance_lock);
3169 }
3170
3171 ret = should_balance_chunk(chunk_root, leaf, chunk,
3172 found_key.offset);
3173 btrfs_release_path(path);
3174 if (!ret)
3175 goto loop;
3176
3177 if (counting) {
3178 spin_lock(&fs_info->balance_lock);
3179 bctl->stat.expected++;
3180 spin_unlock(&fs_info->balance_lock);
3181 goto loop;
3182 }
3183
3184 ret = btrfs_relocate_chunk(chunk_root,
3185 chunk_root->root_key.objectid,
3186 found_key.objectid,
3187 found_key.offset);
3188 if (ret && ret != -ENOSPC)
3189 goto error;
3190 if (ret == -ENOSPC) {
3191 enospc_errors++;
3192 } else {
3193 spin_lock(&fs_info->balance_lock);
3194 bctl->stat.completed++;
3195 spin_unlock(&fs_info->balance_lock);
3196 }
3197 loop:
3198 if (found_key.offset == 0)
3199 break;
3200 key.offset = found_key.offset - 1;
3201 }
3202
3203 if (counting) {
3204 btrfs_release_path(path);
3205 counting = false;
3206 goto again;
3207 }
3208 error:
3209 btrfs_free_path(path);
3210 if (enospc_errors) {
3211 btrfs_info(fs_info, "%d enospc errors during balance",
3212 enospc_errors);
3213 if (!ret)
3214 ret = -ENOSPC;
3215 }
3216
3217 return ret;
3218 }
3219
3220 /**
3221 * alloc_profile_is_valid - see if a given profile is valid and reduced
3222 * @flags: profile to validate
3223 * @extended: if true @flags is treated as an extended profile
3224 */
3225 static int alloc_profile_is_valid(u64 flags, int extended)
3226 {
3227 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3228 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3229
3230 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3231
3232 /* 1) check that all other bits are zeroed */
3233 if (flags & ~mask)
3234 return 0;
3235
3236 /* 2) see if profile is reduced */
3237 if (flags == 0)
3238 return !extended; /* "0" is valid for usual profiles */
3239
3240 /* true if exactly one bit set */
3241 return (flags & (flags - 1)) == 0;
3242 }
3243
3244 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3245 {
3246 /* cancel requested || normal exit path */
3247 return atomic_read(&fs_info->balance_cancel_req) ||
3248 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3249 atomic_read(&fs_info->balance_cancel_req) == 0);
3250 }
3251
3252 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3253 {
3254 int ret;
3255
3256 unset_balance_control(fs_info);
3257 ret = del_balance_item(fs_info->tree_root);
3258 if (ret)
3259 btrfs_std_error(fs_info, ret);
3260
3261 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3262 }
3263
3264 /*
3265 * Should be called with both balance and volume mutexes held
3266 */
3267 int btrfs_balance(struct btrfs_balance_control *bctl,
3268 struct btrfs_ioctl_balance_args *bargs)
3269 {
3270 struct btrfs_fs_info *fs_info = bctl->fs_info;
3271 u64 allowed;
3272 int mixed = 0;
3273 int ret;
3274 u64 num_devices;
3275 unsigned seq;
3276
3277 if (btrfs_fs_closing(fs_info) ||
3278 atomic_read(&fs_info->balance_pause_req) ||
3279 atomic_read(&fs_info->balance_cancel_req)) {
3280 ret = -EINVAL;
3281 goto out;
3282 }
3283
3284 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3285 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3286 mixed = 1;
3287
3288 /*
3289 * In case of mixed groups both data and meta should be picked,
3290 * and identical options should be given for both of them.
3291 */
3292 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3293 if (mixed && (bctl->flags & allowed)) {
3294 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3295 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3296 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3297 btrfs_err(fs_info, "with mixed groups data and "
3298 "metadata balance options must be the same");
3299 ret = -EINVAL;
3300 goto out;
3301 }
3302 }
3303
3304 num_devices = fs_info->fs_devices->num_devices;
3305 btrfs_dev_replace_lock(&fs_info->dev_replace);
3306 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3307 BUG_ON(num_devices < 1);
3308 num_devices--;
3309 }
3310 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3311 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3312 if (num_devices == 1)
3313 allowed |= BTRFS_BLOCK_GROUP_DUP;
3314 else if (num_devices > 1)
3315 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3316 if (num_devices > 2)
3317 allowed |= BTRFS_BLOCK_GROUP_RAID5;
3318 if (num_devices > 3)
3319 allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
3320 BTRFS_BLOCK_GROUP_RAID6);
3321 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3322 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3323 (bctl->data.target & ~allowed))) {
3324 btrfs_err(fs_info, "unable to start balance with target "
3325 "data profile %llu",
3326 bctl->data.target);
3327 ret = -EINVAL;
3328 goto out;
3329 }
3330 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3331 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3332 (bctl->meta.target & ~allowed))) {
3333 btrfs_err(fs_info,
3334 "unable to start balance with target metadata profile %llu",
3335 bctl->meta.target);
3336 ret = -EINVAL;
3337 goto out;
3338 }
3339 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3340 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3341 (bctl->sys.target & ~allowed))) {
3342 btrfs_err(fs_info,
3343 "unable to start balance with target system profile %llu",
3344 bctl->sys.target);
3345 ret = -EINVAL;
3346 goto out;
3347 }
3348
3349 /* allow dup'ed data chunks only in mixed mode */
3350 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3351 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3352 btrfs_err(fs_info, "dup for data is not allowed");
3353 ret = -EINVAL;
3354 goto out;
3355 }
3356
3357 /* allow to reduce meta or sys integrity only if force set */
3358 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3359 BTRFS_BLOCK_GROUP_RAID10 |
3360 BTRFS_BLOCK_GROUP_RAID5 |
3361 BTRFS_BLOCK_GROUP_RAID6;
3362 do {
3363 seq = read_seqbegin(&fs_info->profiles_lock);
3364
3365 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3366 (fs_info->avail_system_alloc_bits & allowed) &&
3367 !(bctl->sys.target & allowed)) ||
3368 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3369 (fs_info->avail_metadata_alloc_bits & allowed) &&
3370 !(bctl->meta.target & allowed))) {
3371 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3372 btrfs_info(fs_info, "force reducing metadata integrity");
3373 } else {
3374 btrfs_err(fs_info, "balance will reduce metadata "
3375 "integrity, use force if you want this");
3376 ret = -EINVAL;
3377 goto out;
3378 }
3379 }
3380 } while (read_seqretry(&fs_info->profiles_lock, seq));
3381
3382 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3383 int num_tolerated_disk_barrier_failures;
3384 u64 target = bctl->sys.target;
3385
3386 num_tolerated_disk_barrier_failures =
3387 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3388 if (num_tolerated_disk_barrier_failures > 0 &&
3389 (target &
3390 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3391 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3392 num_tolerated_disk_barrier_failures = 0;
3393 else if (num_tolerated_disk_barrier_failures > 1 &&
3394 (target &
3395 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3396 num_tolerated_disk_barrier_failures = 1;
3397
3398 fs_info->num_tolerated_disk_barrier_failures =
3399 num_tolerated_disk_barrier_failures;
3400 }
3401
3402 ret = insert_balance_item(fs_info->tree_root, bctl);
3403 if (ret && ret != -EEXIST)
3404 goto out;
3405
3406 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3407 BUG_ON(ret == -EEXIST);
3408 set_balance_control(bctl);
3409 } else {
3410 BUG_ON(ret != -EEXIST);
3411 spin_lock(&fs_info->balance_lock);
3412 update_balance_args(bctl);
3413 spin_unlock(&fs_info->balance_lock);
3414 }
3415
3416 atomic_inc(&fs_info->balance_running);
3417 mutex_unlock(&fs_info->balance_mutex);
3418
3419 ret = __btrfs_balance(fs_info);
3420
3421 mutex_lock(&fs_info->balance_mutex);
3422 atomic_dec(&fs_info->balance_running);
3423
3424 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3425 fs_info->num_tolerated_disk_barrier_failures =
3426 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3427 }
3428
3429 if (bargs) {
3430 memset(bargs, 0, sizeof(*bargs));
3431 update_ioctl_balance_args(fs_info, 0, bargs);
3432 }
3433
3434 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3435 balance_need_close(fs_info)) {
3436 __cancel_balance(fs_info);
3437 }
3438
3439 wake_up(&fs_info->balance_wait_q);
3440
3441 return ret;
3442 out:
3443 if (bctl->flags & BTRFS_BALANCE_RESUME)
3444 __cancel_balance(fs_info);
3445 else {
3446 kfree(bctl);
3447 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3448 }
3449 return ret;
3450 }
3451
3452 static int balance_kthread(void *data)
3453 {
3454 struct btrfs_fs_info *fs_info = data;
3455 int ret = 0;
3456
3457 mutex_lock(&fs_info->volume_mutex);
3458 mutex_lock(&fs_info->balance_mutex);
3459
3460 if (fs_info->balance_ctl) {
3461 btrfs_info(fs_info, "continuing balance");
3462 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3463 }
3464
3465 mutex_unlock(&fs_info->balance_mutex);
3466 mutex_unlock(&fs_info->volume_mutex);
3467
3468 return ret;
3469 }
3470
3471 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3472 {
3473 struct task_struct *tsk;
3474
3475 spin_lock(&fs_info->balance_lock);
3476 if (!fs_info->balance_ctl) {
3477 spin_unlock(&fs_info->balance_lock);
3478 return 0;
3479 }
3480 spin_unlock(&fs_info->balance_lock);
3481
3482 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3483 btrfs_info(fs_info, "force skipping balance");
3484 return 0;
3485 }
3486
3487 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3488 return PTR_ERR_OR_ZERO(tsk);
3489 }
3490
3491 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3492 {
3493 struct btrfs_balance_control *bctl;
3494 struct btrfs_balance_item *item;
3495 struct btrfs_disk_balance_args disk_bargs;
3496 struct btrfs_path *path;
3497 struct extent_buffer *leaf;
3498 struct btrfs_key key;
3499 int ret;
3500
3501 path = btrfs_alloc_path();
3502 if (!path)
3503 return -ENOMEM;
3504
3505 key.objectid = BTRFS_BALANCE_OBJECTID;
3506 key.type = BTRFS_BALANCE_ITEM_KEY;
3507 key.offset = 0;
3508
