]> git.ipfire.org Git - people/arne_f/kernel.git/blob - fs/btrfs/volumes.c
projects / people / arne_f / kernel.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
blame | history | raw | HEAD
Btrfs: fix a crash of clone with inline extents's split
[people/arne_f/kernel.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <linux/ratelimit.h>
27 #include <linux/kthread.h>
28 #include <linux/raid/pq.h>
29 #include <linux/semaphore.h>
30 #include <asm/div64.h>
31 #include "ctree.h"
32 #include "extent_map.h"
33 #include "disk-io.h"
34 #include "transaction.h"
35 #include "print-tree.h"
36 #include "volumes.h"
37 #include "raid56.h"
38 #include "async-thread.h"
39 #include "check-integrity.h"
40 #include "rcu-string.h"
41 #include "math.h"
42 #include "dev-replace.h"
43
44 static int init_first_rw_device(struct btrfs_trans_handle *trans,
45 struct btrfs_root *root,
46 struct btrfs_device *device);
47 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
48 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
49 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
50 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
51
52 static DEFINE_MUTEX(uuid_mutex);
53 static LIST_HEAD(fs_uuids);
54
55 static void lock_chunks(struct btrfs_root *root)
56 {
57 mutex_lock(&root->fs_info->chunk_mutex);
58 }
59
60 static void unlock_chunks(struct btrfs_root *root)
61 {
62 mutex_unlock(&root->fs_info->chunk_mutex);
63 }
64
65 static struct btrfs_fs_devices *__alloc_fs_devices(void)
66 {
67 struct btrfs_fs_devices *fs_devs;
68
69 fs_devs = kzalloc(sizeof(*fs_devs), GFP_NOFS);
70 if (!fs_devs)
71 return ERR_PTR(-ENOMEM);
72
73 mutex_init(&fs_devs->device_list_mutex);
74
75 INIT_LIST_HEAD(&fs_devs->devices);
76 INIT_LIST_HEAD(&fs_devs->alloc_list);
77 INIT_LIST_HEAD(&fs_devs->list);
78
79 return fs_devs;
80 }
81
82 /**
83 * alloc_fs_devices - allocate struct btrfs_fs_devices
84 * @fsid: a pointer to UUID for this FS. If NULL a new UUID is
85 * generated.
86 *
87 * Return: a pointer to a new &struct btrfs_fs_devices on success;
88 * ERR_PTR() on error. Returned struct is not linked onto any lists and
89 * can be destroyed with kfree() right away.
90 */
91 static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid)
92 {
93 struct btrfs_fs_devices *fs_devs;
94
95 fs_devs = __alloc_fs_devices();
96 if (IS_ERR(fs_devs))
97 return fs_devs;
98
99 if (fsid)
100 memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
101 else
102 generate_random_uuid(fs_devs->fsid);
103
104 return fs_devs;
105 }
106
107 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
108 {
109 struct btrfs_device *device;
110 WARN_ON(fs_devices->opened);
111 while (!list_empty(&fs_devices->devices)) {
112 device = list_entry(fs_devices->devices.next,
113 struct btrfs_device, dev_list);
114 list_del(&device->dev_list);
115 rcu_string_free(device->name);
116 kfree(device);
117 }
118 kfree(fs_devices);
119 }
120
121 static void btrfs_kobject_uevent(struct block_device *bdev,
122 enum kobject_action action)
123 {
124 int ret;
125
126 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
127 if (ret)
128 pr_warn("BTRFS: Sending event '%d' to kobject: '%s' (%p): failed\n",
129 action,
130 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
131 &disk_to_dev(bdev->bd_disk)->kobj);
132 }
133
134 void btrfs_cleanup_fs_uuids(void)
135 {
136 struct btrfs_fs_devices *fs_devices;
137
138 while (!list_empty(&fs_uuids)) {
139 fs_devices = list_entry(fs_uuids.next,
140 struct btrfs_fs_devices, list);
141 list_del(&fs_devices->list);
142 free_fs_devices(fs_devices);
143 }
144 }
145
146 static struct btrfs_device *__alloc_device(void)
147 {
148 struct btrfs_device *dev;
149
150 dev = kzalloc(sizeof(*dev), GFP_NOFS);
151 if (!dev)
152 return ERR_PTR(-ENOMEM);
153
154 INIT_LIST_HEAD(&dev->dev_list);
155 INIT_LIST_HEAD(&dev->dev_alloc_list);
156
157 spin_lock_init(&dev->io_lock);
158
159 spin_lock_init(&dev->reada_lock);
160 atomic_set(&dev->reada_in_flight, 0);
161 INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
162 INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);
163
164 return dev;
165 }
166
167 static noinline struct btrfs_device *__find_device(struct list_head *head,
168 u64 devid, u8 *uuid)
169 {
170 struct btrfs_device *dev;
171
172 list_for_each_entry(dev, head, dev_list) {
173 if (dev->devid == devid &&
174 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
175 return dev;
176 }
177 }
178 return NULL;
179 }
180
181 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
182 {
183 struct btrfs_fs_devices *fs_devices;
184
185 list_for_each_entry(fs_devices, &fs_uuids, list) {
186 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
187 return fs_devices;
188 }
189 return NULL;
190 }
191
192 static int
193 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
194 int flush, struct block_device **bdev,
195 struct buffer_head **bh)
196 {
197 int ret;
198
199 *bdev = blkdev_get_by_path(device_path, flags, holder);
200
201 if (IS_ERR(*bdev)) {
202 ret = PTR_ERR(*bdev);
203 printk(KERN_INFO "BTRFS: open %s failed\n", device_path);
204 goto error;
205 }
206
207 if (flush)
208 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
209 ret = set_blocksize(*bdev, 4096);
210 if (ret) {
211 blkdev_put(*bdev, flags);
212 goto error;
213 }
214 invalidate_bdev(*bdev);
215 *bh = btrfs_read_dev_super(*bdev);
216 if (!*bh) {
217 ret = -EINVAL;
218 blkdev_put(*bdev, flags);
219 goto error;
220 }
221
222 return 0;
223
224 error:
225 *bdev = NULL;
226 *bh = NULL;
227 return ret;
228 }
229
230 static void requeue_list(struct btrfs_pending_bios *pending_bios,
231 struct bio *head, struct bio *tail)
232 {
233
234 struct bio *old_head;
235
236 old_head = pending_bios->head;
237 pending_bios->head = head;
238 if (pending_bios->tail)
239 tail->bi_next = old_head;
240 else
241 pending_bios->tail = tail;
242 }
243
244 /*
245 * we try to collect pending bios for a device so we don't get a large
246 * number of procs sending bios down to the same device. This greatly
247 * improves the schedulers ability to collect and merge the bios.
248 *
249 * But, it also turns into a long list of bios to process and that is sure
250 * to eventually make the worker thread block. The solution here is to
251 * make some progress and then put this work struct back at the end of
252 * the list if the block device is congested. This way, multiple devices
253 * can make progress from a single worker thread.
254 */
255 static noinline void run_scheduled_bios(struct btrfs_device *device)
256 {
257 struct bio *pending;
258 struct backing_dev_info *bdi;
259 struct btrfs_fs_info *fs_info;
260 struct btrfs_pending_bios *pending_bios;
261 struct bio *tail;
262 struct bio *cur;
263 int again = 0;
264 unsigned long num_run;
265 unsigned long batch_run = 0;
266 unsigned long limit;
267 unsigned long last_waited = 0;
268 int force_reg = 0;
269 int sync_pending = 0;
270 struct blk_plug plug;
271
272 /*
273 * this function runs all the bios we've collected for
274 * a particular device. We don't want to wander off to
275 * another device without first sending all of these down.
276 * So, setup a plug here and finish it off before we return
277 */
278 blk_start_plug(&plug);
279
280 bdi = blk_get_backing_dev_info(device->bdev);
281 fs_info = device->dev_root->fs_info;
282 limit = btrfs_async_submit_limit(fs_info);
283 limit = limit * 2 / 3;
284
285 loop:
286 spin_lock(&device->io_lock);
287
288 loop_lock:
289 num_run = 0;
290
291 /* take all the bios off the list at once and process them
292 * later on (without the lock held). But, remember the
293 * tail and other pointers so the bios can be properly reinserted
294 * into the list if we hit congestion
295 */
296 if (!force_reg && device->pending_sync_bios.head) {
297 pending_bios = &device->pending_sync_bios;
298 force_reg = 1;
299 } else {
300 pending_bios = &device->pending_bios;
301 force_reg = 0;
302 }
303
304 pending = pending_bios->head;
305 tail = pending_bios->tail;
306 WARN_ON(pending && !tail);
307
308 /*
309 * if pending was null this time around, no bios need processing
310 * at all and we can stop. Otherwise it'll loop back up again
311 * and do an additional check so no bios are missed.
312 *
313 * device->running_pending is used to synchronize with the
314 * schedule_bio code.
315 */
316 if (device->pending_sync_bios.head == NULL &&
317 device->pending_bios.head == NULL) {
318 again = 0;
319 device->running_pending = 0;
320 } else {
321 again = 1;
322 device->running_pending = 1;
323 }
324
325 pending_bios->head = NULL;
326 pending_bios->tail = NULL;
327
328 spin_unlock(&device->io_lock);
329
330 while (pending) {
331
332 rmb();
333 /* we want to work on both lists, but do more bios on the
334 * sync list than the regular list
335 */
336 if ((num_run > 32 &&
337 pending_bios != &device->pending_sync_bios &&
338 device->pending_sync_bios.head) ||
339 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
340 device->pending_bios.head)) {
341 spin_lock(&device->io_lock);
342 requeue_list(pending_bios, pending, tail);
343 goto loop_lock;
344 }
345
346 cur = pending;
347 pending = pending->bi_next;
348 cur->bi_next = NULL;
349
350 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
351 waitqueue_active(&fs_info->async_submit_wait))
352 wake_up(&fs_info->async_submit_wait);
353
354 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
355
356 /*
357 * if we're doing the sync list, record that our
358 * plug has some sync requests on it
359 *
360 * If we're doing the regular list and there are
361 * sync requests sitting around, unplug before
362 * we add more
363 */
364 if (pending_bios == &device->pending_sync_bios) {
365 sync_pending = 1;
366 } else if (sync_pending) {
367 blk_finish_plug(&plug);
368 blk_start_plug(&plug);
369 sync_pending = 0;
370 }
371
372 btrfsic_submit_bio(cur->bi_rw, cur);
373 num_run++;
374 batch_run++;
375 if (need_resched())
376 cond_resched();
377
378 /*
379 * we made progress, there is more work to do and the bdi
380 * is now congested. Back off and let other work structs
381 * run instead
382 */
383 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
384 fs_info->fs_devices->open_devices > 1) {
385 struct io_context *ioc;
386
387 ioc = current->io_context;
388
389 /*
390 * the main goal here is that we don't want to
391 * block if we're going to be able to submit
392 * more requests without blocking.
393 *
394 * This code does two great things, it pokes into
395 * the elevator code from a filesystem _and_
396 * it makes assumptions about how batching works.
397 */
398 if (ioc && ioc->nr_batch_requests > 0 &&
399 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
400 (last_waited == 0 ||
401 ioc->last_waited == last_waited)) {
402 /*
403 * we want to go through our batch of
404 * requests and stop. So, we copy out
405 * the ioc->last_waited time and test
406 * against it before looping
407 */
408 last_waited = ioc->last_waited;
409 if (need_resched())
410 cond_resched();
411 continue;
412 }
413 spin_lock(&device->io_lock);
414 requeue_list(pending_bios, pending, tail);
415 device->running_pending = 1;
416
417 spin_unlock(&device->io_lock);
418 btrfs_queue_work(fs_info->submit_workers,
419 &device->work);
420 goto done;
421 }
422 /* unplug every 64 requests just for good measure */
423 if (batch_run % 64 == 0) {
424 blk_finish_plug(&plug);
425 blk_start_plug(&plug);
426 sync_pending = 0;
427 }
428 }
429
430 cond_resched();
431 if (again)
432 goto loop;
433
434 spin_lock(&device->io_lock);
435 if (device->pending_bios.head || device->pending_sync_bios.head)
436 goto loop_lock;
437 spin_unlock(&device->io_lock);
438
439 done:
440 blk_finish_plug(&plug);
441 }
442
443 static void pending_bios_fn(struct btrfs_work *work)
444 {
445 struct btrfs_device *device;
446
447 device = container_of(work, struct btrfs_device, work);
448 run_scheduled_bios(device);
449 }
450
451 static noinline int device_list_add(const char *path,
452 struct btrfs_super_block *disk_super,
453 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
454 {
455 struct btrfs_device *device;
456 struct btrfs_fs_devices *fs_devices;
457 struct rcu_string *name;
458 u64 found_transid = btrfs_super_generation(disk_super);
459
460 fs_devices = find_fsid(disk_super->fsid);
461 if (!fs_devices) {
462 fs_devices = alloc_fs_devices(disk_super->fsid);
463 if (IS_ERR(fs_devices))
464 return PTR_ERR(fs_devices);
465
466 list_add(&fs_devices->list, &fs_uuids);
467 fs_devices->latest_devid = devid;
468 fs_devices->latest_trans = found_transid;
469
470 device = NULL;
471 } else {
472 device = __find_device(&fs_devices->devices, devid,
473 disk_super->dev_item.uuid);
474 }
475 if (!device) {
476 if (fs_devices->opened)
477 return -EBUSY;
478
479 device = btrfs_alloc_device(NULL, &devid,
480 disk_super->dev_item.uuid);
481 if (IS_ERR(device)) {
482 /* we can safely leave the fs_devices entry around */
483 return PTR_ERR(device);
484 }
485
486 name = rcu_string_strdup(path, GFP_NOFS);
487 if (!name) {
488 kfree(device);
489 return -ENOMEM;
490 }
491 rcu_assign_pointer(device->name, name);
492
493 mutex_lock(&fs_devices->device_list_mutex);
494 list_add_rcu(&device->dev_list, &fs_devices->devices);
495 fs_devices->num_devices++;
496 mutex_unlock(&fs_devices->device_list_mutex);
497
498 device->fs_devices = fs_devices;
499 } else if (!device->name || strcmp(device->name->str, path)) {
500 name = rcu_string_strdup(path, GFP_NOFS);
501 if (!name)
502 return -ENOMEM;
503 rcu_string_free(device->name);
504 rcu_assign_pointer(device->name, name);
505 if (device->missing) {
506 fs_devices->missing_devices--;
507 device->missing = 0;
508 }
509 }
510
511 if (found_transid > fs_devices->latest_trans) {
512 fs_devices->latest_devid = devid;
513 fs_devices->latest_trans = found_transid;
514 }
515 *fs_devices_ret = fs_devices;
516 return 0;
517 }
518
519 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
520 {
521 struct btrfs_fs_devices *fs_devices;
522 struct btrfs_device *device;
523 struct btrfs_device *orig_dev;
524
525 fs_devices = alloc_fs_devices(orig->fsid);
526 if (IS_ERR(fs_devices))
527 return fs_devices;
528
529 fs_devices->latest_devid = orig->latest_devid;
530 fs_devices->latest_trans = orig->latest_trans;
531 fs_devices->total_devices = orig->total_devices;
532
533 /* We have held the volume lock, it is safe to get the devices. */
534 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
535 struct rcu_string *name;
536
537 device = btrfs_alloc_device(NULL, &orig_dev->devid,
538 orig_dev->uuid);
539 if (IS_ERR(device))
540 goto error;
541
542 /*
543 * This is ok to do without rcu read locked because we hold the
544 * uuid mutex so nothing we touch in here is going to disappear.
545 */
546 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
547 if (!name) {
548 kfree(device);
549 goto error;
550 }
551 rcu_assign_pointer(device->name, name);
552
553 list_add(&device->dev_list, &fs_devices->devices);
554 device->fs_devices = fs_devices;
555 fs_devices->num_devices++;
556 }
557 return fs_devices;
558 error:
559 free_fs_devices(fs_devices);
560 return ERR_PTR(-ENOMEM);
561 }
562
563 void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
564 struct btrfs_fs_devices *fs_devices, int step)
565 {
566 struct btrfs_device *device, *next;
567
568 struct block_device *latest_bdev = NULL;
569 u64 latest_devid = 0;
570 u64 latest_transid = 0;
571
572 mutex_lock(&uuid_mutex);
573 again:
574 /* This is the initialized path, it is safe to release the devices. */
575 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
576 if (device->in_fs_metadata) {
577 if (!device->is_tgtdev_for_dev_replace &&
578 (!latest_transid ||
579 device->generation > latest_transid)) {
580 latest_devid = device->devid;
581 latest_transid = device->generation;
582 latest_bdev = device->bdev;
583 }
584 continue;
585 }
586
587 if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
588 /*
589 * In the first step, keep the device which has
590 * the correct fsid and the devid that is used
591 * for the dev_replace procedure.
592 * In the second step, the dev_replace state is
593 * read from the device tree and it is known
594 * whether the procedure is really active or
595 * not, which means whether this device is
596 * used or whether it should be removed.
597 */
598 if (step == 0 || device->is_tgtdev_for_dev_replace) {
599 continue;
600 }
601 }
602 if (device->bdev) {
603 blkdev_put(device->bdev, device->mode);
604 device->bdev = NULL;
605 fs_devices->open_devices--;
606 }
607 if (device->writeable) {
608 list_del_init(&device->dev_alloc_list);
609 device->writeable = 0;
610 if (!device->is_tgtdev_for_dev_replace)
611 fs_devices->rw_devices--;
612 }
613 list_del_init(&device->dev_list);
614 fs_devices->num_devices--;
615 rcu_string_free(device->name);
616 kfree(device);
617 }
618
619 if (fs_devices->seed) {
620 fs_devices = fs_devices->seed;
621 goto again;
622 }
623
624 fs_devices->latest_bdev = latest_bdev;
625 fs_devices->latest_devid = latest_devid;
626 fs_devices->latest_trans = latest_transid;
627
628 mutex_unlock(&uuid_mutex);
629 }
630
631 static void __free_device(struct work_struct *work)
632 {
633 struct btrfs_device *device;
634
635 device = container_of(work, struct btrfs_device, rcu_work);
636
637 if (device->bdev)
638 blkdev_put(device->bdev, device->mode);
639
640 rcu_string_free(device->name);
641 kfree(device);
642 }
643
644 static void free_device(struct rcu_head *head)
645 {
646 struct btrfs_device *device;
647
648 device = container_of(head, struct btrfs_device, rcu);
649
650 INIT_WORK(&device->rcu_work, __free_device);
651 schedule_work(&device->rcu_work);
652 }
653
654 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
655 {
656 struct btrfs_device *device;
657
658 if (--fs_devices->opened > 0)
659 return 0;
660
661 mutex_lock(&fs_devices->device_list_mutex);
662 list_for_each_entry(device, &fs_devices->devices, dev_list) {
663 struct btrfs_device *new_device;
664 struct rcu_string *name;
665
666 if (device->bdev)
667 fs_devices->open_devices--;
668
669 if (device->writeable &&
670 device->devid != BTRFS_DEV_REPLACE_DEVID) {
671 list_del_init(&device->dev_alloc_list);
672 fs_devices->rw_devices--;
673 }
674
675 if (device->can_discard)
676 fs_devices->num_can_discard--;
677 if (device->missing)
678 fs_devices->missing_devices--;
679
680 new_device = btrfs_alloc_device(NULL, &device->devid,
681 device->uuid);
682 BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
683
684 /* Safe because we are under uuid_mutex */
685 if (device->name) {
686 name = rcu_string_strdup(device->name->str, GFP_NOFS);
687 BUG_ON(!name); /* -ENOMEM */
688 rcu_assign_pointer(new_device->name, name);
689 }
690
691 list_replace_rcu(&device->dev_list, &new_device->dev_list);
692 new_device->fs_devices = device->fs_devices;
693
694 call_rcu(&device->rcu, free_device);
695 }
696 mutex_unlock(&fs_devices->device_list_mutex);
697
698 WARN_ON(fs_devices->open_devices);
699 WARN_ON(fs_devices->rw_devices);
700 fs_devices->opened = 0;
701 fs_devices->seeding = 0;
702
703 return 0;
704 }
705
706 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
707 {
708 struct btrfs_fs_devices *seed_devices = NULL;
709 int ret;
710
711 mutex_lock(&uuid_mutex);
712 ret = __btrfs_close_devices(fs_devices);
713 if (!fs_devices->opened) {
714 seed_devices = fs_devices->seed;
715 fs_devices->seed = NULL;
716 }
717 mutex_unlock(&uuid_mutex);
718
719 while (seed_devices) {
720 fs_devices = seed_devices;
721 seed_devices = fs_devices->seed;
722 __btrfs_close_devices(fs_devices);
723 free_fs_devices(fs_devices);
724 }
725 /*
726 * Wait for rcu kworkers under __btrfs_close_devices
727 * to finish all blkdev_puts so device is really
728 * free when umount is done.
729 */
730 rcu_barrier();
731 return ret;
732 }
733
734 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
735 fmode_t flags, void *holder)
736 {
737 struct request_queue *q;
738 struct block_device *bdev;
739 struct list_head *head = &fs_devices->devices;
740 struct btrfs_device *device;
741 struct block_device *latest_bdev = NULL;
742 struct buffer_head *bh;
743 struct btrfs_super_block *disk_super;
744 u64 latest_devid = 0;
745 u64 latest_transid = 0;
746 u64 devid;
747 int seeding = 1;
748 int ret = 0;
749
750 flags |= FMODE_EXCL;
751
752 list_for_each_entry(device, head, dev_list) {
753 if (device->bdev)
754 continue;
755 if (!device->name)
756 continue;
757
758 /* Just open everything we can; ignore failures here */
759 if (btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
760 &bdev, &bh))
761 continue;
762
763 disk_super = (struct btrfs_super_block *)bh->b_data;
764 devid = btrfs_stack_device_id(&disk_super->dev_item);
765 if (devid != device->devid)
766 goto error_brelse;
767
768 if (memcmp(device->uuid, disk_super->dev_item.uuid,
769 BTRFS_UUID_SIZE))
770 goto error_brelse;
771
772 device->generation = btrfs_super_generation(disk_super);
773 if (!latest_transid || device->generation > latest_transid) {
774 latest_devid = devid;
775 latest_transid = device->generation;
776 latest_bdev = bdev;
777 }
778
779 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
780 device->writeable = 0;
781 } else {
782 device->writeable = !bdev_read_only(bdev);
783 seeding = 0;
784 }
785
786 q = bdev_get_queue(bdev);
787 if (blk_queue_discard(q)) {
788 device->can_discard = 1;
789 fs_devices->num_can_discard++;
790 }
791
792 device->bdev = bdev;
793 device->in_fs_metadata = 0;
794 device->mode = flags;
795
796 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
797 fs_devices->rotating = 1;
798
799 fs_devices->open_devices++;
800 if (device->writeable &&
801 device->devid != BTRFS_DEV_REPLACE_DEVID) {
802 fs_devices->rw_devices++;
803 list_add(&device->dev_alloc_list,
804 &fs_devices->alloc_list);
805 }
806 brelse(bh);
807 continue;
808
809 error_brelse:
810 brelse(bh);
811 blkdev_put(bdev, flags);
812 continue;
813 }
814 if (fs_devices->open_devices == 0) {
815 ret = -EINVAL;
816 goto out;
817 }
818 fs_devices->seeding = seeding;
819 fs_devices->opened = 1;
820 fs_devices->latest_bdev = latest_bdev;
821 fs_devices->latest_devid = latest_devid;
822 fs_devices->latest_trans = latest_transid;
823 fs_devices->total_rw_bytes = 0;
824 out:
825 return ret;
826 }
827
828 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
829 fmode_t flags, void *holder)
830 {
831 int ret;
832
833 mutex_lock(&uuid_mutex);
834 if (fs_devices->opened) {
835 fs_devices->opened++;
836 ret = 0;
837 } else {
838 ret = __btrfs_open_devices(fs_devices, flags, holder);
839 }
840 mutex_unlock(&uuid_mutex);
841 return ret;
842 }
843
844 /*
845 * Look for a btrfs signature on a device. This may be called out of the mount path
846 * and we are not allowed to call set_blocksize during the scan. The superblock
847 * is read via pagecache
848 */
849 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
850 struct btrfs_fs_devices **fs_devices_ret)
851 {
852 struct btrfs_super_block *disk_super;
853 struct block_device *bdev;
854 struct page *page;
855 void *p;
856 int ret = -EINVAL;
857 u64 devid;
858 u64 transid;
859 u64 total_devices;
860 u64 bytenr;
861 pgoff_t index;
862
863 /*
864 * we would like to check all the supers, but that would make
865 * a btrfs mount succeed after a mkfs from a different FS.
