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Linux 3.12.5
[linux/fpc-iii.git] / fs / btrfs / volumes.c
blob043b215769c2c68c538ea147d5cde0721221b833
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 "compat.h"
32 #include "ctree.h"
33 #include "extent_map.h"
34 #include "disk-io.h"
35 #include "transaction.h"
36 #include "print-tree.h"
37 #include "volumes.h"
38 #include "raid56.h"
39 #include "async-thread.h"
40 #include "check-integrity.h"
41 #include "rcu-string.h"
42 #include "math.h"
43 #include "dev-replace.h"
44
45 static int init_first_rw_device(struct btrfs_trans_handle *trans,
46 struct btrfs_root *root,
47 struct btrfs_device *device);
48 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
49 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
50 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
51 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
52
53 static DEFINE_MUTEX(uuid_mutex);
54 static LIST_HEAD(fs_uuids);
55
56 static void lock_chunks(struct btrfs_root *root)
57 {
58 mutex_lock(&root->fs_info->chunk_mutex);
59 }
60
61 static void unlock_chunks(struct btrfs_root *root)
62 {
63 mutex_unlock(&root->fs_info->chunk_mutex);
64 }
65
66 static struct btrfs_fs_devices *__alloc_fs_devices(void)
67 {
68 struct btrfs_fs_devices *fs_devs;
69
70 fs_devs = kzalloc(sizeof(*fs_devs), GFP_NOFS);
71 if (!fs_devs)
72 return ERR_PTR(-ENOMEM);
73
74 mutex_init(&fs_devs->device_list_mutex);
75
76 INIT_LIST_HEAD(&fs_devs->devices);
77 INIT_LIST_HEAD(&fs_devs->alloc_list);
78 INIT_LIST_HEAD(&fs_devs->list);
79
80 return fs_devs;
81 }
82
83 /**
84 * alloc_fs_devices - allocate struct btrfs_fs_devices
85 * @fsid: a pointer to UUID for this FS. If NULL a new UUID is
86 * generated.
87 *
88 * Return: a pointer to a new &struct btrfs_fs_devices on success;
89 * ERR_PTR() on error. Returned struct is not linked onto any lists and
90 * can be destroyed with kfree() right away.
91 */
92 static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid)
93 {
94 struct btrfs_fs_devices *fs_devs;
95
96 fs_devs = __alloc_fs_devices();
97 if (IS_ERR(fs_devs))
98 return fs_devs;
99
100 if (fsid)
101 memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE);
102 else
103 generate_random_uuid(fs_devs->fsid);
104
105 return fs_devs;
106 }
107
108 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
109 {
110 struct btrfs_device *device;
111 WARN_ON(fs_devices->opened);
112 while (!list_empty(&fs_devices->devices)) {
113 device = list_entry(fs_devices->devices.next,
114 struct btrfs_device, dev_list);
115 list_del(&device->dev_list);
116 rcu_string_free(device->name);
117 kfree(device);
118 }
119 kfree(fs_devices);
120 }
121
122 static void btrfs_kobject_uevent(struct block_device *bdev,
123 enum kobject_action action)
124 {
125 int ret;
126
127 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
128 if (ret)
129 pr_warn("Sending event '%d' to kobject: '%s' (%p): failed\n",
130 action,
131 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
132 &disk_to_dev(bdev->bd_disk)->kobj);
133 }
134
135 void btrfs_cleanup_fs_uuids(void)
136 {
137 struct btrfs_fs_devices *fs_devices;
138
139 while (!list_empty(&fs_uuids)) {
140 fs_devices = list_entry(fs_uuids.next,
141 struct btrfs_fs_devices, list);
142 list_del(&fs_devices->list);
143 free_fs_devices(fs_devices);
144 }
145 }
146
147 static struct btrfs_device *__alloc_device(void)
148 {
149 struct btrfs_device *dev;
150
151 dev = kzalloc(sizeof(*dev), GFP_NOFS);
152 if (!dev)
153 return ERR_PTR(-ENOMEM);
154
155 INIT_LIST_HEAD(&dev->dev_list);
156 INIT_LIST_HEAD(&dev->dev_alloc_list);
157
158 spin_lock_init(&dev->io_lock);
159
160 spin_lock_init(&dev->reada_lock);
161 atomic_set(&dev->reada_in_flight, 0);
162 INIT_RADIX_TREE(&dev->reada_zones, GFP_NOFS & ~__GFP_WAIT);
163 INIT_RADIX_TREE(&dev->reada_extents, GFP_NOFS & ~__GFP_WAIT);
164
165 return dev;
166 }
167
168 static noinline struct btrfs_device *__find_device(struct list_head *head,
169 u64 devid, u8 *uuid)
170 {
171 struct btrfs_device *dev;
172
173 list_for_each_entry(dev, head, dev_list) {
174 if (dev->devid == devid &&
175 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
176 return dev;
177 }
178 }
179 return NULL;
180 }
181
182 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
183 {
184 struct btrfs_fs_devices *fs_devices;
185
186 list_for_each_entry(fs_devices, &fs_uuids, list) {
187 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
188 return fs_devices;
189 }
190 return NULL;
191 }
192
193 static int
194 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
195 int flush, struct block_device **bdev,
196 struct buffer_head **bh)
197 {
198 int ret;
199
200 *bdev = blkdev_get_by_path(device_path, flags, holder);
201
202 if (IS_ERR(*bdev)) {
203 ret = PTR_ERR(*bdev);
204 printk(KERN_INFO "btrfs: open %s failed\n", device_path);
205 goto error;
206 }
207
208 if (flush)
209 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
210 ret = set_blocksize(*bdev, 4096);
211 if (ret) {
212 blkdev_put(*bdev, flags);
213 goto error;
214 }
215 invalidate_bdev(*bdev);
216 *bh = btrfs_read_dev_super(*bdev);
217 if (!*bh) {
218 ret = -EINVAL;
219 blkdev_put(*bdev, flags);
220 goto error;
221 }
222
223 return 0;
224
225 error:
226 *bdev = NULL;
227 *bh = NULL;
228 return ret;
229 }
230
231 static void requeue_list(struct btrfs_pending_bios *pending_bios,
232 struct bio *head, struct bio *tail)
233 {
234
235 struct bio *old_head;
236
237 old_head = pending_bios->head;
238 pending_bios->head = head;
239 if (pending_bios->tail)
240 tail->bi_next = old_head;
241 else
242 pending_bios->tail = tail;
243 }
244
245 /*
246 * we try to collect pending bios for a device so we don't get a large
247 * number of procs sending bios down to the same device. This greatly
248 * improves the schedulers ability to collect and merge the bios.
249 *
250 * But, it also turns into a long list of bios to process and that is sure
251 * to eventually make the worker thread block. The solution here is to
252 * make some progress and then put this work struct back at the end of
253 * the list if the block device is congested. This way, multiple devices
254 * can make progress from a single worker thread.
255 */
256 static noinline void run_scheduled_bios(struct btrfs_device *device)
257 {
258 struct bio *pending;
259 struct backing_dev_info *bdi;
260 struct btrfs_fs_info *fs_info;
261 struct btrfs_pending_bios *pending_bios;
262 struct bio *tail;
263 struct bio *cur;
264 int again = 0;
265 unsigned long num_run;
266 unsigned long batch_run = 0;
267 unsigned long limit;
268 unsigned long last_waited = 0;
269 int force_reg = 0;
270 int sync_pending = 0;
271 struct blk_plug plug;
272
273 /*
274 * this function runs all the bios we've collected for
275 * a particular device. We don't want to wander off to
276 * another device without first sending all of these down.
277 * So, setup a plug here and finish it off before we return
278 */
279 blk_start_plug(&plug);
280
281 bdi = blk_get_backing_dev_info(device->bdev);
282 fs_info = device->dev_root->fs_info;
283 limit = btrfs_async_submit_limit(fs_info);
284 limit = limit * 2 / 3;
285
286 loop:
287 spin_lock(&device->io_lock);
288
289 loop_lock:
290 num_run = 0;
291
292 /* take all the bios off the list at once and process them
293 * later on (without the lock held). But, remember the
294 * tail and other pointers so the bios can be properly reinserted
295 * into the list if we hit congestion
296 */
297 if (!force_reg && device->pending_sync_bios.head) {
298 pending_bios = &device->pending_sync_bios;
299 force_reg = 1;
300 } else {
301 pending_bios = &device->pending_bios;
302 force_reg = 0;
303 }
304
305 pending = pending_bios->head;
306 tail = pending_bios->tail;
307 WARN_ON(pending && !tail);
308
309 /*
310 * if pending was null this time around, no bios need processing
311 * at all and we can stop. Otherwise it'll loop back up again
312 * and do an additional check so no bios are missed.
313 *
314 * device->running_pending is used to synchronize with the
315 * schedule_bio code.
316 */
317 if (device->pending_sync_bios.head == NULL &&
318 device->pending_bios.head == NULL) {
319 again = 0;
320 device->running_pending = 0;
321 } else {
322 again = 1;
323 device->running_pending = 1;
324 }
325
326 pending_bios->head = NULL;
327 pending_bios->tail = NULL;
328
329 spin_unlock(&device->io_lock);
330
331 while (pending) {
332
333 rmb();
334 /* we want to work on both lists, but do more bios on the
335 * sync list than the regular list
336 */
337 if ((num_run > 32 &&
338 pending_bios != &device->pending_sync_bios &&
339 device->pending_sync_bios.head) ||
340 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
341 device->pending_bios.head)) {
342 spin_lock(&device->io_lock);
343 requeue_list(pending_bios, pending, tail);
344 goto loop_lock;
345 }
346
347 cur = pending;
348 pending = pending->bi_next;
349 cur->bi_next = NULL;
350
351 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
352 waitqueue_active(&fs_info->async_submit_wait))
353 wake_up(&fs_info->async_submit_wait);
354
355 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
356
357 /*
358 * if we're doing the sync list, record that our
359 * plug has some sync requests on it
360 *
361 * If we're doing the regular list and there are
362 * sync requests sitting around, unplug before
363 * we add more
364 */
365 if (pending_bios == &device->pending_sync_bios) {
366 sync_pending = 1;
367 } else if (sync_pending) {
368 blk_finish_plug(&plug);
369 blk_start_plug(&plug);
370 sync_pending = 0;
371 }
372
373 btrfsic_submit_bio(cur->bi_rw, cur);
374 num_run++;
375 batch_run++;
376 if (need_resched())
377 cond_resched();
378
379 /*
380 * we made progress, there is more work to do and the bdi
381 * is now congested. Back off and let other work structs
382 * run instead
383 */
384 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
385 fs_info->fs_devices->open_devices > 1) {
386 struct io_context *ioc;
387
388 ioc = current->io_context;
389
390 /*
391 * the main goal here is that we don't want to
392 * block if we're going to be able to submit
393 * more requests without blocking.
394 *
395 * This code does two great things, it pokes into
396 * the elevator code from a filesystem _and_
397 * it makes assumptions about how batching works.
398 */
399 if (ioc && ioc->nr_batch_requests > 0 &&
400 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
401 (last_waited == 0 ||
402 ioc->last_waited == last_waited)) {
403 /*
404 * we want to go through our batch of
405 * requests and stop. So, we copy out
406 * the ioc->last_waited time and test
407 * against it before looping
408 */
409 last_waited = ioc->last_waited;
410 if (need_resched())
411 cond_resched();
412 continue;
413 }
414 spin_lock(&device->io_lock);
415 requeue_list(pending_bios, pending, tail);
416 device->running_pending = 1;
417
418 spin_unlock(&device->io_lock);
419 btrfs_requeue_work(&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 && !device->is_tgtdev_for_dev_replace) {
670 list_del_init(&device->dev_alloc_list);
671 fs_devices->rw_devices--;
672 }
673
674 if (device->can_discard)
675 fs_devices->num_can_discard--;
676 if (device->missing)
677 fs_devices->missing_devices--;
678
679 new_device = btrfs_alloc_device(NULL, &device->devid,
680 device->uuid);
681 BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
682
683 /* Safe because we are under uuid_mutex */
684 if (device->name) {
685 name = rcu_string_strdup(device->name->str, GFP_NOFS);
686 BUG_ON(!name); /* -ENOMEM */
687 rcu_assign_pointer(new_device->name, name);
688 }
689
690 list_replace_rcu(&device->dev_list, &new_device->dev_list);
691 new_device->fs_devices = device->fs_devices;
692
693 call_rcu(&device->rcu, free_device);
694 }
695 mutex_unlock(&fs_devices->device_list_mutex);
696
697 WARN_ON(fs_devices->open_devices);
698 WARN_ON(fs_devices->rw_devices);
699 fs_devices->opened = 0;
700 fs_devices->seeding = 0;
701
702 return 0;
703 }
704
705 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
706 {
707 struct btrfs_fs_devices *seed_devices = NULL;
708 int ret;
709
710 mutex_lock(&uuid_mutex);
711 ret = __btrfs_close_devices(fs_devices);
712 if (!fs_devices->opened) {
713 seed_devices = fs_devices->seed;
714 fs_devices->seed = NULL;
715 }
716 mutex_unlock(&uuid_mutex);
717
718 while (seed_devices) {
719 fs_devices = seed_devices;
720 seed_devices = fs_devices->seed;
721 __btrfs_close_devices(fs_devices);
722 free_fs_devices(fs_devices);
723 }
724 /*
725 * Wait for rcu kworkers under __btrfs_close_devices
726 * to finish all blkdev_puts so device is really
727 * free when umount is done.