3509 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3510 if (ret < 0)
3511 goto out;
3512 if (ret > 0) { /* ret = -ENOENT; */
3513 ret = 0;
3514 goto out;
3515 }
3516
3517 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3518 if (!bctl) {
3519 ret = -ENOMEM;
3520 goto out;
3521 }
3522
3523 leaf = path->nodes[0];
3524 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3525
3526 bctl->fs_info = fs_info;
3527 bctl->flags = btrfs_balance_flags(leaf, item);
3528 bctl->flags |= BTRFS_BALANCE_RESUME;
3529
3530 btrfs_balance_data(leaf, item, &disk_bargs);
3531 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3532 btrfs_balance_meta(leaf, item, &disk_bargs);
3533 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3534 btrfs_balance_sys(leaf, item, &disk_bargs);
3535 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3536
3537 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3538
3539 mutex_lock(&fs_info->volume_mutex);
3540 mutex_lock(&fs_info->balance_mutex);
3541
3542 set_balance_control(bctl);
3543
3544 mutex_unlock(&fs_info->balance_mutex);
3545 mutex_unlock(&fs_info->volume_mutex);
3546 out:
3547 btrfs_free_path(path);
3548 return ret;
3549 }
3550
3551 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3552 {
3553 int ret = 0;
3554
3555 mutex_lock(&fs_info->balance_mutex);
3556 if (!fs_info->balance_ctl) {
3557 mutex_unlock(&fs_info->balance_mutex);
3558 return -ENOTCONN;
3559 }
3560
3561 if (atomic_read(&fs_info->balance_running)) {
3562 atomic_inc(&fs_info->balance_pause_req);
3563 mutex_unlock(&fs_info->balance_mutex);
3564
3565 wait_event(fs_info->balance_wait_q,
3566 atomic_read(&fs_info->balance_running) == 0);
3567
3568 mutex_lock(&fs_info->balance_mutex);
3569 /* we are good with balance_ctl ripped off from under us */
3570 BUG_ON(atomic_read(&fs_info->balance_running));
3571 atomic_dec(&fs_info->balance_pause_req);
3572 } else {
3573 ret = -ENOTCONN;
3574 }
3575
3576 mutex_unlock(&fs_info->balance_mutex);
3577 return ret;
3578 }
3579
3580 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3581 {
3582 if (fs_info->sb->s_flags & MS_RDONLY)
3583 return -EROFS;
3584
3585 mutex_lock(&fs_info->balance_mutex);
3586 if (!fs_info->balance_ctl) {
3587 mutex_unlock(&fs_info->balance_mutex);
3588 return -ENOTCONN;
3589 }
3590
3591 atomic_inc(&fs_info->balance_cancel_req);
3592 /*
3593 * if we are running just wait and return, balance item is
3594 * deleted in btrfs_balance in this case
3595 */
3596 if (atomic_read(&fs_info->balance_running)) {
3597 mutex_unlock(&fs_info->balance_mutex);
3598 wait_event(fs_info->balance_wait_q,
3599 atomic_read(&fs_info->balance_running) == 0);
3600 mutex_lock(&fs_info->balance_mutex);
3601 } else {
3602 /* __cancel_balance needs volume_mutex */
3603 mutex_unlock(&fs_info->balance_mutex);
3604 mutex_lock(&fs_info->volume_mutex);
3605 mutex_lock(&fs_info->balance_mutex);
3606
3607 if (fs_info->balance_ctl)
3608 __cancel_balance(fs_info);
3609
3610 mutex_unlock(&fs_info->volume_mutex);
3611 }
3612
3613 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3614 atomic_dec(&fs_info->balance_cancel_req);
3615 mutex_unlock(&fs_info->balance_mutex);
3616 return 0;
3617 }
3618
3619 static int btrfs_uuid_scan_kthread(void *data)
3620 {
3621 struct btrfs_fs_info *fs_info = data;
3622 struct btrfs_root *root = fs_info->tree_root;
3623 struct btrfs_key key;
3624 struct btrfs_key max_key;
3625 struct btrfs_path *path = NULL;
3626 int ret = 0;
3627 struct extent_buffer *eb;
3628 int slot;
3629 struct btrfs_root_item root_item;
3630 u32 item_size;
3631 struct btrfs_trans_handle *trans = NULL;
3632
3633 path = btrfs_alloc_path();
3634 if (!path) {
3635 ret = -ENOMEM;
3636 goto out;
3637 }
3638
3639 key.objectid = 0;
3640 key.type = BTRFS_ROOT_ITEM_KEY;
3641 key.offset = 0;
3642
3643 max_key.objectid = (u64)-1;
3644 max_key.type = BTRFS_ROOT_ITEM_KEY;
3645 max_key.offset = (u64)-1;
3646
3647 path->keep_locks = 1;
3648
3649 while (1) {
3650 ret = btrfs_search_forward(root, &key, path, 0);
3651 if (ret) {
3652 if (ret > 0)
3653 ret = 0;
3654 break;
3655 }
3656
3657 if (key.type != BTRFS_ROOT_ITEM_KEY ||
3658 (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
3659 key.objectid != BTRFS_FS_TREE_OBJECTID) ||
3660 key.objectid > BTRFS_LAST_FREE_OBJECTID)
3661 goto skip;
3662
3663 eb = path->nodes[0];
3664 slot = path->slots[0];
3665 item_size = btrfs_item_size_nr(eb, slot);
3666 if (item_size < sizeof(root_item))
3667 goto skip;
3668
3669 read_extent_buffer(eb, &root_item,
3670 btrfs_item_ptr_offset(eb, slot),
3671 (int)sizeof(root_item));
3672 if (btrfs_root_refs(&root_item) == 0)
3673 goto skip;
3674
3675 if (!btrfs_is_empty_uuid(root_item.uuid) ||
3676 !btrfs_is_empty_uuid(root_item.received_uuid)) {
3677 if (trans)
3678 goto update_tree;
3679
3680 btrfs_release_path(path);
3681 /*
3682 * 1 - subvol uuid item
3683 * 1 - received_subvol uuid item
3684 */
3685 trans = btrfs_start_transaction(fs_info->uuid_root, 2);
3686 if (IS_ERR(trans)) {
3687 ret = PTR_ERR(trans);
3688 break;
3689 }
3690 continue;
3691 } else {
3692 goto skip;
3693 }
3694 update_tree:
3695 if (!btrfs_is_empty_uuid(root_item.uuid)) {
3696 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3697 root_item.uuid,
3698 BTRFS_UUID_KEY_SUBVOL,
3699 key.objectid);
3700 if (ret < 0) {
3701 btrfs_warn(fs_info, "uuid_tree_add failed %d",
3702 ret);
3703 break;
3704 }
3705 }
3706
3707 if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
3708 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3709 root_item.received_uuid,
3710 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
3711 key.objectid);
3712 if (ret < 0) {
3713 btrfs_warn(fs_info, "uuid_tree_add failed %d",
3714 ret);
3715 break;
3716 }
3717 }
3718
3719 skip:
3720 if (trans) {
3721 ret = btrfs_end_transaction(trans, fs_info->uuid_root);
3722 trans = NULL;
3723 if (ret)
3724 break;
3725 }
3726
3727 btrfs_release_path(path);
3728 if (key.offset < (u64)-1) {
3729 key.offset++;
3730 } else if (key.type < BTRFS_ROOT_ITEM_KEY) {
3731 key.offset = 0;
3732 key.type = BTRFS_ROOT_ITEM_KEY;
3733 } else if (key.objectid < (u64)-1) {
3734 key.offset = 0;
3735 key.type = BTRFS_ROOT_ITEM_KEY;
3736 key.objectid++;
3737 } else {
3738 break;
3739 }
3740 cond_resched();
3741 }
3742
3743 out:
3744 btrfs_free_path(path);
3745 if (trans && !IS_ERR(trans))
3746 btrfs_end_transaction(trans, fs_info->uuid_root);
3747 if (ret)
3748 btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
3749 else
3750 fs_info->update_uuid_tree_gen = 1;
3751 up(&fs_info->uuid_tree_rescan_sem);
3752 return 0;
3753 }
3754
3755 /*
3756 * Callback for btrfs_uuid_tree_iterate().
3757 * returns:
3758 * 0 check succeeded, the entry is not outdated.
3759 * < 0 if an error occured.
3760 * > 0 if the check failed, which means the caller shall remove the entry.
3761 */
3762 static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
3763 u8 *uuid, u8 type, u64 subid)
3764 {
3765 struct btrfs_key key;
3766 int ret = 0;
3767 struct btrfs_root *subvol_root;
3768
3769 if (type != BTRFS_UUID_KEY_SUBVOL &&
3770 type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
3771 goto out;
3772
3773 key.objectid = subid;
3774 key.type = BTRFS_ROOT_ITEM_KEY;
3775 key.offset = (u64)-1;
3776 subvol_root = btrfs_read_fs_root_no_name(fs_info, &key);
3777 if (IS_ERR(subvol_root)) {
3778 ret = PTR_ERR(subvol_root);
3779 if (ret == -ENOENT)
3780 ret = 1;
3781 goto out;
3782 }
3783
3784 switch (type) {
3785 case BTRFS_UUID_KEY_SUBVOL:
3786 if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
3787 ret = 1;
3788 break;
3789 case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
3790 if (memcmp(uuid, subvol_root->root_item.received_uuid,
3791 BTRFS_UUID_SIZE))
3792 ret = 1;
3793 break;
3794 }
3795
3796 out:
3797 return ret;
3798 }
3799
3800 static int btrfs_uuid_rescan_kthread(void *data)
3801 {
3802 struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
3803 int ret;
3804
3805 /*
3806 * 1st step is to iterate through the existing UUID tree and
3807 * to delete all entries that contain outdated data.
3808 * 2nd step is to add all missing entries to the UUID tree.
3809 */
3810 ret = btrfs_uuid_tree_iterate(fs_info, btrfs_check_uuid_tree_entry);
3811 if (ret < 0) {
3812 btrfs_warn(fs_info, "iterating uuid_tree failed %d", ret);
3813 up(&fs_info->uuid_tree_rescan_sem);
3814 return ret;
3815 }
3816 return btrfs_uuid_scan_kthread(data);
3817 }
3818
3819 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
3820 {
3821 struct btrfs_trans_handle *trans;
3822 struct btrfs_root *tree_root = fs_info->tree_root;
3823 struct btrfs_root *uuid_root;
3824 struct task_struct *task;
3825 int ret;
3826
3827 /*
3828 * 1 - root node
3829 * 1 - root item
3830 */
3831 trans = btrfs_start_transaction(tree_root, 2);
3832 if (IS_ERR(trans))
3833 return PTR_ERR(trans);
3834
3835 uuid_root = btrfs_create_tree(trans, fs_info,
3836 BTRFS_UUID_TREE_OBJECTID);
3837 if (IS_ERR(uuid_root)) {
3838 btrfs_abort_transaction(trans, tree_root,
3839 PTR_ERR(uuid_root));
3840 return PTR_ERR(uuid_root);
3841 }
3842
3843 fs_info->uuid_root = uuid_root;
3844
3845 ret = btrfs_commit_transaction(trans, tree_root);
3846 if (ret)
3847 return ret;
3848
3849 down(&fs_info->uuid_tree_rescan_sem);
3850 task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
3851 if (IS_ERR(task)) {
3852 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3853 btrfs_warn(fs_info, "failed to start uuid_scan task");
3854 up(&fs_info->uuid_tree_rescan_sem);
3855 return PTR_ERR(task);
3856 }
3857
3858 return 0;
3859 }
3860
3861 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3862 {
3863 struct task_struct *task;
3864
3865 down(&fs_info->uuid_tree_rescan_sem);
3866 task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3867 if (IS_ERR(task)) {
3868 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3869 btrfs_warn(fs_info, "failed to start uuid_rescan task");
3870 up(&fs_info->uuid_tree_rescan_sem);
3871 return PTR_ERR(task);
3872 }
3873
3874 return 0;
3875 }
3876
3877 /*
3878 * shrinking a device means finding all of the device extents past
3879 * the new size, and then following the back refs to the chunks.