866 * So, we need to add a special mount option to scan for
867 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
868 */
869 bytenr = btrfs_sb_offset(0);
870 flags |= FMODE_EXCL;
871 mutex_lock(&uuid_mutex);
872
873 bdev = blkdev_get_by_path(path, flags, holder);
874
875 if (IS_ERR(bdev)) {
876 ret = PTR_ERR(bdev);
877 goto error;
878 }
879
880 /* make sure our super fits in the device */
881 if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
882 goto error_bdev_put;
883
884 /* make sure our super fits in the page */
885 if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
886 goto error_bdev_put;
887
888 /* make sure our super doesn't straddle pages on disk */
889 index = bytenr >> PAGE_CACHE_SHIFT;
890 if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
891 goto error_bdev_put;
892
893 /* pull in the page with our super */
894 page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
895 index, GFP_NOFS);
896
897 if (IS_ERR_OR_NULL(page))
898 goto error_bdev_put;
899
900 p = kmap(page);
901
902 /* align our pointer to the offset of the super block */
903 disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
904
905 if (btrfs_super_bytenr(disk_super) != bytenr ||
906 btrfs_super_magic(disk_super) != BTRFS_MAGIC)
907 goto error_unmap;
908
909 devid = btrfs_stack_device_id(&disk_super->dev_item);
910 transid = btrfs_super_generation(disk_super);
911 total_devices = btrfs_super_num_devices(disk_super);
912
913 if (disk_super->label[0]) {
914 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
915 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
916 printk(KERN_INFO "BTRFS: device label %s ", disk_super->label);
917 } else {
918 printk(KERN_INFO "BTRFS: device fsid %pU ", disk_super->fsid);
919 }
920
921 printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
922
923 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
924 if (!ret && fs_devices_ret)
925 (*fs_devices_ret)->total_devices = total_devices;
926
927 error_unmap:
928 kunmap(page);
929 page_cache_release(page);
930
931 error_bdev_put:
932 blkdev_put(bdev, flags);
933 error:
934 mutex_unlock(&uuid_mutex);
935 return ret;
936 }
937
938 /* helper to account the used device space in the range */
939 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
940 u64 end, u64 *length)
941 {
942 struct btrfs_key key;
943 struct btrfs_root *root = device->dev_root;
944 struct btrfs_dev_extent *dev_extent;
945 struct btrfs_path *path;
946 u64 extent_end;
947 int ret;
948 int slot;
949 struct extent_buffer *l;
950
951 *length = 0;
952
953 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
954 return 0;
955
956 path = btrfs_alloc_path();
957 if (!path)
958 return -ENOMEM;
959 path->reada = 2;
960
961 key.objectid = device->devid;
962 key.offset = start;
963 key.type = BTRFS_DEV_EXTENT_KEY;
964
965 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
966 if (ret < 0)
967 goto out;
968 if (ret > 0) {
969 ret = btrfs_previous_item(root, path, key.objectid, key.type);
970 if (ret < 0)
971 goto out;
972 }
973
974 while (1) {
975 l = path->nodes[0];
976 slot = path->slots[0];
977 if (slot >= btrfs_header_nritems(l)) {
978 ret = btrfs_next_leaf(root, path);
979 if (ret == 0)
980 continue;
981 if (ret < 0)
982 goto out;
983
984 break;
985 }
986 btrfs_item_key_to_cpu(l, &key, slot);
987
988 if (key.objectid < device->devid)
989 goto next;
990
991 if (key.objectid > device->devid)
992 break;
993
994 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
995 goto next;
996
997 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
998 extent_end = key.offset + btrfs_dev_extent_length(l,
999 dev_extent);
1000 if (key.offset <= start && extent_end > end) {
1001 *length = end - start + 1;
1002 break;
1003 } else if (key.offset <= start && extent_end > start)
1004 *length += extent_end - start;
1005 else if (key.offset > start && extent_end <= end)
1006 *length += extent_end - key.offset;
1007 else if (key.offset > start && key.offset <= end) {
1008 *length += end - key.offset + 1;
1009 break;
1010 } else if (key.offset > end)
1011 break;
1012
1013 next:
1014 path->slots[0]++;
1015 }
1016 ret = 0;
1017 out:
1018 btrfs_free_path(path);
1019 return ret;
1020 }
1021
1022 static int contains_pending_extent(struct btrfs_trans_handle *trans,
1023 struct btrfs_device *device,
1024 u64 *start, u64 len)
1025 {
1026 struct extent_map *em;
1027 int ret = 0;
1028
1029 list_for_each_entry(em, &trans->transaction->pending_chunks, list) {
1030 struct map_lookup *map;
1031 int i;
1032
1033 map = (struct map_lookup *)em->bdev;
1034 for (i = 0; i < map->num_stripes; i++) {
1035 if (map->stripes[i].dev != device)
1036 continue;
1037 if (map->stripes[i].physical >= *start + len ||
1038 map->stripes[i].physical + em->orig_block_len <=
1039 *start)
1040 continue;
1041 *start = map->stripes[i].physical +
1042 em->orig_block_len;
1043 ret = 1;
1044 }
1045 }
1046
1047 return ret;
1048 }
1049
1050
1051 /*
1052 * find_free_dev_extent - find free space in the specified device
1053 * @device: the device which we search the free space in
1054 * @num_bytes: the size of the free space that we need
1055 * @start: store the start of the free space.
1056 * @len: the size of the free space. that we find, or the size of the max
1057 * free space if we don't find suitable free space
1058 *
1059 * this uses a pretty simple search, the expectation is that it is
1060 * called very infrequently and that a given device has a small number
1061 * of extents
1062 *
1063 * @start is used to store the start of the free space if we find. But if we
1064 * don't find suitable free space, it will be used to store the start position
1065 * of the max free space.
1066 *
1067 * @len is used to store the size of the free space that we find.
1068 * But if we don't find suitable free space, it is used to store the size of
1069 * the max free space.
1070 */
1071 int find_free_dev_extent(struct btrfs_trans_handle *trans,
1072 struct btrfs_device *device, u64 num_bytes,
1073 u64 *start, u64 *len)
1074 {
1075 struct btrfs_key key;
1076 struct btrfs_root *root = device->dev_root;
1077 struct btrfs_dev_extent *dev_extent;
1078 struct btrfs_path *path;
1079 u64 hole_size;
1080 u64 max_hole_start;
1081 u64 max_hole_size;
1082 u64 extent_end;
1083 u64 search_start;
1084 u64 search_end = device->total_bytes;
1085 int ret;
1086 int slot;
1087 struct extent_buffer *l;
1088
1089 /* FIXME use last free of some kind */
1090
1091 /* we don't want to overwrite the superblock on the drive,
1092 * so we make sure to start at an offset of at least 1MB
1093 */
1094 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1095
1096 path = btrfs_alloc_path();
1097 if (!path)
1098 return -ENOMEM;
1099 again:
1100 max_hole_start = search_start;
1101 max_hole_size = 0;
1102 hole_size = 0;
1103
1104 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1105 ret = -ENOSPC;
1106 goto out;
1107 }
1108
1109 path->reada = 2;
1110 path->search_commit_root = 1;
1111 path->skip_locking = 1;
1112
1113 key.objectid = device->devid;
1114 key.offset = search_start;
1115 key.type = BTRFS_DEV_EXTENT_KEY;
1116
1117 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1118 if (ret < 0)
1119 goto out;
1120 if (ret > 0) {
1121 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1122 if (ret < 0)
1123 goto out;
1124 }
1125
1126 while (1) {
1127 l = path->nodes[0];
1128 slot = path->slots[0];
1129 if (slot >= btrfs_header_nritems(l)) {
1130 ret = btrfs_next_leaf(root, path);
1131 if (ret == 0)
1132 continue;
1133 if (ret < 0)
1134 goto out;
1135
1136 break;
1137 }
1138 btrfs_item_key_to_cpu(l, &key, slot);
1139
1140 if (key.objectid < device->devid)
1141 goto next;
1142
1143 if (key.objectid > device->devid)
1144 break;
1145
1146 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1147 goto next;
1148
1149 if (key.offset > search_start) {
1150 hole_size = key.offset - search_start;
1151
1152 /*
1153 * Have to check before we set max_hole_start, otherwise
1154 * we could end up sending back this offset anyway.
1155 */
1156 if (contains_pending_extent(trans, device,
1157 &search_start,
1158 hole_size))
1159 hole_size = 0;
1160
1161 if (hole_size > max_hole_size) {
1162 max_hole_start = search_start;
1163 max_hole_size = hole_size;
1164 }
1165
1166 /*
1167 * If this free space is greater than which we need,
1168 * it must be the max free space that we have found
1169 * until now, so max_hole_start must point to the start
1170 * of this free space and the length of this free space
1171 * is stored in max_hole_size. Thus, we return
1172 * max_hole_start and max_hole_size and go back to the
1173 * caller.
1174 */
1175 if (hole_size >= num_bytes) {
1176 ret = 0;
1177 goto out;
1178 }
1179 }
1180
1181 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1182 extent_end = key.offset + btrfs_dev_extent_length(l,
1183 dev_extent);
1184 if (extent_end > search_start)
1185 search_start = extent_end;
1186 next:
1187 path->slots[0]++;
1188 cond_resched();
1189 }
1190
1191 /*
1192 * At this point, search_start should be the end of
1193 * allocated dev extents, and when shrinking the device,
1194 * search_end may be smaller than search_start.
1195 */
1196 if (search_end > search_start)
1197 hole_size = search_end - search_start;
1198
1199 if (hole_size > max_hole_size) {
1200 max_hole_start = search_start;
1201 max_hole_size = hole_size;
1202 }
1203
1204 if (contains_pending_extent(trans, device, &search_start, hole_size)) {
1205 btrfs_release_path(path);
1206 goto again;
1207 }
1208
1209 /* See above. */
1210 if (hole_size < num_bytes)
1211 ret = -ENOSPC;
1212 else
1213 ret = 0;
1214
1215 out:
1216 btrfs_free_path(path);
1217 *start = max_hole_start;
1218 if (len)
1219 *len = max_hole_size;
1220 return ret;
1221 }
1222
1223 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1224 struct btrfs_device *device,
1225 u64 start)
1226 {
1227 int ret;
1228 struct btrfs_path *path;
1229 struct btrfs_root *root = device->dev_root;
1230 struct btrfs_key key;
1231 struct btrfs_key found_key;
1232 struct extent_buffer *leaf = NULL;
1233 struct btrfs_dev_extent *extent = NULL;
1234
1235 path = btrfs_alloc_path();
1236 if (!path)
1237 return -ENOMEM;
1238
1239 key.objectid = device->devid;
1240 key.offset = start;
1241 key.type = BTRFS_DEV_EXTENT_KEY;
1242 again:
1243 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1244 if (ret > 0) {
1245 ret = btrfs_previous_item(root, path, key.objectid,
1246 BTRFS_DEV_EXTENT_KEY);
1247 if (ret)
1248 goto out;
1249 leaf = path->nodes[0];
1250 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1251 extent = btrfs_item_ptr(leaf, path->slots[0],
1252 struct btrfs_dev_extent);
1253 BUG_ON(found_key.offset > start || found_key.offset +
1254 btrfs_dev_extent_length(leaf, extent) < start);
1255 key = found_key;
1256 btrfs_release_path(path);
1257 goto again;
1258 } else if (ret == 0) {
1259 leaf = path->nodes[0];
1260 extent = btrfs_item_ptr(leaf, path->slots[0],
1261 struct btrfs_dev_extent);
1262 } else {
1263 btrfs_error(root->fs_info, ret, "Slot search failed");
1264 goto out;
1265 }
1266
1267 if (device->bytes_used > 0) {
1268 u64 len = btrfs_dev_extent_length(leaf, extent);
1269 device->bytes_used -= len;
1270 spin_lock(&root->fs_info->free_chunk_lock);
1271 root->fs_info->free_chunk_space += len;
1272 spin_unlock(&root->fs_info->free_chunk_lock);
1273 }
1274 ret = btrfs_del_item(trans, root, path);
1275 if (ret) {
1276 btrfs_error(root->fs_info, ret,
1277 "Failed to remove dev extent item");
1278 }
1279 out:
1280 btrfs_free_path(path);
1281 return ret;
1282 }
1283
1284 static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1285 struct btrfs_device *device,
1286 u64 chunk_tree, u64 chunk_objectid,
1287 u64 chunk_offset, u64 start, u64 num_bytes)
1288 {
1289 int ret;
1290 struct btrfs_path *path;
1291 struct btrfs_root *root = device->dev_root;
1292 struct btrfs_dev_extent *extent;
1293 struct extent_buffer *leaf;
1294 struct btrfs_key key;
1295
1296 WARN_ON(!device->in_fs_metadata);
1297 WARN_ON(device->is_tgtdev_for_dev_replace);
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 ret = btrfs_insert_empty_item(trans, root, path, &key,
1306 sizeof(*extent));
1307 if (ret)
1308 goto out;
1309
1310 leaf = path->nodes[0];
1311 extent = btrfs_item_ptr(leaf, path->slots[0],
1312 struct btrfs_dev_extent);
1313 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1314 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1315 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1316
1317 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1318 btrfs_dev_extent_chunk_tree_uuid(extent), BTRFS_UUID_SIZE);
1319
1320 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1321 btrfs_mark_buffer_dirty(leaf);
1322 out:
1323 btrfs_free_path(path);
1324 return ret;
1325 }
1326
1327 static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
1328 {
1329 struct extent_map_tree *em_tree;
1330 struct extent_map *em;
1331 struct rb_node *n;
1332 u64 ret = 0;
1333
1334 em_tree = &fs_info->mapping_tree.map_tree;
1335 read_lock(&em_tree->lock);
1336 n = rb_last(&em_tree->map);
1337 if (n) {
1338 em = rb_entry(n, struct extent_map, rb_node);
1339 ret = em->start + em->len;
1340 }
1341 read_unlock(&em_tree->lock);
1342
1343 return ret;
1344 }
1345
1346 static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
1347 u64 *devid_ret)
1348 {
1349 int ret;
1350 struct btrfs_key key;
1351 struct btrfs_key found_key;
1352 struct btrfs_path *path;
1353
1354 path = btrfs_alloc_path();
1355 if (!path)
1356 return -ENOMEM;
1357
1358 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1359 key.type = BTRFS_DEV_ITEM_KEY;
1360 key.offset = (u64)-1;
1361
1362 ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
1363 if (ret < 0)
1364 goto error;
1365
1366 BUG_ON(ret == 0); /* Corruption */
1367
1368 ret = btrfs_previous_item(fs_info->chunk_root, path,
1369 BTRFS_DEV_ITEMS_OBJECTID,
1370 BTRFS_DEV_ITEM_KEY);
1371 if (ret) {
1372 *devid_ret = 1;
1373 } else {
1374 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1375 path->slots[0]);
1376 *devid_ret = found_key.offset + 1;
1377 }
1378 ret = 0;
1379 error:
1380 btrfs_free_path(path);
1381 return ret;
1382 }
1383
1384 /*
1385 * the device information is stored in the chunk root
1386 * the btrfs_device struct should be fully filled in
1387 */
1388 static int btrfs_add_device(struct btrfs_trans_handle *trans,
1389 struct btrfs_root *root,
1390 struct btrfs_device *device)
1391 {
1392 int ret;
1393 struct btrfs_path *path;
1394 struct btrfs_dev_item *dev_item;
1395 struct extent_buffer *leaf;
1396 struct btrfs_key key;
1397 unsigned long ptr;
1398
1399 root = root->fs_info->chunk_root;
1400
1401 path = btrfs_alloc_path();
1402 if (!path)
1403 return -ENOMEM;
1404
1405 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1406 key.type = BTRFS_DEV_ITEM_KEY;
1407 key.offset = device->devid;
1408
1409 ret = btrfs_insert_empty_item(trans, root, path, &key,
1410 sizeof(*dev_item));
1411 if (ret)
1412 goto out;
1413
1414 leaf = path->nodes[0];
1415 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1416
1417 btrfs_set_device_id(leaf, dev_item, device->devid);
1418 btrfs_set_device_generation(leaf, dev_item, 0);
1419 btrfs_set_device_type(leaf, dev_item, device->type);
1420 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1421 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1422 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1423 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1424 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1425 btrfs_set_device_group(leaf, dev_item, 0);
1426 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1427 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1428 btrfs_set_device_start_offset(leaf, dev_item, 0);
1429
1430 ptr = btrfs_device_uuid(dev_item);
1431 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1432 ptr = btrfs_device_fsid(dev_item);
1433 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1434 btrfs_mark_buffer_dirty(leaf);
1435
1436 ret = 0;
1437 out:
1438 btrfs_free_path(path);
1439 return ret;
1440 }
1441
1442 static int btrfs_rm_dev_item(struct btrfs_root *root,
1443 struct btrfs_device *device)
1444 {
1445 int ret;
1446 struct btrfs_path *path;
1447 struct btrfs_key key;
1448 struct btrfs_trans_handle *trans;
1449
1450 root = root->fs_info->chunk_root;
1451
1452 path = btrfs_alloc_path();
1453 if (!path)
1454 return -ENOMEM;
1455
1456 trans = btrfs_start_transaction(root, 0);
1457 if (IS_ERR(trans)) {
1458 btrfs_free_path(path);
1459 return PTR_ERR(trans);
1460 }
1461 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1462 key.type = BTRFS_DEV_ITEM_KEY;
1463 key.offset = device->devid;
1464 lock_chunks(root);
1465
1466 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1467 if (ret < 0)
1468 goto out;
1469
1470 if (ret > 0) {
1471 ret = -ENOENT;
1472 goto out;
1473 }
1474
1475 ret = btrfs_del_item(trans, root, path);
1476 if (ret)
1477 goto out;
1478 out:
1479 btrfs_free_path(path);
1480 unlock_chunks(root);
1481 btrfs_commit_transaction(trans, root);
1482 return ret;
1483 }
1484
1485 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1486 {
1487 struct btrfs_device *device;
1488 struct btrfs_device *next_device;
1489 struct block_device *bdev;
1490 struct buffer_head *bh = NULL;
1491 struct btrfs_super_block *disk_super;
1492 struct btrfs_fs_devices *cur_devices;
1493 u64 all_avail;
1494 u64 devid;
1495 u64 num_devices;
1496 u8 *dev_uuid;
1497 unsigned seq;
1498 int ret = 0;
1499 bool clear_super = false;
1500
1501 mutex_lock(&uuid_mutex);
1502
1503 do {
1504 seq = read_seqbegin(&root->fs_info->profiles_lock);
1505
1506 all_avail = root->fs_info->avail_data_alloc_bits |
1507 root->fs_info->avail_system_alloc_bits |
1508 root->fs_info->avail_metadata_alloc_bits;
1509 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
1510
1511 num_devices = root->fs_info->fs_devices->num_devices;
1512 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1513 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1514 WARN_ON(num_devices < 1);
1515 num_devices--;
1516 }
1517 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1518
1519 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1520 ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
1521 goto out;
1522 }
1523
1524 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1525 ret = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
1526 goto out;
1527 }
1528
1529 if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1530 root->fs_info->fs_devices->rw_devices <= 2) {
1531 ret = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
1532 goto out;
1533 }
1534 if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1535 root->fs_info->fs_devices->rw_devices <= 3) {
1536 ret = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
1537 goto out;
1538 }
1539
1540 if (strcmp(device_path, "missing") == 0) {
1541 struct list_head *devices;
1542 struct btrfs_device *tmp;
1543
1544 device = NULL;
1545 devices = &root->fs_info->fs_devices->devices;
1546 /*
1547 * It is safe to read the devices since the volume_mutex
1548 * is held.
1549 */
1550 list_for_each_entry(tmp, devices, dev_list) {
1551 if (tmp->in_fs_metadata &&
1552 !tmp->is_tgtdev_for_dev_replace &&
1553 !tmp->bdev) {
1554 device = tmp;
1555 break;
1556 }
1557 }
1558 bdev = NULL;
1559 bh = NULL;
1560 disk_super = NULL;
1561 if (!device) {
1562 ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
1563 goto out;
1564 }
1565 } else {
1566 ret = btrfs_get_bdev_and_sb(device_path,
1567 FMODE_WRITE | FMODE_EXCL,
1568 root->fs_info->bdev_holder, 0,
1569 &bdev, &bh);
1570 if (ret)
1571 goto out;
1572 disk_super = (struct btrfs_super_block *)bh->b_data;
1573 devid = btrfs_stack_device_id(&disk_super->dev_item);
1574 dev_uuid = disk_super->dev_item.uuid;
1575 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1576 disk_super->fsid);
1577 if (!device) {
1578 ret = -ENOENT;
1579 goto error_brelse;
1580 }
1581 }
1582
1583 if (device->is_tgtdev_for_dev_replace) {
1584 ret = BTRFS_ERROR_DEV_TGT_REPLACE;
1585 goto error_brelse;
1586 }
1587
1588 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1589 ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
1590 goto error_brelse;
1591 }
1592
1593 if (device->writeable) {
1594 lock_chunks(root);
1595 list_del_init(&device->dev_alloc_list);
1596 unlock_chunks(root);
1597 root->fs_info->fs_devices->rw_devices--;
1598 clear_super = true;
1599 }
1600
1601 mutex_unlock(&uuid_mutex);
1602 ret = btrfs_shrink_device(device, 0);
1603 mutex_lock(&uuid_mutex);
1604 if (ret)
1605 goto error_undo;
1606
1607 /*
1608 * TODO: the superblock still includes this device in its num_devices
1609 * counter although write_all_supers() is not locked out. This
1610 * could give a filesystem state which requires a degraded mount.
1611 */
1612 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1613 if (ret)
1614 goto error_undo;
1615
1616 spin_lock(&root->fs_info->free_chunk_lock);
1617 root->fs_info->free_chunk_space = device->total_bytes -
1618 device->bytes_used;
1619 spin_unlock(&root->fs_info->free_chunk_lock);
1620
1621 device->in_fs_metadata = 0;
1622 btrfs_scrub_cancel_dev(root->fs_info, device);
1623
1624 /*
1625 * the device list mutex makes sure that we don't change
1626 * the device list while someone else is writing out all
1627 * the device supers. Whoever is writing all supers, should
1628 * lock the device list mutex before getting the number of
1629 * devices in the super block (super_copy). Conversely,
1630 * whoever updates the number of devices in the super block
1631 * (super_copy) should hold the device list mutex.