728 */
729 rcu_barrier();
730 return ret;
731 }
732
733 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
734 fmode_t flags, void *holder)
735 {
736 struct request_queue *q;
737 struct block_device *bdev;
738 struct list_head *head = &fs_devices->devices;
739 struct btrfs_device *device;
740 struct block_device *latest_bdev = NULL;
741 struct buffer_head *bh;
742 struct btrfs_super_block *disk_super;
743 u64 latest_devid = 0;
744 u64 latest_transid = 0;
745 u64 devid;
746 int seeding = 1;
747 int ret = 0;
748
749 flags |= FMODE_EXCL;
750
751 list_for_each_entry(device, head, dev_list) {
752 if (device->bdev)
753 continue;
754 if (!device->name)
755 continue;
756
757 /* Just open everything we can; ignore failures here */
758 if (btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
759 &bdev, &bh))
760 continue;
761
762 disk_super = (struct btrfs_super_block *)bh->b_data;
763 devid = btrfs_stack_device_id(&disk_super->dev_item);
764 if (devid != device->devid)
765 goto error_brelse;
766
767 if (memcmp(device->uuid, disk_super->dev_item.uuid,
768 BTRFS_UUID_SIZE))
769 goto error_brelse;
770
771 device->generation = btrfs_super_generation(disk_super);
772 if (!latest_transid || device->generation > latest_transid) {
773 latest_devid = devid;
774 latest_transid = device->generation;
775 latest_bdev = bdev;
776 }
777
778 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
779 device->writeable = 0;
780 } else {
781 device->writeable = !bdev_read_only(bdev);
782 seeding = 0;
783 }
784
785 q = bdev_get_queue(bdev);
786 if (blk_queue_discard(q)) {
787 device->can_discard = 1;
788 fs_devices->num_can_discard++;
789 }
790
791 device->bdev = bdev;
792 device->in_fs_metadata = 0;
793 device->mode = flags;
794
795 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
796 fs_devices->rotating = 1;
797
798 fs_devices->open_devices++;
799 if (device->writeable &&
800 device->devid != BTRFS_DEV_REPLACE_DEVID) {
801 fs_devices->rw_devices++;
802 list_add(&device->dev_alloc_list,
803 &fs_devices->alloc_list);
804 }
805 brelse(bh);
806 continue;
807
808 error_brelse:
809 brelse(bh);
810 blkdev_put(bdev, flags);
811 continue;
812 }
813 if (fs_devices->open_devices == 0) {
814 ret = -EINVAL;
815 goto out;
816 }
817 fs_devices->seeding = seeding;
818 fs_devices->opened = 1;
819 fs_devices->latest_bdev = latest_bdev;
820 fs_devices->latest_devid = latest_devid;
821 fs_devices->latest_trans = latest_transid;
822 fs_devices->total_rw_bytes = 0;
823 out:
824 return ret;
825 }
826
827 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
828 fmode_t flags, void *holder)
829 {
830 int ret;
831
832 mutex_lock(&uuid_mutex);
833 if (fs_devices->opened) {
834 fs_devices->opened++;
835 ret = 0;
836 } else {
837 ret = __btrfs_open_devices(fs_devices, flags, holder);
838 }
839 mutex_unlock(&uuid_mutex);
840 return ret;
841 }
842
843 /*
844 * Look for a btrfs signature on a device. This may be called out of the mount path
845 * and we are not allowed to call set_blocksize during the scan. The superblock
846 * is read via pagecache
847 */
848 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
849 struct btrfs_fs_devices **fs_devices_ret)
850 {
851 struct btrfs_super_block *disk_super;
852 struct block_device *bdev;
853 struct page *page;
854 void *p;
855 int ret = -EINVAL;
856 u64 devid;
857 u64 transid;
858 u64 total_devices;
859 u64 bytenr;
860 pgoff_t index;
861
862 /*
863 * we would like to check all the supers, but that would make
864 * a btrfs mount succeed after a mkfs from a different FS.
865 * So, we need to add a special mount option to scan for
866 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
867 */
868 bytenr = btrfs_sb_offset(0);
869 flags |= FMODE_EXCL;
870 mutex_lock(&uuid_mutex);
871
872 bdev = blkdev_get_by_path(path, flags, holder);
873
874 if (IS_ERR(bdev)) {
875 ret = PTR_ERR(bdev);
876 goto error;
877 }
878
879 /* make sure our super fits in the device */
880 if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
881 goto error_bdev_put;
882
883 /* make sure our super fits in the page */
884 if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
885 goto error_bdev_put;
886
887 /* make sure our super doesn't straddle pages on disk */
888 index = bytenr >> PAGE_CACHE_SHIFT;
889 if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
890 goto error_bdev_put;
891
892 /* pull in the page with our super */
893 page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
894 index, GFP_NOFS);
895
896 if (IS_ERR_OR_NULL(page))
897 goto error_bdev_put;
898
899 p = kmap(page);
900
901 /* align our pointer to the offset of the super block */
902 disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
903
904 if (btrfs_super_bytenr(disk_super) != bytenr ||
905 btrfs_super_magic(disk_super) != BTRFS_MAGIC)
906 goto error_unmap;
907
908 devid = btrfs_stack_device_id(&disk_super->dev_item);
909 transid = btrfs_super_generation(disk_super);
910 total_devices = btrfs_super_num_devices(disk_super);
911
912 if (disk_super->label[0]) {
913 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
914 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
915 printk(KERN_INFO "btrfs: device label %s ", disk_super->label);
916 } else {
917 printk(KERN_INFO "btrfs: device fsid %pU ", disk_super->fsid);
918 }
919
920 printk(KERN_CONT "devid %llu transid %llu %s\n", devid, transid, path);
921
922 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
923 if (!ret && fs_devices_ret)
924 (*fs_devices_ret)->total_devices = total_devices;
925
926 error_unmap:
927 kunmap(page);
928 page_cache_release(page);
929
930 error_bdev_put:
931 blkdev_put(bdev, flags);
932 error:
933 mutex_unlock(&uuid_mutex);
934 return ret;
935 }
936
937 /* helper to account the used device space in the range */
938 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
939 u64 end, u64 *length)
940 {
941 struct btrfs_key key;
942 struct btrfs_root *root = device->dev_root;
943 struct btrfs_dev_extent *dev_extent;
944 struct btrfs_path *path;
945 u64 extent_end;
946 int ret;
947 int slot;
948 struct extent_buffer *l;
949
950 *length = 0;
951
952 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
953 return 0;
954
955 path = btrfs_alloc_path();
956 if (!path)
957 return -ENOMEM;
958 path->reada = 2;
959
960 key.objectid = device->devid;
961 key.offset = start;
962 key.type = BTRFS_DEV_EXTENT_KEY;
963
964 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
965 if (ret < 0)
966 goto out;
967 if (ret > 0) {
968 ret = btrfs_previous_item(root, path, key.objectid, key.type);
969 if (ret < 0)
970 goto out;
971 }
972
973 while (1) {
974 l = path->nodes[0];
975 slot = path->slots[0];
976 if (slot >= btrfs_header_nritems(l)) {
977 ret = btrfs_next_leaf(root, path);
978 if (ret == 0)
979 continue;
980 if (ret < 0)
981 goto out;
982
983 break;
984 }
985 btrfs_item_key_to_cpu(l, &key, slot);
986
987 if (key.objectid < device->devid)
988 goto next;
989
990 if (key.objectid > device->devid)
991 break;
992
993 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
994 goto next;
995
996 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
997 extent_end = key.offset + btrfs_dev_extent_length(l,
998 dev_extent);
999 if (key.offset <= start && extent_end > end) {
1000 *length = end - start + 1;
1001 break;
1002 } else if (key.offset <= start && extent_end > start)
1003 *length += extent_end - start;
1004 else if (key.offset > start && extent_end <= end)
1005 *length += extent_end - key.offset;
1006 else if (key.offset > start && key.offset <= end) {
1007 *length += end - key.offset + 1;
1008 break;
1009 } else if (key.offset > end)
1010 break;
1011
1012 next:
1013 path->slots[0]++;
1014 }
1015 ret = 0;
1016 out:
1017 btrfs_free_path(path);
1018 return ret;
1019 }
1020
1021 static int contains_pending_extent(struct btrfs_trans_handle *trans,
1022 struct btrfs_device *device,
1023 u64 *start, u64 len)
1024 {
1025 struct extent_map *em;
1026 int ret = 0;
1027
1028 list_for_each_entry(em, &trans->transaction->pending_chunks, list) {
1029 struct map_lookup *map;
1030 int i;
1031
1032 map = (struct map_lookup *)em->bdev;
1033 for (i = 0; i < map->num_stripes; i++) {
1034 if (map->stripes[i].dev != device)
1035 continue;
1036 if (map->stripes[i].physical >= *start + len ||
1037 map->stripes[i].physical + em->orig_block_len <=
1038 *start)
1039 continue;
1040 *start = map->stripes[i].physical +
1041 em->orig_block_len;
1042 ret = 1;
1043 }
1044 }
1045
1046 return ret;
1047 }
1048
1049
1050 /*
1051 * find_free_dev_extent - find free space in the specified device
1052 * @device: the device which we search the free space in
1053 * @num_bytes: the size of the free space that we need
1054 * @start: store the start of the free space.
1055 * @len: the size of the free space. that we find, or the size of the max
1056 * free space if we don't find suitable free space
1057 *
1058 * this uses a pretty simple search, the expectation is that it is
1059 * called very infrequently and that a given device has a small number
1060 * of extents
1061 *
1062 * @start is used to store the start of the free space if we find. But if we
1063 * don't find suitable free space, it will be used to store the start position
1064 * of the max free space.
1065 *
1066 * @len is used to store the size of the free space that we find.
1067 * But if we don't find suitable free space, it is used to store the size of
1068 * the max free space.
1069 */
1070 int find_free_dev_extent(struct btrfs_trans_handle *trans,
1071 struct btrfs_device *device, u64 num_bytes,
1072 u64 *start, u64 *len)
1073 {
1074 struct btrfs_key key;
1075 struct btrfs_root *root = device->dev_root;
1076 struct btrfs_dev_extent *dev_extent;
1077 struct btrfs_path *path;
1078 u64 hole_size;
1079 u64 max_hole_start;
1080 u64 max_hole_size;
1081 u64 extent_end;
1082 u64 search_start;
1083 u64 search_end = device->total_bytes;
1084 int ret;
1085 int slot;
1086 struct extent_buffer *l;
1087
1088 /* FIXME use last free of some kind */
1089
1090 /* we don't want to overwrite the superblock on the drive,
1091 * so we make sure to start at an offset of at least 1MB
1092 */
1093 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1094
1095 path = btrfs_alloc_path();
1096 if (!path)
1097 return -ENOMEM;
1098 again:
1099 max_hole_start = search_start;
1100 max_hole_size = 0;
1101 hole_size = 0;
1102
1103 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1104 ret = -ENOSPC;
1105 goto out;
1106 }
1107
1108 path->reada = 2;
1109 path->search_commit_root = 1;
1110 path->skip_locking = 1;
1111
1112 key.objectid = device->devid;
1113 key.offset = search_start;
1114 key.type = BTRFS_DEV_EXTENT_KEY;
1115
1116 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1117 if (ret < 0)
1118 goto out;
1119 if (ret > 0) {
1120 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1121 if (ret < 0)
1122 goto out;
1123 }
1124
1125 while (1) {
1126 l = path->nodes[0];
1127 slot = path->slots[0];
1128 if (slot >= btrfs_header_nritems(l)) {
1129 ret = btrfs_next_leaf(root, path);
1130 if (ret == 0)
1131 continue;
1132 if (ret < 0)
1133 goto out;
1134
1135 break;
1136 }
1137 btrfs_item_key_to_cpu(l, &key, slot);
1138
1139 if (key.objectid < device->devid)
1140 goto next;
1141
1142 if (key.objectid > device->devid)
1143 break;
1144
1145 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1146 goto next;
1147
1148 if (key.offset > search_start) {
1149 hole_size = key.offset - search_start;
1150
1151 /*
1152 * Have to check before we set max_hole_start, otherwise
1153 * we could end up sending back this offset anyway.
1154 */
1155 if (contains_pending_extent(trans, device,
1156 &search_start,
1157 hole_size))
1158 hole_size = 0;
1159
1160 if (hole_size > max_hole_size) {
1161 max_hole_start = search_start;
1162 max_hole_size = hole_size;
1163 }
1164
1165 /*
1166 * If this free space is greater than which we need,
1167 * it must be the max free space that we have found
1168 * until now, so max_hole_start must point to the start
1169 * of this free space and the length of this free space
1170 * is stored in max_hole_size. Thus, we return
1171 * max_hole_start and max_hole_size and go back to the
1172 * caller.
1173 */
1174 if (hole_size >= num_bytes) {
1175 ret = 0;
1176 goto out;
1177 }
1178 }
1179
1180 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1181 extent_end = key.offset + btrfs_dev_extent_length(l,
1182 dev_extent);
1183 if (extent_end > search_start)
1184 search_start = extent_end;
1185 next:
1186 path->slots[0]++;
1187 cond_resched();
1188 }
1189
1190 /*
1191 * At this point, search_start should be the end of
1192 * allocated dev extents, and when shrinking the device,
1193 * search_end may be smaller than search_start.