3880 * The chunk relocation code actually frees the device extent
3881 */
3882 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3883 {
3884 struct btrfs_trans_handle *trans;
3885 struct btrfs_root *root = device->dev_root;
3886 struct btrfs_dev_extent *dev_extent = NULL;
3887 struct btrfs_path *path;
3888 u64 length;
3889 u64 chunk_tree;
3890 u64 chunk_objectid;
3891 u64 chunk_offset;
3892 int ret;
3893 int slot;
3894 int failed = 0;
3895 bool retried = false;
3896 struct extent_buffer *l;
3897 struct btrfs_key key;
3898 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3899 u64 old_total = btrfs_super_total_bytes(super_copy);
3900 u64 old_size = device->total_bytes;
3901 u64 diff = device->total_bytes - new_size;
3902
3903 if (device->is_tgtdev_for_dev_replace)
3904 return -EINVAL;
3905
3906 path = btrfs_alloc_path();
3907 if (!path)
3908 return -ENOMEM;
3909
3910 path->reada = 2;
3911
3912 lock_chunks(root);
3913
3914 device->total_bytes = new_size;
3915 if (device->writeable) {
3916 device->fs_devices->total_rw_bytes -= diff;
3917 spin_lock(&root->fs_info->free_chunk_lock);
3918 root->fs_info->free_chunk_space -= diff;
3919 spin_unlock(&root->fs_info->free_chunk_lock);
3920 }
3921 unlock_chunks(root);
3922
3923 again:
3924 key.objectid = device->devid;
3925 key.offset = (u64)-1;
3926 key.type = BTRFS_DEV_EXTENT_KEY;
3927
3928 do {
3929 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3930 if (ret < 0)
3931 goto done;
3932
3933 ret = btrfs_previous_item(root, path, 0, key.type);
3934 if (ret < 0)
3935 goto done;
3936 if (ret) {
3937 ret = 0;
3938 btrfs_release_path(path);
3939 break;
3940 }
3941
3942 l = path->nodes[0];
3943 slot = path->slots[0];
3944 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3945
3946 if (key.objectid != device->devid) {
3947 btrfs_release_path(path);
3948 break;
3949 }
3950
3951 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3952 length = btrfs_dev_extent_length(l, dev_extent);
3953
3954 if (key.offset + length <= new_size) {
3955 btrfs_release_path(path);
3956 break;
3957 }
3958
3959 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3960 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3961 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3962 btrfs_release_path(path);
3963
3964 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3965 chunk_offset);
3966 if (ret && ret != -ENOSPC)
3967 goto done;
3968 if (ret == -ENOSPC)
3969 failed++;
3970 } while (key.offset-- > 0);
3971
3972 if (failed && !retried) {
3973 failed = 0;
3974 retried = true;
3975 goto again;
3976 } else if (failed && retried) {
3977 ret = -ENOSPC;
3978 lock_chunks(root);
3979
3980 device->total_bytes = old_size;
3981 if (device->writeable)
3982 device->fs_devices->total_rw_bytes += diff;
3983 spin_lock(&root->fs_info->free_chunk_lock);
3984 root->fs_info->free_chunk_space += diff;
3985 spin_unlock(&root->fs_info->free_chunk_lock);
3986 unlock_chunks(root);
3987 goto done;
3988 }
3989
3990 /* Shrinking succeeded, else we would be at "done". */
3991 trans = btrfs_start_transaction(root, 0);
3992 if (IS_ERR(trans)) {
3993 ret = PTR_ERR(trans);
3994 goto done;
3995 }
3996
3997 lock_chunks(root);
3998
3999 device->disk_total_bytes = new_size;
4000 /* Now btrfs_update_device() will change the on-disk size. */
4001 ret = btrfs_update_device(trans, device);
4002 if (ret) {
4003 unlock_chunks(root);
4004 btrfs_end_transaction(trans, root);
4005 goto done;
4006 }
4007 WARN_ON(diff > old_total);
4008 btrfs_set_super_total_bytes(super_copy, old_total - diff);
4009 unlock_chunks(root);
4010 btrfs_end_transaction(trans, root);
4011 done:
4012 btrfs_free_path(path);
4013 return ret;
4014 }
4015
4016 static int btrfs_add_system_chunk(struct btrfs_root *root,
4017 struct btrfs_key *key,
4018 struct btrfs_chunk *chunk, int item_size)
4019 {
4020 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
4021 struct btrfs_disk_key disk_key;
4022 u32 array_size;
4023 u8 *ptr;
4024
4025 array_size = btrfs_super_sys_array_size(super_copy);
4026 if (array_size + item_size + sizeof(disk_key)
4027 > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
4028 return -EFBIG;
4029
4030 ptr = super_copy->sys_chunk_array + array_size;
4031 btrfs_cpu_key_to_disk(&disk_key, key);
4032 memcpy(ptr, &disk_key, sizeof(disk_key));
4033 ptr += sizeof(disk_key);
4034 memcpy(ptr, chunk, item_size);
4035 item_size += sizeof(disk_key);
4036 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
4037 return 0;
4038 }
4039
4040 /*
4041 * sort the devices in descending order by max_avail, total_avail
4042 */
4043 static int btrfs_cmp_device_info(const void *a, const void *b)
4044 {
4045 const struct btrfs_device_info *di_a = a;
4046 const struct btrfs_device_info *di_b = b;
4047
4048 if (di_a->max_avail > di_b->max_avail)
4049 return -1;
4050 if (di_a->max_avail < di_b->max_avail)
4051 return 1;
4052 if (di_a->total_avail > di_b->total_avail)
4053 return -1;
4054 if (di_a->total_avail < di_b->total_avail)
4055 return 1;
4056 return 0;
4057 }
4058
4059 static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
4060 [BTRFS_RAID_RAID10] = {
4061 .sub_stripes = 2,
4062 .dev_stripes = 1,
4063 .devs_max = 0, /* 0 == as many as possible */
4064 .devs_min = 4,
4065 .devs_increment = 2,
4066 .ncopies = 2,
4067 },
4068 [BTRFS_RAID_RAID1] = {
4069 .sub_stripes = 1,
4070 .dev_stripes = 1,
4071 .devs_max = 2,
4072 .devs_min = 2,
4073 .devs_increment = 2,
4074 .ncopies = 2,
4075 },
4076 [BTRFS_RAID_DUP] = {
4077 .sub_stripes = 1,
4078 .dev_stripes = 2,
4079 .devs_max = 1,
4080 .devs_min = 1,
4081 .devs_increment = 1,
4082 .ncopies = 2,
4083 },
4084 [BTRFS_RAID_RAID0] = {
4085 .sub_stripes = 1,
4086 .dev_stripes = 1,
4087 .devs_max = 0,
4088 .devs_min = 2,
4089 .devs_increment = 1,
4090 .ncopies = 1,
4091 },
4092 [BTRFS_RAID_SINGLE] = {
4093 .sub_stripes = 1,
4094 .dev_stripes = 1,
4095 .devs_max = 1,
4096 .devs_min = 1,
4097 .devs_increment = 1,
4098 .ncopies = 1,
4099 },
4100 [BTRFS_RAID_RAID5] = {
4101 .sub_stripes = 1,
4102 .dev_stripes = 1,
4103 .devs_max = 0,
4104 .devs_min = 2,
4105 .devs_increment = 1,
4106 .ncopies = 2,
4107 },
4108 [BTRFS_RAID_RAID6] = {
4109 .sub_stripes = 1,
4110 .dev_stripes = 1,
4111 .devs_max = 0,
4112 .devs_min = 3,
4113 .devs_increment = 1,
4114 .ncopies = 3,
4115 },
4116 };
4117
4118 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
4119 {
4120 /* TODO allow them to set a preferred stripe size */
4121 return 64 * 1024;
4122 }
4123
4124 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
4125 {
4126 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
4127 return;
4128
4129 btrfs_set_fs_incompat(info, RAID56);
4130 }
4131
4132 #define BTRFS_MAX_DEVS(r) ((BTRFS_LEAF_DATA_SIZE(r) \
4133 - sizeof(struct btrfs_item) \
4134 - sizeof(struct btrfs_chunk)) \
4135 / sizeof(struct btrfs_stripe) + 1)
4136
4137 #define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE \
4138 - 2 * sizeof(struct btrfs_disk_key) \
4139 - 2 * sizeof(struct btrfs_chunk)) \
4140 / sizeof(struct btrfs_stripe) + 1)
4141
4142 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4143 struct btrfs_root *extent_root, u64 start,
4144 u64 type)
4145 {
4146 struct btrfs_fs_info *info = extent_root->fs_info;
4147 struct btrfs_fs_devices *fs_devices = info->fs_devices;
4148 struct list_head *cur;
4149 struct map_lookup *map = NULL;
4150 struct extent_map_tree *em_tree;
4151 struct extent_map *em;
4152 struct btrfs_device_info *devices_info = NULL;
4153 u64 total_avail;
4154 int num_stripes; /* total number of stripes to allocate */
4155 int data_stripes; /* number of stripes that count for
4156 block group size */
4157 int sub_stripes; /* sub_stripes info for map */
4158 int dev_stripes; /* stripes per dev */
4159 int devs_max; /* max devs to use */
4160 int devs_min; /* min devs needed */
4161 int devs_increment; /* ndevs has to be a multiple of this */
4162 int ncopies; /* how many copies to data has */
4163 int ret;
4164 u64 max_stripe_size;
4165 u64 max_chunk_size;
4166 u64 stripe_size;
4167 u64 num_bytes;
4168 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
4169 int ndevs;
4170 int i;
4171 int j;
4172 int index;
4173
4174 BUG_ON(!alloc_profile_is_valid(type, 0));
4175
4176 if (list_empty(&fs_devices->alloc_list))
4177 return -ENOSPC;
4178
4179 index = __get_raid_index(type);
4180
4181 sub_stripes = btrfs_raid_array[index].sub_stripes;
4182 dev_stripes = btrfs_raid_array[index].dev_stripes;
4183 devs_max = btrfs_raid_array[index].devs_max;
4184 devs_min = btrfs_raid_array[index].devs_min;
4185 devs_increment = btrfs_raid_array[index].devs_increment;
4186 ncopies = btrfs_raid_array[index].ncopies;
4187
4188 if (type & BTRFS_BLOCK_GROUP_DATA) {
4189 max_stripe_size = 1024 * 1024 * 1024;
4190 max_chunk_size = 10 * max_stripe_size;
4191 if (!devs_max)
4192 devs_max = BTRFS_MAX_DEVS(info->chunk_root);
4193 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
4194 /* for larger filesystems, use larger metadata chunks */
4195 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
4196 max_stripe_size = 1024 * 1024 * 1024;
4197 else
4198 max_stripe_size = 256 * 1024 * 1024;
4199 max_chunk_size = max_stripe_size;
4200 if (!devs_max)
4201 devs_max = BTRFS_MAX_DEVS(info->chunk_root);
4202 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
4203 max_stripe_size = 32 * 1024 * 1024;
4204 max_chunk_size = 2 * max_stripe_size;
4205 if (!devs_max)
4206 devs_max = BTRFS_MAX_DEVS_SYS_CHUNK;
4207 } else {
4208 btrfs_err(info, "invalid chunk type 0x%llx requested",
4209 type);
4210 BUG_ON(1);
4211 }
4212
4213 /* we don't want a chunk larger than 10% of writeable space */
4214 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
4215 max_chunk_size);
4216
4217 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
4218 GFP_NOFS);
4219 if (!devices_info)
4220 return -ENOMEM;
4221
4222 cur = fs_devices->alloc_list.next;
4223
4224 /*
4225 * in the first pass through the devices list, we gather information
4226 * about the available holes on each device.
4227 */
4228 ndevs = 0;
4229 while (cur != &fs_devices->alloc_list) {
4230 struct btrfs_device *device;
4231 u64 max_avail;
4232 u64 dev_offset;
4233
4234 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
4235
4236 cur = cur->next;
4237
4238 if (!device->writeable) {
4239 WARN(1, KERN_ERR
4240 "BTRFS: read-only device in alloc_list\n");
4241 continue;
4242 }
4243
4244 if (!device->in_fs_metadata ||
4245 device->is_tgtdev_for_dev_replace)
4246 continue;
4247
4248 if (device->total_bytes > device->bytes_used)
4249 total_avail = device->total_bytes - device->bytes_used;
4250 else
4251 total_avail = 0;
4252
4253 /* If there is no space on this device, skip it. */
4254 if (total_avail == 0)
4255 continue;
4256
4257 ret = find_free_dev_extent(trans, device,
4258 max_stripe_size * dev_stripes,
4259 &dev_offset, &max_avail);
4260 if (ret && ret != -ENOSPC)
4261 goto error;
4262
4263 if (ret == 0)
4264 max_avail = max_stripe_size * dev_stripes;
4265
4266 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
4267 continue;
4268
4269 if (ndevs == fs_devices->rw_devices) {
4270 WARN(1, "%s: found more than %llu devices\n",
4271 __func__, fs_devices->rw_devices);
4272 break;
4273 }
4274 devices_info[ndevs].dev_offset = dev_offset;
4275 devices_info[ndevs].max_avail = max_avail;
4276 devices_info[ndevs].total_avail = total_avail;
4277 devices_info[ndevs].dev = device;
4278 ++ndevs;
4279 }
4280
4281 /*
4282 * now sort the devices by hole size / available space
4283 */
4284 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
4285 btrfs_cmp_device_info, NULL);
4286
4287 /* round down to number of usable stripes */
4288 ndevs -= ndevs % devs_increment;
4289
4290 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
4291 ret = -ENOSPC;
4292 goto error;
4293 }
4294
4295 if (devs_max && ndevs > devs_max)
4296 ndevs = devs_max;
4297 /*
4298 * the primary goal is to maximize the number of stripes, so use as many
4299 * devices as possible, even if the stripes are not maximum sized.