1632 */
1633
1634 cur_devices = device->fs_devices;
1635 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1636 list_del_rcu(&device->dev_list);
1637
1638 device->fs_devices->num_devices--;
1639 device->fs_devices->total_devices--;
1640
1641 if (device->missing)
1642 root->fs_info->fs_devices->missing_devices--;
1643
1644 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1645 struct btrfs_device, dev_list);
1646 if (device->bdev == root->fs_info->sb->s_bdev)
1647 root->fs_info->sb->s_bdev = next_device->bdev;
1648 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1649 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1650
1651 if (device->bdev)
1652 device->fs_devices->open_devices--;
1653
1654 call_rcu(&device->rcu, free_device);
1655
1656 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1657 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1658 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1659
1660 if (cur_devices->open_devices == 0) {
1661 struct btrfs_fs_devices *fs_devices;
1662 fs_devices = root->fs_info->fs_devices;
1663 while (fs_devices) {
1664 if (fs_devices->seed == cur_devices)
1665 break;
1666 fs_devices = fs_devices->seed;
1667 }
1668 fs_devices->seed = cur_devices->seed;
1669 cur_devices->seed = NULL;
1670 lock_chunks(root);
1671 __btrfs_close_devices(cur_devices);
1672 unlock_chunks(root);
1673 free_fs_devices(cur_devices);
1674 }
1675
1676 root->fs_info->num_tolerated_disk_barrier_failures =
1677 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1678
1679 /*
1680 * at this point, the device is zero sized. We want to
1681 * remove it from the devices list and zero out the old super
1682 */
1683 if (clear_super && disk_super) {
1684 /* make sure this device isn't detected as part of
1685 * the FS anymore
1686 */
1687 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1688 set_buffer_dirty(bh);
1689 sync_dirty_buffer(bh);
1690 }
1691
1692 ret = 0;
1693
1694 /* Notify udev that device has changed */
1695 if (bdev)
1696 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1697
1698 error_brelse:
1699 brelse(bh);
1700 if (bdev)
1701 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1702 out:
1703 mutex_unlock(&uuid_mutex);
1704 return ret;
1705 error_undo:
1706 if (device->writeable) {
1707 lock_chunks(root);
1708 list_add(&device->dev_alloc_list,
1709 &root->fs_info->fs_devices->alloc_list);
1710 unlock_chunks(root);
1711 root->fs_info->fs_devices->rw_devices++;
1712 }
1713 goto error_brelse;
1714 }
1715
1716 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1717 struct btrfs_device *srcdev)
1718 {
1719 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1720
1721 list_del_rcu(&srcdev->dev_list);
1722 list_del_rcu(&srcdev->dev_alloc_list);
1723 fs_info->fs_devices->num_devices--;
1724 if (srcdev->missing) {
1725 fs_info->fs_devices->missing_devices--;
1726 fs_info->fs_devices->rw_devices++;
1727 }
1728 if (srcdev->can_discard)
1729 fs_info->fs_devices->num_can_discard--;
1730 if (srcdev->bdev) {
1731 fs_info->fs_devices->open_devices--;
1732
1733 /* zero out the old super */
1734 btrfs_scratch_superblock(srcdev);
1735 }
1736
1737 call_rcu(&srcdev->rcu, free_device);
1738 }
1739
1740 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1741 struct btrfs_device *tgtdev)
1742 {
1743 struct btrfs_device *next_device;
1744
1745 WARN_ON(!tgtdev);
1746 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1747 if (tgtdev->bdev) {
1748 btrfs_scratch_superblock(tgtdev);
1749 fs_info->fs_devices->open_devices--;
1750 }
1751 fs_info->fs_devices->num_devices--;
1752 if (tgtdev->can_discard)
1753 fs_info->fs_devices->num_can_discard++;
1754
1755 next_device = list_entry(fs_info->fs_devices->devices.next,
1756 struct btrfs_device, dev_list);
1757 if (tgtdev->bdev == fs_info->sb->s_bdev)
1758 fs_info->sb->s_bdev = next_device->bdev;
1759 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1760 fs_info->fs_devices->latest_bdev = next_device->bdev;
1761 list_del_rcu(&tgtdev->dev_list);
1762
1763 call_rcu(&tgtdev->rcu, free_device);
1764
1765 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1766 }
1767
1768 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1769 struct btrfs_device **device)
1770 {
1771 int ret = 0;
1772 struct btrfs_super_block *disk_super;
1773 u64 devid;
1774 u8 *dev_uuid;
1775 struct block_device *bdev;
1776 struct buffer_head *bh;
1777
1778 *device = NULL;
1779 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1780 root->fs_info->bdev_holder, 0, &bdev, &bh);
1781 if (ret)
1782 return ret;
1783 disk_super = (struct btrfs_super_block *)bh->b_data;
1784 devid = btrfs_stack_device_id(&disk_super->dev_item);
1785 dev_uuid = disk_super->dev_item.uuid;
1786 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1787 disk_super->fsid);
1788 brelse(bh);
1789 if (!*device)
1790 ret = -ENOENT;
1791 blkdev_put(bdev, FMODE_READ);
1792 return ret;
1793 }
1794
1795 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1796 char *device_path,
1797 struct btrfs_device **device)
1798 {
1799 *device = NULL;
1800 if (strcmp(device_path, "missing") == 0) {
1801 struct list_head *devices;
1802 struct btrfs_device *tmp;
1803
1804 devices = &root->fs_info->fs_devices->devices;
1805 /*
1806 * It is safe to read the devices since the volume_mutex
1807 * is held by the caller.
1808 */
1809 list_for_each_entry(tmp, devices, dev_list) {
1810 if (tmp->in_fs_metadata && !tmp->bdev) {
1811 *device = tmp;
1812 break;
1813 }
1814 }
1815
1816 if (!*device) {
1817 btrfs_err(root->fs_info, "no missing device found");
1818 return -ENOENT;
1819 }
1820
1821 return 0;
1822 } else {
1823 return btrfs_find_device_by_path(root, device_path, device);
1824 }
1825 }
1826
1827 /*
1828 * does all the dirty work required for changing file system's UUID.
1829 */
1830 static int btrfs_prepare_sprout(struct btrfs_root *root)
1831 {
1832 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1833 struct btrfs_fs_devices *old_devices;
1834 struct btrfs_fs_devices *seed_devices;
1835 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1836 struct btrfs_device *device;
1837 u64 super_flags;
1838
1839 BUG_ON(!mutex_is_locked(&uuid_mutex));
1840 if (!fs_devices->seeding)
1841 return -EINVAL;
1842
1843 seed_devices = __alloc_fs_devices();
1844 if (IS_ERR(seed_devices))
1845 return PTR_ERR(seed_devices);
1846
1847 old_devices = clone_fs_devices(fs_devices);
1848 if (IS_ERR(old_devices)) {
1849 kfree(seed_devices);
1850 return PTR_ERR(old_devices);
1851 }
1852
1853 list_add(&old_devices->list, &fs_uuids);
1854
1855 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1856 seed_devices->opened = 1;
1857 INIT_LIST_HEAD(&seed_devices->devices);
1858 INIT_LIST_HEAD(&seed_devices->alloc_list);
1859 mutex_init(&seed_devices->device_list_mutex);
1860
1861 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1862 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1863 synchronize_rcu);
1864
1865 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1866 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1867 device->fs_devices = seed_devices;
1868 }
1869
1870 fs_devices->seeding = 0;
1871 fs_devices->num_devices = 0;
1872 fs_devices->open_devices = 0;
1873 fs_devices->total_devices = 0;
1874 fs_devices->seed = seed_devices;
1875
1876 generate_random_uuid(fs_devices->fsid);
1877 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1878 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1879 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1880
1881 super_flags = btrfs_super_flags(disk_super) &
1882 ~BTRFS_SUPER_FLAG_SEEDING;
1883 btrfs_set_super_flags(disk_super, super_flags);
1884
1885 return 0;
1886 }
1887
1888 /*
1889 * strore the expected generation for seed devices in device items.
1890 */
1891 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1892 struct btrfs_root *root)
1893 {
1894 struct btrfs_path *path;
1895 struct extent_buffer *leaf;
1896 struct btrfs_dev_item *dev_item;
1897 struct btrfs_device *device;
1898 struct btrfs_key key;
1899 u8 fs_uuid[BTRFS_UUID_SIZE];
1900 u8 dev_uuid[BTRFS_UUID_SIZE];
1901 u64 devid;
1902 int ret;
1903
1904 path = btrfs_alloc_path();
1905 if (!path)
1906 return -ENOMEM;
1907
1908 root = root->fs_info->chunk_root;
1909 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1910 key.offset = 0;
1911 key.type = BTRFS_DEV_ITEM_KEY;
1912
1913 while (1) {
1914 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1915 if (ret < 0)
1916 goto error;
1917
1918 leaf = path->nodes[0];
1919 next_slot:
1920 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1921 ret = btrfs_next_leaf(root, path);
1922 if (ret > 0)
1923 break;
1924 if (ret < 0)
1925 goto error;
1926 leaf = path->nodes[0];
1927 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1928 btrfs_release_path(path);
1929 continue;
1930 }
1931
1932 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1933 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1934 key.type != BTRFS_DEV_ITEM_KEY)
1935 break;
1936
1937 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1938 struct btrfs_dev_item);
1939 devid = btrfs_device_id(leaf, dev_item);
1940 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
1941 BTRFS_UUID_SIZE);
1942 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
1943 BTRFS_UUID_SIZE);
1944 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1945 fs_uuid);
1946 BUG_ON(!device); /* Logic error */
1947
1948 if (device->fs_devices->seeding) {
1949 btrfs_set_device_generation(leaf, dev_item,
1950 device->generation);
1951 btrfs_mark_buffer_dirty(leaf);
1952 }
1953
1954 path->slots[0]++;
1955 goto next_slot;
1956 }
1957 ret = 0;
1958 error:
1959 btrfs_free_path(path);
1960 return ret;
1961 }
1962
1963 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1964 {
1965 struct request_queue *q;
1966 struct btrfs_trans_handle *trans;
1967 struct btrfs_device *device;
1968 struct block_device *bdev;
1969 struct list_head *devices;
1970 struct super_block *sb = root->fs_info->sb;
1971 struct rcu_string *name;
1972 u64 total_bytes;
1973 int seeding_dev = 0;
1974 int ret = 0;
1975
1976 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1977 return -EROFS;
1978
1979 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1980 root->fs_info->bdev_holder);
1981 if (IS_ERR(bdev))
1982 return PTR_ERR(bdev);
1983
1984 if (root->fs_info->fs_devices->seeding) {
1985 seeding_dev = 1;
1986 down_write(&sb->s_umount);
1987 mutex_lock(&uuid_mutex);
1988 }
1989
1990 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1991
1992 devices = &root->fs_info->fs_devices->devices;
1993
1994 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1995 list_for_each_entry(device, devices, dev_list) {
1996 if (device->bdev == bdev) {
1997 ret = -EEXIST;
1998 mutex_unlock(
1999 &root->fs_info->fs_devices->device_list_mutex);
2000 goto error;
2001 }
2002 }
2003 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2004
2005 device = btrfs_alloc_device(root->fs_info, NULL, NULL);
2006 if (IS_ERR(device)) {
2007 /* we can safely leave the fs_devices entry around */
2008 ret = PTR_ERR(device);
2009 goto error;
2010 }
2011
2012 name = rcu_string_strdup(device_path, GFP_NOFS);
2013 if (!name) {
2014 kfree(device);
2015 ret = -ENOMEM;
2016 goto error;
2017 }
2018 rcu_assign_pointer(device->name, name);
2019
2020 trans = btrfs_start_transaction(root, 0);
2021 if (IS_ERR(trans)) {
2022 rcu_string_free(device->name);
2023 kfree(device);
2024 ret = PTR_ERR(trans);
2025 goto error;
2026 }
2027
2028 lock_chunks(root);
2029
2030 q = bdev_get_queue(bdev);
2031 if (blk_queue_discard(q))
2032 device->can_discard = 1;
2033 device->writeable = 1;
2034 device->generation = trans->transid;
2035 device->io_width = root->sectorsize;
2036 device->io_align = root->sectorsize;
2037 device->sector_size = root->sectorsize;
2038 device->total_bytes = i_size_read(bdev->bd_inode);
2039 device->disk_total_bytes = device->total_bytes;
2040 device->dev_root = root->fs_info->dev_root;
2041 device->bdev = bdev;
2042 device->in_fs_metadata = 1;
2043 device->is_tgtdev_for_dev_replace = 0;
2044 device->mode = FMODE_EXCL;
2045 device->dev_stats_valid = 1;
2046 set_blocksize(device->bdev, 4096);
2047
2048 if (seeding_dev) {
2049 sb->s_flags &= ~MS_RDONLY;
2050 ret = btrfs_prepare_sprout(root);
2051 BUG_ON(ret); /* -ENOMEM */
2052 }
2053
2054 device->fs_devices = root->fs_info->fs_devices;
2055
2056 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2057 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2058 list_add(&device->dev_alloc_list,
2059 &root->fs_info->fs_devices->alloc_list);
2060 root->fs_info->fs_devices->num_devices++;
2061 root->fs_info->fs_devices->open_devices++;
2062 root->fs_info->fs_devices->rw_devices++;
2063 root->fs_info->fs_devices->total_devices++;
2064 if (device->can_discard)
2065 root->fs_info->fs_devices->num_can_discard++;
2066 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2067
2068 spin_lock(&root->fs_info->free_chunk_lock);
2069 root->fs_info->free_chunk_space += device->total_bytes;
2070 spin_unlock(&root->fs_info->free_chunk_lock);
2071
2072 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2073 root->fs_info->fs_devices->rotating = 1;
2074
2075 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2076 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2077 total_bytes + device->total_bytes);
2078
2079 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2080 btrfs_set_super_num_devices(root->fs_info->super_copy,
2081 total_bytes + 1);
2082 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2083
2084 if (seeding_dev) {
2085 ret = init_first_rw_device(trans, root, device);
2086 if (ret) {
2087 btrfs_abort_transaction(trans, root, ret);
2088 goto error_trans;
2089 }
2090 ret = btrfs_finish_sprout(trans, root);
2091 if (ret) {
2092 btrfs_abort_transaction(trans, root, ret);
2093 goto error_trans;
2094 }
2095 } else {
2096 ret = btrfs_add_device(trans, root, device);
2097 if (ret) {
2098 btrfs_abort_transaction(trans, root, ret);
2099 goto error_trans;
2100 }
2101 }
2102
2103 /*
2104 * we've got more storage, clear any full flags on the space
2105 * infos
2106 */
2107 btrfs_clear_space_info_full(root->fs_info);
2108
2109 unlock_chunks(root);
2110 root->fs_info->num_tolerated_disk_barrier_failures =
2111 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2112 ret = btrfs_commit_transaction(trans, root);
2113
2114 if (seeding_dev) {
2115 mutex_unlock(&uuid_mutex);
2116 up_write(&sb->s_umount);
2117
2118 if (ret) /* transaction commit */
2119 return ret;
2120
2121 ret = btrfs_relocate_sys_chunks(root);
2122 if (ret < 0)
2123 btrfs_error(root->fs_info, ret,
2124 "Failed to relocate sys chunks after "
2125 "device initialization. This can be fixed "
2126 "using the \"btrfs balance\" command.");
2127 trans = btrfs_attach_transaction(root);
2128 if (IS_ERR(trans)) {
2129 if (PTR_ERR(trans) == -ENOENT)
2130 return 0;
2131 return PTR_ERR(trans);
2132 }
2133 ret = btrfs_commit_transaction(trans, root);
2134 }
2135
2136 return ret;
2137
2138 error_trans:
2139 unlock_chunks(root);
2140 btrfs_end_transaction(trans, root);
2141 rcu_string_free(device->name);
2142 kfree(device);
2143 error:
2144 blkdev_put(bdev, FMODE_EXCL);
2145 if (seeding_dev) {
2146 mutex_unlock(&uuid_mutex);
2147 up_write(&sb->s_umount);
2148 }
2149 return ret;
2150 }
2151
2152 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2153 struct btrfs_device **device_out)
2154 {
2155 struct request_queue *q;
2156 struct btrfs_device *device;
2157 struct block_device *bdev;
2158 struct btrfs_fs_info *fs_info = root->fs_info;
2159 struct list_head *devices;
2160 struct rcu_string *name;
2161 u64 devid = BTRFS_DEV_REPLACE_DEVID;
2162 int ret = 0;
2163
2164 *device_out = NULL;
2165 if (fs_info->fs_devices->seeding)
2166 return -EINVAL;
2167
2168 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2169 fs_info->bdev_holder);
2170 if (IS_ERR(bdev))
2171 return PTR_ERR(bdev);
2172
2173 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2174
2175 devices = &fs_info->fs_devices->devices;
2176 list_for_each_entry(device, devices, dev_list) {
2177 if (device->bdev == bdev) {
2178 ret = -EEXIST;
2179 goto error;
2180 }
2181 }
2182
2183 device = btrfs_alloc_device(NULL, &devid, NULL);
2184 if (IS_ERR(device)) {
2185 ret = PTR_ERR(device);
2186 goto error;
2187 }
2188
2189 name = rcu_string_strdup(device_path, GFP_NOFS);
2190 if (!name) {
2191 kfree(device);
2192 ret = -ENOMEM;
2193 goto error;
2194 }
2195 rcu_assign_pointer(device->name, name);
2196
2197 q = bdev_get_queue(bdev);
2198 if (blk_queue_discard(q))
2199 device->can_discard = 1;
2200 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2201 device->writeable = 1;
2202 device->generation = 0;
2203 device->io_width = root->sectorsize;
2204 device->io_align = root->sectorsize;
2205 device->sector_size = root->sectorsize;
2206 device->total_bytes = i_size_read(bdev->bd_inode);
2207 device->disk_total_bytes = device->total_bytes;
2208 device->dev_root = fs_info->dev_root;
2209 device->bdev = bdev;
2210 device->in_fs_metadata = 1;
2211 device->is_tgtdev_for_dev_replace = 1;
2212 device->mode = FMODE_EXCL;
2213 device->dev_stats_valid = 1;
2214 set_blocksize(device->bdev, 4096);
2215 device->fs_devices = fs_info->fs_devices;
2216 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2217 fs_info->fs_devices->num_devices++;
2218 fs_info->fs_devices->open_devices++;
2219 if (device->can_discard)
2220 fs_info->fs_devices->num_can_discard++;
2221 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2222
2223 *device_out = device;
2224 return ret;
2225
2226 error:
2227 blkdev_put(bdev, FMODE_EXCL);
2228 return ret;
2229 }
2230
2231 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2232 struct btrfs_device *tgtdev)
2233 {
2234 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2235 tgtdev->io_width = fs_info->dev_root->sectorsize;
2236 tgtdev->io_align = fs_info->dev_root->sectorsize;
2237 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2238 tgtdev->dev_root = fs_info->dev_root;
2239 tgtdev->in_fs_metadata = 1;
2240 }
2241
2242 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2243 struct btrfs_device *device)
2244 {
2245 int ret;
2246 struct btrfs_path *path;
2247 struct btrfs_root *root;
2248 struct btrfs_dev_item *dev_item;
2249 struct extent_buffer *leaf;
2250 struct btrfs_key key;
2251
2252 root = device->dev_root->fs_info->chunk_root;
2253
2254 path = btrfs_alloc_path();
2255 if (!path)
2256 return -ENOMEM;
2257
2258 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2259 key.type = BTRFS_DEV_ITEM_KEY;
2260 key.offset = device->devid;
2261
2262 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2263 if (ret < 0)
2264 goto out;
2265
2266 if (ret > 0) {
2267 ret = -ENOENT;
2268 goto out;
2269 }
2270
2271 leaf = path->nodes[0];
2272 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2273
2274 btrfs_set_device_id(leaf, dev_item, device->devid);
2275 btrfs_set_device_type(leaf, dev_item, device->type);
2276 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2277 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2278 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2279 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2280 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2281 btrfs_mark_buffer_dirty(leaf);
2282
2283 out:
2284 btrfs_free_path(path);
2285 return ret;
2286 }
2287
2288 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2289 struct btrfs_device *device, u64 new_size)
2290 {
2291 struct btrfs_super_block *super_copy =
2292 device->dev_root->fs_info->super_copy;
2293 u64 old_total = btrfs_super_total_bytes(super_copy);
2294 u64 diff = new_size - device->total_bytes;
2295
2296 if (!device->writeable)
2297 return -EACCES;
2298 if (new_size <= device->total_bytes ||
2299 device->is_tgtdev_for_dev_replace)
2300 return -EINVAL;
2301
2302 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2303 device->fs_devices->total_rw_bytes += diff;
2304
2305 device->total_bytes = new_size;
2306 device->disk_total_bytes = new_size;
2307 btrfs_clear_space_info_full(device->dev_root->fs_info);
2308
2309 return btrfs_update_device(trans, device);
2310 }
2311
2312 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2313 struct btrfs_device *device, u64 new_size)
2314 {
2315 int ret;
2316 lock_chunks(device->dev_root);
2317 ret = __btrfs_grow_device(trans, device, new_size);
2318 unlock_chunks(device->dev_root);
2319 return ret;
2320 }
2321
2322 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2323 struct btrfs_root *root,
2324 u64 chunk_tree, u64 chunk_objectid,
2325 u64 chunk_offset)
2326 {
2327 int ret;
2328 struct btrfs_path *path;
2329 struct btrfs_key key;
2330
2331 root = root->fs_info->chunk_root;
2332 path = btrfs_alloc_path();
2333 if (!path)
2334 return -ENOMEM;
2335
2336 key.objectid = chunk_objectid;
2337 key.offset = chunk_offset;
2338 key.type = BTRFS_CHUNK_ITEM_KEY;
2339
2340 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2341 if (ret < 0)
2342 goto out;
2343 else if (ret > 0) { /* Logic error or corruption */
2344 btrfs_error(root->fs_info, -ENOENT,
2345 "Failed lookup while freeing chunk.");
2346 ret = -ENOENT;
2347 goto out;
2348 }
2349
2350 ret = btrfs_del_item(trans, root, path);
2351 if (ret < 0)
2352 btrfs_error(root->fs_info, ret,
2353 "Failed to delete chunk item.");
2354 out:
2355 btrfs_free_path(path);
2356 return ret;
2357 }
2358
2359 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2360 chunk_offset)
2361 {
2362 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2363 struct btrfs_disk_key *disk_key;
2364 struct btrfs_chunk *chunk;
2365 u8 *ptr;
2366 int ret = 0;
2367 u32 num_stripes;
2368 u32 array_size;
2369 u32 len = 0;
2370 u32 cur;
2371 struct btrfs_key key;
2372
2373 array_size = btrfs_super_sys_array_size(super_copy);
2374
2375 ptr = super_copy->sys_chunk_array;
2376 cur = 0;
2377
2378 while (cur < array_size) {
2379 disk_key = (struct btrfs_disk_key *)ptr;
2380 btrfs_disk_key_to_cpu(&key, disk_key);
2381
2382 len = sizeof(*disk_key);
2383
2384 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2385 chunk = (struct btrfs_chunk *)(ptr + len);
2386 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2387 len += btrfs_chunk_item_size(num_stripes);
2388 } else {
2389 ret = -EIO;
2390 break;
2391 }
2392 if (key.objectid == chunk_objectid &&
2393 key.offset == chunk_offset) {
2394 memmove(ptr, ptr + len, array_size - (cur + len));
2395 array_size -= len;
2396 btrfs_set_super_sys_array_size(super_copy, array_size);
2397 } else {
2398 ptr += len;
2399 cur += len;
2400 }
2401 }
2402 return ret;
2403 }
2404
2405 static int btrfs_relocate_chunk(struct btrfs_root *root,
2406 u64 chunk_tree, u64 chunk_objectid,
2407 u64 chunk_offset)
2408 {
2409 struct extent_map_tree *em_tree;
2410 struct btrfs_root *extent_root;
2411 struct btrfs_trans_handle *trans;
2412 struct extent_map *em;
2413 struct map_lookup *map;
2414 int ret;
2415 int i;
2416
2417 root = root->fs_info->chunk_root;
2418 extent_root = root->fs_info->extent_root;
2419 em_tree = &root->fs_info->mapping_tree.map_tree;
2420
2421 ret = btrfs_can_relocate(extent_root, chunk_offset);
2422 if (ret)
2423 return -ENOSPC;
2424
2425 /* step one, relocate all the extents inside this chunk */
2426 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2427 if (ret)
2428 return ret;
2429
2430 trans = btrfs_start_transaction(root, 0);
2431 if (IS_ERR(trans)) {
2432 ret = PTR_ERR(trans);
2433 btrfs_std_error(root->fs_info, ret);
2434 return ret;
2435 }
2436
2437 lock_chunks(root);
2438
2439 /*
2440 * step two, delete the device extents and the
2441 * chunk tree entries
2442 */
2443 read_lock(&em_tree->lock);
2444 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2445 read_unlock(&em_tree->lock);
2446
2447 BUG_ON(!em || em->start > chunk_offset ||
2448 em->start + em->len < chunk_offset);
2449 map = (struct map_lookup *)em->bdev;
2450
2451 for (i = 0; i < map->num_stripes; i++) {
2452 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2453 map->stripes[i].physical);
2454 BUG_ON(ret);
2455
2456 if (map->stripes[i].dev) {
2457 ret = btrfs_update_device(trans, map->stripes[i].dev);
2458 BUG_ON(ret);
2459 }
2460 }
2461 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2462 chunk_offset);
2463
2464 BUG_ON(ret);
2465
2466 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2467
2468 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2469 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2470 BUG_ON(ret);
2471 }
2472
2473 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2474 BUG_ON(ret);
2475
2476 write_lock(&em_tree->lock);
2477 remove_extent_mapping(em_tree, em);
2478 write_unlock(&em_tree->lock);
2479
2480 kfree(map);
2481 em->bdev = NULL;
2482
2483 /* once for the tree */
2484 free_extent_map(em);
2485 /* once for us */
2486 free_extent_map(em);
2487
2488 unlock_chunks(root);
2489 btrfs_end_transaction(trans, root);
2490 return 0;
2491 }
2492
2493 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2494 {
2495 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2496 struct btrfs_path *path;
2497 struct extent_buffer *leaf;
2498 struct btrfs_chunk *chunk;
2499 struct btrfs_key key;
2500 struct btrfs_key found_key;
2501 u64 chunk_tree = chunk_root->root_key.objectid;
2502 u64 chunk_type;
2503 bool retried = false;
2504 int failed = 0;
2505 int ret;
2506
2507 path = btrfs_alloc_path();
2508 if (!path)
2509 return -ENOMEM;
2510
2511 again:
2512 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2513 key.offset = (u64)-1;
2514 key.type = BTRFS_CHUNK_ITEM_KEY;
2515
2516 while (1) {
2517 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2518 if (ret < 0)
2519 goto error;
2520 BUG_ON(ret == 0); /* Corruption */
2521
2522 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2523 key.type);
2524 if (ret < 0)
2525 goto error;
2526 if (ret > 0)
2527 break;
2528
2529 leaf = path->nodes[0];
2530 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2531
2532 chunk = btrfs_item_ptr(leaf, path->slots[0],
2533 struct btrfs_chunk);
2534 chunk_type = btrfs_chunk_type(leaf, chunk);
2535 btrfs_release_path(path);
2536
2537 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2538 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2539 found_key.objectid,
2540 found_key.offset);
2541 if (ret == -ENOSPC)
2542 failed++;
2543 else if (ret)
2544 BUG();
2545 }
2546
2547 if (found_key.offset == 0)
2548 break;
2549 key.offset = found_key.offset - 1;
2550 }
2551 ret = 0;
2552 if (failed && !retried) {
2553 failed = 0;
2554 retried = true;
2555 goto again;
2556 } else if (WARN_ON(failed && retried)) {
2557 ret = -ENOSPC;
2558 }
2559 error:
2560 btrfs_free_path(path);
2561 return ret;
2562 }
2563
2564 static int insert_balance_item(struct btrfs_root *root,
2565 struct btrfs_balance_control *bctl)
2566 {
2567 struct btrfs_trans_handle *trans;
2568 struct btrfs_balance_item *item;
2569 struct btrfs_disk_balance_args disk_bargs;
2570 struct btrfs_path *path;
2571 struct extent_buffer *leaf;
2572 struct btrfs_key key;
2573 int ret, err;
2574
2575 path = btrfs_alloc_path();
2576 if (!path)
2577 return -ENOMEM;
2578
2579 trans = btrfs_start_transaction(root, 0);
2580 if (IS_ERR(trans)) {
2581 btrfs_free_path(path);
2582 return PTR_ERR(trans);
2583 }
2584
2585 key.objectid = BTRFS_BALANCE_OBJECTID;
2586 key.type = BTRFS_BALANCE_ITEM_KEY;
2587 key.offset = 0;
2588
2589 ret = btrfs_insert_empty_item(trans, root, path, &key,
2590 sizeof(*item));
2591 if (ret)
2592 goto out;
2593
2594 leaf = path->nodes[0];
2595 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2596
2597 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2598
2599 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2600 btrfs_set_balance_data(leaf, item, &disk_bargs);
2601 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2602 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2603 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2604 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2605
2606 btrfs_set_balance_flags(leaf, item, bctl->flags);
2607
2608 btrfs_mark_buffer_dirty(leaf);
2609 out:
2610 btrfs_free_path(path);
2611 err = btrfs_commit_transaction(trans, root);
2612 if (err && !ret)
2613 ret = err;
2614 return ret;
2615 }
2616
2617 static int del_balance_item(struct btrfs_root *root)
2618 {
2619 struct btrfs_trans_handle *trans;
2620 struct btrfs_path *path;
2621 struct btrfs_key key;
2622 int ret, err;
2623
2624 path = btrfs_alloc_path();
2625 if (!path)
2626 return -ENOMEM;
2627
2628 trans = btrfs_start_transaction(root, 0);
2629 if (IS_ERR(trans)) {
2630 btrfs_free_path(path);
2631 return PTR_ERR(trans);
2632 }
2633
2634 key.objectid = BTRFS_BALANCE_OBJECTID;
2635 key.type = BTRFS_BALANCE_ITEM_KEY;
2636 key.offset = 0;
2637
2638 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2639 if (ret < 0)
2640 goto out;
2641 if (ret > 0) {
2642 ret = -ENOENT;
2643 goto out;
2644 }
2645
2646 ret = btrfs_del_item(trans, root, path);
2647 out:
2648 btrfs_free_path(path);
2649 err = btrfs_commit_transaction(trans, root);
2650 if (err && !ret)
2651 ret = err;
2652 return ret;
2653 }
2654
2655 /*
2656 * This is a heuristic used to reduce the number of chunks balanced on
2657 * resume after balance was interrupted.