1194 */
1195 if (search_end > search_start)
1196 hole_size = search_end - search_start;
1197
1198 if (hole_size > max_hole_size) {
1199 max_hole_start = search_start;
1200 max_hole_size = hole_size;
1201 }
1202
1203 if (contains_pending_extent(trans, device, &search_start, hole_size)) {
1204 btrfs_release_path(path);
1205 goto again;
1206 }
1207
1208 /* See above. */
1209 if (hole_size < num_bytes)
1210 ret = -ENOSPC;
1211 else
1212 ret = 0;
1213
1214 out:
1215 btrfs_free_path(path);
1216 *start = max_hole_start;
1217 if (len)
1218 *len = max_hole_size;
1219 return ret;
1220 }
1221
1222 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1223 struct btrfs_device *device,
1224 u64 start)
1225 {
1226 int ret;
1227 struct btrfs_path *path;
1228 struct btrfs_root *root = device->dev_root;
1229 struct btrfs_key key;
1230 struct btrfs_key found_key;
1231 struct extent_buffer *leaf = NULL;
1232 struct btrfs_dev_extent *extent = NULL;
1233
1234 path = btrfs_alloc_path();
1235 if (!path)
1236 return -ENOMEM;
1237
1238 key.objectid = device->devid;
1239 key.offset = start;
1240 key.type = BTRFS_DEV_EXTENT_KEY;
1241 again:
1242 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1243 if (ret > 0) {
1244 ret = btrfs_previous_item(root, path, key.objectid,
1245 BTRFS_DEV_EXTENT_KEY);
1246 if (ret)
1247 goto out;
1248 leaf = path->nodes[0];
1249 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1250 extent = btrfs_item_ptr(leaf, path->slots[0],
1251 struct btrfs_dev_extent);
1252 BUG_ON(found_key.offset > start || found_key.offset +
1253 btrfs_dev_extent_length(leaf, extent) < start);
1254 key = found_key;
1255 btrfs_release_path(path);
1256 goto again;
1257 } else if (ret == 0) {
1258 leaf = path->nodes[0];
1259 extent = btrfs_item_ptr(leaf, path->slots[0],
1260 struct btrfs_dev_extent);
1261 } else {
1262 btrfs_error(root->fs_info, ret, "Slot search failed");
1263 goto out;
1264 }
1265
1266 if (device->bytes_used > 0) {
1267 u64 len = btrfs_dev_extent_length(leaf, extent);
1268 device->bytes_used -= len;
1269 spin_lock(&root->fs_info->free_chunk_lock);
1270 root->fs_info->free_chunk_space += len;
1271 spin_unlock(&root->fs_info->free_chunk_lock);
1272 }
1273 ret = btrfs_del_item(trans, root, path);
1274 if (ret) {
1275 btrfs_error(root->fs_info, ret,
1276 "Failed to remove dev extent item");
1277 }
1278 out:
1279 btrfs_free_path(path);
1280 return ret;
1281 }
1282
1283 static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1284 struct btrfs_device *device,
1285 u64 chunk_tree, u64 chunk_objectid,
1286 u64 chunk_offset, u64 start, u64 num_bytes)
1287 {
1288 int ret;
1289 struct btrfs_path *path;
1290 struct btrfs_root *root = device->dev_root;
1291 struct btrfs_dev_extent *extent;
1292 struct extent_buffer *leaf;
1293 struct btrfs_key key;
1294
1295 WARN_ON(!device->in_fs_metadata);
1296 WARN_ON(device->is_tgtdev_for_dev_replace);
1297 path = btrfs_alloc_path();
1298 if (!path)
1299 return -ENOMEM;
1300
1301 key.objectid = device->devid;
1302 key.offset = start;
1303 key.type = BTRFS_DEV_EXTENT_KEY;
1304 ret = btrfs_insert_empty_item(trans, root, path, &key,
1305 sizeof(*extent));
1306 if (ret)
1307 goto out;
1308
1309 leaf = path->nodes[0];
1310 extent = btrfs_item_ptr(leaf, path->slots[0],
1311 struct btrfs_dev_extent);
1312 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1313 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1314 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1315
1316 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1317 btrfs_dev_extent_chunk_tree_uuid(extent), BTRFS_UUID_SIZE);
1318
1319 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1320 btrfs_mark_buffer_dirty(leaf);
1321 out:
1322 btrfs_free_path(path);
1323 return ret;
1324 }
1325
1326 static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
1327 {
1328 struct extent_map_tree *em_tree;
1329 struct extent_map *em;
1330 struct rb_node *n;
1331 u64 ret = 0;
1332
1333 em_tree = &fs_info->mapping_tree.map_tree;
1334 read_lock(&em_tree->lock);
1335 n = rb_last(&em_tree->map);
1336 if (n) {
1337 em = rb_entry(n, struct extent_map, rb_node);
1338 ret = em->start + em->len;
1339 }
1340 read_unlock(&em_tree->lock);
1341
1342 return ret;
1343 }
1344
1345 static noinline int find_next_devid(struct btrfs_fs_info *fs_info,
1346 u64 *devid_ret)
1347 {
1348 int ret;
1349 struct btrfs_key key;
1350 struct btrfs_key found_key;
1351 struct btrfs_path *path;
1352
1353 path = btrfs_alloc_path();
1354 if (!path)
1355 return -ENOMEM;
1356
1357 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1358 key.type = BTRFS_DEV_ITEM_KEY;
1359 key.offset = (u64)-1;
1360
1361 ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0);
1362 if (ret < 0)
1363 goto error;
1364
1365 BUG_ON(ret == 0); /* Corruption */
1366
1367 ret = btrfs_previous_item(fs_info->chunk_root, path,
1368 BTRFS_DEV_ITEMS_OBJECTID,
1369 BTRFS_DEV_ITEM_KEY);
1370 if (ret) {
1371 *devid_ret = 1;
1372 } else {
1373 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1374 path->slots[0]);
1375 *devid_ret = found_key.offset + 1;
1376 }
1377 ret = 0;
1378 error:
1379 btrfs_free_path(path);
1380 return ret;
1381 }
1382
1383 /*
1384 * the device information is stored in the chunk root
1385 * the btrfs_device struct should be fully filled in
1386 */
1387 static int btrfs_add_device(struct btrfs_trans_handle *trans,
1388 struct btrfs_root *root,
1389 struct btrfs_device *device)
1390 {
1391 int ret;
1392 struct btrfs_path *path;
1393 struct btrfs_dev_item *dev_item;
1394 struct extent_buffer *leaf;
1395 struct btrfs_key key;
1396 unsigned long ptr;
1397
1398 root = root->fs_info->chunk_root;
1399
1400 path = btrfs_alloc_path();
1401 if (!path)
1402 return -ENOMEM;
1403
1404 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1405 key.type = BTRFS_DEV_ITEM_KEY;
1406 key.offset = device->devid;
1407
1408 ret = btrfs_insert_empty_item(trans, root, path, &key,
1409 sizeof(*dev_item));
1410 if (ret)
1411 goto out;
1412
1413 leaf = path->nodes[0];
1414 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1415
1416 btrfs_set_device_id(leaf, dev_item, device->devid);
1417 btrfs_set_device_generation(leaf, dev_item, 0);
1418 btrfs_set_device_type(leaf, dev_item, device->type);
1419 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1420 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1421 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1422 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1423 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1424 btrfs_set_device_group(leaf, dev_item, 0);
1425 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1426 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1427 btrfs_set_device_start_offset(leaf, dev_item, 0);
1428
1429 ptr = btrfs_device_uuid(dev_item);
1430 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1431 ptr = btrfs_device_fsid(dev_item);
1432 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1433 btrfs_mark_buffer_dirty(leaf);
1434
1435 ret = 0;
1436 out:
1437 btrfs_free_path(path);
1438 return ret;
1439 }
1440
1441 static int btrfs_rm_dev_item(struct btrfs_root *root,
1442 struct btrfs_device *device)
1443 {
1444 int ret;
1445 struct btrfs_path *path;
1446 struct btrfs_key key;
1447 struct btrfs_trans_handle *trans;
1448
1449 root = root->fs_info->chunk_root;
1450
1451 path = btrfs_alloc_path();
1452 if (!path)
1453 return -ENOMEM;
1454
1455 trans = btrfs_start_transaction(root, 0);
1456 if (IS_ERR(trans)) {
1457 btrfs_free_path(path);
1458 return PTR_ERR(trans);
1459 }
1460 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1461 key.type = BTRFS_DEV_ITEM_KEY;
1462 key.offset = device->devid;
1463 lock_chunks(root);
1464
1465 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1466 if (ret < 0)
1467 goto out;
1468
1469 if (ret > 0) {
1470 ret = -ENOENT;
1471 goto out;
1472 }
1473
1474 ret = btrfs_del_item(trans, root, path);
1475 if (ret)
1476 goto out;
1477 out:
1478 btrfs_free_path(path);
1479 unlock_chunks(root);
1480 btrfs_commit_transaction(trans, root);
1481 return ret;
1482 }
1483
1484 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1485 {
1486 struct btrfs_device *device;
1487 struct btrfs_device *next_device;
1488 struct block_device *bdev;
1489 struct buffer_head *bh = NULL;
1490 struct btrfs_super_block *disk_super;
1491 struct btrfs_fs_devices *cur_devices;
1492 u64 all_avail;
1493 u64 devid;
1494 u64 num_devices;
1495 u8 *dev_uuid;
1496 unsigned seq;
1497 int ret = 0;
1498 bool clear_super = false;
1499
1500 mutex_lock(&uuid_mutex);
1501
1502 do {
1503 seq = read_seqbegin(&root->fs_info->profiles_lock);
1504
1505 all_avail = root->fs_info->avail_data_alloc_bits |
1506 root->fs_info->avail_system_alloc_bits |
1507 root->fs_info->avail_metadata_alloc_bits;
1508 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
1509
1510 num_devices = root->fs_info->fs_devices->num_devices;
1511 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1512 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1513 WARN_ON(num_devices < 1);
1514 num_devices--;
1515 }
1516 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1517
1518 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1519 ret = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET;
1520 goto out;
1521 }
1522
1523 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1524 ret = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET;
1525 goto out;
1526 }
1527
1528 if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1529 root->fs_info->fs_devices->rw_devices <= 2) {
1530 ret = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET;
1531 goto out;
1532 }
1533 if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1534 root->fs_info->fs_devices->rw_devices <= 3) {
1535 ret = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET;
1536 goto out;
1537 }
1538
1539 if (strcmp(device_path, "missing") == 0) {
1540 struct list_head *devices;
1541 struct btrfs_device *tmp;
1542
1543 device = NULL;
1544 devices = &root->fs_info->fs_devices->devices;
1545 /*
1546 * It is safe to read the devices since the volume_mutex
1547 * is held.
1548 */
1549 list_for_each_entry(tmp, devices, dev_list) {
1550 if (tmp->in_fs_metadata &&
1551 !tmp->is_tgtdev_for_dev_replace &&
1552 !tmp->bdev) {
1553 device = tmp;
1554 break;
1555 }
1556 }
1557 bdev = NULL;
1558 bh = NULL;
1559 disk_super = NULL;
1560 if (!device) {
1561 ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND;
1562 goto out;
1563 }
1564 } else {
1565 ret = btrfs_get_bdev_and_sb(device_path,
1566 FMODE_WRITE | FMODE_EXCL,
1567 root->fs_info->bdev_holder, 0,
1568 &bdev, &bh);
1569 if (ret)
1570 goto out;
1571 disk_super = (struct btrfs_super_block *)bh->b_data;
1572 devid = btrfs_stack_device_id(&disk_super->dev_item);
1573 dev_uuid = disk_super->dev_item.uuid;
1574 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1575 disk_super->fsid);
1576 if (!device) {
1577 ret = -ENOENT;
1578 goto error_brelse;
1579 }
1580 }
1581
1582 if (device->is_tgtdev_for_dev_replace) {
1583 ret = BTRFS_ERROR_DEV_TGT_REPLACE;
1584 goto error_brelse;
1585 }
1586
1587 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1588 ret = BTRFS_ERROR_DEV_ONLY_WRITABLE;
1589 goto error_brelse;
1590 }
1591
1592 if (device->writeable) {
1593 lock_chunks(root);
1594 list_del_init(&device->dev_alloc_list);
1595 unlock_chunks(root);
1596 root->fs_info->fs_devices->rw_devices--;
1597 clear_super = true;
1598 }
1599
1600 mutex_unlock(&uuid_mutex);
1601 ret = btrfs_shrink_device(device, 0);
1602 mutex_lock(&uuid_mutex);
1603 if (ret)
1604 goto error_undo;
1605
1606 /*
1607 * TODO: the superblock still includes this device in its num_devices
1608 * counter although write_all_supers() is not locked out. This
1609 * could give a filesystem state which requires a degraded mount.
1610 */
1611 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1612 if (ret)
1613 goto error_undo;
1614
1615 spin_lock(&root->fs_info->free_chunk_lock);
1616 root->fs_info->free_chunk_space = device->total_bytes -
1617 device->bytes_used;
1618 spin_unlock(&root->fs_info->free_chunk_lock);
1619
1620 device->in_fs_metadata = 0;
1621 btrfs_scrub_cancel_dev(root->fs_info, device);
1622
1623 /*
1624 * the device list mutex makes sure that we don't change
1625 * the device list while someone else is writing out all
1626 * the device supers. Whoever is writing all supers, should
1627 * lock the device list mutex before getting the number of
1628 * devices in the super block (super_copy). Conversely,
1629 * whoever updates the number of devices in the super block
1630 * (super_copy) should hold the device list mutex.
1631 */
1632
1633 cur_devices = device->fs_devices;
1634 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1635 list_del_rcu(&device->dev_list);
1636
1637 device->fs_devices->num_devices--;
1638 device->fs_devices->total_devices--;
1639
1640 if (device->missing)
1641 root->fs_info->fs_devices->missing_devices--;
1642
1643 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1644 struct btrfs_device, dev_list);
1645 if (device->bdev == root->fs_info->sb->s_bdev)
1646 root->fs_info->sb->s_bdev = next_device->bdev;
1647 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1648 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1649
1650 if (device->bdev)
1651 device->fs_devices->open_devices--;
1652
1653 call_rcu(&device->rcu, free_device);
1654
1655 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1656 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1657 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1658
1659 if (cur_devices->open_devices == 0) {
1660 struct btrfs_fs_devices *fs_devices;
1661 fs_devices = root->fs_info->fs_devices;
1662 while (fs_devices) {
1663 if (fs_devices->seed == cur_devices)
1664 break;
1665 fs_devices = fs_devices->seed;
1666 }
1667 fs_devices->seed = cur_devices->seed;
1668 cur_devices->seed = NULL;
1669 lock_chunks(root);
1670 __btrfs_close_devices(cur_devices);
1671 unlock_chunks(root);
1672 free_fs_devices(cur_devices);
1673 }
1674
1675 root->fs_info->num_tolerated_disk_barrier_failures =
1676 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1677
1678 /*
1679 * at this point, the device is zero sized. We want to
1680 * remove it from the devices list and zero out the old super
1681 */
1682 if (clear_super && disk_super) {
1683 /* make sure this device isn't detected as part of
1684 * the FS anymore
1685 */
1686 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1687 set_buffer_dirty(bh);
1688 sync_dirty_buffer(bh);
1689 }
1690
1691 ret = 0;
1692
1693 /* Notify udev that device has changed */
1694 if (bdev)
1695 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1696
1697 error_brelse:
1698 brelse(bh);
1699 if (bdev)
1700 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1701 out:
1702 mutex_unlock(&uuid_mutex);
1703 return ret;
1704 error_undo:
1705 if (device->writeable) {
1706 lock_chunks(root);
1707 list_add(&device->dev_alloc_list,
1708 &root->fs_info->fs_devices->alloc_list);
1709 unlock_chunks(root);
1710 root->fs_info->fs_devices->rw_devices++;
1711 }
1712 goto error_brelse;
1713 }
1714
1715 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1716 struct btrfs_device *srcdev)
1717 {
1718 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1719
1720 list_del_rcu(&srcdev->dev_list);
1721 list_del_rcu(&srcdev->dev_alloc_list);
1722 fs_info->fs_devices->num_devices--;
1723 if (srcdev->missing) {
1724 fs_info->fs_devices->missing_devices--;
1725 fs_info->fs_devices->rw_devices++;
1726 }
1727 if (srcdev->can_discard)
1728 fs_info->fs_devices->num_can_discard--;
1729 if (srcdev->bdev) {
1730 fs_info->fs_devices->open_devices--;
1731
1732 /* zero out the old super */
1733 btrfs_scratch_superblock(srcdev);
1734 }
1735
1736 call_rcu(&srcdev->rcu, free_device);
1737 }
1738
1739 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1740 struct btrfs_device *tgtdev)
1741 {
1742 struct btrfs_device *next_device;
1743
1744 WARN_ON(!tgtdev);
1745 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1746 if (tgtdev->bdev) {
1747 btrfs_scratch_superblock(tgtdev);
1748 fs_info->fs_devices->open_devices--;
1749 }
1750 fs_info->fs_devices->num_devices--;
1751 if (tgtdev->can_discard)
1752 fs_info->fs_devices->num_can_discard++;
1753
1754 next_device = list_entry(fs_info->fs_devices->devices.next,
1755 struct btrfs_device, dev_list);
1756 if (tgtdev->bdev == fs_info->sb->s_bdev)
1757 fs_info->sb->s_bdev = next_device->bdev;
1758 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1759 fs_info->fs_devices->latest_bdev = next_device->bdev;
1760 list_del_rcu(&tgtdev->dev_list);
1761
1762 call_rcu(&tgtdev->rcu, free_device);
1763
1764 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1765 }
1766
1767 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1768 struct btrfs_device **device)
1769 {
1770 int ret = 0;
1771 struct btrfs_super_block *disk_super;
1772 u64 devid;
1773 u8 *dev_uuid;
1774 struct block_device *bdev;
1775 struct buffer_head *bh;
1776
1777 *device = NULL;
1778 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1779 root->fs_info->bdev_holder, 0, &bdev, &bh);
1780 if (ret)
1781 return ret;
1782 disk_super = (struct btrfs_super_block *)bh->b_data;
1783 devid = btrfs_stack_device_id(&disk_super->dev_item);
1784 dev_uuid = disk_super->dev_item.uuid;
1785 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1786 disk_super->fsid);
1787 brelse(bh);
1788 if (!*device)
1789 ret = -ENOENT;
1790 blkdev_put(bdev, FMODE_READ);
1791 return ret;
1792 }
1793
1794 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1795 char *device_path,
1796 struct btrfs_device **device)
1797 {
1798 *device = NULL;
1799 if (strcmp(device_path, "missing") == 0) {
1800 struct list_head *devices;
1801 struct btrfs_device *tmp;
1802
1803 devices = &root->fs_info->fs_devices->devices;
1804 /*
1805 * It is safe to read the devices since the volume_mutex
1806 * is held by the caller.