4300 */
4301 stripe_size = devices_info[ndevs-1].max_avail;
4302 num_stripes = ndevs * dev_stripes;
4303
4304 /*
4305 * this will have to be fixed for RAID1 and RAID10 over
4306 * more drives
4307 */
4308 data_stripes = num_stripes / ncopies;
4309
4310 if (type & BTRFS_BLOCK_GROUP_RAID5) {
4311 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
4312 btrfs_super_stripesize(info->super_copy));
4313 data_stripes = num_stripes - 1;
4314 }
4315 if (type & BTRFS_BLOCK_GROUP_RAID6) {
4316 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
4317 btrfs_super_stripesize(info->super_copy));
4318 data_stripes = num_stripes - 2;
4319 }
4320
4321 /*
4322 * Use the number of data stripes to figure out how big this chunk
4323 * is really going to be in terms of logical address space,
4324 * and compare that answer with the max chunk size
4325 */
4326 if (stripe_size * data_stripes > max_chunk_size) {
4327 u64 mask = (1ULL << 24) - 1;
4328 stripe_size = max_chunk_size;
4329 do_div(stripe_size, data_stripes);
4330
4331 /* bump the answer up to a 16MB boundary */
4332 stripe_size = (stripe_size + mask) & ~mask;
4333
4334 /* but don't go higher than the limits we found
4335 * while searching for free extents
4336 */
4337 if (stripe_size > devices_info[ndevs-1].max_avail)
4338 stripe_size = devices_info[ndevs-1].max_avail;
4339 }
4340
4341 do_div(stripe_size, dev_stripes);
4342
4343 /* align to BTRFS_STRIPE_LEN */
4344 do_div(stripe_size, raid_stripe_len);
4345 stripe_size *= raid_stripe_len;
4346
4347 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4348 if (!map) {
4349 ret = -ENOMEM;
4350 goto error;
4351 }
4352 map->num_stripes = num_stripes;
4353
4354 for (i = 0; i < ndevs; ++i) {
4355 for (j = 0; j < dev_stripes; ++j) {
4356 int s = i * dev_stripes + j;
4357 map->stripes[s].dev = devices_info[i].dev;
4358 map->stripes[s].physical = devices_info[i].dev_offset +
4359 j * stripe_size;
4360 }
4361 }
4362 map->sector_size = extent_root->sectorsize;
4363 map->stripe_len = raid_stripe_len;
4364 map->io_align = raid_stripe_len;
4365 map->io_width = raid_stripe_len;
4366 map->type = type;
4367 map->sub_stripes = sub_stripes;
4368
4369 num_bytes = stripe_size * data_stripes;
4370
4371 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
4372
4373 em = alloc_extent_map();
4374 if (!em) {
4375 kfree(map);
4376 ret = -ENOMEM;
4377 goto error;
4378 }
4379 set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
4380 em->bdev = (struct block_device *)map;
4381 em->start = start;
4382 em->len = num_bytes;
4383 em->block_start = 0;
4384 em->block_len = em->len;
4385 em->orig_block_len = stripe_size;
4386
4387 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4388 write_lock(&em_tree->lock);
4389 ret = add_extent_mapping(em_tree, em, 0);
4390 if (!ret) {
4391 list_add_tail(&em->list, &trans->transaction->pending_chunks);
4392 atomic_inc(&em->refs);
4393 }
4394 write_unlock(&em_tree->lock);
4395 if (ret) {
4396 free_extent_map(em);
4397 goto error;
4398 }
4399
4400 ret = btrfs_make_block_group(trans, extent_root, 0, type,
4401 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4402 start, num_bytes);
4403 if (ret)
4404 goto error_del_extent;
4405
4406 free_extent_map(em);
4407 check_raid56_incompat_flag(extent_root->fs_info, type);
4408
4409 kfree(devices_info);
4410 return 0;
4411
4412 error_del_extent:
4413 write_lock(&em_tree->lock);
4414 remove_extent_mapping(em_tree, em);
4415 write_unlock(&em_tree->lock);
4416
4417 /* One for our allocation */
4418 free_extent_map(em);
4419 /* One for the tree reference */
4420 free_extent_map(em);
4421 error:
4422 kfree(devices_info);
4423 return ret;
4424 }
4425
4426 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
4427 struct btrfs_root *extent_root,
4428 u64 chunk_offset, u64 chunk_size)
4429 {
4430 struct btrfs_key key;
4431 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4432 struct btrfs_device *device;
4433 struct btrfs_chunk *chunk;
4434 struct btrfs_stripe *stripe;
4435 struct extent_map_tree *em_tree;
4436 struct extent_map *em;
4437 struct map_lookup *map;
4438 size_t item_size;
4439 u64 dev_offset;
4440 u64 stripe_size;
4441 int i = 0;
4442 int ret;
4443
4444 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4445 read_lock(&em_tree->lock);
4446 em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
4447 read_unlock(&em_tree->lock);
4448
4449 if (!em) {
4450 btrfs_crit(extent_root->fs_info, "unable to find logical "
4451 "%Lu len %Lu", chunk_offset, chunk_size);
4452 return -EINVAL;
4453 }
4454
4455 if (em->start != chunk_offset || em->len != chunk_size) {
4456 btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
4457 " %Lu-%Lu, found %Lu-%Lu", chunk_offset,
4458 chunk_size, em->start, em->len);
4459 free_extent_map(em);
4460 return -EINVAL;
4461 }
4462
4463 map = (struct map_lookup *)em->bdev;
4464 item_size = btrfs_chunk_item_size(map->num_stripes);
4465 stripe_size = em->orig_block_len;
4466
4467 chunk = kzalloc(item_size, GFP_NOFS);
4468 if (!chunk) {
4469 ret = -ENOMEM;
4470 goto out;
4471 }
4472
4473 for (i = 0; i < map->num_stripes; i++) {
4474 device = map->stripes[i].dev;
4475 dev_offset = map->stripes[i].physical;
4476
4477 device->bytes_used += stripe_size;
4478 ret = btrfs_update_device(trans, device);
4479 if (ret)
4480 goto out;
4481 ret = btrfs_alloc_dev_extent(trans, device,
4482 chunk_root->root_key.objectid,
4483 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4484 chunk_offset, dev_offset,
4485 stripe_size);
4486 if (ret)
4487 goto out;
4488 }
4489
4490 spin_lock(&extent_root->fs_info->free_chunk_lock);
4491 extent_root->fs_info->free_chunk_space -= (stripe_size *
4492 map->num_stripes);
4493 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4494
4495 stripe = &chunk->stripe;
4496 for (i = 0; i < map->num_stripes; i++) {
4497 device = map->stripes[i].dev;
4498 dev_offset = map->stripes[i].physical;
4499
4500 btrfs_set_stack_stripe_devid(stripe, device->devid);
4501 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4502 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4503 stripe++;
4504 }
4505
4506 btrfs_set_stack_chunk_length(chunk, chunk_size);
4507 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4508 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4509 btrfs_set_stack_chunk_type(chunk, map->type);
4510 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4511 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4512 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4513 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4514 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4515
4516 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4517 key.type = BTRFS_CHUNK_ITEM_KEY;
4518 key.offset = chunk_offset;
4519
4520 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4521 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4522 /*
4523 * TODO: Cleanup of inserted chunk root in case of
4524 * failure.
4525 */
4526 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4527 item_size);
4528 }
4529
4530 out:
4531 kfree(chunk);
4532 free_extent_map(em);
4533 return ret;
4534 }
4535
4536 /*
4537 * Chunk allocation falls into two parts. The first part does works
4538 * that make the new allocated chunk useable, but not do any operation
4539 * that modifies the chunk tree. The second part does the works that
4540 * require modifying the chunk tree. This division is important for the
4541 * bootstrap process of adding storage to a seed btrfs.
4542 */
4543 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4544 struct btrfs_root *extent_root, u64 type)
4545 {
4546 u64 chunk_offset;
4547
4548 chunk_offset = find_next_chunk(extent_root->fs_info);
4549 return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
4550 }
4551
4552 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4553 struct btrfs_root *root,
4554 struct btrfs_device *device)
4555 {
4556 u64 chunk_offset;
4557 u64 sys_chunk_offset;
4558 u64 alloc_profile;
4559 struct btrfs_fs_info *fs_info = root->fs_info;
4560 struct btrfs_root *extent_root = fs_info->extent_root;
4561 int ret;
4562
4563 chunk_offset = find_next_chunk(fs_info);
4564 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4565 ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
4566 alloc_profile);
4567 if (ret)
4568 return ret;
4569
4570 sys_chunk_offset = find_next_chunk(root->fs_info);
4571 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4572 ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
4573 alloc_profile);
4574 if (ret) {
4575 btrfs_abort_transaction(trans, root, ret);
4576 goto out;
4577 }
4578
4579 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4580 if (ret)
4581 btrfs_abort_transaction(trans, root, ret);
4582 out:
4583 return ret;
4584 }
4585
4586 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4587 {
4588 struct extent_map *em;
4589 struct map_lookup *map;
4590 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4591 int readonly = 0;
4592 int i;
4593
4594 read_lock(&map_tree->map_tree.lock);
4595 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4596 read_unlock(&map_tree->map_tree.lock);
4597 if (!em)
4598 return 1;
4599
4600 if (btrfs_test_opt(root, DEGRADED)) {
4601 free_extent_map(em);
4602 return 0;
4603 }
4604
4605 map = (struct map_lookup *)em->bdev;
4606 for (i = 0; i < map->num_stripes; i++) {
4607 if (!map->stripes[i].dev->writeable) {
4608 readonly = 1;
4609 break;
4610 }
4611 }
4612 free_extent_map(em);
4613 return readonly;
4614 }
4615
4616 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4617 {
4618 extent_map_tree_init(&tree->map_tree);
4619 }
4620
4621 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4622 {
4623 struct extent_map *em;
4624
4625 while (1) {
4626 write_lock(&tree->map_tree.lock);
4627 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4628 if (em)
4629 remove_extent_mapping(&tree->map_tree, em);
4630 write_unlock(&tree->map_tree.lock);
4631 if (!em)
4632 break;
4633 /* once for us */
4634 free_extent_map(em);
4635 /* once for the tree */
4636 free_extent_map(em);
4637 }
4638 }
4639
4640 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4641 {
4642 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4643 struct extent_map *em;
4644 struct map_lookup *map;
4645 struct extent_map_tree *em_tree = &map_tree->map_tree;
4646 int ret;
4647
4648 read_lock(&em_tree->lock);
4649 em = lookup_extent_mapping(em_tree, logical, len);
4650 read_unlock(&em_tree->lock);
4651
4652 /*
4653 * We could return errors for these cases, but that could get ugly and
4654 * we'd probably do the same thing which is just not do anything else
4655 * and exit, so return 1 so the callers don't try to use other copies.
4656 */
4657 if (!em) {
4658 btrfs_crit(fs_info, "No mapping for %Lu-%Lu", logical,
4659 logical+len);
4660 return 1;
4661 }
4662
4663 if (em->start > logical || em->start + em->len < logical) {
4664 btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got "
4665 "%Lu-%Lu", logical, logical+len, em->start,
4666 em->start + em->len);
4667 free_extent_map(em);
4668 return 1;
4669 }
4670
4671 map = (struct map_lookup *)em->bdev;
4672 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4673 ret = map->num_stripes;
4674 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4675 ret = map->sub_stripes;
4676 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4677 ret = 2;
4678 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4679 ret = 3;
4680 else
4681 ret = 1;
4682 free_extent_map(em);
4683
4684 btrfs_dev_replace_lock(&fs_info->dev_replace);
4685 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4686 ret++;
4687 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4688
4689 return ret;
4690 }
4691
4692 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4693 struct btrfs_mapping_tree *map_tree,
4694 u64 logical)
4695 {
4696 struct extent_map *em;
4697 struct map_lookup *map;
4698 struct extent_map_tree *em_tree = &map_tree->map_tree;
4699 unsigned long len = root->sectorsize;
4700
4701 read_lock(&em_tree->lock);
4702 em = lookup_extent_mapping(em_tree, logical, len);
4703 read_unlock(&em_tree->lock);
4704 BUG_ON(!em);
4705
4706 BUG_ON(em->start > logical || em->start + em->len < logical);
4707 map = (struct map_lookup *)em->bdev;
4708 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4709 BTRFS_BLOCK_GROUP_RAID6)) {
4710 len = map->stripe_len * nr_data_stripes(map);
4711 }
4712 free_extent_map(em);
4713 return len;
4714 }
4715
4716 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4717 u64 logical, u64 len, int mirror_num)
4718 {
4719 struct extent_map *em;
4720 struct map_lookup *map;
4721 struct extent_map_tree *em_tree = &map_tree->map_tree;
4722 int ret = 0;
4723
4724 read_lock(&em_tree->lock);
4725 em = lookup_extent_mapping(em_tree, logical, len);
4726 read_unlock(&em_tree->lock);
4727 BUG_ON(!em);
4728
4729 BUG_ON(em->start > logical || em->start + em->len < logical);
4730 map = (struct map_lookup *)em->bdev;
4731 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4732 BTRFS_BLOCK_GROUP_RAID6))
4733 ret = 1;
4734 free_extent_map(em);
4735 return ret;
4736 }
4737
4738 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4739 struct map_lookup *map, int first, int num,
4740 int optimal, int dev_replace_is_ongoing)
4741 {
4742 int i;
4743 int tolerance;
4744 struct btrfs_device *srcdev;
4745
4746 if (dev_replace_is_ongoing &&
4747 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4748 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4749 srcdev = fs_info->dev_replace.srcdev;
4750 else
4751 srcdev = NULL;
4752
4753 /*
4754 * try to avoid the drive that is the source drive for a
4755 * dev-replace procedure, only choose it if no other non-missing
4756 * mirror is available
4757 */
4758 for (tolerance = 0; tolerance < 2; tolerance++) {
4759 if (map->stripes[optimal].dev->bdev &&
4760 (tolerance || map->stripes[optimal].dev != srcdev))
4761 return optimal;
4762 for (i = first; i < first + num; i++) {
4763 if (map->stripes[i].dev->bdev &&
4764 (tolerance || map->stripes[i].dev != srcdev))
4765 return i;
4766 }
4767 }
4768
4769 /* we couldn't find one that doesn't fail. Just return something
4770 * and the io error handling code will clean up eventually
4771 */
4772 return optimal;
4773 }
4774
4775 static inline int parity_smaller(u64 a, u64 b)
4776 {
4777 return a > b;
4778 }
4779
4780 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4781 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4782 {
4783 struct btrfs_bio_stripe s;
4784 int i;
4785 u64 l;
4786 int again = 1;
4787
4788 while (again) {
4789 again = 0;
4790 for (i = 0; i < bbio->num_stripes - 1; i++) {
4791 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4792 s = bbio->stripes[i];
4793 l = raid_map[i];
4794 bbio->stripes[i] = bbio->stripes[i+1];
4795 raid_map[i] = raid_map[i+1];
4796 bbio->stripes[i+1] = s;
4797 raid_map[i+1] = l;
4798 again = 1;
4799 }
4800 }
4801 }
4802 }
4803
4804 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4805 u64 logical, u64 *length,
4806 struct btrfs_bio **bbio_ret,
4807 int mirror_num, u64 **raid_map_ret)
4808 {
4809 struct extent_map *em;
4810 struct map_lookup *map;
4811 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4812 struct extent_map_tree *em_tree = &map_tree->map_tree;
4813 u64 offset;
4814 u64 stripe_offset;
4815 u64 stripe_end_offset;
4816 u64 stripe_nr;
4817 u64 stripe_nr_orig;
4818 u64 stripe_nr_end;
4819 u64 stripe_len;
4820 u64 *raid_map = NULL;
4821 int stripe_index;
4822 int i;
4823 int ret = 0;
4824 int num_stripes;
4825 int max_errors = 0;
4826 struct btrfs_bio *bbio = NULL;
4827 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4828 int dev_replace_is_ongoing = 0;
4829 int num_alloc_stripes;
4830 int patch_the_first_stripe_for_dev_replace = 0;
4831 u64 physical_to_patch_in_first_stripe = 0;
4832 u64 raid56_full_stripe_start = (u64)-1;
4833
4834 read_lock(&em_tree->lock);
4835 em = lookup_extent_mapping(em_tree, logical, *length);
4836 read_unlock(&em_tree->lock);
4837
4838 if (!em) {
4839 btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4840 logical, *length);
4841 return -EINVAL;
4842 }
4843
4844 if (em->start > logical || em->start + em->len < logical) {
4845 btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4846 "found %Lu-%Lu", logical, em->start,
4847 em->start + em->len);
4848 free_extent_map(em);
4849 return -EINVAL;
4850 }
4851
4852 map = (struct map_lookup *)em->bdev;
4853 offset = logical - em->start;
4854
4855 stripe_len = map->stripe_len;
4856 stripe_nr = offset;
4857 /*
4858 * stripe_nr counts the total number of stripes we have to stride
4859 * to get to this block
4860 */
4861 do_div(stripe_nr, stripe_len);
4862
4863 stripe_offset = stripe_nr * stripe_len;
4864 BUG_ON(offset < stripe_offset);
4865
4866 /* stripe_offset is the offset of this block in its stripe*/
4867 stripe_offset = offset - stripe_offset;
4868
4869 /* if we're here for raid56, we need to know the stripe aligned start */
4870 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4871 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4872 raid56_full_stripe_start = offset;
4873
4874 /* allow a write of a full stripe, but make sure we don't
4875 * allow straddling of stripes
4876 */
4877 do_div(raid56_full_stripe_start, full_stripe_len);
4878 raid56_full_stripe_start *= full_stripe_len;
4879 }
4880
4881 if (rw & REQ_DISCARD) {
4882 /* we don't discard raid56 yet */
4883 if (map->type &
4884 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4885 ret = -EOPNOTSUPP;
4886 goto out;
4887 }
4888 *length = min_t(u64, em->len - offset, *length);
4889 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4890 u64 max_len;
4891 /* For writes to RAID[56], allow a full stripeset across all disks.