2658 */
2659 static void update_balance_args(struct btrfs_balance_control *bctl)
2660 {
2661 /*
2662 * Turn on soft mode for chunk types that were being converted.
2663 */
2664 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2665 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2666 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2667 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2668 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2669 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2670
2671 /*
2672 * Turn on usage filter if is not already used. The idea is
2673 * that chunks that we have already balanced should be
2674 * reasonably full. Don't do it for chunks that are being
2675 * converted - that will keep us from relocating unconverted
2676 * (albeit full) chunks.
2677 */
2678 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2679 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2680 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2681 bctl->data.usage = 90;
2682 }
2683 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2684 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2685 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2686 bctl->sys.usage = 90;
2687 }
2688 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2689 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2690 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2691 bctl->meta.usage = 90;
2692 }
2693 }
2694
2695 /*
2696 * Should be called with both balance and volume mutexes held to
2697 * serialize other volume operations (add_dev/rm_dev/resize) with
2698 * restriper. Same goes for unset_balance_control.
2699 */
2700 static void set_balance_control(struct btrfs_balance_control *bctl)
2701 {
2702 struct btrfs_fs_info *fs_info = bctl->fs_info;
2703
2704 BUG_ON(fs_info->balance_ctl);
2705
2706 spin_lock(&fs_info->balance_lock);
2707 fs_info->balance_ctl = bctl;
2708 spin_unlock(&fs_info->balance_lock);
2709 }
2710
2711 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2712 {
2713 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2714
2715 BUG_ON(!fs_info->balance_ctl);
2716
2717 spin_lock(&fs_info->balance_lock);
2718 fs_info->balance_ctl = NULL;
2719 spin_unlock(&fs_info->balance_lock);
2720
2721 kfree(bctl);
2722 }
2723
2724 /*
2725 * Balance filters. Return 1 if chunk should be filtered out
2726 * (should not be balanced).
2727 */
2728 static int chunk_profiles_filter(u64 chunk_type,
2729 struct btrfs_balance_args *bargs)
2730 {
2731 chunk_type = chunk_to_extended(chunk_type) &
2732 BTRFS_EXTENDED_PROFILE_MASK;
2733
2734 if (bargs->profiles & chunk_type)
2735 return 0;
2736
2737 return 1;
2738 }
2739
2740 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2741 struct btrfs_balance_args *bargs)
2742 {
2743 struct btrfs_block_group_cache *cache;
2744 u64 chunk_used, user_thresh;
2745 int ret = 1;
2746
2747 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2748 chunk_used = btrfs_block_group_used(&cache->item);
2749
2750 if (bargs->usage == 0)
2751 user_thresh = 1;
2752 else if (bargs->usage > 100)
2753 user_thresh = cache->key.offset;
2754 else
2755 user_thresh = div_factor_fine(cache->key.offset,
2756 bargs->usage);
2757
2758 if (chunk_used < user_thresh)
2759 ret = 0;
2760
2761 btrfs_put_block_group(cache);
2762 return ret;
2763 }
2764
2765 static int chunk_devid_filter(struct extent_buffer *leaf,
2766 struct btrfs_chunk *chunk,
2767 struct btrfs_balance_args *bargs)
2768 {
2769 struct btrfs_stripe *stripe;
2770 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2771 int i;
2772
2773 for (i = 0; i < num_stripes; i++) {
2774 stripe = btrfs_stripe_nr(chunk, i);
2775 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2776 return 0;
2777 }
2778
2779 return 1;
2780 }
2781
2782 /* [pstart, pend) */
2783 static int chunk_drange_filter(struct extent_buffer *leaf,
2784 struct btrfs_chunk *chunk,
2785 u64 chunk_offset,
2786 struct btrfs_balance_args *bargs)
2787 {
2788 struct btrfs_stripe *stripe;
2789 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2790 u64 stripe_offset;
2791 u64 stripe_length;
2792 int factor;
2793 int i;
2794
2795 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2796 return 0;
2797
2798 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2799 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2800 factor = num_stripes / 2;
2801 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2802 factor = num_stripes - 1;
2803 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2804 factor = num_stripes - 2;
2805 } else {
2806 factor = num_stripes;
2807 }
2808
2809 for (i = 0; i < num_stripes; i++) {
2810 stripe = btrfs_stripe_nr(chunk, i);
2811 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2812 continue;
2813
2814 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2815 stripe_length = btrfs_chunk_length(leaf, chunk);
2816 do_div(stripe_length, factor);
2817
2818 if (stripe_offset < bargs->pend &&
2819 stripe_offset + stripe_length > bargs->pstart)
2820 return 0;
2821 }
2822
2823 return 1;
2824 }
2825
2826 /* [vstart, vend) */
2827 static int chunk_vrange_filter(struct extent_buffer *leaf,
2828 struct btrfs_chunk *chunk,
2829 u64 chunk_offset,
2830 struct btrfs_balance_args *bargs)
2831 {
2832 if (chunk_offset < bargs->vend &&
2833 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2834 /* at least part of the chunk is inside this vrange */
2835 return 0;
2836
2837 return 1;
2838 }
2839
2840 static int chunk_soft_convert_filter(u64 chunk_type,
2841 struct btrfs_balance_args *bargs)
2842 {
2843 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2844 return 0;
2845
2846 chunk_type = chunk_to_extended(chunk_type) &
2847 BTRFS_EXTENDED_PROFILE_MASK;
2848
2849 if (bargs->target == chunk_type)
2850 return 1;
2851
2852 return 0;
2853 }
2854
2855 static int should_balance_chunk(struct btrfs_root *root,
2856 struct extent_buffer *leaf,
2857 struct btrfs_chunk *chunk, u64 chunk_offset)
2858 {
2859 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2860 struct btrfs_balance_args *bargs = NULL;
2861 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2862
2863 /* type filter */
2864 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2865 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2866 return 0;
2867 }
2868
2869 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2870 bargs = &bctl->data;
2871 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2872 bargs = &bctl->sys;
2873 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2874 bargs = &bctl->meta;
2875
2876 /* profiles filter */
2877 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2878 chunk_profiles_filter(chunk_type, bargs)) {
2879 return 0;
2880 }
2881
2882 /* usage filter */
2883 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2884 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2885 return 0;
2886 }
2887
2888 /* devid filter */
2889 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2890 chunk_devid_filter(leaf, chunk, bargs)) {
2891 return 0;
2892 }
2893
2894 /* drange filter, makes sense only with devid filter */
2895 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2896 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2897 return 0;
2898 }
2899
2900 /* vrange filter */
2901 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2902 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2903 return 0;
2904 }
2905
2906 /* soft profile changing mode */
2907 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2908 chunk_soft_convert_filter(chunk_type, bargs)) {
2909 return 0;
2910 }
2911
2912 return 1;
2913 }
2914
2915 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2916 {
2917 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2918 struct btrfs_root *chunk_root = fs_info->chunk_root;
2919 struct btrfs_root *dev_root = fs_info->dev_root;
2920 struct list_head *devices;
2921 struct btrfs_device *device;
2922 u64 old_size;
2923 u64 size_to_free;
2924 struct btrfs_chunk *chunk;
2925 struct btrfs_path *path;
2926 struct btrfs_key key;
2927 struct btrfs_key found_key;
2928 struct btrfs_trans_handle *trans;
2929 struct extent_buffer *leaf;
2930 int slot;
2931 int ret;
2932 int enospc_errors = 0;
2933 bool counting = true;
2934
2935 /* step one make some room on all the devices */
2936 devices = &fs_info->fs_devices->devices;
2937 list_for_each_entry(device, devices, dev_list) {
2938 old_size = device->total_bytes;
2939 size_to_free = div_factor(old_size, 1);
2940 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2941 if (!device->writeable ||
2942 device->total_bytes - device->bytes_used > size_to_free ||
2943 device->is_tgtdev_for_dev_replace)
2944 continue;
2945
2946 ret = btrfs_shrink_device(device, old_size - size_to_free);
2947 if (ret == -ENOSPC)
2948 break;
2949 BUG_ON(ret);
2950
2951 trans = btrfs_start_transaction(dev_root, 0);
2952 BUG_ON(IS_ERR(trans));
2953
2954 ret = btrfs_grow_device(trans, device, old_size);
2955 BUG_ON(ret);
2956
2957 btrfs_end_transaction(trans, dev_root);
2958 }
2959
2960 /* step two, relocate all the chunks */
2961 path = btrfs_alloc_path();
2962 if (!path) {
2963 ret = -ENOMEM;
2964 goto error;
2965 }
2966
2967 /* zero out stat counters */
2968 spin_lock(&fs_info->balance_lock);
2969 memset(&bctl->stat, 0, sizeof(bctl->stat));
2970 spin_unlock(&fs_info->balance_lock);
2971 again:
2972 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2973 key.offset = (u64)-1;
2974 key.type = BTRFS_CHUNK_ITEM_KEY;
2975
2976 while (1) {
2977 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2978 atomic_read(&fs_info->balance_cancel_req)) {
2979 ret = -ECANCELED;
2980 goto error;
2981 }
2982
2983 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2984 if (ret < 0)
2985 goto error;
2986
2987 /*
2988 * this shouldn't happen, it means the last relocate
2989 * failed
2990 */
2991 if (ret == 0)
2992 BUG(); /* FIXME break ? */
2993
2994 ret = btrfs_previous_item(chunk_root, path, 0,
2995 BTRFS_CHUNK_ITEM_KEY);
2996 if (ret) {
2997 ret = 0;
2998 break;
2999 }
3000
3001 leaf = path->nodes[0];
3002 slot = path->slots[0];
3003 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3004
3005 if (found_key.objectid != key.objectid)
3006 break;
3007
3008 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3009
3010 if (!counting) {
3011 spin_lock(&fs_info->balance_lock);
3012 bctl->stat.considered++;
3013 spin_unlock(&fs_info->balance_lock);
3014 }
3015
3016 ret = should_balance_chunk(chunk_root, leaf, chunk,
3017 found_key.offset);
3018 btrfs_release_path(path);
3019 if (!ret)
3020 goto loop;
3021
3022 if (counting) {
3023 spin_lock(&fs_info->balance_lock);
3024 bctl->stat.expected++;
3025 spin_unlock(&fs_info->balance_lock);
3026 goto loop;
3027 }
3028
3029 ret = btrfs_relocate_chunk(chunk_root,
3030 chunk_root->root_key.objectid,
3031 found_key.objectid,
3032 found_key.offset);
3033 if (ret && ret != -ENOSPC)
3034 goto error;
3035 if (ret == -ENOSPC) {
3036 enospc_errors++;
3037 } else {
3038 spin_lock(&fs_info->balance_lock);
3039 bctl->stat.completed++;
3040 spin_unlock(&fs_info->balance_lock);
3041 }
3042 loop:
3043 if (found_key.offset == 0)
3044 break;
3045 key.offset = found_key.offset - 1;
3046 }
3047
3048 if (counting) {
3049 btrfs_release_path(path);
3050 counting = false;
3051 goto again;
3052 }
3053 error:
3054 btrfs_free_path(path);
3055 if (enospc_errors) {
3056 btrfs_info(fs_info, "%d enospc errors during balance",
3057 enospc_errors);
3058 if (!ret)
3059 ret = -ENOSPC;
3060 }
3061
3062 return ret;
3063 }
3064
3065 /**
3066 * alloc_profile_is_valid - see if a given profile is valid and reduced
3067 * @flags: profile to validate
3068 * @extended: if true @flags is treated as an extended profile
3069 */
3070 static int alloc_profile_is_valid(u64 flags, int extended)
3071 {
3072 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3073 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3074
3075 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3076
3077 /* 1) check that all other bits are zeroed */
3078 if (flags & ~mask)
3079 return 0;
3080
3081 /* 2) see if profile is reduced */
3082 if (flags == 0)
3083 return !extended; /* "0" is valid for usual profiles */
3084
3085 /* true if exactly one bit set */
3086 return (flags & (flags - 1)) == 0;
3087 }
3088
3089 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3090 {
3091 /* cancel requested || normal exit path */
3092 return atomic_read(&fs_info->balance_cancel_req) ||
3093 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3094 atomic_read(&fs_info->balance_cancel_req) == 0);
3095 }
3096
3097 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3098 {
3099 int ret;
3100
3101 unset_balance_control(fs_info);
3102 ret = del_balance_item(fs_info->tree_root);
3103 if (ret)
3104 btrfs_std_error(fs_info, ret);
3105
3106 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3107 }
3108
3109 /*
3110 * Should be called with both balance and volume mutexes held
3111 */
3112 int btrfs_balance(struct btrfs_balance_control *bctl,
3113 struct btrfs_ioctl_balance_args *bargs)
3114 {
3115 struct btrfs_fs_info *fs_info = bctl->fs_info;
3116 u64 allowed;
3117 int mixed = 0;
3118 int ret;
3119 u64 num_devices;
3120 unsigned seq;
3121
3122 if (btrfs_fs_closing(fs_info) ||
3123 atomic_read(&fs_info->balance_pause_req) ||
3124 atomic_read(&fs_info->balance_cancel_req)) {
3125 ret = -EINVAL;
3126 goto out;
3127 }
3128
3129 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3130 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3131 mixed = 1;
3132
3133 /*
3134 * In case of mixed groups both data and meta should be picked,
3135 * and identical options should be given for both of them.