1807 */
1808 list_for_each_entry(tmp, devices, dev_list) {
1809 if (tmp->in_fs_metadata && !tmp->bdev) {
1810 *device = tmp;
1811 break;
1812 }
1813 }
1814
1815 if (!*device) {
1816 pr_err("btrfs: no missing device found\n");
1817 return -ENOENT;
1818 }
1819
1820 return 0;
1821 } else {
1822 return btrfs_find_device_by_path(root, device_path, device);
1823 }
1824 }
1825
1826 /*
1827 * does all the dirty work required for changing file system's UUID.
1828 */
1829 static int btrfs_prepare_sprout(struct btrfs_root *root)
1830 {
1831 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1832 struct btrfs_fs_devices *old_devices;
1833 struct btrfs_fs_devices *seed_devices;
1834 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1835 struct btrfs_device *device;
1836 u64 super_flags;
1837
1838 BUG_ON(!mutex_is_locked(&uuid_mutex));
1839 if (!fs_devices->seeding)
1840 return -EINVAL;
1841
1842 seed_devices = __alloc_fs_devices();
1843 if (IS_ERR(seed_devices))
1844 return PTR_ERR(seed_devices);
1845
1846 old_devices = clone_fs_devices(fs_devices);
1847 if (IS_ERR(old_devices)) {
1848 kfree(seed_devices);
1849 return PTR_ERR(old_devices);
1850 }
1851
1852 list_add(&old_devices->list, &fs_uuids);
1853
1854 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1855 seed_devices->opened = 1;
1856 INIT_LIST_HEAD(&seed_devices->devices);
1857 INIT_LIST_HEAD(&seed_devices->alloc_list);
1858 mutex_init(&seed_devices->device_list_mutex);
1859
1860 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1861 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1862 synchronize_rcu);
1863
1864 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1865 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1866 device->fs_devices = seed_devices;
1867 }
1868
1869 fs_devices->seeding = 0;
1870 fs_devices->num_devices = 0;
1871 fs_devices->open_devices = 0;
1872 fs_devices->total_devices = 0;
1873 fs_devices->seed = seed_devices;
1874
1875 generate_random_uuid(fs_devices->fsid);
1876 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1877 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1878 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1879
1880 super_flags = btrfs_super_flags(disk_super) &
1881 ~BTRFS_SUPER_FLAG_SEEDING;
1882 btrfs_set_super_flags(disk_super, super_flags);
1883
1884 return 0;
1885 }
1886
1887 /*
1888 * strore the expected generation for seed devices in device items.
1889 */
1890 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1891 struct btrfs_root *root)
1892 {
1893 struct btrfs_path *path;
1894 struct extent_buffer *leaf;
1895 struct btrfs_dev_item *dev_item;
1896 struct btrfs_device *device;
1897 struct btrfs_key key;
1898 u8 fs_uuid[BTRFS_UUID_SIZE];
1899 u8 dev_uuid[BTRFS_UUID_SIZE];
1900 u64 devid;
1901 int ret;
1902
1903 path = btrfs_alloc_path();
1904 if (!path)
1905 return -ENOMEM;
1906
1907 root = root->fs_info->chunk_root;
1908 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1909 key.offset = 0;
1910 key.type = BTRFS_DEV_ITEM_KEY;
1911
1912 while (1) {
1913 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1914 if (ret < 0)
1915 goto error;
1916
1917 leaf = path->nodes[0];
1918 next_slot:
1919 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1920 ret = btrfs_next_leaf(root, path);
1921 if (ret > 0)
1922 break;
1923 if (ret < 0)
1924 goto error;
1925 leaf = path->nodes[0];
1926 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1927 btrfs_release_path(path);
1928 continue;
1929 }
1930
1931 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1932 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1933 key.type != BTRFS_DEV_ITEM_KEY)
1934 break;
1935
1936 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1937 struct btrfs_dev_item);
1938 devid = btrfs_device_id(leaf, dev_item);
1939 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
1940 BTRFS_UUID_SIZE);
1941 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
1942 BTRFS_UUID_SIZE);
1943 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1944 fs_uuid);
1945 BUG_ON(!device); /* Logic error */
1946
1947 if (device->fs_devices->seeding) {
1948 btrfs_set_device_generation(leaf, dev_item,
1949 device->generation);
1950 btrfs_mark_buffer_dirty(leaf);
1951 }
1952
1953 path->slots[0]++;
1954 goto next_slot;
1955 }
1956 ret = 0;
1957 error:
1958 btrfs_free_path(path);
1959 return ret;
1960 }
1961
1962 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1963 {
1964 struct request_queue *q;
1965 struct btrfs_trans_handle *trans;
1966 struct btrfs_device *device;
1967 struct block_device *bdev;
1968 struct list_head *devices;
1969 struct super_block *sb = root->fs_info->sb;
1970 struct rcu_string *name;
1971 u64 total_bytes;
1972 int seeding_dev = 0;
1973 int ret = 0;
1974
1975 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1976 return -EROFS;
1977
1978 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1979 root->fs_info->bdev_holder);
1980 if (IS_ERR(bdev))
1981 return PTR_ERR(bdev);
1982
1983 if (root->fs_info->fs_devices->seeding) {
1984 seeding_dev = 1;
1985 down_write(&sb->s_umount);
1986 mutex_lock(&uuid_mutex);
1987 }
1988
1989 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1990
1991 devices = &root->fs_info->fs_devices->devices;
1992
1993 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1994 list_for_each_entry(device, devices, dev_list) {
1995 if (device->bdev == bdev) {
1996 ret = -EEXIST;
1997 mutex_unlock(
1998 &root->fs_info->fs_devices->device_list_mutex);
1999 goto error;
2000 }
2001 }
2002 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2003
2004 device = btrfs_alloc_device(root->fs_info, NULL, NULL);
2005 if (IS_ERR(device)) {
2006 /* we can safely leave the fs_devices entry around */
2007 ret = PTR_ERR(device);
2008 goto error;
2009 }
2010
2011 name = rcu_string_strdup(device_path, GFP_NOFS);
2012 if (!name) {
2013 kfree(device);
2014 ret = -ENOMEM;
2015 goto error;
2016 }
2017 rcu_assign_pointer(device->name, name);
2018
2019 trans = btrfs_start_transaction(root, 0);
2020 if (IS_ERR(trans)) {
2021 rcu_string_free(device->name);
2022 kfree(device);
2023 ret = PTR_ERR(trans);
2024 goto error;
2025 }
2026
2027 lock_chunks(root);
2028
2029 q = bdev_get_queue(bdev);
2030 if (blk_queue_discard(q))
2031 device->can_discard = 1;
2032 device->writeable = 1;
2033 device->generation = trans->transid;
2034 device->io_width = root->sectorsize;
2035 device->io_align = root->sectorsize;
2036 device->sector_size = root->sectorsize;
2037 device->total_bytes = i_size_read(bdev->bd_inode);
2038 device->disk_total_bytes = device->total_bytes;
2039 device->dev_root = root->fs_info->dev_root;
2040 device->bdev = bdev;
2041 device->in_fs_metadata = 1;
2042 device->is_tgtdev_for_dev_replace = 0;
2043 device->mode = FMODE_EXCL;
2044 set_blocksize(device->bdev, 4096);
2045
2046 if (seeding_dev) {
2047 sb->s_flags &= ~MS_RDONLY;
2048 ret = btrfs_prepare_sprout(root);
2049 BUG_ON(ret); /* -ENOMEM */
2050 }
2051
2052 device->fs_devices = root->fs_info->fs_devices;
2053
2054 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2055 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2056 list_add(&device->dev_alloc_list,
2057 &root->fs_info->fs_devices->alloc_list);
2058 root->fs_info->fs_devices->num_devices++;
2059 root->fs_info->fs_devices->open_devices++;
2060 root->fs_info->fs_devices->rw_devices++;
2061 root->fs_info->fs_devices->total_devices++;
2062 if (device->can_discard)
2063 root->fs_info->fs_devices->num_can_discard++;
2064 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2065
2066 spin_lock(&root->fs_info->free_chunk_lock);
2067 root->fs_info->free_chunk_space += device->total_bytes;
2068 spin_unlock(&root->fs_info->free_chunk_lock);
2069
2070 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2071 root->fs_info->fs_devices->rotating = 1;
2072
2073 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2074 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2075 total_bytes + device->total_bytes);
2076
2077 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2078 btrfs_set_super_num_devices(root->fs_info->super_copy,
2079 total_bytes + 1);
2080 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2081
2082 if (seeding_dev) {
2083 ret = init_first_rw_device(trans, root, device);
2084 if (ret) {
2085 btrfs_abort_transaction(trans, root, ret);
2086 goto error_trans;
2087 }
2088 ret = btrfs_finish_sprout(trans, root);
2089 if (ret) {
2090 btrfs_abort_transaction(trans, root, ret);
2091 goto error_trans;
2092 }
2093 } else {
2094 ret = btrfs_add_device(trans, root, device);
2095 if (ret) {
2096 btrfs_abort_transaction(trans, root, ret);
2097 goto error_trans;
2098 }
2099 }
2100
2101 /*
2102 * we've got more storage, clear any full flags on the space
2103 * infos
2104 */
2105 btrfs_clear_space_info_full(root->fs_info);
2106
2107 unlock_chunks(root);
2108 root->fs_info->num_tolerated_disk_barrier_failures =
2109 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2110 ret = btrfs_commit_transaction(trans, root);
2111
2112 if (seeding_dev) {
2113 mutex_unlock(&uuid_mutex);
2114 up_write(&sb->s_umount);
2115
2116 if (ret) /* transaction commit */
2117 return ret;
2118
2119 ret = btrfs_relocate_sys_chunks(root);
2120 if (ret < 0)
2121 btrfs_error(root->fs_info, ret,
2122 "Failed to relocate sys chunks after "
2123 "device initialization. This can be fixed "
2124 "using the \"btrfs balance\" command.");
2125 trans = btrfs_attach_transaction(root);
2126 if (IS_ERR(trans)) {
2127 if (PTR_ERR(trans) == -ENOENT)
2128 return 0;
2129 return PTR_ERR(trans);
2130 }
2131 ret = btrfs_commit_transaction(trans, root);
2132 }
2133
2134 return ret;
2135
2136 error_trans:
2137 unlock_chunks(root);
2138 btrfs_end_transaction(trans, root);
2139 rcu_string_free(device->name);
2140 kfree(device);
2141 error:
2142 blkdev_put(bdev, FMODE_EXCL);
2143 if (seeding_dev) {
2144 mutex_unlock(&uuid_mutex);
2145 up_write(&sb->s_umount);
2146 }
2147 return ret;
2148 }
2149
2150 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2151 struct btrfs_device **device_out)
2152 {
2153 struct request_queue *q;
2154 struct btrfs_device *device;
2155 struct block_device *bdev;
2156 struct btrfs_fs_info *fs_info = root->fs_info;
2157 struct list_head *devices;
2158 struct rcu_string *name;
2159 u64 devid = BTRFS_DEV_REPLACE_DEVID;
2160 int ret = 0;
2161
2162 *device_out = NULL;
2163 if (fs_info->fs_devices->seeding)
2164 return -EINVAL;
2165
2166 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2167 fs_info->bdev_holder);
2168 if (IS_ERR(bdev))
2169 return PTR_ERR(bdev);
2170
2171 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2172
2173 devices = &fs_info->fs_devices->devices;
2174 list_for_each_entry(device, devices, dev_list) {
2175 if (device->bdev == bdev) {
2176 ret = -EEXIST;
2177 goto error;
2178 }
2179 }
2180
2181 device = btrfs_alloc_device(NULL, &devid, NULL);
2182 if (IS_ERR(device)) {
2183 ret = PTR_ERR(device);
2184 goto error;
2185 }
2186
2187 name = rcu_string_strdup(device_path, GFP_NOFS);
2188 if (!name) {
2189 kfree(device);
2190 ret = -ENOMEM;
2191 goto error;
2192 }
2193 rcu_assign_pointer(device->name, name);
2194
2195 q = bdev_get_queue(bdev);
2196 if (blk_queue_discard(q))
2197 device->can_discard = 1;
2198 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2199 device->writeable = 1;
2200 device->generation = 0;
2201 device->io_width = root->sectorsize;
2202 device->io_align = root->sectorsize;
2203 device->sector_size = root->sectorsize;
2204 device->total_bytes = i_size_read(bdev->bd_inode);
2205 device->disk_total_bytes = device->total_bytes;
2206 device->dev_root = fs_info->dev_root;
2207 device->bdev = bdev;
2208 device->in_fs_metadata = 1;
2209 device->is_tgtdev_for_dev_replace = 1;
2210 device->mode = FMODE_EXCL;
2211 set_blocksize(device->bdev, 4096);
2212 device->fs_devices = fs_info->fs_devices;
2213 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2214 fs_info->fs_devices->num_devices++;
2215 fs_info->fs_devices->open_devices++;
2216 if (device->can_discard)
2217 fs_info->fs_devices->num_can_discard++;
2218 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2219
2220 *device_out = device;
2221 return ret;
2222
2223 error:
2224 blkdev_put(bdev, FMODE_EXCL);
2225 return ret;
2226 }
2227
2228 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2229 struct btrfs_device *tgtdev)
2230 {
2231 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2232 tgtdev->io_width = fs_info->dev_root->sectorsize;
2233 tgtdev->io_align = fs_info->dev_root->sectorsize;
2234 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2235 tgtdev->dev_root = fs_info->dev_root;
2236 tgtdev->in_fs_metadata = 1;
2237 }
2238
2239 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2240 struct btrfs_device *device)
2241 {
2242 int ret;
2243 struct btrfs_path *path;
2244 struct btrfs_root *root;
2245 struct btrfs_dev_item *dev_item;
2246 struct extent_buffer *leaf;
2247 struct btrfs_key key;
2248
2249 root = device->dev_root->fs_info->chunk_root;
2250
2251 path = btrfs_alloc_path();
2252 if (!path)
2253 return -ENOMEM;
2254
2255 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2256 key.type = BTRFS_DEV_ITEM_KEY;