4892 For other RAID types and for RAID[56] reads, just allow a single
4893 stripe (on a single disk). */
4894 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4895 (rw & REQ_WRITE)) {
4896 max_len = stripe_len * nr_data_stripes(map) -
4897 (offset - raid56_full_stripe_start);
4898 } else {
4899 /* we limit the length of each bio to what fits in a stripe */
4900 max_len = stripe_len - stripe_offset;
4901 }
4902 *length = min_t(u64, em->len - offset, max_len);
4903 } else {
4904 *length = em->len - offset;
4905 }
4906
4907 /* This is for when we're called from btrfs_merge_bio_hook() and all
4908 it cares about is the length */
4909 if (!bbio_ret)
4910 goto out;
4911
4912 btrfs_dev_replace_lock(dev_replace);
4913 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4914 if (!dev_replace_is_ongoing)
4915 btrfs_dev_replace_unlock(dev_replace);
4916
4917 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4918 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4919 dev_replace->tgtdev != NULL) {
4920 /*
4921 * in dev-replace case, for repair case (that's the only
4922 * case where the mirror is selected explicitly when
4923 * calling btrfs_map_block), blocks left of the left cursor
4924 * can also be read from the target drive.
4925 * For REQ_GET_READ_MIRRORS, the target drive is added as
4926 * the last one to the array of stripes. For READ, it also
4927 * needs to be supported using the same mirror number.
4928 * If the requested block is not left of the left cursor,
4929 * EIO is returned. This can happen because btrfs_num_copies()
4930 * returns one more in the dev-replace case.
4931 */
4932 u64 tmp_length = *length;
4933 struct btrfs_bio *tmp_bbio = NULL;
4934 int tmp_num_stripes;
4935 u64 srcdev_devid = dev_replace->srcdev->devid;
4936 int index_srcdev = 0;
4937 int found = 0;
4938 u64 physical_of_found = 0;
4939
4940 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4941 logical, &tmp_length, &tmp_bbio, 0, NULL);
4942 if (ret) {
4943 WARN_ON(tmp_bbio != NULL);
4944 goto out;
4945 }
4946
4947 tmp_num_stripes = tmp_bbio->num_stripes;
4948 if (mirror_num > tmp_num_stripes) {
4949 /*
4950 * REQ_GET_READ_MIRRORS does not contain this
4951 * mirror, that means that the requested area
4952 * is not left of the left cursor
4953 */
4954 ret = -EIO;
4955 kfree(tmp_bbio);
4956 goto out;
4957 }
4958
4959 /*
4960 * process the rest of the function using the mirror_num
4961 * of the source drive. Therefore look it up first.
4962 * At the end, patch the device pointer to the one of the
4963 * target drive.
4964 */
4965 for (i = 0; i < tmp_num_stripes; i++) {
4966 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4967 /*
4968 * In case of DUP, in order to keep it
4969 * simple, only add the mirror with the
4970 * lowest physical address
4971 */
4972 if (found &&
4973 physical_of_found <=
4974 tmp_bbio->stripes[i].physical)
4975 continue;
4976 index_srcdev = i;
4977 found = 1;
4978 physical_of_found =
4979 tmp_bbio->stripes[i].physical;
4980 }
4981 }
4982
4983 if (found) {
4984 mirror_num = index_srcdev + 1;
4985 patch_the_first_stripe_for_dev_replace = 1;
4986 physical_to_patch_in_first_stripe = physical_of_found;
4987 } else {
4988 WARN_ON(1);
4989 ret = -EIO;
4990 kfree(tmp_bbio);
4991 goto out;
4992 }
4993
4994 kfree(tmp_bbio);
4995 } else if (mirror_num > map->num_stripes) {
4996 mirror_num = 0;
4997 }
4998
4999 num_stripes = 1;
5000 stripe_index = 0;
5001 stripe_nr_orig = stripe_nr;
5002 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
5003 do_div(stripe_nr_end, map->stripe_len);
5004 stripe_end_offset = stripe_nr_end * map->stripe_len -
5005 (offset + *length);
5006
5007 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
5008 if (rw & REQ_DISCARD)
5009 num_stripes = min_t(u64, map->num_stripes,
5010 stripe_nr_end - stripe_nr_orig);
5011 stripe_index = do_div(stripe_nr, map->num_stripes);
5012 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
5013 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
5014 num_stripes = map->num_stripes;
5015 else if (mirror_num)
5016 stripe_index = mirror_num - 1;
5017 else {
5018 stripe_index = find_live_mirror(fs_info, map, 0,
5019 map->num_stripes,
5020 current->pid % map->num_stripes,
5021 dev_replace_is_ongoing);
5022 mirror_num = stripe_index + 1;
5023 }
5024
5025 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
5026 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
5027 num_stripes = map->num_stripes;
5028 } else if (mirror_num) {
5029 stripe_index = mirror_num - 1;
5030 } else {
5031 mirror_num = 1;
5032 }
5033
5034 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
5035 int factor = map->num_stripes / map->sub_stripes;
5036
5037 stripe_index = do_div(stripe_nr, factor);
5038 stripe_index *= map->sub_stripes;
5039
5040 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
5041 num_stripes = map->sub_stripes;
5042 else if (rw & REQ_DISCARD)
5043 num_stripes = min_t(u64, map->sub_stripes *
5044 (stripe_nr_end - stripe_nr_orig),
5045 map->num_stripes);
5046 else if (mirror_num)
5047 stripe_index += mirror_num - 1;
5048 else {
5049 int old_stripe_index = stripe_index;
5050 stripe_index = find_live_mirror(fs_info, map,
5051 stripe_index,
5052 map->sub_stripes, stripe_index +
5053 current->pid % map->sub_stripes,
5054 dev_replace_is_ongoing);
5055 mirror_num = stripe_index - old_stripe_index + 1;
5056 }
5057
5058 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
5059 BTRFS_BLOCK_GROUP_RAID6)) {
5060 u64 tmp;
5061
5062 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
5063 && raid_map_ret) {
5064 int i, rot;
5065
5066 /* push stripe_nr back to the start of the full stripe */
5067 stripe_nr = raid56_full_stripe_start;
5068 do_div(stripe_nr, stripe_len);
5069
5070 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
5071
5072 /* RAID[56] write or recovery. Return all stripes */
5073 num_stripes = map->num_stripes;
5074 max_errors = nr_parity_stripes(map);
5075
5076 raid_map = kmalloc_array(num_stripes, sizeof(u64),
5077 GFP_NOFS);
5078 if (!raid_map) {
5079 ret = -ENOMEM;
5080 goto out;
5081 }
5082
5083 /* Work out the disk rotation on this stripe-set */
5084 tmp = stripe_nr;
5085 rot = do_div(tmp, num_stripes);
5086
5087 /* Fill in the logical address of each stripe */
5088 tmp = stripe_nr * nr_data_stripes(map);
5089 for (i = 0; i < nr_data_stripes(map); i++)
5090 raid_map[(i+rot) % num_stripes] =
5091 em->start + (tmp + i) * map->stripe_len;
5092
5093 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
5094 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
5095 raid_map[(i+rot+1) % num_stripes] =
5096 RAID6_Q_STRIPE;
5097
5098 *length = map->stripe_len;
5099 stripe_index = 0;
5100 stripe_offset = 0;
5101 } else {
5102 /*
5103 * Mirror #0 or #1 means the original data block.
5104 * Mirror #2 is RAID5 parity block.
5105 * Mirror #3 is RAID6 Q block.
5106 */
5107 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
5108 if (mirror_num > 1)
5109 stripe_index = nr_data_stripes(map) +
5110 mirror_num - 2;
5111
5112 /* We distribute the parity blocks across stripes */
5113 tmp = stripe_nr + stripe_index;
5114 stripe_index = do_div(tmp, map->num_stripes);
5115 }
5116 } else {
5117 /*
5118 * after this do_div call, stripe_nr is the number of stripes
5119 * on this device we have to walk to find the data, and
5120 * stripe_index is the number of our device in the stripe array
5121 */
5122 stripe_index = do_div(stripe_nr, map->num_stripes);
5123 mirror_num = stripe_index + 1;
5124 }
5125 BUG_ON(stripe_index >= map->num_stripes);
5126
5127 num_alloc_stripes = num_stripes;
5128 if (dev_replace_is_ongoing) {
5129 if (rw & (REQ_WRITE | REQ_DISCARD))
5130 num_alloc_stripes <<= 1;
5131 if (rw & REQ_GET_READ_MIRRORS)
5132 num_alloc_stripes++;
5133 }
5134 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
5135 if (!bbio) {
5136 kfree(raid_map);
5137 ret = -ENOMEM;
5138 goto out;
5139 }
5140 atomic_set(&bbio->error, 0);
5141
5142 if (rw & REQ_DISCARD) {
5143 int factor = 0;
5144 int sub_stripes = 0;
5145 u64 stripes_per_dev = 0;
5146 u32 remaining_stripes = 0;
5147 u32 last_stripe = 0;
5148
5149 if (map->type &
5150 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
5151 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
5152 sub_stripes = 1;
5153 else
5154 sub_stripes = map->sub_stripes;
5155
5156 factor = map->num_stripes / sub_stripes;
5157 stripes_per_dev = div_u64_rem(stripe_nr_end -
5158 stripe_nr_orig,
5159 factor,
5160 &remaining_stripes);
5161 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
5162 last_stripe *= sub_stripes;
5163 }
5164
5165 for (i = 0; i < num_stripes; i++) {
5166 bbio->stripes[i].physical =
5167 map->stripes[stripe_index].physical +
5168 stripe_offset + stripe_nr * map->stripe_len;
5169 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
5170
5171 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
5172 BTRFS_BLOCK_GROUP_RAID10)) {
5173 bbio->stripes[i].length = stripes_per_dev *
5174 map->stripe_len;
5175
5176 if (i / sub_stripes < remaining_stripes)
5177 bbio->stripes[i].length +=
5178 map->stripe_len;
5179
5180 /*
5181 * Special for the first stripe and
5182 * the last stripe:
5183 *
5184 * |-------|...|-------|
5185 * |----------|
5186 * off end_off
5187 */
5188 if (i < sub_stripes)
5189 bbio->stripes[i].length -=
5190 stripe_offset;
5191
5192 if (stripe_index >= last_stripe &&
5193 stripe_index <= (last_stripe +
5194 sub_stripes - 1))
5195 bbio->stripes[i].length -=
5196 stripe_end_offset;
5197
5198 if (i == sub_stripes - 1)
5199 stripe_offset = 0;
5200 } else
5201 bbio->stripes[i].length = *length;
5202
5203 stripe_index++;
5204 if (stripe_index == map->num_stripes) {
5205 /* This could only happen for RAID0/10 */
5206 stripe_index = 0;
5207 stripe_nr++;
5208 }
5209 }
5210 } else {
5211 for (i = 0; i < num_stripes; i++) {
5212 bbio->stripes[i].physical =
5213 map->stripes[stripe_index].physical +
5214 stripe_offset +
5215 stripe_nr * map->stripe_len;
5216 bbio->stripes[i].dev =
5217 map->stripes[stripe_index].dev;
5218 stripe_index++;
5219 }
5220 }
5221
5222 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
5223 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
5224 BTRFS_BLOCK_GROUP_RAID10 |
5225 BTRFS_BLOCK_GROUP_RAID5 |
5226 BTRFS_BLOCK_GROUP_DUP)) {
5227 max_errors = 1;
5228 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
5229 max_errors = 2;
5230 }
5231 }
5232
5233 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
5234 dev_replace->tgtdev != NULL) {
5235 int index_where_to_add;
5236 u64 srcdev_devid = dev_replace->srcdev->devid;
5237
5238 /*
5239 * duplicate the write operations while the dev replace
5240 * procedure is running. Since the copying of the old disk
5241 * to the new disk takes place at run time while the
5242 * filesystem is mounted writable, the regular write
5243 * operations to the old disk have to be duplicated to go
5244 * to the new disk as well.