3136 */
3137 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3138 if (mixed && (bctl->flags & allowed)) {
3139 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3140 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3141 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3142 btrfs_err(fs_info, "with mixed groups data and "
3143 "metadata balance options must be the same");
3144 ret = -EINVAL;
3145 goto out;
3146 }
3147 }
3148
3149 num_devices = fs_info->fs_devices->num_devices;
3150 btrfs_dev_replace_lock(&fs_info->dev_replace);
3151 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3152 BUG_ON(num_devices < 1);
3153 num_devices--;
3154 }
3155 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3156 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3157 if (num_devices == 1)
3158 allowed |= BTRFS_BLOCK_GROUP_DUP;
3159 else if (num_devices > 1)
3160 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3161 if (num_devices > 2)
3162 allowed |= BTRFS_BLOCK_GROUP_RAID5;
3163 if (num_devices > 3)
3164 allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
3165 BTRFS_BLOCK_GROUP_RAID6);
3166 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3167 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3168 (bctl->data.target & ~allowed))) {
3169 btrfs_err(fs_info, "unable to start balance with target "
3170 "data profile %llu",
3171 bctl->data.target);
3172 ret = -EINVAL;
3173 goto out;
3174 }
3175 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3176 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3177 (bctl->meta.target & ~allowed))) {
3178 btrfs_err(fs_info,
3179 "unable to start balance with target metadata profile %llu",
3180 bctl->meta.target);
3181 ret = -EINVAL;
3182 goto out;
3183 }
3184 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3185 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3186 (bctl->sys.target & ~allowed))) {
3187 btrfs_err(fs_info,
3188 "unable to start balance with target system profile %llu",
3189 bctl->sys.target);
3190 ret = -EINVAL;
3191 goto out;
3192 }
3193
3194 /* allow dup'ed data chunks only in mixed mode */
3195 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3196 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3197 btrfs_err(fs_info, "dup for data is not allowed");
3198 ret = -EINVAL;
3199 goto out;
3200 }
3201
3202 /* allow to reduce meta or sys integrity only if force set */
3203 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3204 BTRFS_BLOCK_GROUP_RAID10 |
3205 BTRFS_BLOCK_GROUP_RAID5 |
3206 BTRFS_BLOCK_GROUP_RAID6;
3207 do {
3208 seq = read_seqbegin(&fs_info->profiles_lock);
3209
3210 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3211 (fs_info->avail_system_alloc_bits & allowed) &&
3212 !(bctl->sys.target & allowed)) ||
3213 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3214 (fs_info->avail_metadata_alloc_bits & allowed) &&
3215 !(bctl->meta.target & allowed))) {
3216 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3217 btrfs_info(fs_info, "force reducing metadata integrity");
3218 } else {
3219 btrfs_err(fs_info, "balance will reduce metadata "
3220 "integrity, use force if you want this");
3221 ret = -EINVAL;
3222 goto out;
3223 }
3224 }
3225 } while (read_seqretry(&fs_info->profiles_lock, seq));
3226
3227 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3228 int num_tolerated_disk_barrier_failures;
3229 u64 target = bctl->sys.target;
3230
3231 num_tolerated_disk_barrier_failures =
3232 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3233 if (num_tolerated_disk_barrier_failures > 0 &&
3234 (target &
3235 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3236 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3237 num_tolerated_disk_barrier_failures = 0;
3238 else if (num_tolerated_disk_barrier_failures > 1 &&
3239 (target &
3240 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3241 num_tolerated_disk_barrier_failures = 1;
3242
3243 fs_info->num_tolerated_disk_barrier_failures =
3244 num_tolerated_disk_barrier_failures;
3245 }
3246
3247 ret = insert_balance_item(fs_info->tree_root, bctl);
3248 if (ret && ret != -EEXIST)
3249 goto out;
3250
3251 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3252 BUG_ON(ret == -EEXIST);
3253 set_balance_control(bctl);
3254 } else {
3255 BUG_ON(ret != -EEXIST);
3256 spin_lock(&fs_info->balance_lock);
3257 update_balance_args(bctl);
3258 spin_unlock(&fs_info->balance_lock);
3259 }
3260
3261 atomic_inc(&fs_info->balance_running);
3262 mutex_unlock(&fs_info->balance_mutex);
3263
3264 ret = __btrfs_balance(fs_info);
3265
3266 mutex_lock(&fs_info->balance_mutex);
3267 atomic_dec(&fs_info->balance_running);
3268
3269 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3270 fs_info->num_tolerated_disk_barrier_failures =
3271 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3272 }
3273
3274 if (bargs) {
3275 memset(bargs, 0, sizeof(*bargs));
3276 update_ioctl_balance_args(fs_info, 0, bargs);
3277 }
3278
3279 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3280 balance_need_close(fs_info)) {
3281 __cancel_balance(fs_info);
3282 }
3283
3284 wake_up(&fs_info->balance_wait_q);
3285
3286 return ret;
3287 out:
3288 if (bctl->flags & BTRFS_BALANCE_RESUME)
3289 __cancel_balance(fs_info);
3290 else {
3291 kfree(bctl);
3292 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3293 }
3294 return ret;
3295 }
3296
3297 static int balance_kthread(void *data)
3298 {
3299 struct btrfs_fs_info *fs_info = data;
3300 int ret = 0;
3301
3302 mutex_lock(&fs_info->volume_mutex);
3303 mutex_lock(&fs_info->balance_mutex);
3304
3305 if (fs_info->balance_ctl) {
3306 btrfs_info(fs_info, "continuing balance");
3307 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3308 }
3309
3310 mutex_unlock(&fs_info->balance_mutex);
3311 mutex_unlock(&fs_info->volume_mutex);
3312
3313 return ret;
3314 }
3315
3316 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3317 {
3318 struct task_struct *tsk;
3319
3320 spin_lock(&fs_info->balance_lock);
3321 if (!fs_info->balance_ctl) {
3322 spin_unlock(&fs_info->balance_lock);
3323 return 0;
3324 }
3325 spin_unlock(&fs_info->balance_lock);
3326
3327 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3328 btrfs_info(fs_info, "force skipping balance");
3329 return 0;
3330 }
3331
3332 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3333 return PTR_ERR_OR_ZERO(tsk);
3334 }
3335
3336 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3337 {
3338 struct btrfs_balance_control *bctl;
3339 struct btrfs_balance_item *item;
3340 struct btrfs_disk_balance_args disk_bargs;
3341 struct btrfs_path *path;
3342 struct extent_buffer *leaf;
3343 struct btrfs_key key;
3344 int ret;
3345
3346 path = btrfs_alloc_path();
3347 if (!path)
3348 return -ENOMEM;
3349
3350 key.objectid = BTRFS_BALANCE_OBJECTID;
3351 key.type = BTRFS_BALANCE_ITEM_KEY;
3352 key.offset = 0;
3353
3354 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3355 if (ret < 0)
3356 goto out;
3357 if (ret > 0) { /* ret = -ENOENT; */
3358 ret = 0;
3359 goto out;
3360 }
3361
3362 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3363 if (!bctl) {
3364 ret = -ENOMEM;
3365 goto out;
3366 }
3367
3368 leaf = path->nodes[0];
3369 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3370
3371 bctl->fs_info = fs_info;
3372 bctl->flags = btrfs_balance_flags(leaf, item);
3373 bctl->flags |= BTRFS_BALANCE_RESUME;
3374
3375 btrfs_balance_data(leaf, item, &disk_bargs);
3376 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3377 btrfs_balance_meta(leaf, item, &disk_bargs);
3378 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3379 btrfs_balance_sys(leaf, item, &disk_bargs);
3380 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3381
3382 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3383
3384 mutex_lock(&fs_info->volume_mutex);
3385 mutex_lock(&fs_info->balance_mutex);
3386
3387 set_balance_control(bctl);
3388
3389 mutex_unlock(&fs_info->balance_mutex);
3390 mutex_unlock(&fs_info->volume_mutex);
3391 out:
3392 btrfs_free_path(path);
3393 return ret;
3394 }
3395
3396 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3397 {
3398 int ret = 0;
3399
3400 mutex_lock(&fs_info->balance_mutex);
3401 if (!fs_info->balance_ctl) {
3402 mutex_unlock(&fs_info->balance_mutex);
3403 return -ENOTCONN;
3404 }
3405
3406 if (atomic_read(&fs_info->balance_running)) {
3407 atomic_inc(&fs_info->balance_pause_req);
3408 mutex_unlock(&fs_info->balance_mutex);
3409
3410 wait_event(fs_info->balance_wait_q,
3411 atomic_read(&fs_info->balance_running) == 0);
3412
3413 mutex_lock(&fs_info->balance_mutex);
3414 /* we are good with balance_ctl ripped off from under us */
3415 BUG_ON(atomic_read(&fs_info->balance_running));
3416 atomic_dec(&fs_info->balance_pause_req);
3417 } else {
3418 ret = -ENOTCONN;
3419 }
3420
3421 mutex_unlock(&fs_info->balance_mutex);
3422 return ret;
3423 }
3424
3425 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3426 {
3427 if (fs_info->sb->s_flags & MS_RDONLY)
3428 return -EROFS;
3429
3430 mutex_lock(&fs_info->balance_mutex);
3431 if (!fs_info->balance_ctl) {
3432 mutex_unlock(&fs_info->balance_mutex);
3433 return -ENOTCONN;
3434 }
3435
3436 atomic_inc(&fs_info->balance_cancel_req);
3437 /*
3438 * if we are running just wait and return, balance item is
3439 * deleted in btrfs_balance in this case
3440 */
3441 if (atomic_read(&fs_info->balance_running)) {
3442 mutex_unlock(&fs_info->balance_mutex);
3443 wait_event(fs_info->balance_wait_q,
3444 atomic_read(&fs_info->balance_running) == 0);
3445 mutex_lock(&fs_info->balance_mutex);
3446 } else {
3447 /* __cancel_balance needs volume_mutex */
3448 mutex_unlock(&fs_info->balance_mutex);
3449 mutex_lock(&fs_info->volume_mutex);
3450 mutex_lock(&fs_info->balance_mutex);
3451
3452 if (fs_info->balance_ctl)
3453 __cancel_balance(fs_info);
3454
3455 mutex_unlock(&fs_info->volume_mutex);
3456 }
3457
3458 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3459 atomic_dec(&fs_info->balance_cancel_req);
3460 mutex_unlock(&fs_info->balance_mutex);
3461 return 0;
3462 }
3463
3464 static int btrfs_uuid_scan_kthread(void *data)
3465 {
3466 struct btrfs_fs_info *fs_info = data;
3467 struct btrfs_root *root = fs_info->tree_root;
3468 struct btrfs_key key;
3469 struct btrfs_key max_key;
3470 struct btrfs_path *path = NULL;
3471 int ret = 0;
3472 struct extent_buffer *eb;
3473 int slot;
3474 struct btrfs_root_item root_item;
3475 u32 item_size;
3476 struct btrfs_trans_handle *trans = NULL;
3477
3478 path = btrfs_alloc_path();
3479 if (!path) {
3480 ret = -ENOMEM;
3481 goto out;
3482 }
3483
3484 key.objectid = 0;
3485 key.type = BTRFS_ROOT_ITEM_KEY;
3486 key.offset = 0;
3487
3488 max_key.objectid = (u64)-1;
3489 max_key.type = BTRFS_ROOT_ITEM_KEY;
3490 max_key.offset = (u64)-1;
3491
3492 path->keep_locks = 1;
3493
3494 while (1) {
3495 ret = btrfs_search_forward(root, &key, path, 0);
3496 if (ret) {
3497 if (ret > 0)
3498 ret = 0;
3499 break;
3500 }
3501
3502 if (key.type != BTRFS_ROOT_ITEM_KEY ||
3503 (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
3504 key.objectid != BTRFS_FS_TREE_OBJECTID) ||
3505 key.objectid > BTRFS_LAST_FREE_OBJECTID)
3506 goto skip;
3507
3508 eb = path->nodes[0];
3509 slot = path->slots[0];
3510 item_size = btrfs_item_size_nr(eb, slot);
3511 if (item_size < sizeof(root_item))
3512 goto skip;
3513
3514 read_extent_buffer(eb, &root_item,
3515 btrfs_item_ptr_offset(eb, slot),
3516 (int)sizeof(root_item));
3517 if (btrfs_root_refs(&root_item) == 0)
3518 goto skip;
3519
3520 if (!btrfs_is_empty_uuid(root_item.uuid) ||
3521 !btrfs_is_empty_uuid(root_item.received_uuid)) {
3522 if (trans)
3523 goto update_tree;
3524
3525 btrfs_release_path(path);
3526 /*
3527 * 1 - subvol uuid item
3528 * 1 - received_subvol uuid item
3529 */
3530 trans = btrfs_start_transaction(fs_info->uuid_root, 2);
3531 if (IS_ERR(trans)) {
3532 ret = PTR_ERR(trans);
3533 break;
3534 }
3535 continue;
3536 } else {
3537 goto skip;
3538 }
3539 update_tree:
3540 if (!btrfs_is_empty_uuid(root_item.uuid)) {
3541 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3542 root_item.uuid,
3543 BTRFS_UUID_KEY_SUBVOL,
3544 key.objectid);
3545 if (ret < 0) {
3546 btrfs_warn(fs_info, "uuid_tree_add failed %d",
3547 ret);
3548 break;
3549 }
3550 }
3551
3552 if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
3553 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3554 root_item.received_uuid,
3555 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
3556 key.objectid);
3557 if (ret < 0) {
3558 btrfs_warn(fs_info, "uuid_tree_add failed %d",
3559 ret);
3560 break;
3561 }
3562 }
3563
3564 skip:
3565 if (trans) {
3566 ret = btrfs_end_transaction(trans, fs_info->uuid_root);
3567 trans = NULL;
3568 if (ret)
3569 break;
3570 }
3571
3572 btrfs_release_path(path);
3573 if (key.offset < (u64)-1) {
3574 key.offset++;
3575 } else if (key.type < BTRFS_ROOT_ITEM_KEY) {
3576 key.offset = 0;
3577 key.type = BTRFS_ROOT_ITEM_KEY;
3578 } else if (key.objectid < (u64)-1) {
3579 key.offset = 0;
3580 key.type = BTRFS_ROOT_ITEM_KEY;
3581 key.objectid++;
3582 } else {
3583 break;
3584 }
3585 cond_resched();
3586 }
3587
3588 out:
3589 btrfs_free_path(path);
3590 if (trans && !IS_ERR(trans))
3591 btrfs_end_transaction(trans, fs_info->uuid_root);
3592 if (ret)
3593 btrfs_warn(fs_info, "btrfs_uuid_scan_kthread failed %d", ret);
3594 else
3595 fs_info->update_uuid_tree_gen = 1;
3596 up(&fs_info->uuid_tree_rescan_sem);
3597 return 0;
3598 }
3599
3600 /*
3601 * Callback for btrfs_uuid_tree_iterate().
3602 * returns:
3603 * 0 check succeeded, the entry is not outdated.
3604 * < 0 if an error occured.
3605 * > 0 if the check failed, which means the caller shall remove the entry.
3606 */
3607 static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
3608 u8 *uuid, u8 type, u64 subid)
3609 {
3610 struct btrfs_key key;
3611 int ret = 0;
3612 struct btrfs_root *subvol_root;
3613
3614 if (type != BTRFS_UUID_KEY_SUBVOL &&
3615 type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
3616 goto out;
3617
3618 key.objectid = subid;
3619 key.type = BTRFS_ROOT_ITEM_KEY;
3620 key.offset = (u64)-1;
3621 subvol_root = btrfs_read_fs_root_no_name(fs_info, &key);
3622 if (IS_ERR(subvol_root)) {
3623 ret = PTR_ERR(subvol_root);
3624 if (ret == -ENOENT)
3625 ret = 1;
3626 goto out;
3627 }
3628
3629 switch (type) {
3630 case BTRFS_UUID_KEY_SUBVOL:
3631 if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
3632 ret = 1;
3633 break;
3634 case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
3635 if (memcmp(uuid, subvol_root->root_item.received_uuid,
3636 BTRFS_UUID_SIZE))
3637 ret = 1;
3638 break;
3639 }
3640
3641 out:
3642 return ret;
3643 }
3644
3645 static int btrfs_uuid_rescan_kthread(void *data)
3646 {
3647 struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
3648 int ret;
3649
3650 /*
3651 * 1st step is to iterate through the existing UUID tree and
3652 * to delete all entries that contain outdated data.
3653 * 2nd step is to add all missing entries to the UUID tree.
3654 */
3655 ret = btrfs_uuid_tree_iterate(fs_info, btrfs_check_uuid_tree_entry);
3656 if (ret < 0) {
3657 btrfs_warn(fs_info, "iterating uuid_tree failed %d", ret);
3658 up(&fs_info->uuid_tree_rescan_sem);
3659 return ret;
3660 }
3661 return btrfs_uuid_scan_kthread(data);
3662 }
3663
3664 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
3665 {
3666 struct btrfs_trans_handle *trans;
3667 struct btrfs_root *tree_root = fs_info->tree_root;
3668 struct btrfs_root *uuid_root;
3669 struct task_struct *task;
3670 int ret;
3671
3672 /*
3673 * 1 - root node
3674 * 1 - root item
3675 */
3676 trans = btrfs_start_transaction(tree_root, 2);
3677 if (IS_ERR(trans))
3678 return PTR_ERR(trans);
3679
3680 uuid_root = btrfs_create_tree(trans, fs_info,
3681 BTRFS_UUID_TREE_OBJECTID);
3682 if (IS_ERR(uuid_root)) {
3683 btrfs_abort_transaction(trans, tree_root,
3684 PTR_ERR(uuid_root));
3685 return PTR_ERR(uuid_root);
3686 }
3687
3688 fs_info->uuid_root = uuid_root;
3689
3690 ret = btrfs_commit_transaction(trans, tree_root);
3691 if (ret)
3692 return ret;
3693
3694 down(&fs_info->uuid_tree_rescan_sem);
3695 task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
3696 if (IS_ERR(task)) {
3697 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3698 btrfs_warn(fs_info, "failed to start uuid_scan task");
3699 up(&fs_info->uuid_tree_rescan_sem);
3700 return PTR_ERR(task);
3701 }
3702
3703 return 0;
3704 }
3705
3706 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3707 {
3708 struct task_struct *task;
3709
3710 down(&fs_info->uuid_tree_rescan_sem);
3711 task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3712 if (IS_ERR(task)) {
3713 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3714 btrfs_warn(fs_info, "failed to start uuid_rescan task");
3715 up(&fs_info->uuid_tree_rescan_sem);
3716 return PTR_ERR(task);
3717 }
3718
3719 return 0;
3720 }
3721
3722 /*
3723 * shrinking a device means finding all of the device extents past
3724 * the new size, and then following the back refs to the chunks.
3725 * The chunk relocation code actually frees the device extent
3726 */
3727 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3728 {
3729 struct btrfs_trans_handle *trans;
3730 struct btrfs_root *root = device->dev_root;
3731 struct btrfs_dev_extent *dev_extent = NULL;
3732 struct btrfs_path *path;
3733 u64 length;
3734 u64 chunk_tree;
3735 u64 chunk_objectid;
3736 u64 chunk_offset;
3737 int ret;
3738 int slot;
3739 int failed = 0;
3740 bool retried = false;
3741 struct extent_buffer *l;
3742 struct btrfs_key key;
3743 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3744 u64 old_total = btrfs_super_total_bytes(super_copy);
3745 u64 old_size = device->total_bytes;
3746 u64 diff = device->total_bytes - new_size;
3747
3748 if (device->is_tgtdev_for_dev_replace)
3749 return -EINVAL;
3750
3751 path = btrfs_alloc_path();
3752 if (!path)
3753 return -ENOMEM;
3754
3755 path->reada = 2;
3756
3757 lock_chunks(root);
3758
3759 device->total_bytes = new_size;
3760 if (device->writeable) {
3761 device->fs_devices->total_rw_bytes -= diff;
3762 spin_lock(&root->fs_info->free_chunk_lock);
3763 root->fs_info->free_chunk_space -= diff;
3764 spin_unlock(&root->fs_info->free_chunk_lock);
3765 }
3766 unlock_chunks(root);
3767
3768 again:
3769 key.objectid = device->devid;
3770 key.offset = (u64)-1;
3771 key.type = BTRFS_DEV_EXTENT_KEY;
3772
3773 do {
3774 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3775 if (ret < 0)
3776 goto done;
3777
3778 ret = btrfs_previous_item(root, path, 0, key.type);
3779 if (ret < 0)
3780 goto done;
3781 if (ret) {
3782 ret = 0;
3783 btrfs_release_path(path);
3784 break;
3785 }
3786
3787 l = path->nodes[0];
3788 slot = path->slots[0];
3789 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3790
3791 if (key.objectid != device->devid) {
3792 btrfs_release_path(path);
3793 break;
3794 }
3795
3796 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3797 length = btrfs_dev_extent_length(l, dev_extent);
3798
3799 if (key.offset + length <= new_size) {
3800 btrfs_release_path(path);
3801 break;
3802 }
3803
3804 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3805 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3806 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3807 btrfs_release_path(path);
3808
3809 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3810 chunk_offset);
3811 if (ret && ret != -ENOSPC)
3812 goto done;
3813 if (ret == -ENOSPC)
3814 failed++;
3815 } while (key.offset-- > 0);
3816
3817 if (failed && !retried) {
3818 failed = 0;
3819 retried = true;
3820 goto again;
3821 } else if (failed && retried) {
3822 ret = -ENOSPC;
3823 lock_chunks(root);
3824
3825 device->total_bytes = old_size;
3826 if (device->writeable)
3827 device->fs_devices->total_rw_bytes += diff;
3828 spin_lock(&root->fs_info->free_chunk_lock);
3829 root->fs_info->free_chunk_space += diff;
3830 spin_unlock(&root->fs_info->free_chunk_lock);
3831 unlock_chunks(root);
3832 goto done;
3833 }
3834
3835 /* Shrinking succeeded, else we would be at "done". */
3836 trans = btrfs_start_transaction(root, 0);
3837 if (IS_ERR(trans)) {
3838 ret = PTR_ERR(trans);
3839 goto done;
3840 }
3841
3842 lock_chunks(root);
3843
3844 device->disk_total_bytes = new_size;
3845 /* Now btrfs_update_device() will change the on-disk size. */
3846 ret = btrfs_update_device(trans, device);
3847 if (ret) {
3848 unlock_chunks(root);
3849 btrfs_end_transaction(trans, root);
3850 goto done;
3851 }
3852 WARN_ON(diff > old_total);
3853 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3854 unlock_chunks(root);
3855 btrfs_end_transaction(trans, root);
3856 done:
3857 btrfs_free_path(path);
3858 return ret;
3859 }
3860
3861 static int btrfs_add_system_chunk(struct btrfs_root *root,
3862 struct btrfs_key *key,
3863 struct btrfs_chunk *chunk, int item_size)
3864 {
3865 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3866 struct btrfs_disk_key disk_key;
3867 u32 array_size;
3868 u8 *ptr;
3869
3870 array_size = btrfs_super_sys_array_size(super_copy);
3871 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3872 return -EFBIG;
3873
3874 ptr = super_copy->sys_chunk_array + array_size;
3875 btrfs_cpu_key_to_disk(&disk_key, key);
3876 memcpy(ptr, &disk_key, sizeof(disk_key));
3877 ptr += sizeof(disk_key);
3878 memcpy(ptr, chunk, item_size);
3879 item_size += sizeof(disk_key);
3880 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3881 return 0;
3882 }
3883
3884 /*
3885 * sort the devices in descending order by max_avail, total_avail
3886 */
3887 static int btrfs_cmp_device_info(const void *a, const void *b)
3888 {
3889 const struct btrfs_device_info *di_a = a;
3890 const struct btrfs_device_info *di_b = b;
3891
3892 if (di_a->max_avail > di_b->max_avail)
3893 return -1;
3894 if (di_a->max_avail < di_b->max_avail)
3895 return 1;
3896 if (di_a->total_avail > di_b->total_avail)
3897 return -1;
3898 if (di_a->total_avail < di_b->total_avail)
3899 return 1;
3900 return 0;
3901 }
3902
3903 static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3904 [BTRFS_RAID_RAID10] = {
3905 .sub_stripes = 2,
3906 .dev_stripes = 1,
3907 .devs_max = 0, /* 0 == as many as possible */
3908 .devs_min = 4,
3909 .devs_increment = 2,
3910 .ncopies = 2,
3911 },
3912 [BTRFS_RAID_RAID1] = {
3913 .sub_stripes = 1,
3914 .dev_stripes = 1,
3915 .devs_max = 2,
3916 .devs_min = 2,
3917 .devs_increment = 2,
3918 .ncopies = 2,
3919 },
3920 [BTRFS_RAID_DUP] = {
3921 .sub_stripes = 1,
3922 .dev_stripes = 2,
3923 .devs_max = 1,
3924 .devs_min = 1,
3925 .devs_increment = 1,
3926 .ncopies = 2,
3927 },
3928 [BTRFS_RAID_RAID0] = {
3929 .sub_stripes = 1,
3930 .dev_stripes = 1,
3931 .devs_max = 0,
3932 .devs_min = 2,
3933 .devs_increment = 1,
3934 .ncopies = 1,
3935 },
3936 [BTRFS_RAID_SINGLE] = {
3937 .sub_stripes = 1,
3938 .dev_stripes = 1,
3939 .devs_max = 1,
3940 .devs_min = 1,
3941 .devs_increment = 1,
3942 .ncopies = 1,
3943 },
3944 [BTRFS_RAID_RAID5] = {
3945 .sub_stripes = 1,
3946 .dev_stripes = 1,
3947 .devs_max = 0,
3948 .devs_min = 2,
3949 .devs_increment = 1,
3950 .ncopies = 2,
3951 },
3952 [BTRFS_RAID_RAID6] = {
3953 .sub_stripes = 1,
3954 .dev_stripes = 1,
3955 .devs_max = 0,
3956 .devs_min = 3,
3957 .devs_increment = 1,
3958 .ncopies = 3,
3959 },
3960 };
3961
3962 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3963 {
3964 /* TODO allow them to set a preferred stripe size */
3965 return 64 * 1024;
3966 }
3967
3968 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3969 {
3970 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3971 return;
3972
3973 btrfs_set_fs_incompat(info, RAID56);
3974 }
3975
3976 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3977 struct btrfs_root *extent_root, u64 start,
3978 u64 type)
3979 {
3980 struct btrfs_fs_info *info = extent_root->fs_info;
3981 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3982 struct list_head *cur;
3983 struct map_lookup *map = NULL;
3984 struct extent_map_tree *em_tree;
3985 struct extent_map *em;
3986 struct btrfs_device_info *devices_info = NULL;
3987 u64 total_avail;
3988 int num_stripes; /* total number of stripes to allocate */
3989 int data_stripes; /* number of stripes that count for
3990 block group size */
3991 int sub_stripes; /* sub_stripes info for map */
3992 int dev_stripes; /* stripes per dev */
3993 int devs_max; /* max devs to use */
3994 int devs_min; /* min devs needed */
3995 int devs_increment; /* ndevs has to be a multiple of this */
3996 int ncopies; /* how many copies to data has */
3997 int ret;
3998 u64 max_stripe_size;
3999 u64 max_chunk_size;
4000 u64 stripe_size;
4001 u64 num_bytes;
4002 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
4003 int ndevs;
4004 int i;
4005 int j;
4006 int index;
4007
4008 BUG_ON(!alloc_profile_is_valid(type, 0));
4009
4010 if (list_empty(&fs_devices->alloc_list))
4011 return -ENOSPC;
4012
4013 index = __get_raid_index(type);
4014
4015 sub_stripes = btrfs_raid_array[index].sub_stripes;
4016 dev_stripes = btrfs_raid_array[index].dev_stripes;
4017 devs_max = btrfs_raid_array[index].devs_max;
4018 devs_min = btrfs_raid_array[index].devs_min;
4019 devs_increment = btrfs_raid_array[index].devs_increment;
4020 ncopies = btrfs_raid_array[index].ncopies;
4021
4022 if (type & BTRFS_BLOCK_GROUP_DATA) {
4023 max_stripe_size = 1024 * 1024 * 1024;
4024 max_chunk_size = 10 * max_stripe_size;
4025 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
4026 /* for larger filesystems, use larger metadata chunks */
4027 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
4028 max_stripe_size = 1024 * 1024 * 1024;
4029 else
4030 max_stripe_size = 256 * 1024 * 1024;
4031 max_chunk_size = max_stripe_size;
4032 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
4033 max_stripe_size = 32 * 1024 * 1024;
4034 max_chunk_size = 2 * max_stripe_size;
4035 } else {
4036 btrfs_err(info, "invalid chunk type 0x%llx requested\n",
4037 type);
4038 BUG_ON(1);
4039 }
4040
4041 /* we don't want a chunk larger than 10% of writeable space */
4042 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
4043 max_chunk_size);
4044
4045 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
4046 GFP_NOFS);
4047 if (!devices_info)
4048 return -ENOMEM;
4049
4050 cur = fs_devices->alloc_list.next;
4051
4052 /*
4053 * in the first pass through the devices list, we gather information
4054 * about the available holes on each device.