2257 key.offset = device->devid;
2258
2259 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2260 if (ret < 0)
2261 goto out;
2262
2263 if (ret > 0) {
2264 ret = -ENOENT;
2265 goto out;
2266 }
2267
2268 leaf = path->nodes[0];
2269 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2270
2271 btrfs_set_device_id(leaf, dev_item, device->devid);
2272 btrfs_set_device_type(leaf, dev_item, device->type);
2273 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2274 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2275 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2276 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2277 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2278 btrfs_mark_buffer_dirty(leaf);
2279
2280 out:
2281 btrfs_free_path(path);
2282 return ret;
2283 }
2284
2285 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2286 struct btrfs_device *device, u64 new_size)
2287 {
2288 struct btrfs_super_block *super_copy =
2289 device->dev_root->fs_info->super_copy;
2290 u64 old_total = btrfs_super_total_bytes(super_copy);
2291 u64 diff = new_size - device->total_bytes;
2292
2293 if (!device->writeable)
2294 return -EACCES;
2295 if (new_size <= device->total_bytes ||
2296 device->is_tgtdev_for_dev_replace)
2297 return -EINVAL;
2298
2299 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2300 device->fs_devices->total_rw_bytes += diff;
2301
2302 device->total_bytes = new_size;
2303 device->disk_total_bytes = new_size;
2304 btrfs_clear_space_info_full(device->dev_root->fs_info);
2305
2306 return btrfs_update_device(trans, device);
2307 }
2308
2309 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2310 struct btrfs_device *device, u64 new_size)
2311 {
2312 int ret;
2313 lock_chunks(device->dev_root);
2314 ret = __btrfs_grow_device(trans, device, new_size);
2315 unlock_chunks(device->dev_root);
2316 return ret;
2317 }
2318
2319 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2320 struct btrfs_root *root,
2321 u64 chunk_tree, u64 chunk_objectid,
2322 u64 chunk_offset)
2323 {
2324 int ret;
2325 struct btrfs_path *path;
2326 struct btrfs_key key;
2327
2328 root = root->fs_info->chunk_root;
2329 path = btrfs_alloc_path();
2330 if (!path)
2331 return -ENOMEM;
2332
2333 key.objectid = chunk_objectid;
2334 key.offset = chunk_offset;
2335 key.type = BTRFS_CHUNK_ITEM_KEY;
2336
2337 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2338 if (ret < 0)
2339 goto out;
2340 else if (ret > 0) { /* Logic error or corruption */
2341 btrfs_error(root->fs_info, -ENOENT,
2342 "Failed lookup while freeing chunk.");
2343 ret = -ENOENT;
2344 goto out;
2345 }
2346
2347 ret = btrfs_del_item(trans, root, path);
2348 if (ret < 0)
2349 btrfs_error(root->fs_info, ret,
2350 "Failed to delete chunk item.");
2351 out:
2352 btrfs_free_path(path);
2353 return ret;
2354 }
2355
2356 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2357 chunk_offset)
2358 {
2359 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2360 struct btrfs_disk_key *disk_key;
2361 struct btrfs_chunk *chunk;
2362 u8 *ptr;
2363 int ret = 0;
2364 u32 num_stripes;
2365 u32 array_size;
2366 u32 len = 0;
2367 u32 cur;
2368 struct btrfs_key key;
2369
2370 array_size = btrfs_super_sys_array_size(super_copy);
2371
2372 ptr = super_copy->sys_chunk_array;
2373 cur = 0;
2374
2375 while (cur < array_size) {
2376 disk_key = (struct btrfs_disk_key *)ptr;
2377 btrfs_disk_key_to_cpu(&key, disk_key);
2378
2379 len = sizeof(*disk_key);
2380
2381 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2382 chunk = (struct btrfs_chunk *)(ptr + len);
2383 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2384 len += btrfs_chunk_item_size(num_stripes);
2385 } else {
2386 ret = -EIO;
2387 break;
2388 }
2389 if (key.objectid == chunk_objectid &&
2390 key.offset == chunk_offset) {
2391 memmove(ptr, ptr + len, array_size - (cur + len));
2392 array_size -= len;
2393 btrfs_set_super_sys_array_size(super_copy, array_size);
2394 } else {
2395 ptr += len;
2396 cur += len;
2397 }
2398 }
2399 return ret;
2400 }
2401
2402 static int btrfs_relocate_chunk(struct btrfs_root *root,
2403 u64 chunk_tree, u64 chunk_objectid,
2404 u64 chunk_offset)
2405 {
2406 struct extent_map_tree *em_tree;
2407 struct btrfs_root *extent_root;
2408 struct btrfs_trans_handle *trans;
2409 struct extent_map *em;
2410 struct map_lookup *map;
2411 int ret;
2412 int i;
2413
2414 root = root->fs_info->chunk_root;
2415 extent_root = root->fs_info->extent_root;
2416 em_tree = &root->fs_info->mapping_tree.map_tree;
2417
2418 ret = btrfs_can_relocate(extent_root, chunk_offset);
2419 if (ret)
2420 return -ENOSPC;
2421
2422 /* step one, relocate all the extents inside this chunk */
2423 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2424 if (ret)
2425 return ret;
2426
2427 trans = btrfs_start_transaction(root, 0);
2428 if (IS_ERR(trans)) {
2429 ret = PTR_ERR(trans);
2430 btrfs_std_error(root->fs_info, ret);
2431 return ret;
2432 }
2433
2434 lock_chunks(root);
2435
2436 /*
2437 * step two, delete the device extents and the
2438 * chunk tree entries
2439 */
2440 read_lock(&em_tree->lock);
2441 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2442 read_unlock(&em_tree->lock);
2443
2444 BUG_ON(!em || em->start > chunk_offset ||
2445 em->start + em->len < chunk_offset);
2446 map = (struct map_lookup *)em->bdev;
2447
2448 for (i = 0; i < map->num_stripes; i++) {
2449 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2450 map->stripes[i].physical);
2451 BUG_ON(ret);
2452
2453 if (map->stripes[i].dev) {
2454 ret = btrfs_update_device(trans, map->stripes[i].dev);
2455 BUG_ON(ret);
2456 }
2457 }
2458 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2459 chunk_offset);
2460
2461 BUG_ON(ret);
2462
2463 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2464
2465 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2466 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2467 BUG_ON(ret);
2468 }
2469
2470 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2471 BUG_ON(ret);
2472
2473 write_lock(&em_tree->lock);
2474 remove_extent_mapping(em_tree, em);
2475 write_unlock(&em_tree->lock);
2476
2477 kfree(map);
2478 em->bdev = NULL;
2479
2480 /* once for the tree */
2481 free_extent_map(em);
2482 /* once for us */
2483 free_extent_map(em);
2484
2485 unlock_chunks(root);
2486 btrfs_end_transaction(trans, root);
2487 return 0;
2488 }
2489
2490 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2491 {
2492 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2493 struct btrfs_path *path;
2494 struct extent_buffer *leaf;
2495 struct btrfs_chunk *chunk;
2496 struct btrfs_key key;
2497 struct btrfs_key found_key;
2498 u64 chunk_tree = chunk_root->root_key.objectid;
2499 u64 chunk_type;
2500 bool retried = false;
2501 int failed = 0;
2502 int ret;
2503
2504 path = btrfs_alloc_path();
2505 if (!path)
2506 return -ENOMEM;
2507
2508 again:
2509 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2510 key.offset = (u64)-1;
2511 key.type = BTRFS_CHUNK_ITEM_KEY;
2512
2513 while (1) {
2514 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2515 if (ret < 0)
2516 goto error;
2517 BUG_ON(ret == 0); /* Corruption */
2518
2519 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2520 key.type);
2521 if (ret < 0)
2522 goto error;
2523 if (ret > 0)
2524 break;
2525
2526 leaf = path->nodes[0];
2527 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2528
2529 chunk = btrfs_item_ptr(leaf, path->slots[0],
2530 struct btrfs_chunk);
2531 chunk_type = btrfs_chunk_type(leaf, chunk);
2532 btrfs_release_path(path);
2533
2534 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2535 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2536 found_key.objectid,
2537 found_key.offset);
2538 if (ret == -ENOSPC)
2539 failed++;
2540 else if (ret)
2541 BUG();
2542 }
2543
2544 if (found_key.offset == 0)
2545 break;
2546 key.offset = found_key.offset - 1;
2547 }
2548 ret = 0;
2549 if (failed && !retried) {
2550 failed = 0;
2551 retried = true;
2552 goto again;
2553 } else if (failed && retried) {
2554 WARN_ON(1);
2555 ret = -ENOSPC;
2556 }
2557 error:
2558 btrfs_free_path(path);
2559 return ret;
2560 }
2561
2562 static int insert_balance_item(struct btrfs_root *root,
2563 struct btrfs_balance_control *bctl)
2564 {
2565 struct btrfs_trans_handle *trans;
2566 struct btrfs_balance_item *item;
2567 struct btrfs_disk_balance_args disk_bargs;
2568 struct btrfs_path *path;
2569 struct extent_buffer *leaf;
2570 struct btrfs_key key;
2571 int ret, err;
2572
2573 path = btrfs_alloc_path();
2574 if (!path)
2575 return -ENOMEM;
2576
2577 trans = btrfs_start_transaction(root, 0);
2578 if (IS_ERR(trans)) {
2579 btrfs_free_path(path);
2580 return PTR_ERR(trans);
2581 }
2582
2583 key.objectid = BTRFS_BALANCE_OBJECTID;
2584 key.type = BTRFS_BALANCE_ITEM_KEY;
2585 key.offset = 0;
2586
2587 ret = btrfs_insert_empty_item(trans, root, path, &key,
2588 sizeof(*item));
2589 if (ret)
2590 goto out;
2591
2592 leaf = path->nodes[0];
2593 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2594
2595 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2596
2597 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2598 btrfs_set_balance_data(leaf, item, &disk_bargs);
2599 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2600 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2601 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2602 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2603
2604 btrfs_set_balance_flags(leaf, item, bctl->flags);
2605
2606 btrfs_mark_buffer_dirty(leaf);
2607 out:
2608 btrfs_free_path(path);
2609 err = btrfs_commit_transaction(trans, root);
2610 if (err && !ret)
2611 ret = err;
2612 return ret;
2613 }
2614
2615 static int del_balance_item(struct btrfs_root *root)
2616 {
2617 struct btrfs_trans_handle *trans;
2618 struct btrfs_path *path;
2619 struct btrfs_key key;
2620 int ret, err;
2621
2622 path = btrfs_alloc_path();
2623 if (!path)
2624 return -ENOMEM;
2625
2626 trans = btrfs_start_transaction(root, 0);
2627 if (IS_ERR(trans)) {
2628 btrfs_free_path(path);
2629 return PTR_ERR(trans);
2630 }
2631
2632 key.objectid = BTRFS_BALANCE_OBJECTID;
2633 key.type = BTRFS_BALANCE_ITEM_KEY;
2634 key.offset = 0;
2635
2636 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2637 if (ret < 0)
2638 goto out;
2639 if (ret > 0) {
2640 ret = -ENOENT;
2641 goto out;
2642 }
2643
2644 ret = btrfs_del_item(trans, root, path);
2645 out:
2646 btrfs_free_path(path);
2647 err = btrfs_commit_transaction(trans, root);
2648 if (err && !ret)
2649 ret = err;
2650 return ret;
2651 }
2652
2653 /*
2654 * This is a heuristic used to reduce the number of chunks balanced on
2655 * resume after balance was interrupted.
2656 */
2657 static void update_balance_args(struct btrfs_balance_control *bctl)
2658 {
2659 /*
2660 * Turn on soft mode for chunk types that were being converted.
2661 */
2662 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2663 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2664 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2665 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2666 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2667 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2668
2669 /*
2670 * Turn on usage filter if is not already used. The idea is
2671 * that chunks that we have already balanced should be
2672 * reasonably full. Don't do it for chunks that are being
2673 * converted - that will keep us from relocating unconverted
2674 * (albeit full) chunks.
2675 */
2676 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2677 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2678 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2679 bctl->data.usage = 90;
2680 }
2681 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2682 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2683 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2684 bctl->sys.usage = 90;
2685 }
2686 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2687 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2688 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2689 bctl->meta.usage = 90;
2690 }
2691 }
2692
2693 /*
2694 * Should be called with both balance and volume mutexes held to
2695 * serialize other volume operations (add_dev/rm_dev/resize) with
2696 * restriper. Same goes for unset_balance_control.
2697 */
2698 static void set_balance_control(struct btrfs_balance_control *bctl)
2699 {
2700 struct btrfs_fs_info *fs_info = bctl->fs_info;
2701
2702 BUG_ON(fs_info->balance_ctl);
2703
2704 spin_lock(&fs_info->balance_lock);
2705 fs_info->balance_ctl = bctl;
2706 spin_unlock(&fs_info->balance_lock);
2707 }
2708
2709 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2710 {
2711 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2712
2713 BUG_ON(!fs_info->balance_ctl);
2714
2715 spin_lock(&fs_info->balance_lock);
2716 fs_info->balance_ctl = NULL;
2717 spin_unlock(&fs_info->balance_lock);
2718
2719 kfree(bctl);
2720 }
2721
2722 /*
2723 * Balance filters. Return 1 if chunk should be filtered out
2724 * (should not be balanced).