5245 * Note that device->missing is handled by the caller, and
5246 * that the write to the old disk is already set up in the
5247 * stripes array.
5248 */
5249 index_where_to_add = num_stripes;
5250 for (i = 0; i < num_stripes; i++) {
5251 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5252 /* write to new disk, too */
5253 struct btrfs_bio_stripe *new =
5254 bbio->stripes + index_where_to_add;
5255 struct btrfs_bio_stripe *old =
5256 bbio->stripes + i;
5257
5258 new->physical = old->physical;
5259 new->length = old->length;
5260 new->dev = dev_replace->tgtdev;
5261 index_where_to_add++;
5262 max_errors++;
5263 }
5264 }
5265 num_stripes = index_where_to_add;
5266 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
5267 dev_replace->tgtdev != NULL) {
5268 u64 srcdev_devid = dev_replace->srcdev->devid;
5269 int index_srcdev = 0;
5270 int found = 0;
5271 u64 physical_of_found = 0;
5272
5273 /*
5274 * During the dev-replace procedure, the target drive can
5275 * also be used to read data in case it is needed to repair
5276 * a corrupt block elsewhere. This is possible if the
5277 * requested area is left of the left cursor. In this area,
5278 * the target drive is a full copy of the source drive.
5279 */
5280 for (i = 0; i < num_stripes; i++) {
5281 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5282 /*
5283 * In case of DUP, in order to keep it
5284 * simple, only add the mirror with the
5285 * lowest physical address
5286 */
5287 if (found &&
5288 physical_of_found <=
5289 bbio->stripes[i].physical)
5290 continue;
5291 index_srcdev = i;
5292 found = 1;
5293 physical_of_found = bbio->stripes[i].physical;
5294 }
5295 }
5296 if (found) {
5297 u64 length = map->stripe_len;
5298
5299 if (physical_of_found + length <=
5300 dev_replace->cursor_left) {
5301 struct btrfs_bio_stripe *tgtdev_stripe =
5302 bbio->stripes + num_stripes;
5303
5304 tgtdev_stripe->physical = physical_of_found;
5305 tgtdev_stripe->length =
5306 bbio->stripes[index_srcdev].length;
5307 tgtdev_stripe->dev = dev_replace->tgtdev;
5308
5309 num_stripes++;
5310 }
5311 }
5312 }
5313
5314 *bbio_ret = bbio;
5315 bbio->num_stripes = num_stripes;
5316 bbio->max_errors = max_errors;
5317 bbio->mirror_num = mirror_num;
5318
5319 /*
5320 * this is the case that REQ_READ && dev_replace_is_ongoing &&
5321 * mirror_num == num_stripes + 1 && dev_replace target drive is
5322 * available as a mirror
5323 */
5324 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
5325 WARN_ON(num_stripes > 1);
5326 bbio->stripes[0].dev = dev_replace->tgtdev;
5327 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
5328 bbio->mirror_num = map->num_stripes + 1;
5329 }
5330 if (raid_map) {
5331 sort_parity_stripes(bbio, raid_map);
5332 *raid_map_ret = raid_map;
5333 }
5334 out:
5335 if (dev_replace_is_ongoing)
5336 btrfs_dev_replace_unlock(dev_replace);
5337 free_extent_map(em);
5338 return ret;
5339 }
5340
5341 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
5342 u64 logical, u64 *length,
5343 struct btrfs_bio **bbio_ret, int mirror_num)
5344 {
5345 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
5346 mirror_num, NULL);
5347 }
5348
5349 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
5350 u64 chunk_start, u64 physical, u64 devid,
5351 u64 **logical, int *naddrs, int *stripe_len)
5352 {
5353 struct extent_map_tree *em_tree = &map_tree->map_tree;
5354 struct extent_map *em;
5355 struct map_lookup *map;
5356 u64 *buf;
5357 u64 bytenr;
5358 u64 length;
5359 u64 stripe_nr;
5360 u64 rmap_len;
5361 int i, j, nr = 0;
5362
5363 read_lock(&em_tree->lock);
5364 em = lookup_extent_mapping(em_tree, chunk_start, 1);
5365 read_unlock(&em_tree->lock);
5366
5367 if (!em) {
5368 printk(KERN_ERR "BTRFS: couldn't find em for chunk %Lu\n",
5369 chunk_start);
5370 return -EIO;
5371 }
5372
5373 if (em->start != chunk_start) {
5374 printk(KERN_ERR "BTRFS: bad chunk start, em=%Lu, wanted=%Lu\n",
5375 em->start, chunk_start);
5376 free_extent_map(em);
5377 return -EIO;
5378 }
5379 map = (struct map_lookup *)em->bdev;
5380
5381 length = em->len;
5382 rmap_len = map->stripe_len;
5383
5384 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
5385 do_div(length, map->num_stripes / map->sub_stripes);
5386 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
5387 do_div(length, map->num_stripes);
5388 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
5389 BTRFS_BLOCK_GROUP_RAID6)) {
5390 do_div(length, nr_data_stripes(map));
5391 rmap_len = map->stripe_len * nr_data_stripes(map);
5392 }
5393
5394 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
5395 BUG_ON(!buf); /* -ENOMEM */
5396
5397 for (i = 0; i < map->num_stripes; i++) {
5398 if (devid && map->stripes[i].dev->devid != devid)
5399 continue;
5400 if (map->stripes[i].physical > physical ||
5401 map->stripes[i].physical + length <= physical)
5402 continue;
5403
5404 stripe_nr = physical - map->stripes[i].physical;
5405 do_div(stripe_nr, map->stripe_len);
5406
5407 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
5408 stripe_nr = stripe_nr * map->num_stripes + i;
5409 do_div(stripe_nr, map->sub_stripes);
5410 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
5411 stripe_nr = stripe_nr * map->num_stripes + i;
5412 } /* else if RAID[56], multiply by nr_data_stripes().
5413 * Alternatively, just use rmap_len below instead of
5414 * map->stripe_len */
5415
5416 bytenr = chunk_start + stripe_nr * rmap_len;
5417 WARN_ON(nr >= map->num_stripes);
5418 for (j = 0; j < nr; j++) {
5419 if (buf[j] == bytenr)
5420 break;
5421 }
5422 if (j == nr) {
5423 WARN_ON(nr >= map->num_stripes);
5424 buf[nr++] = bytenr;
5425 }
5426 }
5427
5428 *logical = buf;
5429 *naddrs = nr;
5430 *stripe_len = rmap_len;
5431
5432 free_extent_map(em);
5433 return 0;
5434 }
5435
5436 static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio, int err)
5437 {
5438 if (likely(bbio->flags & BTRFS_BIO_ORIG_BIO_SUBMITTED))
5439 bio_endio_nodec(bio, err);
5440 else
5441 bio_endio(bio, err);
5442 kfree(bbio);
5443 }
5444
5445 static void btrfs_end_bio(struct bio *bio, int err)
5446 {
5447 struct btrfs_bio *bbio = bio->bi_private;
5448 struct btrfs_device *dev = bbio->stripes[0].dev;
5449 int is_orig_bio = 0;
5450
5451 if (err) {
5452 atomic_inc(&bbio->error);
5453 if (err == -EIO || err == -EREMOTEIO) {
5454 unsigned int stripe_index =
5455 btrfs_io_bio(bio)->stripe_index;
5456
5457 BUG_ON(stripe_index >= bbio->num_stripes);
5458 dev = bbio->stripes[stripe_index].dev;
5459 if (dev->bdev) {
5460 if (bio->bi_rw & WRITE)
5461 btrfs_dev_stat_inc(dev,
5462 BTRFS_DEV_STAT_WRITE_ERRS);
5463 else
5464 btrfs_dev_stat_inc(dev,
5465 BTRFS_DEV_STAT_READ_ERRS);
5466 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5467 btrfs_dev_stat_inc(dev,
5468 BTRFS_DEV_STAT_FLUSH_ERRS);
5469 btrfs_dev_stat_print_on_error(dev);
5470 }
5471 }
5472 }
5473
5474 if (bio == bbio->orig_bio)
5475 is_orig_bio = 1;
5476
5477 btrfs_bio_counter_dec(bbio->fs_info);
5478
5479 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5480 if (!is_orig_bio) {
5481 bio_put(bio);
5482 bio = bbio->orig_bio;
5483 }
5484
5485 bio->bi_private = bbio->private;
5486 bio->bi_end_io = bbio->end_io;
5487 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5488 /* only send an error to the higher layers if it is
5489 * beyond the tolerance of the btrfs bio
5490 */
5491 if (atomic_read(&bbio->error) > bbio->max_errors) {
5492 err = -EIO;
5493 } else {
5494 /*
5495 * this bio is actually up to date, we didn't
5496 * go over the max number of errors
5497 */
5498 set_bit(BIO_UPTODATE, &bio->bi_flags);
5499 err = 0;
5500 }
5501
5502 btrfs_end_bbio(bbio, bio, err);
5503 } else if (!is_orig_bio) {
5504 bio_put(bio);
5505 }
5506 }
5507
5508 /*
5509 * see run_scheduled_bios for a description of why bios are collected for
5510 * async submit.
5511 *
5512 * This will add one bio to the pending list for a device and make sure
5513 * the work struct is scheduled.
5514 */
5515 static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5516 struct btrfs_device *device,
5517 int rw, struct bio *bio)
5518 {
5519 int should_queue = 1;
5520 struct btrfs_pending_bios *pending_bios;
5521
5522 if (device->missing || !device->bdev) {
5523 bio_endio(bio, -EIO);
5524 return;
5525 }
5526
5527 /* don't bother with additional async steps for reads, right now */
5528 if (!(rw & REQ_WRITE)) {
5529 bio_get(bio);
5530 btrfsic_submit_bio(rw, bio);
5531 bio_put(bio);
5532 return;
5533 }
5534
5535 /*
5536 * nr_async_bios allows us to reliably return congestion to the
5537 * higher layers. Otherwise, the async bio makes it appear we have
5538 * made progress against dirty pages when we've really just put it
5539 * on a queue for later
5540 */
5541 atomic_inc(&root->fs_info->nr_async_bios);
5542 WARN_ON(bio->bi_next);
5543 bio->bi_next = NULL;
5544 bio->bi_rw |= rw;
5545
5546 spin_lock(&device->io_lock);
5547 if (bio->bi_rw & REQ_SYNC)
5548 pending_bios = &device->pending_sync_bios;
5549 else
5550 pending_bios = &device->pending_bios;
5551
5552 if (pending_bios->tail)
5553 pending_bios->tail->bi_next = bio;
5554
5555 pending_bios->tail = bio;
5556 if (!pending_bios->head)
5557 pending_bios->head = bio;
5558 if (device->running_pending)
5559 should_queue = 0;
5560
5561 spin_unlock(&device->io_lock);
5562
5563 if (should_queue)
5564 btrfs_queue_work(root->fs_info->submit_workers,
5565 &device->work);
5566 }
5567
5568 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5569 sector_t sector)
5570 {
5571 struct bio_vec *prev;
5572 struct request_queue *q = bdev_get_queue(bdev);
5573 unsigned int max_sectors = queue_max_sectors(q);
5574 struct bvec_merge_data bvm = {
5575 .bi_bdev = bdev,
5576 .bi_sector = sector,
5577 .bi_rw = bio->bi_rw,
5578 };
5579
5580 if (WARN_ON(bio->bi_vcnt == 0))
5581 return 1;
5582
5583 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5584 if (bio_sectors(bio) > max_sectors)
5585 return 0;
5586
5587 if (!q->merge_bvec_fn)
5588 return 1;
5589
5590 bvm.bi_size = bio->bi_iter.bi_size - prev->bv_len;
5591 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5592 return 0;
5593 return 1;
5594 }
5595
5596 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5597 struct bio *bio, u64 physical, int dev_nr,
5598 int rw, int async)
5599 {
5600 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5601
5602 bio->bi_private = bbio;
5603 btrfs_io_bio(bio)->stripe_index = dev_nr;
5604 bio->bi_end_io = btrfs_end_bio;
5605 bio->bi_iter.bi_sector = physical >> 9;
5606 #ifdef DEBUG
5607 {
5608 struct rcu_string *name;
5609
5610 rcu_read_lock();
5611 name = rcu_dereference(dev->name);
5612 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5613 "(%s id %llu), size=%u\n", rw,
5614 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5615 name->str, dev->devid, bio->bi_size);
5616 rcu_read_unlock();
5617 }
5618 #endif
5619 bio->bi_bdev = dev->bdev;
5620
5621 btrfs_bio_counter_inc_noblocked(root->fs_info);
5622
5623 if (async)
5624 btrfs_schedule_bio(root, dev, rw, bio);
5625 else
5626 btrfsic_submit_bio(rw, bio);
5627 }
5628
5629 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5630 struct bio *first_bio, struct btrfs_device *dev,
5631 int dev_nr, int rw, int async)
5632 {
5633 struct bio_vec *bvec = first_bio->bi_io_vec;
5634 struct bio *bio;
5635 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5636 u64 physical = bbio->stripes[dev_nr].physical;
5637
5638 again:
5639 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5640 if (!bio)
5641 return -ENOMEM;
5642
5643 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5644 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5645 bvec->bv_offset) < bvec->bv_len) {
5646 u64 len = bio->bi_iter.bi_size;
5647
5648 atomic_inc(&bbio->stripes_pending);
5649 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5650 rw, async);
5651 physical += len;
5652 goto again;
5653 }
5654 bvec++;
5655 }
5656
5657 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5658 return 0;
5659 }
5660
5661 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5662 {
5663 atomic_inc(&bbio->error);
5664 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5665 /* Shoud be the original bio. */
5666 WARN_ON(bio != bbio->orig_bio);
5667
5668 bio->bi_private = bbio->private;
5669 bio->bi_end_io = bbio->end_io;
5670 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5671 bio->bi_iter.bi_sector = logical >> 9;
5672
5673 btrfs_end_bbio(bbio, bio, -EIO);
5674 }
5675 }
5676
5677 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5678 int mirror_num, int async_submit)
5679 {
5680 struct btrfs_device *dev;
5681 struct bio *first_bio = bio;
5682 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
5683 u64 length = 0;
5684 u64 map_length;
5685 u64 *raid_map = NULL;
5686 int ret;
5687 int dev_nr = 0;
5688 int total_devs = 1;
5689 struct btrfs_bio *bbio = NULL;
5690
5691 length = bio->bi_iter.bi_size;
5692 map_length = length;
5693
5694 btrfs_bio_counter_inc_blocked(root->fs_info);
5695 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5696 mirror_num, &raid_map);
5697 if (ret) {
5698 btrfs_bio_counter_dec(root->fs_info);
5699 return ret;
5700 }
5701
5702 total_devs = bbio->num_stripes;
5703 bbio->orig_bio = first_bio;
5704 bbio->private = first_bio->bi_private;
5705 bbio->end_io = first_bio->bi_end_io;
5706 bbio->fs_info = root->fs_info;
5707 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5708
5709 if (raid_map) {
5710 /* In this case, map_length has been set to the length of
5711 a single stripe; not the whole write */
5712 if (rw & WRITE) {
5713 ret = raid56_parity_write(root, bio, bbio,
5714 raid_map, map_length);
5715 } else {
5716 ret = raid56_parity_recover(root, bio, bbio,
5717 raid_map, map_length,
5718 mirror_num);
5719 }
5720 /*
5721 * FIXME, replace dosen't support raid56 yet, please fix
5722 * it in the future.