4055 */
4056 ndevs = 0;
4057 while (cur != &fs_devices->alloc_list) {
4058 struct btrfs_device *device;
4059 u64 max_avail;
4060 u64 dev_offset;
4061
4062 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
4063
4064 cur = cur->next;
4065
4066 if (!device->writeable) {
4067 WARN(1, KERN_ERR
4068 "BTRFS: read-only device in alloc_list\n");
4069 continue;
4070 }
4071
4072 if (!device->in_fs_metadata ||
4073 device->is_tgtdev_for_dev_replace)
4074 continue;
4075
4076 if (device->total_bytes > device->bytes_used)
4077 total_avail = device->total_bytes - device->bytes_used;
4078 else
4079 total_avail = 0;
4080
4081 /* If there is no space on this device, skip it. */
4082 if (total_avail == 0)
4083 continue;
4084
4085 ret = find_free_dev_extent(trans, device,
4086 max_stripe_size * dev_stripes,
4087 &dev_offset, &max_avail);
4088 if (ret && ret != -ENOSPC)
4089 goto error;
4090
4091 if (ret == 0)
4092 max_avail = max_stripe_size * dev_stripes;
4093
4094 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
4095 continue;
4096
4097 if (ndevs == fs_devices->rw_devices) {
4098 WARN(1, "%s: found more than %llu devices\n",
4099 __func__, fs_devices->rw_devices);
4100 break;
4101 }
4102 devices_info[ndevs].dev_offset = dev_offset;
4103 devices_info[ndevs].max_avail = max_avail;
4104 devices_info[ndevs].total_avail = total_avail;
4105 devices_info[ndevs].dev = device;
4106 ++ndevs;
4107 }
4108
4109 /*
4110 * now sort the devices by hole size / available space
4111 */
4112 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
4113 btrfs_cmp_device_info, NULL);
4114
4115 /* round down to number of usable stripes */
4116 ndevs -= ndevs % devs_increment;
4117
4118 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
4119 ret = -ENOSPC;
4120 goto error;
4121 }
4122
4123 if (devs_max && ndevs > devs_max)
4124 ndevs = devs_max;
4125 /*
4126 * the primary goal is to maximize the number of stripes, so use as many
4127 * devices as possible, even if the stripes are not maximum sized.
4128 */
4129 stripe_size = devices_info[ndevs-1].max_avail;
4130 num_stripes = ndevs * dev_stripes;
4131
4132 /*
4133 * this will have to be fixed for RAID1 and RAID10 over
4134 * more drives
4135 */
4136 data_stripes = num_stripes / ncopies;
4137
4138 if (type & BTRFS_BLOCK_GROUP_RAID5) {
4139 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
4140 btrfs_super_stripesize(info->super_copy));
4141 data_stripes = num_stripes - 1;
4142 }
4143 if (type & BTRFS_BLOCK_GROUP_RAID6) {
4144 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
4145 btrfs_super_stripesize(info->super_copy));
4146 data_stripes = num_stripes - 2;
4147 }
4148
4149 /*
4150 * Use the number of data stripes to figure out how big this chunk
4151 * is really going to be in terms of logical address space,
4152 * and compare that answer with the max chunk size
4153 */
4154 if (stripe_size * data_stripes > max_chunk_size) {
4155 u64 mask = (1ULL << 24) - 1;
4156 stripe_size = max_chunk_size;
4157 do_div(stripe_size, data_stripes);
4158
4159 /* bump the answer up to a 16MB boundary */
4160 stripe_size = (stripe_size + mask) & ~mask;
4161
4162 /* but don't go higher than the limits we found
4163 * while searching for free extents
4164 */
4165 if (stripe_size > devices_info[ndevs-1].max_avail)
4166 stripe_size = devices_info[ndevs-1].max_avail;
4167 }
4168
4169 do_div(stripe_size, dev_stripes);
4170
4171 /* align to BTRFS_STRIPE_LEN */
4172 do_div(stripe_size, raid_stripe_len);
4173 stripe_size *= raid_stripe_len;
4174
4175 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4176 if (!map) {
4177 ret = -ENOMEM;
4178 goto error;
4179 }
4180 map->num_stripes = num_stripes;
4181
4182 for (i = 0; i < ndevs; ++i) {
4183 for (j = 0; j < dev_stripes; ++j) {
4184 int s = i * dev_stripes + j;
4185 map->stripes[s].dev = devices_info[i].dev;
4186 map->stripes[s].physical = devices_info[i].dev_offset +
4187 j * stripe_size;
4188 }
4189 }
4190 map->sector_size = extent_root->sectorsize;
4191 map->stripe_len = raid_stripe_len;
4192 map->io_align = raid_stripe_len;
4193 map->io_width = raid_stripe_len;
4194 map->type = type;
4195 map->sub_stripes = sub_stripes;
4196
4197 num_bytes = stripe_size * data_stripes;
4198
4199 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
4200
4201 em = alloc_extent_map();
4202 if (!em) {
4203 ret = -ENOMEM;
4204 goto error;
4205 }
4206 em->bdev = (struct block_device *)map;
4207 em->start = start;
4208 em->len = num_bytes;
4209 em->block_start = 0;
4210 em->block_len = em->len;
4211 em->orig_block_len = stripe_size;
4212
4213 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4214 write_lock(&em_tree->lock);
4215 ret = add_extent_mapping(em_tree, em, 0);
4216 if (!ret) {
4217 list_add_tail(&em->list, &trans->transaction->pending_chunks);
4218 atomic_inc(&em->refs);
4219 }
4220 write_unlock(&em_tree->lock);
4221 if (ret) {
4222 free_extent_map(em);
4223 goto error;
4224 }
4225
4226 ret = btrfs_make_block_group(trans, extent_root, 0, type,
4227 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4228 start, num_bytes);
4229 if (ret)
4230 goto error_del_extent;
4231
4232 free_extent_map(em);
4233 check_raid56_incompat_flag(extent_root->fs_info, type);
4234
4235 kfree(devices_info);
4236 return 0;
4237
4238 error_del_extent:
4239 write_lock(&em_tree->lock);
4240 remove_extent_mapping(em_tree, em);
4241 write_unlock(&em_tree->lock);
4242
4243 /* One for our allocation */
4244 free_extent_map(em);
4245 /* One for the tree reference */
4246 free_extent_map(em);
4247 error:
4248 kfree(map);
4249 kfree(devices_info);
4250 return ret;
4251 }
4252
4253 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
4254 struct btrfs_root *extent_root,
4255 u64 chunk_offset, u64 chunk_size)
4256 {
4257 struct btrfs_key key;
4258 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4259 struct btrfs_device *device;
4260 struct btrfs_chunk *chunk;
4261 struct btrfs_stripe *stripe;
4262 struct extent_map_tree *em_tree;
4263 struct extent_map *em;
4264 struct map_lookup *map;
4265 size_t item_size;
4266 u64 dev_offset;
4267 u64 stripe_size;
4268 int i = 0;
4269 int ret;
4270
4271 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4272 read_lock(&em_tree->lock);
4273 em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
4274 read_unlock(&em_tree->lock);
4275
4276 if (!em) {
4277 btrfs_crit(extent_root->fs_info, "unable to find logical "
4278 "%Lu len %Lu", chunk_offset, chunk_size);
4279 return -EINVAL;
4280 }
4281
4282 if (em->start != chunk_offset || em->len != chunk_size) {
4283 btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
4284 " %Lu-%Lu, found %Lu-%Lu\n", chunk_offset,
4285 chunk_size, em->start, em->len);
4286 free_extent_map(em);
4287 return -EINVAL;
4288 }
4289
4290 map = (struct map_lookup *)em->bdev;
4291 item_size = btrfs_chunk_item_size(map->num_stripes);
4292 stripe_size = em->orig_block_len;
4293
4294 chunk = kzalloc(item_size, GFP_NOFS);
4295 if (!chunk) {
4296 ret = -ENOMEM;
4297 goto out;
4298 }
4299
4300 for (i = 0; i < map->num_stripes; i++) {
4301 device = map->stripes[i].dev;
4302 dev_offset = map->stripes[i].physical;
4303
4304 device->bytes_used += stripe_size;
4305 ret = btrfs_update_device(trans, device);
4306 if (ret)
4307 goto out;
4308 ret = btrfs_alloc_dev_extent(trans, device,
4309 chunk_root->root_key.objectid,
4310 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4311 chunk_offset, dev_offset,
4312 stripe_size);
4313 if (ret)
4314 goto out;
4315 }
4316
4317 spin_lock(&extent_root->fs_info->free_chunk_lock);
4318 extent_root->fs_info->free_chunk_space -= (stripe_size *
4319 map->num_stripes);
4320 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4321
4322 stripe = &chunk->stripe;
4323 for (i = 0; i < map->num_stripes; i++) {
4324 device = map->stripes[i].dev;
4325 dev_offset = map->stripes[i].physical;
4326
4327 btrfs_set_stack_stripe_devid(stripe, device->devid);
4328 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4329 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4330 stripe++;
4331 }
4332
4333 btrfs_set_stack_chunk_length(chunk, chunk_size);
4334 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4335 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4336 btrfs_set_stack_chunk_type(chunk, map->type);
4337 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4338 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4339 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4340 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4341 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4342
4343 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4344 key.type = BTRFS_CHUNK_ITEM_KEY;
4345 key.offset = chunk_offset;
4346
4347 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4348 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4349 /*
4350 * TODO: Cleanup of inserted chunk root in case of
4351 * failure.
4352 */
4353 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4354 item_size);
4355 }
4356
4357 out:
4358 kfree(chunk);
4359 free_extent_map(em);
4360 return ret;
4361 }
4362
4363 /*
4364 * Chunk allocation falls into two parts. The first part does works
4365 * that make the new allocated chunk useable, but not do any operation
4366 * that modifies the chunk tree. The second part does the works that
4367 * require modifying the chunk tree. This division is important for the
4368 * bootstrap process of adding storage to a seed btrfs.
4369 */
4370 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4371 struct btrfs_root *extent_root, u64 type)
4372 {
4373 u64 chunk_offset;
4374
4375 chunk_offset = find_next_chunk(extent_root->fs_info);
4376 return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
4377 }
4378
4379 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4380 struct btrfs_root *root,
4381 struct btrfs_device *device)
4382 {
4383 u64 chunk_offset;
4384 u64 sys_chunk_offset;
4385 u64 alloc_profile;
4386 struct btrfs_fs_info *fs_info = root->fs_info;
4387 struct btrfs_root *extent_root = fs_info->extent_root;
4388 int ret;
4389
4390 chunk_offset = find_next_chunk(fs_info);
4391 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4392 ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
4393 alloc_profile);
4394 if (ret)
4395 return ret;
4396
4397 sys_chunk_offset = find_next_chunk(root->fs_info);
4398 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4399 ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
4400 alloc_profile);
4401 if (ret) {
4402 btrfs_abort_transaction(trans, root, ret);
4403 goto out;
4404 }
4405
4406 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4407 if (ret)
4408 btrfs_abort_transaction(trans, root, ret);
4409 out:
4410 return ret;
4411 }
4412
4413 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4414 {
4415 struct extent_map *em;
4416 struct map_lookup *map;
4417 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4418 int readonly = 0;
4419 int i;
4420
4421 read_lock(&map_tree->map_tree.lock);
4422 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4423 read_unlock(&map_tree->map_tree.lock);
4424 if (!em)
4425 return 1;
4426
4427 if (btrfs_test_opt(root, DEGRADED)) {
4428 free_extent_map(em);
4429 return 0;
4430 }
4431
4432 map = (struct map_lookup *)em->bdev;
4433 for (i = 0; i < map->num_stripes; i++) {
4434 if (!map->stripes[i].dev->writeable) {
4435 readonly = 1;
4436 break;
4437 }
4438 }
4439 free_extent_map(em);
4440 return readonly;
4441 }
4442
4443 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4444 {
4445 extent_map_tree_init(&tree->map_tree);
4446 }
4447
4448 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4449 {
4450 struct extent_map *em;
4451
4452 while (1) {
4453 write_lock(&tree->map_tree.lock);
4454 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4455 if (em)
4456 remove_extent_mapping(&tree->map_tree, em);
4457 write_unlock(&tree->map_tree.lock);
4458 if (!em)
4459 break;
4460 kfree(em->bdev);
4461 /* once for us */
4462 free_extent_map(em);
4463 /* once for the tree */
4464 free_extent_map(em);
4465 }
4466 }
4467
4468 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4469 {
4470 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4471 struct extent_map *em;
4472 struct map_lookup *map;
4473 struct extent_map_tree *em_tree = &map_tree->map_tree;
4474 int ret;
4475
4476 read_lock(&em_tree->lock);
4477 em = lookup_extent_mapping(em_tree, logical, len);
4478 read_unlock(&em_tree->lock);
4479
4480 /*
4481 * We could return errors for these cases, but that could get ugly and
4482 * we'd probably do the same thing which is just not do anything else
4483 * and exit, so return 1 so the callers don't try to use other copies.
4484 */
4485 if (!em) {
4486 btrfs_crit(fs_info, "No mapping for %Lu-%Lu\n", logical,
4487 logical+len);
4488 return 1;
4489 }
4490
4491 if (em->start > logical || em->start + em->len < logical) {
4492 btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got "
4493 "%Lu-%Lu\n", logical, logical+len, em->start,
4494 em->start + em->len);
4495 free_extent_map(em);
4496 return 1;
4497 }
4498
4499 map = (struct map_lookup *)em->bdev;
4500 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4501 ret = map->num_stripes;
4502 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4503 ret = map->sub_stripes;
4504 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4505 ret = 2;
4506 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4507 ret = 3;
4508 else
4509 ret = 1;
4510 free_extent_map(em);
4511
4512 btrfs_dev_replace_lock(&fs_info->dev_replace);
4513 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4514 ret++;
4515 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4516
4517 return ret;
4518 }
4519
4520 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4521 struct btrfs_mapping_tree *map_tree,
4522 u64 logical)
4523 {
4524 struct extent_map *em;
4525 struct map_lookup *map;
4526 struct extent_map_tree *em_tree = &map_tree->map_tree;
4527 unsigned long len = root->sectorsize;
4528
4529 read_lock(&em_tree->lock);
4530 em = lookup_extent_mapping(em_tree, logical, len);
4531 read_unlock(&em_tree->lock);
4532 BUG_ON(!em);
4533
4534 BUG_ON(em->start > logical || em->start + em->len < logical);
4535 map = (struct map_lookup *)em->bdev;
4536 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4537 BTRFS_BLOCK_GROUP_RAID6)) {
4538 len = map->stripe_len * nr_data_stripes(map);
4539 }
4540 free_extent_map(em);
4541 return len;
4542 }
4543
4544 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4545 u64 logical, u64 len, int mirror_num)
4546 {
4547 struct extent_map *em;
4548 struct map_lookup *map;
4549 struct extent_map_tree *em_tree = &map_tree->map_tree;
4550 int ret = 0;
4551
4552 read_lock(&em_tree->lock);
4553 em = lookup_extent_mapping(em_tree, logical, len);
4554 read_unlock(&em_tree->lock);
4555 BUG_ON(!em);
4556
4557 BUG_ON(em->start > logical || em->start + em->len < logical);
4558 map = (struct map_lookup *)em->bdev;
4559 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4560 BTRFS_BLOCK_GROUP_RAID6))
4561 ret = 1;
4562 free_extent_map(em);
4563 return ret;
4564 }
4565
4566 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4567 struct map_lookup *map, int first, int num,
4568 int optimal, int dev_replace_is_ongoing)
4569 {
4570 int i;
4571 int tolerance;
4572 struct btrfs_device *srcdev;
4573
4574 if (dev_replace_is_ongoing &&
4575 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4576 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4577 srcdev = fs_info->dev_replace.srcdev;
4578 else
4579 srcdev = NULL;
4580
4581 /*
4582 * try to avoid the drive that is the source drive for a
4583 * dev-replace procedure, only choose it if no other non-missing
4584 * mirror is available
4585 */
4586 for (tolerance = 0; tolerance < 2; tolerance++) {
4587 if (map->stripes[optimal].dev->bdev &&
4588 (tolerance || map->stripes[optimal].dev != srcdev))
4589 return optimal;
4590 for (i = first; i < first + num; i++) {
4591 if (map->stripes[i].dev->bdev &&
4592 (tolerance || map->stripes[i].dev != srcdev))
4593 return i;
4594 }
4595 }
4596
4597 /* we couldn't find one that doesn't fail. Just return something
4598 * and the io error handling code will clean up eventually
4599 */
4600 return optimal;
4601 }
4602
4603 static inline int parity_smaller(u64 a, u64 b)
4604 {
4605 return a > b;
4606 }
4607
4608 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4609 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4610 {
4611 struct btrfs_bio_stripe s;
4612 int i;
4613 u64 l;
4614 int again = 1;
4615
4616 while (again) {
4617 again = 0;
4618 for (i = 0; i < bbio->num_stripes - 1; i++) {
4619 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4620 s = bbio->stripes[i];
4621 l = raid_map[i];
4622 bbio->stripes[i] = bbio->stripes[i+1];
4623 raid_map[i] = raid_map[i+1];
4624 bbio->stripes[i+1] = s;
4625 raid_map[i+1] = l;
4626 again = 1;
4627 }
4628 }
4629 }
4630 }
4631
4632 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4633 u64 logical, u64 *length,
4634 struct btrfs_bio **bbio_ret,
4635 int mirror_num, u64 **raid_map_ret)
4636 {
4637 struct extent_map *em;
4638 struct map_lookup *map;
4639 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4640 struct extent_map_tree *em_tree = &map_tree->map_tree;
4641 u64 offset;
4642 u64 stripe_offset;
4643 u64 stripe_end_offset;
4644 u64 stripe_nr;
4645 u64 stripe_nr_orig;
4646 u64 stripe_nr_end;
4647 u64 stripe_len;
4648 u64 *raid_map = NULL;
4649 int stripe_index;
4650 int i;
4651 int ret = 0;
4652 int num_stripes;
4653 int max_errors = 0;
4654 struct btrfs_bio *bbio = NULL;
4655 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4656 int dev_replace_is_ongoing = 0;
4657 int num_alloc_stripes;
4658 int patch_the_first_stripe_for_dev_replace = 0;
4659 u64 physical_to_patch_in_first_stripe = 0;
4660 u64 raid56_full_stripe_start = (u64)-1;
4661
4662 read_lock(&em_tree->lock);
4663 em = lookup_extent_mapping(em_tree, logical, *length);
4664 read_unlock(&em_tree->lock);
4665
4666 if (!em) {
4667 btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4668 logical, *length);
4669 return -EINVAL;
4670 }
4671
4672 if (em->start > logical || em->start + em->len < logical) {
4673 btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4674 "found %Lu-%Lu\n", logical, em->start,
4675 em->start + em->len);
4676 free_extent_map(em);
4677 return -EINVAL;
4678 }
4679
4680 map = (struct map_lookup *)em->bdev;
4681 offset = logical - em->start;
4682
4683 stripe_len = map->stripe_len;
4684 stripe_nr = offset;
4685 /*
4686 * stripe_nr counts the total number of stripes we have to stride
4687 * to get to this block
4688 */
4689 do_div(stripe_nr, stripe_len);
4690
4691 stripe_offset = stripe_nr * stripe_len;
4692 BUG_ON(offset < stripe_offset);
4693
4694 /* stripe_offset is the offset of this block in its stripe*/
4695 stripe_offset = offset - stripe_offset;
4696
4697 /* if we're here for raid56, we need to know the stripe aligned start */
4698 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4699 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4700 raid56_full_stripe_start = offset;
4701
4702 /* allow a write of a full stripe, but make sure we don't
4703 * allow straddling of stripes
4704 */
4705 do_div(raid56_full_stripe_start, full_stripe_len);
4706 raid56_full_stripe_start *= full_stripe_len;
4707 }
4708
4709 if (rw & REQ_DISCARD) {
4710 /* we don't discard raid56 yet */
4711 if (map->type &
4712 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4713 ret = -EOPNOTSUPP;
4714 goto out;
4715 }
4716 *length = min_t(u64, em->len - offset, *length);
4717 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4718 u64 max_len;
4719 /* For writes to RAID[56], allow a full stripeset across all disks.
4720 For other RAID types and for RAID[56] reads, just allow a single
4721 stripe (on a single disk). */
4722 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4723 (rw & REQ_WRITE)) {
4724 max_len = stripe_len * nr_data_stripes(map) -
4725 (offset - raid56_full_stripe_start);
4726 } else {
4727 /* we limit the length of each bio to what fits in a stripe */
4728 max_len = stripe_len - stripe_offset;
4729 }
4730 *length = min_t(u64, em->len - offset, max_len);
4731 } else {
4732 *length = em->len - offset;
4733 }
4734
4735 /* This is for when we're called from btrfs_merge_bio_hook() and all
4736 it cares about is the length */
4737 if (!bbio_ret)
4738 goto out;
4739
4740 btrfs_dev_replace_lock(dev_replace);
4741 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4742 if (!dev_replace_is_ongoing)
4743 btrfs_dev_replace_unlock(dev_replace);
4744
4745 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4746 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4747 dev_replace->tgtdev != NULL) {
4748 /*
4749 * in dev-replace case, for repair case (that's the only
4750 * case where the mirror is selected explicitly when
4751 * calling btrfs_map_block), blocks left of the left cursor
4752 * can also be read from the target drive.
4753 * For REQ_GET_READ_MIRRORS, the target drive is added as
4754 * the last one to the array of stripes. For READ, it also
4755 * needs to be supported using the same mirror number.
4756 * If the requested block is not left of the left cursor,
4757 * EIO is returned. This can happen because btrfs_num_copies()
4758 * returns one more in the dev-replace case.