2725 */
2726 static int chunk_profiles_filter(u64 chunk_type,
2727 struct btrfs_balance_args *bargs)
2728 {
2729 chunk_type = chunk_to_extended(chunk_type) &
2730 BTRFS_EXTENDED_PROFILE_MASK;
2731
2732 if (bargs->profiles & chunk_type)
2733 return 0;
2734
2735 return 1;
2736 }
2737
2738 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2739 struct btrfs_balance_args *bargs)
2740 {
2741 struct btrfs_block_group_cache *cache;
2742 u64 chunk_used, user_thresh;
2743 int ret = 1;
2744
2745 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2746 chunk_used = btrfs_block_group_used(&cache->item);
2747
2748 if (bargs->usage == 0)
2749 user_thresh = 1;
2750 else if (bargs->usage > 100)
2751 user_thresh = cache->key.offset;
2752 else
2753 user_thresh = div_factor_fine(cache->key.offset,
2754 bargs->usage);
2755
2756 if (chunk_used < user_thresh)
2757 ret = 0;
2758
2759 btrfs_put_block_group(cache);
2760 return ret;
2761 }
2762
2763 static int chunk_devid_filter(struct extent_buffer *leaf,
2764 struct btrfs_chunk *chunk,
2765 struct btrfs_balance_args *bargs)
2766 {
2767 struct btrfs_stripe *stripe;
2768 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2769 int i;
2770
2771 for (i = 0; i < num_stripes; i++) {
2772 stripe = btrfs_stripe_nr(chunk, i);
2773 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2774 return 0;
2775 }
2776
2777 return 1;
2778 }
2779
2780 /* [pstart, pend) */
2781 static int chunk_drange_filter(struct extent_buffer *leaf,
2782 struct btrfs_chunk *chunk,
2783 u64 chunk_offset,
2784 struct btrfs_balance_args *bargs)
2785 {
2786 struct btrfs_stripe *stripe;
2787 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2788 u64 stripe_offset;
2789 u64 stripe_length;
2790 int factor;
2791 int i;
2792
2793 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2794 return 0;
2795
2796 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2797 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2798 factor = num_stripes / 2;
2799 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2800 factor = num_stripes - 1;
2801 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2802 factor = num_stripes - 2;
2803 } else {
2804 factor = num_stripes;
2805 }
2806
2807 for (i = 0; i < num_stripes; i++) {
2808 stripe = btrfs_stripe_nr(chunk, i);
2809 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2810 continue;
2811
2812 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2813 stripe_length = btrfs_chunk_length(leaf, chunk);
2814 do_div(stripe_length, factor);
2815
2816 if (stripe_offset < bargs->pend &&
2817 stripe_offset + stripe_length > bargs->pstart)
2818 return 0;
2819 }
2820
2821 return 1;
2822 }
2823
2824 /* [vstart, vend) */
2825 static int chunk_vrange_filter(struct extent_buffer *leaf,
2826 struct btrfs_chunk *chunk,
2827 u64 chunk_offset,
2828 struct btrfs_balance_args *bargs)
2829 {
2830 if (chunk_offset < bargs->vend &&
2831 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2832 /* at least part of the chunk is inside this vrange */
2833 return 0;
2834
2835 return 1;
2836 }
2837
2838 static int chunk_soft_convert_filter(u64 chunk_type,
2839 struct btrfs_balance_args *bargs)
2840 {
2841 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2842 return 0;
2843
2844 chunk_type = chunk_to_extended(chunk_type) &
2845 BTRFS_EXTENDED_PROFILE_MASK;
2846
2847 if (bargs->target == chunk_type)
2848 return 1;
2849
2850 return 0;
2851 }
2852
2853 static int should_balance_chunk(struct btrfs_root *root,
2854 struct extent_buffer *leaf,
2855 struct btrfs_chunk *chunk, u64 chunk_offset)
2856 {
2857 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2858 struct btrfs_balance_args *bargs = NULL;
2859 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2860
2861 /* type filter */
2862 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2863 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2864 return 0;
2865 }
2866
2867 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2868 bargs = &bctl->data;
2869 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2870 bargs = &bctl->sys;
2871 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2872 bargs = &bctl->meta;
2873
2874 /* profiles filter */
2875 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2876 chunk_profiles_filter(chunk_type, bargs)) {
2877 return 0;
2878 }
2879
2880 /* usage filter */
2881 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2882 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2883 return 0;
2884 }
2885
2886 /* devid filter */
2887 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2888 chunk_devid_filter(leaf, chunk, bargs)) {
2889 return 0;
2890 }
2891
2892 /* drange filter, makes sense only with devid filter */
2893 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2894 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2895 return 0;
2896 }
2897
2898 /* vrange filter */
2899 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2900 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2901 return 0;
2902 }
2903
2904 /* soft profile changing mode */
2905 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2906 chunk_soft_convert_filter(chunk_type, bargs)) {
2907 return 0;
2908 }
2909
2910 return 1;
2911 }
2912
2913 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2914 {
2915 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2916 struct btrfs_root *chunk_root = fs_info->chunk_root;
2917 struct btrfs_root *dev_root = fs_info->dev_root;
2918 struct list_head *devices;
2919 struct btrfs_device *device;
2920 u64 old_size;
2921 u64 size_to_free;
2922 struct btrfs_chunk *chunk;
2923 struct btrfs_path *path;
2924 struct btrfs_key key;
2925 struct btrfs_key found_key;
2926 struct btrfs_trans_handle *trans;
2927 struct extent_buffer *leaf;
2928 int slot;
2929 int ret;
2930 int enospc_errors = 0;
2931 bool counting = true;
2932
2933 /* step one make some room on all the devices */
2934 devices = &fs_info->fs_devices->devices;
2935 list_for_each_entry(device, devices, dev_list) {
2936 old_size = device->total_bytes;
2937 size_to_free = div_factor(old_size, 1);
2938 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2939 if (!device->writeable ||
2940 device->total_bytes - device->bytes_used > size_to_free ||
2941 device->is_tgtdev_for_dev_replace)
2942 continue;
2943
2944 ret = btrfs_shrink_device(device, old_size - size_to_free);
2945 if (ret == -ENOSPC)
2946 break;
2947 BUG_ON(ret);
2948
2949 trans = btrfs_start_transaction(dev_root, 0);
2950 BUG_ON(IS_ERR(trans));
2951
2952 ret = btrfs_grow_device(trans, device, old_size);
2953 BUG_ON(ret);
2954
2955 btrfs_end_transaction(trans, dev_root);
2956 }
2957
2958 /* step two, relocate all the chunks */
2959 path = btrfs_alloc_path();
2960 if (!path) {
2961 ret = -ENOMEM;
2962 goto error;
2963 }
2964
2965 /* zero out stat counters */
2966 spin_lock(&fs_info->balance_lock);
2967 memset(&bctl->stat, 0, sizeof(bctl->stat));
2968 spin_unlock(&fs_info->balance_lock);
2969 again:
2970 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2971 key.offset = (u64)-1;
2972 key.type = BTRFS_CHUNK_ITEM_KEY;
2973
2974 while (1) {
2975 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2976 atomic_read(&fs_info->balance_cancel_req)) {
2977 ret = -ECANCELED;
2978 goto error;
2979 }
2980
2981 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2982 if (ret < 0)
2983 goto error;
2984
2985 /*
2986 * this shouldn't happen, it means the last relocate
2987 * failed
2988 */
2989 if (ret == 0)
2990 BUG(); /* FIXME break ? */
2991
2992 ret = btrfs_previous_item(chunk_root, path, 0,
2993 BTRFS_CHUNK_ITEM_KEY);
2994 if (ret) {
2995 ret = 0;
2996 break;
2997 }
2998
2999 leaf = path->nodes[0];
3000 slot = path->slots[0];
3001 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3002
3003 if (found_key.objectid != key.objectid)
3004 break;
3005
3006 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3007
3008 if (!counting) {
3009 spin_lock(&fs_info->balance_lock);
3010 bctl->stat.considered++;
3011 spin_unlock(&fs_info->balance_lock);
3012 }
3013
3014 ret = should_balance_chunk(chunk_root, leaf, chunk,
3015 found_key.offset);
3016 btrfs_release_path(path);
3017 if (!ret)
3018 goto loop;
3019
3020 if (counting) {
3021 spin_lock(&fs_info->balance_lock);
3022 bctl->stat.expected++;
3023 spin_unlock(&fs_info->balance_lock);
3024 goto loop;
3025 }
3026
3027 ret = btrfs_relocate_chunk(chunk_root,
3028 chunk_root->root_key.objectid,
3029 found_key.objectid,
3030 found_key.offset);
3031 if (ret && ret != -ENOSPC)
3032 goto error;
3033 if (ret == -ENOSPC) {
3034 enospc_errors++;
3035 } else {
3036 spin_lock(&fs_info->balance_lock);
3037 bctl->stat.completed++;
3038 spin_unlock(&fs_info->balance_lock);
3039 }
3040 loop:
3041 if (found_key.offset == 0)
3042 break;
3043 key.offset = found_key.offset - 1;
3044 }
3045
3046 if (counting) {
3047 btrfs_release_path(path);
3048 counting = false;
3049 goto again;
3050 }
3051 error:
3052 btrfs_free_path(path);
3053 if (enospc_errors) {
3054 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
3055 enospc_errors);
3056 if (!ret)
3057 ret = -ENOSPC;
3058 }
3059
3060 return ret;
3061 }
3062
3063 /**
3064 * alloc_profile_is_valid - see if a given profile is valid and reduced
3065 * @flags: profile to validate
3066 * @extended: if true @flags is treated as an extended profile
3067 */
3068 static int alloc_profile_is_valid(u64 flags, int extended)
3069 {
3070 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3071 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3072
3073 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3074
3075 /* 1) check that all other bits are zeroed */
3076 if (flags & ~mask)
3077 return 0;
3078
3079 /* 2) see if profile is reduced */
3080 if (flags == 0)
3081 return !extended; /* "0" is valid for usual profiles */
3082
3083 /* true if exactly one bit set */
3084 return (flags & (flags - 1)) == 0;
3085 }
3086
3087 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3088 {
3089 /* cancel requested || normal exit path */
3090 return atomic_read(&fs_info->balance_cancel_req) ||
3091 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3092 atomic_read(&fs_info->balance_cancel_req) == 0);
3093 }
3094
3095 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3096 {
3097 int ret;
3098
3099 unset_balance_control(fs_info);
3100 ret = del_balance_item(fs_info->tree_root);
3101 if (ret)
3102 btrfs_std_error(fs_info, ret);
3103
3104 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3105 }
3106
3107 /*
3108 * Should be called with both balance and volume mutexes held
3109 */
3110 int btrfs_balance(struct btrfs_balance_control *bctl,
3111 struct btrfs_ioctl_balance_args *bargs)
3112 {
3113 struct btrfs_fs_info *fs_info = bctl->fs_info;
3114 u64 allowed;
3115 int mixed = 0;
3116 int ret;
3117 u64 num_devices;
3118 unsigned seq;
3119
3120 if (btrfs_fs_closing(fs_info) ||
3121 atomic_read(&fs_info->balance_pause_req) ||
3122 atomic_read(&fs_info->balance_cancel_req)) {
3123 ret = -EINVAL;
3124 goto out;
3125 }
3126
3127 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3128 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3129 mixed = 1;
3130
3131 /*
3132 * In case of mixed groups both data and meta should be picked,
3133 * and identical options should be given for both of them.
3134 */
3135 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3136 if (mixed && (bctl->flags & allowed)) {
3137 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3138 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3139 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3140 printk(KERN_ERR "btrfs: with mixed groups data and "
3141 "metadata balance options must be the same\n");
3142 ret = -EINVAL;
3143 goto out;
3144 }
3145 }
3146
3147 num_devices = fs_info->fs_devices->num_devices;
3148 btrfs_dev_replace_lock(&fs_info->dev_replace);
3149 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3150 BUG_ON(num_devices < 1);
3151 num_devices--;
3152 }
3153 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3154 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3155 if (num_devices == 1)
3156 allowed |= BTRFS_BLOCK_GROUP_DUP;
3157 else if (num_devices > 1)
3158 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3159 if (num_devices > 2)
3160 allowed |= BTRFS_BLOCK_GROUP_RAID5;
3161 if (num_devices > 3)
3162 allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
3163 BTRFS_BLOCK_GROUP_RAID6);
3164 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3165 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3166 (bctl->data.target & ~allowed))) {
3167 printk(KERN_ERR "btrfs: unable to start balance with target "
3168 "data profile %llu\n",
3169 bctl->data.target);
3170 ret = -EINVAL;
3171 goto out;
3172 }
3173 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3174 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3175 (bctl->meta.target & ~allowed))) {
3176 printk(KERN_ERR "btrfs: unable to start balance with target "
3177 "metadata profile %llu\n",
3178 bctl->meta.target);
3179 ret = -EINVAL;
3180 goto out;
3181 }
3182 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3183 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3184 (bctl->sys.target & ~allowed))) {
3185 printk(KERN_ERR "btrfs: unable to start balance with target "
3186 "system profile %llu\n",
3187 bctl->sys.target);
3188 ret = -EINVAL;
3189 goto out;
3190 }
3191
3192 /* allow dup'ed data chunks only in mixed mode */
3193 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3194 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3195 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3196 ret = -EINVAL;
3197 goto out;
3198 }
3199
3200 /* allow to reduce meta or sys integrity only if force set */
3201 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3202 BTRFS_BLOCK_GROUP_RAID10 |
3203 BTRFS_BLOCK_GROUP_RAID5 |
3204 BTRFS_BLOCK_GROUP_RAID6;
3205 do {
3206 seq = read_seqbegin(&fs_info->profiles_lock);
3207
3208 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3209 (fs_info->avail_system_alloc_bits & allowed) &&
3210 !(bctl->sys.target & allowed)) ||
3211 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3212 (fs_info->avail_metadata_alloc_bits & allowed) &&