5723 */
5724 btrfs_bio_counter_dec(root->fs_info);
5725 return ret;
5726 }
5727
5728 if (map_length < length) {
5729 btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5730 logical, length, map_length);
5731 BUG();
5732 }
5733
5734 while (dev_nr < total_devs) {
5735 dev = bbio->stripes[dev_nr].dev;
5736 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5737 bbio_error(bbio, first_bio, logical);
5738 dev_nr++;
5739 continue;
5740 }
5741
5742 /*
5743 * Check and see if we're ok with this bio based on it's size
5744 * and offset with the given device.
5745 */
5746 if (!bio_size_ok(dev->bdev, first_bio,
5747 bbio->stripes[dev_nr].physical >> 9)) {
5748 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5749 dev_nr, rw, async_submit);
5750 BUG_ON(ret);
5751 dev_nr++;
5752 continue;
5753 }
5754
5755 if (dev_nr < total_devs - 1) {
5756 bio = btrfs_bio_clone(first_bio, GFP_NOFS);
5757 BUG_ON(!bio); /* -ENOMEM */
5758 } else {
5759 bio = first_bio;
5760 bbio->flags |= BTRFS_BIO_ORIG_BIO_SUBMITTED;
5761 }
5762
5763 submit_stripe_bio(root, bbio, bio,
5764 bbio->stripes[dev_nr].physical, dev_nr, rw,
5765 async_submit);
5766 dev_nr++;
5767 }
5768 btrfs_bio_counter_dec(root->fs_info);
5769 return 0;
5770 }
5771
5772 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5773 u8 *uuid, u8 *fsid)
5774 {
5775 struct btrfs_device *device;
5776 struct btrfs_fs_devices *cur_devices;
5777
5778 cur_devices = fs_info->fs_devices;
5779 while (cur_devices) {
5780 if (!fsid ||
5781 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5782 device = __find_device(&cur_devices->devices,
5783 devid, uuid);
5784 if (device)
5785 return device;
5786 }
5787 cur_devices = cur_devices->seed;
5788 }
5789 return NULL;
5790 }
5791
5792 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5793 u64 devid, u8 *dev_uuid)
5794 {
5795 struct btrfs_device *device;
5796 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5797
5798 device = btrfs_alloc_device(NULL, &devid, dev_uuid);
5799 if (IS_ERR(device))
5800 return NULL;
5801
5802 list_add(&device->dev_list, &fs_devices->devices);
5803 device->fs_devices = fs_devices;
5804 fs_devices->num_devices++;
5805
5806 device->missing = 1;
5807 fs_devices->missing_devices++;
5808
5809 return device;
5810 }
5811
5812 /**
5813 * btrfs_alloc_device - allocate struct btrfs_device
5814 * @fs_info: used only for generating a new devid, can be NULL if
5815 * devid is provided (i.e. @devid != NULL).
5816 * @devid: a pointer to devid for this device. If NULL a new devid
5817 * is generated.
5818 * @uuid: a pointer to UUID for this device. If NULL a new UUID
5819 * is generated.
5820 *
5821 * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
5822 * on error. Returned struct is not linked onto any lists and can be
5823 * destroyed with kfree() right away.
5824 */
5825 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
5826 const u64 *devid,
5827 const u8 *uuid)
5828 {
5829 struct btrfs_device *dev;
5830 u64 tmp;
5831
5832 if (WARN_ON(!devid && !fs_info))
5833 return ERR_PTR(-EINVAL);
5834
5835 dev = __alloc_device();
5836 if (IS_ERR(dev))
5837 return dev;
5838
5839 if (devid)
5840 tmp = *devid;
5841 else {
5842 int ret;
5843
5844 ret = find_next_devid(fs_info, &tmp);
5845 if (ret) {
5846 kfree(dev);
5847 return ERR_PTR(ret);
5848 }
5849 }
5850 dev->devid = tmp;
5851
5852 if (uuid)
5853 memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
5854 else
5855 generate_random_uuid(dev->uuid);
5856
5857 btrfs_init_work(&dev->work, btrfs_submit_helper,
5858 pending_bios_fn, NULL, NULL);
5859
5860 return dev;
5861 }
5862
5863 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5864 struct extent_buffer *leaf,
5865 struct btrfs_chunk *chunk)
5866 {
5867 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5868 struct map_lookup *map;
5869 struct extent_map *em;
5870 u64 logical;
5871 u64 length;
5872 u64 devid;
5873 u8 uuid[BTRFS_UUID_SIZE];
5874 int num_stripes;
5875 int ret;
5876 int i;
5877
5878 logical = key->offset;
5879 length = btrfs_chunk_length(leaf, chunk);
5880
5881 read_lock(&map_tree->map_tree.lock);
5882 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5883 read_unlock(&map_tree->map_tree.lock);
5884
5885 /* already mapped? */
5886 if (em && em->start <= logical && em->start + em->len > logical) {
5887 free_extent_map(em);
5888 return 0;
5889 } else if (em) {
5890 free_extent_map(em);
5891 }
5892
5893 em = alloc_extent_map();
5894 if (!em)
5895 return -ENOMEM;
5896 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5897 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5898 if (!map) {
5899 free_extent_map(em);
5900 return -ENOMEM;
5901 }
5902
5903 set_bit(EXTENT_FLAG_FS_MAPPING, &em->flags);
5904 em->bdev = (struct block_device *)map;
5905 em->start = logical;
5906 em->len = length;
5907 em->orig_start = 0;
5908 em->block_start = 0;
5909 em->block_len = em->len;
5910
5911 map->num_stripes = num_stripes;
5912 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5913 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5914 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5915 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5916 map->type = btrfs_chunk_type(leaf, chunk);
5917 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5918 for (i = 0; i < num_stripes; i++) {
5919 map->stripes[i].physical =
5920 btrfs_stripe_offset_nr(leaf, chunk, i);
5921 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5922 read_extent_buffer(leaf, uuid, (unsigned long)
5923 btrfs_stripe_dev_uuid_nr(chunk, i),
5924 BTRFS_UUID_SIZE);
5925 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5926 uuid, NULL);
5927 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5928 free_extent_map(em);
5929 return -EIO;
5930 }
5931 if (!map->stripes[i].dev) {
5932 map->stripes[i].dev =
5933 add_missing_dev(root, devid, uuid);
5934 if (!map->stripes[i].dev) {
5935 free_extent_map(em);
5936 return -EIO;
5937 }
5938 }
5939 map->stripes[i].dev->in_fs_metadata = 1;
5940 }
5941
5942 write_lock(&map_tree->map_tree.lock);
5943 ret = add_extent_mapping(&map_tree->map_tree, em, 0);
5944 write_unlock(&map_tree->map_tree.lock);
5945 BUG_ON(ret); /* Tree corruption */
5946 free_extent_map(em);
5947
5948 return 0;
5949 }
5950
5951 static void fill_device_from_item(struct extent_buffer *leaf,
5952 struct btrfs_dev_item *dev_item,
5953 struct btrfs_device *device)
5954 {
5955 unsigned long ptr;
5956
5957 device->devid = btrfs_device_id(leaf, dev_item);
5958 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5959 device->total_bytes = device->disk_total_bytes;
5960 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5961 device->type = btrfs_device_type(leaf, dev_item);
5962 device->io_align = btrfs_device_io_align(leaf, dev_item);
5963 device->io_width = btrfs_device_io_width(leaf, dev_item);
5964 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5965 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5966 device->is_tgtdev_for_dev_replace = 0;
5967
5968 ptr = btrfs_device_uuid(dev_item);
5969 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5970 }
5971
5972 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5973 {
5974 struct btrfs_fs_devices *fs_devices;
5975 int ret;
5976
5977 BUG_ON(!mutex_is_locked(&uuid_mutex));
5978
5979 fs_devices = root->fs_info->fs_devices->seed;
5980 while (fs_devices) {
5981 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5982 ret = 0;
5983 goto out;
5984 }
5985 fs_devices = fs_devices->seed;
5986 }
5987
5988 fs_devices = find_fsid(fsid);
5989 if (!fs_devices) {
5990 ret = -ENOENT;
5991 goto out;
5992 }
5993
5994 fs_devices = clone_fs_devices(fs_devices);
5995 if (IS_ERR(fs_devices)) {
5996 ret = PTR_ERR(fs_devices);
5997 goto out;
5998 }
5999
6000 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
6001 root->fs_info->bdev_holder);
6002 if (ret) {
6003 free_fs_devices(fs_devices);
6004 goto out;
6005 }
6006
6007 if (!fs_devices->seeding) {
6008 __btrfs_close_devices(fs_devices);
6009 free_fs_devices(fs_devices);
6010 ret = -EINVAL;
6011 goto out;
6012 }
6013
6014 fs_devices->seed = root->fs_info->fs_devices->seed;
6015 root->fs_info->fs_devices->seed = fs_devices;
6016 out:
6017 return ret;
6018 }
6019
6020 static int read_one_dev(struct btrfs_root *root,
6021 struct extent_buffer *leaf,
6022 struct btrfs_dev_item *dev_item)
6023 {
6024 struct btrfs_device *device;
6025 u64 devid;
6026 int ret;
6027 u8 fs_uuid[BTRFS_UUID_SIZE];
6028 u8 dev_uuid[BTRFS_UUID_SIZE];
6029
6030 devid = btrfs_device_id(leaf, dev_item);
6031 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
6032 BTRFS_UUID_SIZE);
6033 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
6034 BTRFS_UUID_SIZE);
6035
6036 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
6037 ret = open_seed_devices(root, fs_uuid);
6038 if (ret && !btrfs_test_opt(root, DEGRADED))
6039 return ret;
6040 }
6041
6042 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
6043 if (!device || !device->bdev) {
6044 if (!btrfs_test_opt(root, DEGRADED))
6045 return -EIO;
6046
6047 if (!device) {
6048 btrfs_warn(root->fs_info, "devid %llu missing", devid);
6049 device = add_missing_dev(root, devid, dev_uuid);
6050 if (!device)
6051 return -ENOMEM;
6052 } else if (!device->missing) {
6053 /*
6054 * this happens when a device that was properly setup
6055 * in the device info lists suddenly goes bad.