4759 */
4760 u64 tmp_length = *length;
4761 struct btrfs_bio *tmp_bbio = NULL;
4762 int tmp_num_stripes;
4763 u64 srcdev_devid = dev_replace->srcdev->devid;
4764 int index_srcdev = 0;
4765 int found = 0;
4766 u64 physical_of_found = 0;
4767
4768 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4769 logical, &tmp_length, &tmp_bbio, 0, NULL);
4770 if (ret) {
4771 WARN_ON(tmp_bbio != NULL);
4772 goto out;
4773 }
4774
4775 tmp_num_stripes = tmp_bbio->num_stripes;
4776 if (mirror_num > tmp_num_stripes) {
4777 /*
4778 * REQ_GET_READ_MIRRORS does not contain this
4779 * mirror, that means that the requested area
4780 * is not left of the left cursor
4781 */
4782 ret = -EIO;
4783 kfree(tmp_bbio);
4784 goto out;
4785 }
4786
4787 /*
4788 * process the rest of the function using the mirror_num
4789 * of the source drive. Therefore look it up first.
4790 * At the end, patch the device pointer to the one of the
4791 * target drive.
4792 */
4793 for (i = 0; i < tmp_num_stripes; i++) {
4794 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4795 /*
4796 * In case of DUP, in order to keep it
4797 * simple, only add the mirror with the
4798 * lowest physical address
4799 */
4800 if (found &&
4801 physical_of_found <=
4802 tmp_bbio->stripes[i].physical)
4803 continue;
4804 index_srcdev = i;
4805 found = 1;
4806 physical_of_found =
4807 tmp_bbio->stripes[i].physical;
4808 }
4809 }
4810
4811 if (found) {
4812 mirror_num = index_srcdev + 1;
4813 patch_the_first_stripe_for_dev_replace = 1;
4814 physical_to_patch_in_first_stripe = physical_of_found;
4815 } else {
4816 WARN_ON(1);
4817 ret = -EIO;
4818 kfree(tmp_bbio);
4819 goto out;
4820 }
4821
4822 kfree(tmp_bbio);
4823 } else if (mirror_num > map->num_stripes) {
4824 mirror_num = 0;
4825 }
4826
4827 num_stripes = 1;
4828 stripe_index = 0;
4829 stripe_nr_orig = stripe_nr;
4830 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
4831 do_div(stripe_nr_end, map->stripe_len);
4832 stripe_end_offset = stripe_nr_end * map->stripe_len -
4833 (offset + *length);
4834
4835 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4836 if (rw & REQ_DISCARD)
4837 num_stripes = min_t(u64, map->num_stripes,
4838 stripe_nr_end - stripe_nr_orig);
4839 stripe_index = do_div(stripe_nr, map->num_stripes);
4840 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4841 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4842 num_stripes = map->num_stripes;
4843 else if (mirror_num)
4844 stripe_index = mirror_num - 1;
4845 else {
4846 stripe_index = find_live_mirror(fs_info, map, 0,
4847 map->num_stripes,
4848 current->pid % map->num_stripes,
4849 dev_replace_is_ongoing);
4850 mirror_num = stripe_index + 1;
4851 }
4852
4853 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4854 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4855 num_stripes = map->num_stripes;
4856 } else if (mirror_num) {
4857 stripe_index = mirror_num - 1;
4858 } else {
4859 mirror_num = 1;
4860 }
4861
4862 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4863 int factor = map->num_stripes / map->sub_stripes;
4864
4865 stripe_index = do_div(stripe_nr, factor);
4866 stripe_index *= map->sub_stripes;
4867
4868 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4869 num_stripes = map->sub_stripes;
4870 else if (rw & REQ_DISCARD)
4871 num_stripes = min_t(u64, map->sub_stripes *
4872 (stripe_nr_end - stripe_nr_orig),
4873 map->num_stripes);
4874 else if (mirror_num)
4875 stripe_index += mirror_num - 1;
4876 else {
4877 int old_stripe_index = stripe_index;
4878 stripe_index = find_live_mirror(fs_info, map,
4879 stripe_index,
4880 map->sub_stripes, stripe_index +
4881 current->pid % map->sub_stripes,
4882 dev_replace_is_ongoing);
4883 mirror_num = stripe_index - old_stripe_index + 1;
4884 }
4885
4886 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4887 BTRFS_BLOCK_GROUP_RAID6)) {
4888 u64 tmp;
4889
4890 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4891 && raid_map_ret) {
4892 int i, rot;
4893
4894 /* push stripe_nr back to the start of the full stripe */
4895 stripe_nr = raid56_full_stripe_start;
4896 do_div(stripe_nr, stripe_len);
4897
4898 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4899
4900 /* RAID[56] write or recovery. Return all stripes */
4901 num_stripes = map->num_stripes;
4902 max_errors = nr_parity_stripes(map);
4903
4904 raid_map = kmalloc_array(num_stripes, sizeof(u64),
4905 GFP_NOFS);
4906 if (!raid_map) {
4907 ret = -ENOMEM;
4908 goto out;
4909 }
4910
4911 /* Work out the disk rotation on this stripe-set */
4912 tmp = stripe_nr;
4913 rot = do_div(tmp, num_stripes);
4914
4915 /* Fill in the logical address of each stripe */
4916 tmp = stripe_nr * nr_data_stripes(map);
4917 for (i = 0; i < nr_data_stripes(map); i++)
4918 raid_map[(i+rot) % num_stripes] =
4919 em->start + (tmp + i) * map->stripe_len;
4920
4921 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4922 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4923 raid_map[(i+rot+1) % num_stripes] =
4924 RAID6_Q_STRIPE;
4925
4926 *length = map->stripe_len;
4927 stripe_index = 0;
4928 stripe_offset = 0;
4929 } else {
4930 /*
4931 * Mirror #0 or #1 means the original data block.
4932 * Mirror #2 is RAID5 parity block.
4933 * Mirror #3 is RAID6 Q block.
4934 */
4935 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4936 if (mirror_num > 1)
4937 stripe_index = nr_data_stripes(map) +
4938 mirror_num - 2;
4939
4940 /* We distribute the parity blocks across stripes */
4941 tmp = stripe_nr + stripe_index;
4942 stripe_index = do_div(tmp, map->num_stripes);
4943 }
4944 } else {
4945 /*
4946 * after this do_div call, stripe_nr is the number of stripes
4947 * on this device we have to walk to find the data, and
4948 * stripe_index is the number of our device in the stripe array
4949 */
4950 stripe_index = do_div(stripe_nr, map->num_stripes);
4951 mirror_num = stripe_index + 1;
4952 }
4953 BUG_ON(stripe_index >= map->num_stripes);
4954
4955 num_alloc_stripes = num_stripes;
4956 if (dev_replace_is_ongoing) {
4957 if (rw & (REQ_WRITE | REQ_DISCARD))
4958 num_alloc_stripes <<= 1;
4959 if (rw & REQ_GET_READ_MIRRORS)
4960 num_alloc_stripes++;
4961 }
4962 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4963 if (!bbio) {
4964 kfree(raid_map);
4965 ret = -ENOMEM;
4966 goto out;
4967 }
4968 atomic_set(&bbio->error, 0);
4969
4970 if (rw & REQ_DISCARD) {
4971 int factor = 0;
4972 int sub_stripes = 0;
4973 u64 stripes_per_dev = 0;
4974 u32 remaining_stripes = 0;
4975 u32 last_stripe = 0;
4976
4977 if (map->type &
4978 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4979 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4980 sub_stripes = 1;
4981 else
4982 sub_stripes = map->sub_stripes;
4983
4984 factor = map->num_stripes / sub_stripes;
4985 stripes_per_dev = div_u64_rem(stripe_nr_end -
4986 stripe_nr_orig,
4987 factor,
4988 &remaining_stripes);
4989 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4990 last_stripe *= sub_stripes;
4991 }
4992
4993 for (i = 0; i < num_stripes; i++) {
4994 bbio->stripes[i].physical =
4995 map->stripes[stripe_index].physical +
4996 stripe_offset + stripe_nr * map->stripe_len;
4997 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4998
4999 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
5000 BTRFS_BLOCK_GROUP_RAID10)) {
5001 bbio->stripes[i].length = stripes_per_dev *
5002 map->stripe_len;
5003
5004 if (i / sub_stripes < remaining_stripes)
5005 bbio->stripes[i].length +=
5006 map->stripe_len;
5007
5008 /*
5009 * Special for the first stripe and
5010 * the last stripe:
5011 *
5012 * |-------|...|-------|
5013 * |----------|
5014 * off end_off
5015 */
5016 if (i < sub_stripes)
5017 bbio->stripes[i].length -=
5018 stripe_offset;
5019
5020 if (stripe_index >= last_stripe &&
5021 stripe_index <= (last_stripe +
5022 sub_stripes - 1))
5023 bbio->stripes[i].length -=
5024 stripe_end_offset;
5025
5026 if (i == sub_stripes - 1)
5027 stripe_offset = 0;
5028 } else
5029 bbio->stripes[i].length = *length;
5030
5031 stripe_index++;
5032 if (stripe_index == map->num_stripes) {
5033 /* This could only happen for RAID0/10 */
5034 stripe_index = 0;
5035 stripe_nr++;
5036 }
5037 }
5038 } else {
5039 for (i = 0; i < num_stripes; i++) {
5040 bbio->stripes[i].physical =
5041 map->stripes[stripe_index].physical +
5042 stripe_offset +
5043 stripe_nr * map->stripe_len;
5044 bbio->stripes[i].dev =
5045 map->stripes[stripe_index].dev;
5046 stripe_index++;
5047 }
5048 }
5049
5050 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
5051 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
5052 BTRFS_BLOCK_GROUP_RAID10 |
5053 BTRFS_BLOCK_GROUP_RAID5 |
5054 BTRFS_BLOCK_GROUP_DUP)) {
5055 max_errors = 1;
5056 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
5057 max_errors = 2;
5058 }
5059 }
5060
5061 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
5062 dev_replace->tgtdev != NULL) {
5063 int index_where_to_add;
5064 u64 srcdev_devid = dev_replace->srcdev->devid;
5065
5066 /*
5067 * duplicate the write operations while the dev replace
5068 * procedure is running. Since the copying of the old disk
5069 * to the new disk takes place at run time while the
5070 * filesystem is mounted writable, the regular write
5071 * operations to the old disk have to be duplicated to go
5072 * to the new disk as well.
5073 * Note that device->missing is handled by the caller, and
5074 * that the write to the old disk is already set up in the
5075 * stripes array.
5076 */
5077 index_where_to_add = num_stripes;
5078 for (i = 0; i < num_stripes; i++) {
5079 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5080 /* write to new disk, too */
5081 struct btrfs_bio_stripe *new =
5082 bbio->stripes + index_where_to_add;
5083 struct btrfs_bio_stripe *old =
5084 bbio->stripes + i;
5085
5086 new->physical = old->physical;
5087 new->length = old->length;
5088 new->dev = dev_replace->tgtdev;
5089 index_where_to_add++;
5090 max_errors++;
5091 }
5092 }
5093 num_stripes = index_where_to_add;
5094 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
5095 dev_replace->tgtdev != NULL) {
5096 u64 srcdev_devid = dev_replace->srcdev->devid;
5097 int index_srcdev = 0;
5098 int found = 0;
5099 u64 physical_of_found = 0;
5100
5101 /*
5102 * During the dev-replace procedure, the target drive can
5103 * also be used to read data in case it is needed to repair
5104 * a corrupt block elsewhere. This is possible if the
5105 * requested area is left of the left cursor. In this area,
5106 * the target drive is a full copy of the source drive.
5107 */
5108 for (i = 0; i < num_stripes; i++) {
5109 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5110 /*
5111 * In case of DUP, in order to keep it
5112 * simple, only add the mirror with the
5113 * lowest physical address
5114 */
5115 if (found &&
5116 physical_of_found <=
5117 bbio->stripes[i].physical)
5118 continue;
5119 index_srcdev = i;
5120 found = 1;
5121 physical_of_found = bbio->stripes[i].physical;
5122 }
5123 }
5124 if (found) {
5125 u64 length = map->stripe_len;
5126
5127 if (physical_of_found + length <=
5128 dev_replace->cursor_left) {
5129 struct btrfs_bio_stripe *tgtdev_stripe =
5130 bbio->stripes + num_stripes;
5131
5132 tgtdev_stripe->physical = physical_of_found;
5133 tgtdev_stripe->length =
5134 bbio->stripes[index_srcdev].length;
5135 tgtdev_stripe->dev = dev_replace->tgtdev;
5136
5137 num_stripes++;
5138 }
5139 }
5140 }
5141
5142 *bbio_ret = bbio;
5143 bbio->num_stripes = num_stripes;
5144 bbio->max_errors = max_errors;
5145 bbio->mirror_num = mirror_num;
5146
5147 /*
5148 * this is the case that REQ_READ && dev_replace_is_ongoing &&
5149 * mirror_num == num_stripes + 1 && dev_replace target drive is
5150 * available as a mirror
5151 */
5152 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
5153 WARN_ON(num_stripes > 1);
5154 bbio->stripes[0].dev = dev_replace->tgtdev;
5155 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
5156 bbio->mirror_num = map->num_stripes + 1;
5157 }
5158 if (raid_map) {
5159 sort_parity_stripes(bbio, raid_map);
5160 *raid_map_ret = raid_map;
5161 }
5162 out:
5163 if (dev_replace_is_ongoing)
5164 btrfs_dev_replace_unlock(dev_replace);
5165 free_extent_map(em);
5166 return ret;
5167 }
5168
5169 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
5170 u64 logical, u64 *length,
5171 struct btrfs_bio **bbio_ret, int mirror_num)
5172 {
5173 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
5174 mirror_num, NULL);
5175 }
5176
5177 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
5178 u64 chunk_start, u64 physical, u64 devid,
5179 u64 **logical, int *naddrs, int *stripe_len)
5180 {
5181 struct extent_map_tree *em_tree = &map_tree->map_tree;
5182 struct extent_map *em;
5183 struct map_lookup *map;
5184 u64 *buf;
5185 u64 bytenr;
5186 u64 length;
5187 u64 stripe_nr;
5188 u64 rmap_len;
5189 int i, j, nr = 0;
5190
5191 read_lock(&em_tree->lock);
5192 em = lookup_extent_mapping(em_tree, chunk_start, 1);
5193 read_unlock(&em_tree->lock);
5194
5195 if (!em) {
5196 printk(KERN_ERR "BTRFS: couldn't find em for chunk %Lu\n",
5197 chunk_start);
5198 return -EIO;
5199 }
5200
5201 if (em->start != chunk_start) {
5202 printk(KERN_ERR "BTRFS: bad chunk start, em=%Lu, wanted=%Lu\n",
5203 em->start, chunk_start);
5204 free_extent_map(em);
5205 return -EIO;
5206 }
5207 map = (struct map_lookup *)em->bdev;
5208
5209 length = em->len;
5210 rmap_len = map->stripe_len;
5211
5212 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
5213 do_div(length, map->num_stripes / map->sub_stripes);
5214 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
5215 do_div(length, map->num_stripes);
5216 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
5217 BTRFS_BLOCK_GROUP_RAID6)) {
5218 do_div(length, nr_data_stripes(map));
5219 rmap_len = map->stripe_len * nr_data_stripes(map);
5220 }
5221
5222 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
5223 BUG_ON(!buf); /* -ENOMEM */
5224
5225 for (i = 0; i < map->num_stripes; i++) {
5226 if (devid && map->stripes[i].dev->devid != devid)
5227 continue;
5228 if (map->stripes[i].physical > physical ||
5229 map->stripes[i].physical + length <= physical)
5230 continue;
5231
5232 stripe_nr = physical - map->stripes[i].physical;
5233 do_div(stripe_nr, map->stripe_len);
5234
5235 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
5236 stripe_nr = stripe_nr * map->num_stripes + i;
5237 do_div(stripe_nr, map->sub_stripes);
5238 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
5239 stripe_nr = stripe_nr * map->num_stripes + i;
5240 } /* else if RAID[56], multiply by nr_data_stripes().
5241 * Alternatively, just use rmap_len below instead of
5242 * map->stripe_len */
5243
5244 bytenr = chunk_start + stripe_nr * rmap_len;
5245 WARN_ON(nr >= map->num_stripes);
5246 for (j = 0; j < nr; j++) {
5247 if (buf[j] == bytenr)
5248 break;
5249 }
5250 if (j == nr) {
5251 WARN_ON(nr >= map->num_stripes);
5252 buf[nr++] = bytenr;
5253 }
5254 }
5255
5256 *logical = buf;
5257 *naddrs = nr;
5258 *stripe_len = rmap_len;
5259
5260 free_extent_map(em);
5261 return 0;
5262 }
5263
5264 static void btrfs_end_bio(struct bio *bio, int err)
5265 {
5266 struct btrfs_bio *bbio = bio->bi_private;
5267 struct btrfs_device *dev = bbio->stripes[0].dev;
5268 int is_orig_bio = 0;
5269
5270 if (err) {
5271 atomic_inc(&bbio->error);
5272 if (err == -EIO || err == -EREMOTEIO) {
5273 unsigned int stripe_index =
5274 btrfs_io_bio(bio)->stripe_index;
5275
5276 BUG_ON(stripe_index >= bbio->num_stripes);
5277 dev = bbio->stripes[stripe_index].dev;
5278 if (dev->bdev) {
5279 if (bio->bi_rw & WRITE)
5280 btrfs_dev_stat_inc(dev,
5281 BTRFS_DEV_STAT_WRITE_ERRS);
5282 else
5283 btrfs_dev_stat_inc(dev,
5284 BTRFS_DEV_STAT_READ_ERRS);
5285 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5286 btrfs_dev_stat_inc(dev,
5287 BTRFS_DEV_STAT_FLUSH_ERRS);
5288 btrfs_dev_stat_print_on_error(dev);
5289 }
5290 }
5291 }
5292
5293 if (bio == bbio->orig_bio)
5294 is_orig_bio = 1;
5295
5296 btrfs_bio_counter_dec(bbio->fs_info);
5297
5298 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5299 if (!is_orig_bio) {
5300 bio_put(bio);
5301 bio = bbio->orig_bio;
5302 }
5303 bio->bi_private = bbio->private;
5304 bio->bi_end_io = bbio->end_io;
5305 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5306 /* only send an error to the higher layers if it is
5307 * beyond the tolerance of the btrfs bio
5308 */
5309 if (atomic_read(&bbio->error) > bbio->max_errors) {
5310 err = -EIO;
5311 } else {
5312 /*
5313 * this bio is actually up to date, we didn't
5314 * go over the max number of errors
5315 */
5316 set_bit(BIO_UPTODATE, &bio->bi_flags);
5317 err = 0;
5318 }
5319 kfree(bbio);
5320
5321 bio_endio(bio, err);
5322 } else if (!is_orig_bio) {
5323 bio_put(bio);
5324 }
5325 }
5326
5327 /*
5328 * see run_scheduled_bios for a description of why bios are collected for
5329 * async submit.
5330 *
5331 * This will add one bio to the pending list for a device and make sure
5332 * the work struct is scheduled.
5333 */
5334 static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5335 struct btrfs_device *device,
5336 int rw, struct bio *bio)
5337 {
5338 int should_queue = 1;
5339 struct btrfs_pending_bios *pending_bios;
5340
5341 if (device->missing || !device->bdev) {
5342 bio_endio(bio, -EIO);
5343 return;
5344 }
5345
5346 /* don't bother with additional async steps for reads, right now */
5347 if (!(rw & REQ_WRITE)) {
5348 bio_get(bio);
5349 btrfsic_submit_bio(rw, bio);
5350 bio_put(bio);
5351 return;
5352 }
5353
5354 /*
5355 * nr_async_bios allows us to reliably return congestion to the
5356 * higher layers. Otherwise, the async bio makes it appear we have
5357 * made progress against dirty pages when we've really just put it
5358 * on a queue for later
5359 */
5360 atomic_inc(&root->fs_info->nr_async_bios);
5361 WARN_ON(bio->bi_next);
5362 bio->bi_next = NULL;
5363 bio->bi_rw |= rw;
5364
5365 spin_lock(&device->io_lock);
5366 if (bio->bi_rw & REQ_SYNC)
5367 pending_bios = &device->pending_sync_bios;
5368 else
5369 pending_bios = &device->pending_bios;
5370
5371 if (pending_bios->tail)
5372 pending_bios->tail->bi_next = bio;
5373
5374 pending_bios->tail = bio;
5375 if (!pending_bios->head)
5376 pending_bios->head = bio;
5377 if (device->running_pending)
5378 should_queue = 0;
5379
5380 spin_unlock(&device->io_lock);
5381
5382 if (should_queue)
5383 btrfs_queue_work(root->fs_info->submit_workers,
5384 &device->work);
5385 }
5386
5387 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5388 sector_t sector)
5389 {
5390 struct bio_vec *prev;
5391 struct request_queue *q = bdev_get_queue(bdev);
5392 unsigned int max_sectors = queue_max_sectors(q);
5393 struct bvec_merge_data bvm = {
5394 .bi_bdev = bdev,
5395 .bi_sector = sector,
5396 .bi_rw = bio->bi_rw,
5397 };
5398
5399 if (WARN_ON(bio->bi_vcnt == 0))
5400 return 1;
5401
5402 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5403 if (bio_sectors(bio) > max_sectors)
5404 return 0;
5405
5406 if (!q->merge_bvec_fn)
5407 return 1;
5408
5409 bvm.bi_size = bio->bi_size - prev->bv_len;
5410 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5411 return 0;
5412 return 1;
5413 }
5414
5415 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5416 struct bio *bio, u64 physical, int dev_nr,
5417 int rw, int async)
5418 {
5419 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5420
5421 bio->bi_private = bbio;
5422 btrfs_io_bio(bio)->stripe_index = dev_nr;
5423 bio->bi_end_io = btrfs_end_bio;
5424 bio->bi_sector = physical >> 9;
5425 #ifdef DEBUG
5426 {
5427 struct rcu_string *name;
5428
5429 rcu_read_lock();
5430 name = rcu_dereference(dev->name);
5431 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5432 "(%s id %llu), size=%u\n", rw,
5433 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5434 name->str, dev->devid, bio->bi_size);
5435 rcu_read_unlock();
5436 }
5437 #endif
5438 bio->bi_bdev = dev->bdev;
5439
5440 btrfs_bio_counter_inc_noblocked(root->fs_info);
5441
5442 if (async)
5443 btrfs_schedule_bio(root, dev, rw, bio);
5444 else
5445 btrfsic_submit_bio(rw, bio);
5446 }
5447
5448 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5449 struct bio *first_bio, struct btrfs_device *dev,
5450 int dev_nr, int rw, int async)
5451 {
5452 struct bio_vec *bvec = first_bio->bi_io_vec;
5453 struct bio *bio;
5454 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5455 u64 physical = bbio->stripes[dev_nr].physical;
5456
5457 again:
5458 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5459 if (!bio)
5460 return -ENOMEM;
5461
5462 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5463 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5464 bvec->bv_offset) < bvec->bv_len) {
5465 u64 len = bio->bi_size;
5466
5467 atomic_inc(&bbio->stripes_pending);
5468 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5469 rw, async);
5470 physical += len;
5471 goto again;
5472 }
5473 bvec++;
5474 }
5475
5476 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5477 return 0;
5478 }
5479
5480 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5481 {
5482 atomic_inc(&bbio->error);
5483 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5484 bio->bi_private = bbio->private;
5485 bio->bi_end_io = bbio->end_io;
5486 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5487 bio->bi_sector = logical >> 9;
5488 kfree(bbio);
5489 bio_endio(bio, -EIO);
5490 }
5491 }
5492
5493 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5494 int mirror_num, int async_submit)
5495 {
5496 struct btrfs_device *dev;
5497 struct bio *first_bio = bio;
5498 u64 logical = (u64)bio->bi_sector << 9;
5499 u64 length = 0;
5500 u64 map_length;
5501 u64 *raid_map = NULL;
5502 int ret;
5503 int dev_nr = 0;
5504 int total_devs = 1;
5505 struct btrfs_bio *bbio = NULL;
5506
5507 length = bio->bi_size;
5508 map_length = length;
5509
5510 btrfs_bio_counter_inc_blocked(root->fs_info);
5511 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5512 mirror_num, &raid_map);
5513 if (ret) {
5514 btrfs_bio_counter_dec(root->fs_info);
5515 return ret;
5516 }
5517
5518 total_devs = bbio->num_stripes;
5519 bbio->orig_bio = first_bio;
5520 bbio->private = first_bio->bi_private;
5521 bbio->end_io = first_bio->bi_end_io;
5522 bbio->fs_info = root->fs_info;
5523 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5524
5525 if (raid_map) {
5526 /* In this case, map_length has been set to the length of
5527 a single stripe; not the whole write */
5528 if (rw & WRITE) {
5529 ret = raid56_parity_write(root, bio, bbio,
5530 raid_map, map_length);
5531 } else {
5532 ret = raid56_parity_recover(root, bio, bbio,
5533 raid_map, map_length,
5534 mirror_num);
5535 }
5536 /*
5537 * FIXME, replace dosen't support raid56 yet, please fix
5538 * it in the future.