3213 !(bctl->meta.target & allowed))) {
3214 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3215 printk(KERN_INFO "btrfs: force reducing metadata "
3216 "integrity\n");
3217 } else {
3218 printk(KERN_ERR "btrfs: balance will reduce metadata "
3219 "integrity, use force if you want this\n");
3220 ret = -EINVAL;
3221 goto out;
3222 }
3223 }
3224 } while (read_seqretry(&fs_info->profiles_lock, seq));
3225
3226 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3227 int num_tolerated_disk_barrier_failures;
3228 u64 target = bctl->sys.target;
3229
3230 num_tolerated_disk_barrier_failures =
3231 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3232 if (num_tolerated_disk_barrier_failures > 0 &&
3233 (target &
3234 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3235 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3236 num_tolerated_disk_barrier_failures = 0;
3237 else if (num_tolerated_disk_barrier_failures > 1 &&
3238 (target &
3239 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3240 num_tolerated_disk_barrier_failures = 1;
3241
3242 fs_info->num_tolerated_disk_barrier_failures =
3243 num_tolerated_disk_barrier_failures;
3244 }
3245
3246 ret = insert_balance_item(fs_info->tree_root, bctl);
3247 if (ret && ret != -EEXIST)
3248 goto out;
3249
3250 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3251 BUG_ON(ret == -EEXIST);
3252 set_balance_control(bctl);
3253 } else {
3254 BUG_ON(ret != -EEXIST);
3255 spin_lock(&fs_info->balance_lock);
3256 update_balance_args(bctl);
3257 spin_unlock(&fs_info->balance_lock);
3258 }
3259
3260 atomic_inc(&fs_info->balance_running);
3261 mutex_unlock(&fs_info->balance_mutex);
3262
3263 ret = __btrfs_balance(fs_info);
3264
3265 mutex_lock(&fs_info->balance_mutex);
3266 atomic_dec(&fs_info->balance_running);
3267
3268 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3269 fs_info->num_tolerated_disk_barrier_failures =
3270 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3271 }
3272
3273 if (bargs) {
3274 memset(bargs, 0, sizeof(*bargs));
3275 update_ioctl_balance_args(fs_info, 0, bargs);
3276 }
3277
3278 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3279 balance_need_close(fs_info)) {
3280 __cancel_balance(fs_info);
3281 }
3282
3283 wake_up(&fs_info->balance_wait_q);
3284
3285 return ret;
3286 out:
3287 if (bctl->flags & BTRFS_BALANCE_RESUME)
3288 __cancel_balance(fs_info);
3289 else {
3290 kfree(bctl);
3291 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3292 }
3293 return ret;
3294 }
3295
3296 static int balance_kthread(void *data)
3297 {
3298 struct btrfs_fs_info *fs_info = data;
3299 int ret = 0;
3300
3301 mutex_lock(&fs_info->volume_mutex);
3302 mutex_lock(&fs_info->balance_mutex);
3303
3304 if (fs_info->balance_ctl) {
3305 printk(KERN_INFO "btrfs: continuing balance\n");
3306 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3307 }
3308
3309 mutex_unlock(&fs_info->balance_mutex);
3310 mutex_unlock(&fs_info->volume_mutex);
3311
3312 return ret;
3313 }
3314
3315 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3316 {
3317 struct task_struct *tsk;
3318
3319 spin_lock(&fs_info->balance_lock);
3320 if (!fs_info->balance_ctl) {
3321 spin_unlock(&fs_info->balance_lock);
3322 return 0;
3323 }
3324 spin_unlock(&fs_info->balance_lock);
3325
3326 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3327 printk(KERN_INFO "btrfs: force skipping balance\n");
3328 return 0;
3329 }
3330
3331 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3332 return PTR_ERR_OR_ZERO(tsk);
3333 }
3334
3335 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3336 {
3337 struct btrfs_balance_control *bctl;
3338 struct btrfs_balance_item *item;
3339 struct btrfs_disk_balance_args disk_bargs;
3340 struct btrfs_path *path;
3341 struct extent_buffer *leaf;
3342 struct btrfs_key key;
3343 int ret;
3344
3345 path = btrfs_alloc_path();
3346 if (!path)
3347 return -ENOMEM;
3348
3349 key.objectid = BTRFS_BALANCE_OBJECTID;
3350 key.type = BTRFS_BALANCE_ITEM_KEY;
3351 key.offset = 0;
3352
3353 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3354 if (ret < 0)
3355 goto out;
3356 if (ret > 0) { /* ret = -ENOENT; */
3357 ret = 0;
3358 goto out;
3359 }
3360
3361 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3362 if (!bctl) {
3363 ret = -ENOMEM;
3364 goto out;
3365 }
3366
3367 leaf = path->nodes[0];
3368 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3369
3370 bctl->fs_info = fs_info;
3371 bctl->flags = btrfs_balance_flags(leaf, item);
3372 bctl->flags |= BTRFS_BALANCE_RESUME;
3373
3374 btrfs_balance_data(leaf, item, &disk_bargs);
3375 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3376 btrfs_balance_meta(leaf, item, &disk_bargs);
3377 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3378 btrfs_balance_sys(leaf, item, &disk_bargs);
3379 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3380
3381 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3382
3383 mutex_lock(&fs_info->volume_mutex);
3384 mutex_lock(&fs_info->balance_mutex);
3385
3386 set_balance_control(bctl);
3387
3388 mutex_unlock(&fs_info->balance_mutex);
3389 mutex_unlock(&fs_info->volume_mutex);
3390 out:
3391 btrfs_free_path(path);
3392 return ret;
3393 }
3394
3395 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3396 {
3397 int ret = 0;
3398
3399 mutex_lock(&fs_info->balance_mutex);
3400 if (!fs_info->balance_ctl) {
3401 mutex_unlock(&fs_info->balance_mutex);
3402 return -ENOTCONN;
3403 }
3404
3405 if (atomic_read(&fs_info->balance_running)) {
3406 atomic_inc(&fs_info->balance_pause_req);
3407 mutex_unlock(&fs_info->balance_mutex);
3408
3409 wait_event(fs_info->balance_wait_q,
3410 atomic_read(&fs_info->balance_running) == 0);
3411
3412 mutex_lock(&fs_info->balance_mutex);
3413 /* we are good with balance_ctl ripped off from under us */
3414 BUG_ON(atomic_read(&fs_info->balance_running));
3415 atomic_dec(&fs_info->balance_pause_req);
3416 } else {
3417 ret = -ENOTCONN;
3418 }
3419
3420 mutex_unlock(&fs_info->balance_mutex);
3421 return ret;
3422 }
3423
3424 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3425 {
3426 mutex_lock(&fs_info->balance_mutex);
3427 if (!fs_info->balance_ctl) {
3428 mutex_unlock(&fs_info->balance_mutex);
3429 return -ENOTCONN;
3430 }
3431
3432 atomic_inc(&fs_info->balance_cancel_req);
3433 /*
3434 * if we are running just wait and return, balance item is
3435 * deleted in btrfs_balance in this case
3436 */
3437 if (atomic_read(&fs_info->balance_running)) {
3438 mutex_unlock(&fs_info->balance_mutex);
3439 wait_event(fs_info->balance_wait_q,
3440 atomic_read(&fs_info->balance_running) == 0);
3441 mutex_lock(&fs_info->balance_mutex);
3442 } else {
3443 /* __cancel_balance needs volume_mutex */
3444 mutex_unlock(&fs_info->balance_mutex);
3445 mutex_lock(&fs_info->volume_mutex);
3446 mutex_lock(&fs_info->balance_mutex);
3447
3448 if (fs_info->balance_ctl)
3449 __cancel_balance(fs_info);
3450
3451 mutex_unlock(&fs_info->volume_mutex);
3452 }
3453
3454 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3455 atomic_dec(&fs_info->balance_cancel_req);
3456 mutex_unlock(&fs_info->balance_mutex);
3457 return 0;
3458 }
3459
3460 static int btrfs_uuid_scan_kthread(void *data)
3461 {
3462 struct btrfs_fs_info *fs_info = data;
3463 struct btrfs_root *root = fs_info->tree_root;
3464 struct btrfs_key key;
3465 struct btrfs_key max_key;
3466 struct btrfs_path *path = NULL;
3467 int ret = 0;
3468 struct extent_buffer *eb;
3469 int slot;
3470 struct btrfs_root_item root_item;
3471 u32 item_size;
3472 struct btrfs_trans_handle *trans = NULL;
3473
3474 path = btrfs_alloc_path();
3475 if (!path) {
3476 ret = -ENOMEM;
3477 goto out;
3478 }
3479
3480 key.objectid = 0;
3481 key.type = BTRFS_ROOT_ITEM_KEY;
3482 key.offset = 0;
3483
3484 max_key.objectid = (u64)-1;
3485 max_key.type = BTRFS_ROOT_ITEM_KEY;
3486 max_key.offset = (u64)-1;
3487
3488 path->keep_locks = 1;
3489
3490 while (1) {
3491 ret = btrfs_search_forward(root, &key, &max_key, path, 0);
3492 if (ret) {
3493 if (ret > 0)
3494 ret = 0;
3495 break;
3496 }
3497
3498 if (key.type != BTRFS_ROOT_ITEM_KEY ||
3499 (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
3500 key.objectid != BTRFS_FS_TREE_OBJECTID) ||
3501 key.objectid > BTRFS_LAST_FREE_OBJECTID)
3502 goto skip;
3503
3504 eb = path->nodes[0];
3505 slot = path->slots[0];
3506 item_size = btrfs_item_size_nr(eb, slot);
3507 if (item_size < sizeof(root_item))
3508 goto skip;
3509
3510 read_extent_buffer(eb, &root_item,
3511 btrfs_item_ptr_offset(eb, slot),
3512 (int)sizeof(root_item));
3513 if (btrfs_root_refs(&root_item) == 0)
3514 goto skip;
3515
3516 if (!btrfs_is_empty_uuid(root_item.uuid) ||
3517 !btrfs_is_empty_uuid(root_item.received_uuid)) {
3518 if (trans)
3519 goto update_tree;
3520
3521 btrfs_release_path(path);
3522 /*
3523 * 1 - subvol uuid item
3524 * 1 - received_subvol uuid item
3525 */
3526 trans = btrfs_start_transaction(fs_info->uuid_root, 2);
3527 if (IS_ERR(trans)) {
3528 ret = PTR_ERR(trans);
3529 break;
3530 }
3531 continue;
3532 } else {
3533 goto skip;
3534 }
3535 update_tree:
3536 if (!btrfs_is_empty_uuid(root_item.uuid)) {
3537 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3538 root_item.uuid,
3539 BTRFS_UUID_KEY_SUBVOL,
3540 key.objectid);
3541 if (ret < 0) {
3542 pr_warn("btrfs: uuid_tree_add failed %d\n",
3543 ret);
3544 break;
3545 }
3546 }
3547
3548 if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
3549 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3550 root_item.received_uuid,
3551 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
3552 key.objectid);
3553 if (ret < 0) {
3554 pr_warn("btrfs: uuid_tree_add failed %d\n",
3555 ret);
3556 break;
3557 }
3558 }
3559
3560 skip:
3561 if (trans) {
3562 ret = btrfs_end_transaction(trans, fs_info->uuid_root);
3563 trans = NULL;
3564 if (ret)
3565 break;
3566 }
3567
3568 btrfs_release_path(path);
3569 if (key.offset < (u64)-1) {
3570 key.offset++;
3571 } else if (key.type < BTRFS_ROOT_ITEM_KEY) {
3572 key.offset = 0;
3573 key.type = BTRFS_ROOT_ITEM_KEY;
3574 } else if (key.objectid < (u64)-1) {
3575 key.offset = 0;
3576 key.type = BTRFS_ROOT_ITEM_KEY;
3577 key.objectid++;
3578 } else {
3579 break;
3580 }
3581 cond_resched();
3582 }
3583
3584 out:
3585 btrfs_free_path(path);
3586 if (trans && !IS_ERR(trans))
3587 btrfs_end_transaction(trans, fs_info->uuid_root);
3588 if (ret)
3589 pr_warn("btrfs: btrfs_uuid_scan_kthread failed %d\n", ret);
3590 else
3591 fs_info->update_uuid_tree_gen = 1;
3592 up(&fs_info->uuid_tree_rescan_sem);
3593 return 0;
3594 }
3595
3596 /*
3597 * Callback for btrfs_uuid_tree_iterate().
3598 * returns:
3599 * 0 check succeeded, the entry is not outdated.
3600 * < 0 if an error occured.
3601 * > 0 if the check failed, which means the caller shall remove the entry.
3602 */
3603 static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
3604 u8 *uuid, u8 type, u64 subid)
3605 {
3606 struct btrfs_key key;
3607 int ret = 0;
3608 struct btrfs_root *subvol_root;
3609
3610 if (type != BTRFS_UUID_KEY_SUBVOL &&
3611 type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
3612 goto out;
3613
3614 key.objectid = subid;
3615 key.type = BTRFS_ROOT_ITEM_KEY;
3616 key.offset = (u64)-1;
3617 subvol_root = btrfs_read_fs_root_no_name(fs_info, &key);
3618 if (IS_ERR(subvol_root)) {
3619 ret = PTR_ERR(subvol_root);
3620 if (ret == -ENOENT)
3621 ret = 1;
3622 goto out;
3623 }
3624
3625 switch (type) {
3626 case BTRFS_UUID_KEY_SUBVOL:
3627 if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
3628 ret = 1;
3629 break;
3630 case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
3631 if (memcmp(uuid, subvol_root->root_item.received_uuid,
3632 BTRFS_UUID_SIZE))
3633 ret = 1;
3634 break;
3635 }
3636
3637 out:
3638 return ret;
3639 }
3640
3641 static int btrfs_uuid_rescan_kthread(void *data)
3642 {
3643 struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
3644 int ret;
3645
3646 /*
3647 * 1st step is to iterate through the existing UUID tree and
3648 * to delete all entries that contain outdated data.
3649 * 2nd step is to add all missing entries to the UUID tree.
3650 */
3651 ret = btrfs_uuid_tree_iterate(fs_info, btrfs_check_uuid_tree_entry);
3652 if (ret < 0) {
3653 pr_warn("btrfs: iterating uuid_tree failed %d\n", ret);
3654 up(&fs_info->uuid_tree_rescan_sem);
3655 return ret;
3656 }
3657 return btrfs_uuid_scan_kthread(data);
3658 }
3659
3660 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
3661 {
3662 struct btrfs_trans_handle *trans;
3663 struct btrfs_root *tree_root = fs_info->tree_root;
3664 struct btrfs_root *uuid_root;
3665 struct task_struct *task;
3666 int ret;
3667
3668 /*
3669 * 1 - root node
3670 * 1 - root item
3671 */
3672 trans = btrfs_start_transaction(tree_root, 2);
3673 if (IS_ERR(trans))
3674 return PTR_ERR(trans);
3675
3676 uuid_root = btrfs_create_tree(trans, fs_info,
3677 BTRFS_UUID_TREE_OBJECTID);
3678 if (IS_ERR(uuid_root)) {
3679 btrfs_abort_transaction(trans, tree_root,
3680 PTR_ERR(uuid_root));
3681 return PTR_ERR(uuid_root);
3682 }
3683
3684 fs_info->uuid_root = uuid_root;
3685
3686 ret = btrfs_commit_transaction(trans, tree_root);
3687 if (ret)
3688 return ret;
3689
3690 down(&fs_info->uuid_tree_rescan_sem);
3691 task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
3692 if (IS_ERR(task)) {
3693 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3694 pr_warn("btrfs: failed to start uuid_scan task\n");
3695 up(&fs_info->uuid_tree_rescan_sem);
3696 return PTR_ERR(task);
3697 }
3698
3699 return 0;
3700 }
3701
3702 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3703 {
3704 struct task_struct *task;
3705
3706 down(&fs_info->uuid_tree_rescan_sem);
3707 task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3708 if (IS_ERR(task)) {
3709 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3710 pr_warn("btrfs: failed to start uuid_rescan task\n");
3711 up(&fs_info->uuid_tree_rescan_sem);
3712 return PTR_ERR(task);
3713 }
3714
3715 return 0;
3716 }
3717
3718 /*
3719 * shrinking a device means finding all of the device extents past
3720 * the new size, and then following the back refs to the chunks.