6056 * device->bdev is NULL, and so we have to set
6057 * device->missing to one here
6058 */
6059 root->fs_info->fs_devices->missing_devices++;
6060 device->missing = 1;
6061 }
6062 }
6063
6064 if (device->fs_devices != root->fs_info->fs_devices) {
6065 BUG_ON(device->writeable);
6066 if (device->generation !=
6067 btrfs_device_generation(leaf, dev_item))
6068 return -EINVAL;
6069 }
6070
6071 fill_device_from_item(leaf, dev_item, device);
6072 device->in_fs_metadata = 1;
6073 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
6074 device->fs_devices->total_rw_bytes += device->total_bytes;
6075 spin_lock(&root->fs_info->free_chunk_lock);
6076 root->fs_info->free_chunk_space += device->total_bytes -
6077 device->bytes_used;
6078 spin_unlock(&root->fs_info->free_chunk_lock);
6079 }
6080 ret = 0;
6081 return ret;
6082 }
6083
6084 int btrfs_read_sys_array(struct btrfs_root *root)
6085 {
6086 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
6087 struct extent_buffer *sb;
6088 struct btrfs_disk_key *disk_key;
6089 struct btrfs_chunk *chunk;
6090 u8 *ptr;
6091 unsigned long sb_ptr;
6092 int ret = 0;
6093 u32 num_stripes;
6094 u32 array_size;
6095 u32 len = 0;
6096 u32 cur;
6097 struct btrfs_key key;
6098
6099 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
6100 BTRFS_SUPER_INFO_SIZE);
6101 if (!sb)
6102 return -ENOMEM;
6103 btrfs_set_buffer_uptodate(sb);
6104 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
6105 /*
6106 * The sb extent buffer is artifical and just used to read the system array.
6107 * btrfs_set_buffer_uptodate() call does not properly mark all it's
6108 * pages up-to-date when the page is larger: extent does not cover the
6109 * whole page and consequently check_page_uptodate does not find all
6110 * the page's extents up-to-date (the hole beyond sb),
6111 * write_extent_buffer then triggers a WARN_ON.
6112 *
6113 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
6114 * but sb spans only this function. Add an explicit SetPageUptodate call
6115 * to silence the warning eg. on PowerPC 64.
6116 */
6117 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
6118 SetPageUptodate(sb->pages[0]);
6119
6120 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
6121 array_size = btrfs_super_sys_array_size(super_copy);
6122
6123 ptr = super_copy->sys_chunk_array;
6124 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
6125 cur = 0;
6126
6127 while (cur < array_size) {
6128 disk_key = (struct btrfs_disk_key *)ptr;
6129 btrfs_disk_key_to_cpu(&key, disk_key);
6130
6131 len = sizeof(*disk_key); ptr += len;
6132 sb_ptr += len;
6133 cur += len;
6134
6135 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
6136 chunk = (struct btrfs_chunk *)sb_ptr;
6137 ret = read_one_chunk(root, &key, sb, chunk);
6138 if (ret)
6139 break;
6140 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
6141 len = btrfs_chunk_item_size(num_stripes);
6142 } else {
6143 ret = -EIO;
6144 break;
6145 }
6146 ptr += len;
6147 sb_ptr += len;
6148 cur += len;
6149 }
6150 free_extent_buffer(sb);
6151 return ret;
6152 }
6153
6154 int btrfs_read_chunk_tree(struct btrfs_root *root)
6155 {
6156 struct btrfs_path *path;
6157 struct extent_buffer *leaf;
6158 struct btrfs_key key;
6159 struct btrfs_key found_key;
6160 int ret;
6161 int slot;
6162
6163 root = root->fs_info->chunk_root;
6164
6165 path = btrfs_alloc_path();
6166 if (!path)
6167 return -ENOMEM;
6168
6169 mutex_lock(&uuid_mutex);
6170 lock_chunks(root);
6171
6172 /*
6173 * Read all device items, and then all the chunk items. All
6174 * device items are found before any chunk item (their object id
6175 * is smaller than the lowest possible object id for a chunk
6176 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
6177 */
6178 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
6179 key.offset = 0;
6180 key.type = 0;
6181 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6182 if (ret < 0)
6183 goto error;
6184 while (1) {
6185 leaf = path->nodes[0];
6186 slot = path->slots[0];
6187 if (slot >= btrfs_header_nritems(leaf)) {
6188 ret = btrfs_next_leaf(root, path);
6189 if (ret == 0)
6190 continue;
6191 if (ret < 0)
6192 goto error;
6193 break;
6194 }
6195 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6196 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
6197 struct btrfs_dev_item *dev_item;
6198 dev_item = btrfs_item_ptr(leaf, slot,
6199 struct btrfs_dev_item);
6200 ret = read_one_dev(root, leaf, dev_item);
6201 if (ret)
6202 goto error;
6203 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
6204 struct btrfs_chunk *chunk;
6205 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
6206 ret = read_one_chunk(root, &found_key, leaf, chunk);
6207 if (ret)
6208 goto error;
6209 }
6210 path->slots[0]++;
6211 }
6212 ret = 0;
6213 error:
6214 unlock_chunks(root);
6215 mutex_unlock(&uuid_mutex);
6216
6217 btrfs_free_path(path);
6218 return ret;
6219 }
6220
6221 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
6222 {
6223 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6224 struct btrfs_device *device;
6225
6226 while (fs_devices) {
6227 mutex_lock(&fs_devices->device_list_mutex);
6228 list_for_each_entry(device, &fs_devices->devices, dev_list)
6229 device->dev_root = fs_info->dev_root;
6230 mutex_unlock(&fs_devices->device_list_mutex);
6231
6232 fs_devices = fs_devices->seed;
6233 }
6234 }
6235
6236 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
6237 {
6238 int i;
6239
6240 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6241 btrfs_dev_stat_reset(dev, i);
6242 }
6243
6244 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
6245 {
6246 struct btrfs_key key;
6247 struct btrfs_key found_key;
6248 struct btrfs_root *dev_root = fs_info->dev_root;
6249 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6250 struct extent_buffer *eb;
6251 int slot;
6252 int ret = 0;
6253 struct btrfs_device *device;
6254 struct btrfs_path *path = NULL;
6255 int i;
6256
6257 path = btrfs_alloc_path();
6258 if (!path) {
6259 ret = -ENOMEM;
6260 goto out;
6261 }
6262
6263 mutex_lock(&fs_devices->device_list_mutex);
6264 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6265 int item_size;
6266 struct btrfs_dev_stats_item *ptr;
6267
6268 key.objectid = 0;
6269 key.type = BTRFS_DEV_STATS_KEY;
6270 key.offset = device->devid;
6271 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
6272 if (ret) {
6273 __btrfs_reset_dev_stats(device);
6274 device->dev_stats_valid = 1;
6275 btrfs_release_path(path);
6276 continue;
6277 }
6278 slot = path->slots[0];
6279 eb = path->nodes[0];
6280 btrfs_item_key_to_cpu(eb, &found_key, slot);
6281 item_size = btrfs_item_size_nr(eb, slot);
6282
6283 ptr = btrfs_item_ptr(eb, slot,
6284 struct btrfs_dev_stats_item);
6285
6286 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6287 if (item_size >= (1 + i) * sizeof(__le64))
6288 btrfs_dev_stat_set(device, i,
6289 btrfs_dev_stats_value(eb, ptr, i));
6290 else
6291 btrfs_dev_stat_reset(device, i);
6292 }
6293
6294 device->dev_stats_valid = 1;
6295 btrfs_dev_stat_print_on_load(device);
6296 btrfs_release_path(path);
6297 }
6298 mutex_unlock(&fs_devices->device_list_mutex);
6299
6300 out:
6301 btrfs_free_path(path);
6302 return ret < 0 ? ret : 0;
6303 }
6304
6305 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
6306 struct btrfs_root *dev_root,
6307 struct btrfs_device *device)
6308 {
6309 struct btrfs_path *path;
6310 struct btrfs_key key;
6311 struct extent_buffer *eb;
6312 struct btrfs_dev_stats_item *ptr;
6313 int ret;
6314 int i;
6315
6316 key.objectid = 0;
6317 key.type = BTRFS_DEV_STATS_KEY;
6318 key.offset = device->devid;
6319
6320 path = btrfs_alloc_path();
6321 BUG_ON(!path);
6322 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
6323 if (ret < 0) {
6324 printk_in_rcu(KERN_WARNING "BTRFS: "
6325 "error %d while searching for dev_stats item for device %s!\n",
6326 ret, rcu_str_deref(device->name));
6327 goto out;
6328 }
6329
6330 if (ret == 0 &&
6331 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
6332 /* need to delete old one and insert a new one */
6333 ret = btrfs_del_item(trans, dev_root, path);
6334 if (ret != 0) {
6335 printk_in_rcu(KERN_WARNING "BTRFS: "
6336 "delete too small dev_stats item for device %s failed %d!\n",
6337 rcu_str_deref(device->name), ret);
6338 goto out;
6339 }
6340 ret = 1;
6341 }
6342
6343 if (ret == 1) {
6344 /* need to insert a new item */
6345 btrfs_release_path(path);
6346 ret = btrfs_insert_empty_item(trans, dev_root, path,
6347 &key, sizeof(*ptr));
6348 if (ret < 0) {
6349 printk_in_rcu(KERN_WARNING "BTRFS: "
6350 "insert dev_stats item for device %s failed %d!\n",
6351 rcu_str_deref(device->name), ret);
6352 goto out;
6353 }
6354 }
6355
6356 eb = path->nodes[0];
6357 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
6358 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6359 btrfs_set_dev_stats_value(eb, ptr, i,
6360 btrfs_dev_stat_read(device, i));
6361 btrfs_mark_buffer_dirty(eb);
6362
6363 out:
6364 btrfs_free_path(path);
6365 return ret;
6366 }
6367
6368 /*
6369 * called from commit_transaction. Writes all changed device stats to disk.
6370 */
6371 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
6372 struct btrfs_fs_info *fs_info)
6373 {
6374 struct btrfs_root *dev_root = fs_info->dev_root;
6375 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6376 struct btrfs_device *device;
6377 int ret = 0;
6378
6379 mutex_lock(&fs_devices->device_list_mutex);
6380 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6381 if (!device->dev_stats_valid || !device->dev_stats_dirty)
6382 continue;
6383
6384 ret = update_dev_stat_item(trans, dev_root, device);
6385 if (!ret)
6386 device->dev_stats_dirty = 0;
6387 }
6388 mutex_unlock(&fs_devices->device_list_mutex);
6389
6390 return ret;
6391 }
6392
6393 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
6394 {
6395 btrfs_dev_stat_inc(dev, index);
6396 btrfs_dev_stat_print_on_error(dev);
6397 }
6398
6399 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
6400 {
6401 if (!dev->dev_stats_valid)
6402 return;
6403 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
6404 "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6405 rcu_str_deref(dev->name),
6406 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6407 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6408 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6409 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6410 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6411 }
6412
6413 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
6414 {
6415 int i;
6416
6417 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6418 if (btrfs_dev_stat_read(dev, i) != 0)
6419 break;
6420 if (i == BTRFS_DEV_STAT_VALUES_MAX)
6421 return; /* all values == 0, suppress message */
6422
6423 printk_in_rcu(KERN_INFO "BTRFS: "
6424 "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6425 rcu_str_deref(dev->name),
6426 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6427 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6428 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6429 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6430 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6431 }
6432
6433 int btrfs_get_dev_stats(struct btrfs_root *root,
6434 struct btrfs_ioctl_get_dev_stats *stats)
6435 {
6436 struct btrfs_device *dev;
6437 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6438 int i;
6439
6440 mutex_lock(&fs_devices->device_list_mutex);
6441 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
6442 mutex_unlock(&fs_devices->device_list_mutex);
6443
6444 if (!dev) {
6445 btrfs_warn(root->fs_info, "get dev_stats failed, device not found");
6446 return -ENODEV;
6447 } else if (!dev->dev_stats_valid) {
6448 btrfs_warn(root->fs_info, "get dev_stats failed, not yet valid");
6449 return -ENODEV;
6450 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
6451 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6452 if (stats->nr_items > i)
6453 stats->values[i] =
6454 btrfs_dev_stat_read_and_reset(dev, i);
6455 else
6456 btrfs_dev_stat_reset(dev, i);
6457 }
6458 } else {
6459 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6460 if (stats->nr_items > i)
6461 stats->values[i] = btrfs_dev_stat_read(dev, i);
6462 }
6463 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
6464 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
6465 return 0;
6466 }
6467
6468 int btrfs_scratch_superblock(struct btrfs_device *device)
6469 {
6470 struct buffer_head *bh;
6471 struct btrfs_super_block *disk_super;
6472
6473 bh = btrfs_read_dev_super(device->bdev);
6474 if (!bh)
6475 return -EINVAL;
6476 disk_super = (struct btrfs_super_block *)bh->b_data;
6477
6478 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
6479 set_buffer_dirty(bh);
6480 sync_dirty_buffer(bh);
6481 brelse(bh);
6482
6483 return 0;
6484 }
Linux kernel - Deliverables
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