5539 */
5540 btrfs_bio_counter_dec(root->fs_info);
5541 return ret;
5542 }
5543
5544 if (map_length < length) {
5545 btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5546 logical, length, map_length);
5547 BUG();
5548 }
5549
5550 while (dev_nr < total_devs) {
5551 dev = bbio->stripes[dev_nr].dev;
5552 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5553 bbio_error(bbio, first_bio, logical);
5554 dev_nr++;
5555 continue;
5556 }
5557
5558 /*
5559 * Check and see if we're ok with this bio based on it's size
5560 * and offset with the given device.
5561 */
5562 if (!bio_size_ok(dev->bdev, first_bio,
5563 bbio->stripes[dev_nr].physical >> 9)) {
5564 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5565 dev_nr, rw, async_submit);
5566 BUG_ON(ret);
5567 dev_nr++;
5568 continue;
5569 }
5570
5571 if (dev_nr < total_devs - 1) {
5572 bio = btrfs_bio_clone(first_bio, GFP_NOFS);
5573 BUG_ON(!bio); /* -ENOMEM */
5574 } else {
5575 bio = first_bio;
5576 }
5577
5578 submit_stripe_bio(root, bbio, bio,
5579 bbio->stripes[dev_nr].physical, dev_nr, rw,
5580 async_submit);
5581 dev_nr++;
5582 }
5583 btrfs_bio_counter_dec(root->fs_info);
5584 return 0;
5585 }
5586
5587 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5588 u8 *uuid, u8 *fsid)
5589 {
5590 struct btrfs_device *device;
5591 struct btrfs_fs_devices *cur_devices;
5592
5593 cur_devices = fs_info->fs_devices;
5594 while (cur_devices) {
5595 if (!fsid ||
5596 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5597 device = __find_device(&cur_devices->devices,
5598 devid, uuid);
5599 if (device)
5600 return device;
5601 }
5602 cur_devices = cur_devices->seed;
5603 }
5604 return NULL;
5605 }
5606
5607 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5608 u64 devid, u8 *dev_uuid)
5609 {
5610 struct btrfs_device *device;
5611 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5612
5613 device = btrfs_alloc_device(NULL, &devid, dev_uuid);
5614 if (IS_ERR(device))
5615 return NULL;
5616
5617 list_add(&device->dev_list, &fs_devices->devices);
5618 device->fs_devices = fs_devices;
5619 fs_devices->num_devices++;
5620
5621 device->missing = 1;
5622 fs_devices->missing_devices++;
5623
5624 return device;
5625 }
5626
5627 /**
5628 * btrfs_alloc_device - allocate struct btrfs_device
5629 * @fs_info: used only for generating a new devid, can be NULL if
5630 * devid is provided (i.e. @devid != NULL).
5631 * @devid: a pointer to devid for this device. If NULL a new devid
5632 * is generated.
5633 * @uuid: a pointer to UUID for this device. If NULL a new UUID
5634 * is generated.
5635 *
5636 * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
5637 * on error. Returned struct is not linked onto any lists and can be
5638 * destroyed with kfree() right away.
5639 */
5640 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
5641 const u64 *devid,
5642 const u8 *uuid)
5643 {
5644 struct btrfs_device *dev;
5645 u64 tmp;
5646
5647 if (WARN_ON(!devid && !fs_info))
5648 return ERR_PTR(-EINVAL);
5649
5650 dev = __alloc_device();
5651 if (IS_ERR(dev))
5652 return dev;
5653
5654 if (devid)
5655 tmp = *devid;
5656 else {
5657 int ret;
5658
5659 ret = find_next_devid(fs_info, &tmp);
5660 if (ret) {
5661 kfree(dev);
5662 return ERR_PTR(ret);
5663 }
5664 }
5665 dev->devid = tmp;
5666
5667 if (uuid)
5668 memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
5669 else
5670 generate_random_uuid(dev->uuid);
5671
5672 btrfs_init_work(&dev->work, pending_bios_fn, NULL, NULL);
5673
5674 return dev;
5675 }
5676
5677 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5678 struct extent_buffer *leaf,
5679 struct btrfs_chunk *chunk)
5680 {
5681 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5682 struct map_lookup *map;
5683 struct extent_map *em;
5684 u64 logical;
5685 u64 length;
5686 u64 devid;
5687 u8 uuid[BTRFS_UUID_SIZE];
5688 int num_stripes;
5689 int ret;
5690 int i;
5691
5692 logical = key->offset;
5693 length = btrfs_chunk_length(leaf, chunk);
5694
5695 read_lock(&map_tree->map_tree.lock);
5696 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5697 read_unlock(&map_tree->map_tree.lock);
5698
5699 /* already mapped? */
5700 if (em && em->start <= logical && em->start + em->len > logical) {
5701 free_extent_map(em);
5702 return 0;
5703 } else if (em) {
5704 free_extent_map(em);
5705 }
5706
5707 em = alloc_extent_map();
5708 if (!em)
5709 return -ENOMEM;
5710 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5711 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5712 if (!map) {
5713 free_extent_map(em);
5714 return -ENOMEM;
5715 }
5716
5717 em->bdev = (struct block_device *)map;
5718 em->start = logical;
5719 em->len = length;
5720 em->orig_start = 0;
5721 em->block_start = 0;
5722 em->block_len = em->len;
5723
5724 map->num_stripes = num_stripes;
5725 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5726 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5727 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5728 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5729 map->type = btrfs_chunk_type(leaf, chunk);
5730 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5731 for (i = 0; i < num_stripes; i++) {
5732 map->stripes[i].physical =
5733 btrfs_stripe_offset_nr(leaf, chunk, i);
5734 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5735 read_extent_buffer(leaf, uuid, (unsigned long)
5736 btrfs_stripe_dev_uuid_nr(chunk, i),
5737 BTRFS_UUID_SIZE);
5738 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5739 uuid, NULL);
5740 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5741 kfree(map);
5742 free_extent_map(em);
5743 return -EIO;
5744 }
5745 if (!map->stripes[i].dev) {
5746 map->stripes[i].dev =
5747 add_missing_dev(root, devid, uuid);
5748 if (!map->stripes[i].dev) {
5749 kfree(map);
5750 free_extent_map(em);
5751 return -EIO;
5752 }
5753 }
5754 map->stripes[i].dev->in_fs_metadata = 1;
5755 }
5756
5757 write_lock(&map_tree->map_tree.lock);
5758 ret = add_extent_mapping(&map_tree->map_tree, em, 0);
5759 write_unlock(&map_tree->map_tree.lock);
5760 BUG_ON(ret); /* Tree corruption */
5761 free_extent_map(em);
5762
5763 return 0;
5764 }
5765
5766 static void fill_device_from_item(struct extent_buffer *leaf,
5767 struct btrfs_dev_item *dev_item,
5768 struct btrfs_device *device)
5769 {
5770 unsigned long ptr;
5771
5772 device->devid = btrfs_device_id(leaf, dev_item);
5773 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5774 device->total_bytes = device->disk_total_bytes;
5775 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5776 device->type = btrfs_device_type(leaf, dev_item);
5777 device->io_align = btrfs_device_io_align(leaf, dev_item);
5778 device->io_width = btrfs_device_io_width(leaf, dev_item);
5779 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5780 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5781 device->is_tgtdev_for_dev_replace = 0;
5782
5783 ptr = btrfs_device_uuid(dev_item);
5784 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5785 }
5786
5787 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5788 {
5789 struct btrfs_fs_devices *fs_devices;
5790 int ret;
5791
5792 BUG_ON(!mutex_is_locked(&uuid_mutex));
5793
5794 fs_devices = root->fs_info->fs_devices->seed;
5795 while (fs_devices) {
5796 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5797 ret = 0;
5798 goto out;
5799 }
5800 fs_devices = fs_devices->seed;
5801 }
5802
5803 fs_devices = find_fsid(fsid);
5804 if (!fs_devices) {
5805 ret = -ENOENT;
5806 goto out;
5807 }
5808
5809 fs_devices = clone_fs_devices(fs_devices);
5810 if (IS_ERR(fs_devices)) {
5811 ret = PTR_ERR(fs_devices);
5812 goto out;
5813 }
5814
5815 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5816 root->fs_info->bdev_holder);
5817 if (ret) {
5818 free_fs_devices(fs_devices);
5819 goto out;
5820 }
5821
5822 if (!fs_devices->seeding) {
5823 __btrfs_close_devices(fs_devices);
5824 free_fs_devices(fs_devices);
5825 ret = -EINVAL;
5826 goto out;
5827 }
5828
5829 fs_devices->seed = root->fs_info->fs_devices->seed;
5830 root->fs_info->fs_devices->seed = fs_devices;
5831 out:
5832 return ret;
5833 }
5834
5835 static int read_one_dev(struct btrfs_root *root,
5836 struct extent_buffer *leaf,
5837 struct btrfs_dev_item *dev_item)
5838 {
5839 struct btrfs_device *device;
5840 u64 devid;
5841 int ret;
5842 u8 fs_uuid[BTRFS_UUID_SIZE];
5843 u8 dev_uuid[BTRFS_UUID_SIZE];
5844
5845 devid = btrfs_device_id(leaf, dev_item);
5846 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
5847 BTRFS_UUID_SIZE);
5848 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
5849 BTRFS_UUID_SIZE);
5850
5851 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5852 ret = open_seed_devices(root, fs_uuid);
5853 if (ret && !btrfs_test_opt(root, DEGRADED))
5854 return ret;
5855 }
5856
5857 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5858 if (!device || !device->bdev) {
5859 if (!btrfs_test_opt(root, DEGRADED))
5860 return -EIO;
5861
5862 if (!device) {
5863 btrfs_warn(root->fs_info, "devid %llu missing", devid);
5864 device = add_missing_dev(root, devid, dev_uuid);
5865 if (!device)
5866 return -ENOMEM;
5867 } else if (!device->missing) {
5868 /*
5869 * this happens when a device that was properly setup
5870 * in the device info lists suddenly goes bad.
5871 * device->bdev is NULL, and so we have to set
5872 * device->missing to one here
5873 */
5874 root->fs_info->fs_devices->missing_devices++;
5875 device->missing = 1;
5876 }
5877 }
5878
5879 if (device->fs_devices != root->fs_info->fs_devices) {
5880 BUG_ON(device->writeable);
5881 if (device->generation !=
5882 btrfs_device_generation(leaf, dev_item))
5883 return -EINVAL;
5884 }
5885
5886 fill_device_from_item(leaf, dev_item, device);
5887 device->in_fs_metadata = 1;
5888 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5889 device->fs_devices->total_rw_bytes += device->total_bytes;
5890 spin_lock(&root->fs_info->free_chunk_lock);
5891 root->fs_info->free_chunk_space += device->total_bytes -
5892 device->bytes_used;
5893 spin_unlock(&root->fs_info->free_chunk_lock);
5894 }
5895 ret = 0;
5896 return ret;
5897 }
5898
5899 int btrfs_read_sys_array(struct btrfs_root *root)
5900 {
5901 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5902 struct extent_buffer *sb;
5903 struct btrfs_disk_key *disk_key;
5904 struct btrfs_chunk *chunk;
5905 u8 *ptr;
5906 unsigned long sb_ptr;
5907 int ret = 0;
5908 u32 num_stripes;
5909 u32 array_size;
5910 u32 len = 0;
5911 u32 cur;
5912 struct btrfs_key key;
5913
5914 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5915 BTRFS_SUPER_INFO_SIZE);
5916 if (!sb)
5917 return -ENOMEM;
5918 btrfs_set_buffer_uptodate(sb);
5919 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5920 /*
5921 * The sb extent buffer is artifical and just used to read the system array.
5922 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5923 * pages up-to-date when the page is larger: extent does not cover the
5924 * whole page and consequently check_page_uptodate does not find all
5925 * the page's extents up-to-date (the hole beyond sb),
5926 * write_extent_buffer then triggers a WARN_ON.
5927 *
5928 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5929 * but sb spans only this function. Add an explicit SetPageUptodate call
5930 * to silence the warning eg. on PowerPC 64.
5931 */
5932 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5933 SetPageUptodate(sb->pages[0]);
5934
5935 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5936 array_size = btrfs_super_sys_array_size(super_copy);
5937
5938 ptr = super_copy->sys_chunk_array;
5939 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5940 cur = 0;
5941
5942 while (cur < array_size) {
5943 disk_key = (struct btrfs_disk_key *)ptr;
5944 btrfs_disk_key_to_cpu(&key, disk_key);
5945
5946 len = sizeof(*disk_key); ptr += len;
5947 sb_ptr += len;
5948 cur += len;
5949
5950 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5951 chunk = (struct btrfs_chunk *)sb_ptr;
5952 ret = read_one_chunk(root, &key, sb, chunk);
5953 if (ret)
5954 break;
5955 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5956 len = btrfs_chunk_item_size(num_stripes);
5957 } else {
5958 ret = -EIO;
5959 break;
5960 }
5961 ptr += len;
5962 sb_ptr += len;
5963 cur += len;
5964 }
5965 free_extent_buffer(sb);
5966 return ret;
5967 }
5968
5969 int btrfs_read_chunk_tree(struct btrfs_root *root)
5970 {
5971 struct btrfs_path *path;
5972 struct extent_buffer *leaf;
5973 struct btrfs_key key;
5974 struct btrfs_key found_key;
5975 int ret;
5976 int slot;
5977
5978 root = root->fs_info->chunk_root;
5979
5980 path = btrfs_alloc_path();
5981 if (!path)
5982 return -ENOMEM;
5983
5984 mutex_lock(&uuid_mutex);
5985 lock_chunks(root);
5986
5987 /*
5988 * Read all device items, and then all the chunk items. All
5989 * device items are found before any chunk item (their object id
5990 * is smaller than the lowest possible object id for a chunk
5991 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
5992 */
5993 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5994 key.offset = 0;
5995 key.type = 0;
5996 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5997 if (ret < 0)
5998 goto error;
5999 while (1) {
6000 leaf = path->nodes[0];
6001 slot = path->slots[0];
6002 if (slot >= btrfs_header_nritems(leaf)) {
6003 ret = btrfs_next_leaf(root, path);
6004 if (ret == 0)
6005 continue;
6006 if (ret < 0)
6007 goto error;
6008 break;
6009 }
6010 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6011 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
6012 struct btrfs_dev_item *dev_item;
6013 dev_item = btrfs_item_ptr(leaf, slot,
6014 struct btrfs_dev_item);
6015 ret = read_one_dev(root, leaf, dev_item);
6016 if (ret)
6017 goto error;
6018 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
6019 struct btrfs_chunk *chunk;
6020 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
6021 ret = read_one_chunk(root, &found_key, leaf, chunk);
6022 if (ret)
6023 goto error;
6024 }
6025 path->slots[0]++;
6026 }
6027 ret = 0;
6028 error:
6029 unlock_chunks(root);
6030 mutex_unlock(&uuid_mutex);
6031
6032 btrfs_free_path(path);
6033 return ret;
6034 }
6035
6036 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
6037 {
6038 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6039 struct btrfs_device *device;
6040
6041 mutex_lock(&fs_devices->device_list_mutex);
6042 list_for_each_entry(device, &fs_devices->devices, dev_list)
6043 device->dev_root = fs_info->dev_root;
6044 mutex_unlock(&fs_devices->device_list_mutex);
6045 }
6046
6047 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
6048 {
6049 int i;
6050
6051 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6052 btrfs_dev_stat_reset(dev, i);
6053 }
6054
6055 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
6056 {
6057 struct btrfs_key key;
6058 struct btrfs_key found_key;
6059 struct btrfs_root *dev_root = fs_info->dev_root;
6060 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6061 struct extent_buffer *eb;
6062 int slot;
6063 int ret = 0;
6064 struct btrfs_device *device;
6065 struct btrfs_path *path = NULL;
6066 int i;
6067
6068 path = btrfs_alloc_path();
6069 if (!path) {
6070 ret = -ENOMEM;
6071 goto out;
6072 }
6073
6074 mutex_lock(&fs_devices->device_list_mutex);
6075 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6076 int item_size;
6077 struct btrfs_dev_stats_item *ptr;
6078
6079 key.objectid = 0;
6080 key.type = BTRFS_DEV_STATS_KEY;
6081 key.offset = device->devid;
6082 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
6083 if (ret) {
6084 __btrfs_reset_dev_stats(device);
6085 device->dev_stats_valid = 1;
6086 btrfs_release_path(path);
6087 continue;
6088 }
6089 slot = path->slots[0];
6090 eb = path->nodes[0];
6091 btrfs_item_key_to_cpu(eb, &found_key, slot);
6092 item_size = btrfs_item_size_nr(eb, slot);
6093
6094 ptr = btrfs_item_ptr(eb, slot,
6095 struct btrfs_dev_stats_item);
6096
6097 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6098 if (item_size >= (1 + i) * sizeof(__le64))
6099 btrfs_dev_stat_set(device, i,
6100 btrfs_dev_stats_value(eb, ptr, i));
6101 else
6102 btrfs_dev_stat_reset(device, i);
6103 }
6104
6105 device->dev_stats_valid = 1;
6106 btrfs_dev_stat_print_on_load(device);
6107 btrfs_release_path(path);
6108 }
6109 mutex_unlock(&fs_devices->device_list_mutex);
6110
6111 out:
6112 btrfs_free_path(path);
6113 return ret < 0 ? ret : 0;
6114 }
6115
6116 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
6117 struct btrfs_root *dev_root,
6118 struct btrfs_device *device)
6119 {
6120 struct btrfs_path *path;
6121 struct btrfs_key key;
6122 struct extent_buffer *eb;
6123 struct btrfs_dev_stats_item *ptr;
6124 int ret;
6125 int i;
6126
6127 key.objectid = 0;
6128 key.type = BTRFS_DEV_STATS_KEY;
6129 key.offset = device->devid;
6130
6131 path = btrfs_alloc_path();
6132 BUG_ON(!path);
6133 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
6134 if (ret < 0) {
6135 printk_in_rcu(KERN_WARNING "BTRFS: "
6136 "error %d while searching for dev_stats item for device %s!\n",
6137 ret, rcu_str_deref(device->name));
6138 goto out;
6139 }
6140
6141 if (ret == 0 &&
6142 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
6143 /* need to delete old one and insert a new one */
6144 ret = btrfs_del_item(trans, dev_root, path);
6145 if (ret != 0) {
6146 printk_in_rcu(KERN_WARNING "BTRFS: "
6147 "delete too small dev_stats item for device %s failed %d!\n",
6148 rcu_str_deref(device->name), ret);
6149 goto out;
6150 }
6151 ret = 1;
6152 }
6153
6154 if (ret == 1) {
6155 /* need to insert a new item */
6156 btrfs_release_path(path);
6157 ret = btrfs_insert_empty_item(trans, dev_root, path,
6158 &key, sizeof(*ptr));
6159 if (ret < 0) {
6160 printk_in_rcu(KERN_WARNING "BTRFS: "
6161 "insert dev_stats item for device %s failed %d!\n",
6162 rcu_str_deref(device->name), ret);
6163 goto out;
6164 }
6165 }
6166
6167 eb = path->nodes[0];
6168 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
6169 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6170 btrfs_set_dev_stats_value(eb, ptr, i,
6171 btrfs_dev_stat_read(device, i));
6172 btrfs_mark_buffer_dirty(eb);
6173
6174 out:
6175 btrfs_free_path(path);
6176 return ret;
6177 }
6178
6179 /*
6180 * called from commit_transaction. Writes all changed device stats to disk.
6181 */
6182 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
6183 struct btrfs_fs_info *fs_info)
6184 {
6185 struct btrfs_root *dev_root = fs_info->dev_root;
6186 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6187 struct btrfs_device *device;
6188 int ret = 0;
6189
6190 mutex_lock(&fs_devices->device_list_mutex);
6191 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6192 if (!device->dev_stats_valid || !device->dev_stats_dirty)
6193 continue;
6194
6195 ret = update_dev_stat_item(trans, dev_root, device);
6196 if (!ret)
6197 device->dev_stats_dirty = 0;
6198 }
6199 mutex_unlock(&fs_devices->device_list_mutex);
6200
6201 return ret;
6202 }
6203
6204 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
6205 {
6206 btrfs_dev_stat_inc(dev, index);
6207 btrfs_dev_stat_print_on_error(dev);
6208 }
6209
6210 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
6211 {
6212 if (!dev->dev_stats_valid)
6213 return;
6214 printk_ratelimited_in_rcu(KERN_ERR "BTRFS: "
6215 "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6216 rcu_str_deref(dev->name),
6217 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6218 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6219 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6220 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6221 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6222 }
6223
6224 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
6225 {
6226 int i;
6227
6228 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6229 if (btrfs_dev_stat_read(dev, i) != 0)
6230 break;
6231 if (i == BTRFS_DEV_STAT_VALUES_MAX)
6232 return; /* all values == 0, suppress message */
6233
6234 printk_in_rcu(KERN_INFO "BTRFS: "
6235 "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6236 rcu_str_deref(dev->name),
6237 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6238 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6239 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6240 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6241 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6242 }
6243
6244 int btrfs_get_dev_stats(struct btrfs_root *root,
6245 struct btrfs_ioctl_get_dev_stats *stats)
6246 {
6247 struct btrfs_device *dev;
6248 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6249 int i;
6250
6251 mutex_lock(&fs_devices->device_list_mutex);
6252 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
6253 mutex_unlock(&fs_devices->device_list_mutex);
6254
6255 if (!dev) {
6256 btrfs_warn(root->fs_info, "get dev_stats failed, device not found");
6257 return -ENODEV;
6258 } else if (!dev->dev_stats_valid) {
6259 btrfs_warn(root->fs_info, "get dev_stats failed, not yet valid");
6260 return -ENODEV;
6261 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
6262 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6263 if (stats->nr_items > i)
6264 stats->values[i] =
6265 btrfs_dev_stat_read_and_reset(dev, i);
6266 else
6267 btrfs_dev_stat_reset(dev, i);
6268 }
6269 } else {
6270 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6271 if (stats->nr_items > i)
6272 stats->values[i] = btrfs_dev_stat_read(dev, i);
6273 }
6274 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
6275 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
6276 return 0;
6277 }
6278
6279 int btrfs_scratch_superblock(struct btrfs_device *device)
6280 {
6281 struct buffer_head *bh;
6282 struct btrfs_super_block *disk_super;
6283
6284 bh = btrfs_read_dev_super(device->bdev);
6285 if (!bh)
6286 return -EINVAL;
6287 disk_super = (struct btrfs_super_block *)bh->b_data;
6288
6289 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
6290 set_buffer_dirty(bh);
6291 sync_dirty_buffer(bh);
6292 brelse(bh);
6293
6294 return 0;
6295 }
Arne's tree of linux kernel.