3721 * The chunk relocation code actually frees the device extent
3722 */
3723 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3724 {
3725 struct btrfs_trans_handle *trans;
3726 struct btrfs_root *root = device->dev_root;
3727 struct btrfs_dev_extent *dev_extent = NULL;
3728 struct btrfs_path *path;
3729 u64 length;
3730 u64 chunk_tree;
3731 u64 chunk_objectid;
3732 u64 chunk_offset;
3733 int ret;
3734 int slot;
3735 int failed = 0;
3736 bool retried = false;
3737 struct extent_buffer *l;
3738 struct btrfs_key key;
3739 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3740 u64 old_total = btrfs_super_total_bytes(super_copy);
3741 u64 old_size = device->total_bytes;
3742 u64 diff = device->total_bytes - new_size;
3743
3744 if (device->is_tgtdev_for_dev_replace)
3745 return -EINVAL;
3746
3747 path = btrfs_alloc_path();
3748 if (!path)
3749 return -ENOMEM;
3750
3751 path->reada = 2;
3752
3753 lock_chunks(root);
3754
3755 device->total_bytes = new_size;
3756 if (device->writeable) {
3757 device->fs_devices->total_rw_bytes -= diff;
3758 spin_lock(&root->fs_info->free_chunk_lock);
3759 root->fs_info->free_chunk_space -= diff;
3760 spin_unlock(&root->fs_info->free_chunk_lock);
3761 }
3762 unlock_chunks(root);
3763
3764 again:
3765 key.objectid = device->devid;
3766 key.offset = (u64)-1;
3767 key.type = BTRFS_DEV_EXTENT_KEY;
3768
3769 do {
3770 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3771 if (ret < 0)
3772 goto done;
3773
3774 ret = btrfs_previous_item(root, path, 0, key.type);
3775 if (ret < 0)
3776 goto done;
3777 if (ret) {
3778 ret = 0;
3779 btrfs_release_path(path);
3780 break;
3781 }
3782
3783 l = path->nodes[0];
3784 slot = path->slots[0];
3785 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3786
3787 if (key.objectid != device->devid) {
3788 btrfs_release_path(path);
3789 break;
3790 }
3791
3792 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3793 length = btrfs_dev_extent_length(l, dev_extent);
3794
3795 if (key.offset + length <= new_size) {
3796 btrfs_release_path(path);
3797 break;
3798 }
3799
3800 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3801 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3802 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3803 btrfs_release_path(path);
3804
3805 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3806 chunk_offset);
3807 if (ret && ret != -ENOSPC)
3808 goto done;
3809 if (ret == -ENOSPC)
3810 failed++;
3811 } while (key.offset-- > 0);
3812
3813 if (failed && !retried) {
3814 failed = 0;
3815 retried = true;
3816 goto again;
3817 } else if (failed && retried) {
3818 ret = -ENOSPC;
3819 lock_chunks(root);
3820
3821 device->total_bytes = old_size;
3822 if (device->writeable)
3823 device->fs_devices->total_rw_bytes += diff;
3824 spin_lock(&root->fs_info->free_chunk_lock);
3825 root->fs_info->free_chunk_space += diff;
3826 spin_unlock(&root->fs_info->free_chunk_lock);
3827 unlock_chunks(root);
3828 goto done;
3829 }
3830
3831 /* Shrinking succeeded, else we would be at "done". */
3832 trans = btrfs_start_transaction(root, 0);
3833 if (IS_ERR(trans)) {
3834 ret = PTR_ERR(trans);
3835 goto done;
3836 }
3837
3838 lock_chunks(root);
3839
3840 device->disk_total_bytes = new_size;
3841 /* Now btrfs_update_device() will change the on-disk size. */
3842 ret = btrfs_update_device(trans, device);
3843 if (ret) {
3844 unlock_chunks(root);
3845 btrfs_end_transaction(trans, root);
3846 goto done;
3847 }
3848 WARN_ON(diff > old_total);
3849 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3850 unlock_chunks(root);
3851 btrfs_end_transaction(trans, root);
3852 done:
3853 btrfs_free_path(path);
3854 return ret;
3855 }
3856
3857 static int btrfs_add_system_chunk(struct btrfs_root *root,
3858 struct btrfs_key *key,
3859 struct btrfs_chunk *chunk, int item_size)
3860 {
3861 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3862 struct btrfs_disk_key disk_key;
3863 u32 array_size;
3864 u8 *ptr;
3865
3866 array_size = btrfs_super_sys_array_size(super_copy);
3867 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3868 return -EFBIG;
3869
3870 ptr = super_copy->sys_chunk_array + array_size;
3871 btrfs_cpu_key_to_disk(&disk_key, key);
3872 memcpy(ptr, &disk_key, sizeof(disk_key));
3873 ptr += sizeof(disk_key);
3874 memcpy(ptr, chunk, item_size);
3875 item_size += sizeof(disk_key);
3876 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3877 return 0;
3878 }
3879
3880 /*
3881 * sort the devices in descending order by max_avail, total_avail
3882 */
3883 static int btrfs_cmp_device_info(const void *a, const void *b)
3884 {
3885 const struct btrfs_device_info *di_a = a;
3886 const struct btrfs_device_info *di_b = b;
3887
3888 if (di_a->max_avail > di_b->max_avail)
3889 return -1;
3890 if (di_a->max_avail < di_b->max_avail)
3891 return 1;
3892 if (di_a->total_avail > di_b->total_avail)
3893 return -1;
3894 if (di_a->total_avail < di_b->total_avail)
3895 return 1;
3896 return 0;
3897 }
3898
3899 static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3900 [BTRFS_RAID_RAID10] = {
3901 .sub_stripes = 2,
3902 .dev_stripes = 1,
3903 .devs_max = 0, /* 0 == as many as possible */
3904 .devs_min = 4,
3905 .devs_increment = 2,
3906 .ncopies = 2,
3907 },
3908 [BTRFS_RAID_RAID1] = {
3909 .sub_stripes = 1,
3910 .dev_stripes = 1,
3911 .devs_max = 2,
3912 .devs_min = 2,
3913 .devs_increment = 2,
3914 .ncopies = 2,
3915 },
3916 [BTRFS_RAID_DUP] = {
3917 .sub_stripes = 1,
3918 .dev_stripes = 2,
3919 .devs_max = 1,
3920 .devs_min = 1,
3921 .devs_increment = 1,
3922 .ncopies = 2,
3923 },
3924 [BTRFS_RAID_RAID0] = {
3925 .sub_stripes = 1,
3926 .dev_stripes = 1,
3927 .devs_max = 0,
3928 .devs_min = 2,
3929 .devs_increment = 1,
3930 .ncopies = 1,
3931 },
3932 [BTRFS_RAID_SINGLE] = {
3933 .sub_stripes = 1,
3934 .dev_stripes = 1,
3935 .devs_max = 1,
3936 .devs_min = 1,
3937 .devs_increment = 1,
3938 .ncopies = 1,
3939 },
3940 [BTRFS_RAID_RAID5] = {
3941 .sub_stripes = 1,
3942 .dev_stripes = 1,
3943 .devs_max = 0,
3944 .devs_min = 2,
3945 .devs_increment = 1,
3946 .ncopies = 2,
3947 },
3948 [BTRFS_RAID_RAID6] = {
3949 .sub_stripes = 1,
3950 .dev_stripes = 1,
3951 .devs_max = 0,
3952 .devs_min = 3,
3953 .devs_increment = 1,
3954 .ncopies = 3,
3955 },
3956 };
3957
3958 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3959 {
3960 /* TODO allow them to set a preferred stripe size */
3961 return 64 * 1024;
3962 }
3963
3964 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3965 {
3966 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3967 return;
3968
3969 btrfs_set_fs_incompat(info, RAID56);
3970 }
3971
3972 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3973 struct btrfs_root *extent_root, u64 start,
3974 u64 type)
3975 {
3976 struct btrfs_fs_info *info = extent_root->fs_info;
3977 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3978 struct list_head *cur;
3979 struct map_lookup *map = NULL;
3980 struct extent_map_tree *em_tree;
3981 struct extent_map *em;
3982 struct btrfs_device_info *devices_info = NULL;
3983 u64 total_avail;
3984 int num_stripes; /* total number of stripes to allocate */
3985 int data_stripes; /* number of stripes that count for
3986 block group size */
3987 int sub_stripes; /* sub_stripes info for map */
3988 int dev_stripes; /* stripes per dev */
3989 int devs_max; /* max devs to use */
3990 int devs_min; /* min devs needed */
3991 int devs_increment; /* ndevs has to be a multiple of this */
3992 int ncopies; /* how many copies to data has */
3993 int ret;
3994 u64 max_stripe_size;
3995 u64 max_chunk_size;
3996 u64 stripe_size;
3997 u64 num_bytes;
3998 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
3999 int ndevs;
4000 int i;
4001 int j;
4002 int index;
4003
4004 BUG_ON(!alloc_profile_is_valid(type, 0));
4005
4006 if (list_empty(&fs_devices->alloc_list))
4007 return -ENOSPC;
4008
4009 index = __get_raid_index(type);
4010
4011 sub_stripes = btrfs_raid_array[index].sub_stripes;
4012 dev_stripes = btrfs_raid_array[index].dev_stripes;
4013 devs_max = btrfs_raid_array[index].devs_max;
4014 devs_min = btrfs_raid_array[index].devs_min;
4015 devs_increment = btrfs_raid_array[index].devs_increment;
4016 ncopies = btrfs_raid_array[index].ncopies;
4017
4018 if (type & BTRFS_BLOCK_GROUP_DATA) {
4019 max_stripe_size = 1024 * 1024 * 1024;
4020 max_chunk_size = 10 * max_stripe_size;
4021 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
4022 /* for larger filesystems, use larger metadata chunks */
4023 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
4024 max_stripe_size = 1024 * 1024 * 1024;
4025 else
4026 max_stripe_size = 256 * 1024 * 1024;
4027 max_chunk_size = max_stripe_size;
4028 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
4029 max_stripe_size = 32 * 1024 * 1024;
4030 max_chunk_size = 2 * max_stripe_size;
4031 } else {
4032 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
4033 type);
4034 BUG_ON(1);
4035 }
4036
4037 /* we don't want a chunk larger than 10% of writeable space */
4038 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
4039 max_chunk_size);
4040
4041 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
4042 GFP_NOFS);
4043 if (!devices_info)
4044 return -ENOMEM;
4045
4046 cur = fs_devices->alloc_list.next;
4047
4048 /*
4049 * in the first pass through the devices list, we gather information
4050 * about the available holes on each device.
4051 */
4052 ndevs = 0;
4053 while (cur != &fs_devices->alloc_list) {
4054 struct btrfs_device *device;
4055 u64 max_avail;
4056 u64 dev_offset;
4057
4058 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
4059
4060 cur = cur->next;
4061
4062 if (!device->writeable) {
4063 WARN(1, KERN_ERR
4064 "btrfs: read-only device in alloc_list\n");
4065 continue;
4066 }
4067
4068 if (!device->in_fs_metadata ||
4069 device->is_tgtdev_for_dev_replace)
4070 continue;
4071
4072 if (device->total_bytes > device->bytes_used)
4073 total_avail = device->total_bytes - device->bytes_used;
4074 else
4075 total_avail = 0;
4076
4077 /* If there is no space on this device, skip it. */
4078 if (total_avail == 0)
4079 continue;
4080
4081 ret = find_free_dev_extent(trans, device,
4082 max_stripe_size * dev_stripes,
4083 &dev_offset, &max_avail);
4084 if (ret && ret != -ENOSPC)
4085 goto error;
4086
4087 if (ret == 0)
4088 max_avail = max_stripe_size * dev_stripes;
4089
4090 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
4091 continue;
4092
4093 if (ndevs == fs_devices->rw_devices) {
4094 WARN(1, "%s: found more than %llu devices\n",
4095 __func__, fs_devices->rw_devices);
4096 break;
4097 }
4098 devices_info[ndevs].dev_offset = dev_offset;
4099 devices_info[ndevs].max_avail = max_avail;
4100 devices_info[ndevs].total_avail = total_avail;
4101 devices_info[ndevs].dev = device;
4102 ++ndevs;
4103 }
4104
4105 /*
4106 * now sort the devices by hole size / available space
4107 */
4108 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
4109 btrfs_cmp_device_info, NULL);
4110
4111 /* round down to number of usable stripes */
4112 ndevs -= ndevs % devs_increment;
4113
4114 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
4115 ret = -ENOSPC;
4116 goto error;
4117 }
4118
4119 if (devs_max && ndevs > devs_max)
4120 ndevs = devs_max;
4121 /*
4122 * the primary goal is to maximize the number of stripes, so use as many
4123 * devices as possible, even if the stripes are not maximum sized.
4124 */
4125 stripe_size = devices_info[ndevs-1].max_avail;
4126 num_stripes = ndevs * dev_stripes;
4127
4128 /*
4129 * this will have to be fixed for RAID1 and RAID10 over
4130 * more drives
4131 */
4132 data_stripes = num_stripes / ncopies;
4133
4134 if (type & BTRFS_BLOCK_GROUP_RAID5) {
4135 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
4136 btrfs_super_stripesize(info->super_copy));
4137 data_stripes = num_stripes - 1;
4138 }
4139 if (type & BTRFS_BLOCK_GROUP_RAID6) {
4140 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
4141 btrfs_super_stripesize(info->super_copy));
4142 data_stripes = num_stripes - 2;
4143 }
4144
4145 /*
4146 * Use the number of data stripes to figure out how big this chunk
4147 * is really going to be in terms of logical address space,
4148 * and compare that answer with the max chunk size
4149 */
4150 if (stripe_size * data_stripes > max_chunk_size) {
4151 u64 mask = (1ULL << 24) - 1;
4152 stripe_size = max_chunk_size;
4153 do_div(stripe_size, data_stripes);
4154
4155 /* bump the answer up to a 16MB boundary */
4156 stripe_size = (stripe_size + mask) & ~mask;
4157
4158 /* but don't go higher than the limits we found
4159 * while searching for free extents
4160 */
4161 if (stripe_size > devices_info[ndevs-1].max_avail)
4162 stripe_size = devices_info[ndevs-1].max_avail;
4163 }
4164
4165 do_div(stripe_size, dev_stripes);
4166
4167 /* align to BTRFS_STRIPE_LEN */
4168 do_div(stripe_size, raid_stripe_len);
4169 stripe_size *= raid_stripe_len;
4170
4171 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4172 if (!map) {
4173 ret = -ENOMEM;
4174 goto error;
4175 }
4176 map->num_stripes = num_stripes;
4177
4178 for (i = 0; i < ndevs; ++i) {
4179 for (j = 0; j < dev_stripes; ++j) {
4180 int s = i * dev_stripes + j;
4181 map->stripes[s].dev = devices_info[i].dev;
4182 map->stripes[s].physical = devices_info[i].dev_offset +
4183 j * stripe_size;
4184 }
4185 }
4186 map->sector_size = extent_root->sectorsize;
4187 map->stripe_len = raid_stripe_len;
4188 map->io_align = raid_stripe_len;
4189 map->io_width = raid_stripe_len;
4190 map->type = type;
4191 map->sub_stripes = sub_stripes;
4192
4193 num_bytes = stripe_size * data_stripes;
4194
4195 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
4196
4197 em = alloc_extent_map();
4198 if (!em) {
4199 ret = -ENOMEM;
4200 goto error;
4201 }
4202 em->bdev = (struct block_device *)map;
4203 em->start = start;
4204 em->len = num_bytes;
4205 em->block_start = 0;
4206 em->block_len = em->len;
4207 em->orig_block_len = stripe_size;
4208
4209 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4210 write_lock(&em_tree->lock);
4211 ret = add_extent_mapping(em_tree, em, 0);
4212 if (!ret) {
4213 list_add_tail(&em->list, &trans->transaction->pending_chunks);
4214 atomic_inc(&em->refs);
4215 }
4216 write_unlock(&em_tree->lock);
4217 if (ret) {
4218 free_extent_map(em);
4219 goto error;
4220 }
4221
4222 ret = btrfs_make_block_group(trans, extent_root, 0, type,
4223 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4224 start, num_bytes);
4225 if (ret)
4226 goto error_del_extent;
4227
4228 free_extent_map(em);
4229 check_raid56_incompat_flag(extent_root->fs_info, type);
4230
4231 kfree(devices_info);
4232 return 0;
4233
4234 error_del_extent:
4235 write_lock(&em_tree->lock);
4236 remove_extent_mapping(em_tree, em);
4237 write_unlock(&em_tree->lock);
4238
4239 /* One for our allocation */
4240 free_extent_map(em);
4241 /* One for the tree reference */
4242 free_extent_map(em);
4243 error:
4244 kfree(map);
4245 kfree(devices_info);
4246 return ret;
4247 }
4248
4249 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
4250 struct btrfs_root *extent_root,
4251 u64 chunk_offset, u64 chunk_size)
4252 {
4253 struct btrfs_key key;
4254 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4255 struct btrfs_device *device;
4256 struct btrfs_chunk *chunk;
4257 struct btrfs_stripe *stripe;
4258 struct extent_map_tree *em_tree;
4259 struct extent_map *em;
4260 struct map_lookup *map;
4261 size_t item_size;
4262 u64 dev_offset;
4263 u64 stripe_size;
4264 int i = 0;
4265 int ret;
4266
4267 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4268 read_lock(&em_tree->lock);
4269 em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
4270 read_unlock(&em_tree->lock);
4271
4272 if (!em) {
4273 btrfs_crit(extent_root->fs_info, "unable to find logical "
4274 "%Lu len %Lu", chunk_offset, chunk_size);
4275 return -EINVAL;
4276 }
4277
4278 if (em->start != chunk_offset || em->len != chunk_size) {
4279 btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
4280 " %Lu-%Lu, found %Lu-%Lu\n", chunk_offset,
4281 chunk_size, em->start, em->len);
4282 free_extent_map(em);
4283 return -EINVAL;
4284 }
4285
4286 map = (struct map_lookup *)em->bdev;
4287 item_size = btrfs_chunk_item_size(map->num_stripes);
4288 stripe_size = em->orig_block_len;
4289
4290 chunk = kzalloc(item_size, GFP_NOFS);
4291 if (!chunk) {
4292 ret = -ENOMEM;
4293 goto out;
4294 }
4295
4296 for (i = 0; i < map->num_stripes; i++) {
4297 device = map->stripes[i].dev;
4298 dev_offset = map->stripes[i].physical;
4299
4300 device->bytes_used += stripe_size;
4301 ret = btrfs_update_device(trans, device);
4302 if (ret)
4303 goto out;
4304 ret = btrfs_alloc_dev_extent(trans, device,
4305 chunk_root->root_key.objectid,
4306 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4307 chunk_offset, dev_offset,
4308 stripe_size);
4309 if (ret)
4310 goto out;
4311 }
4312
4313 spin_lock(&extent_root->fs_info->free_chunk_lock);
4314 extent_root->fs_info->free_chunk_space -= (stripe_size *
4315 map->num_stripes);
4316 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4317
4318 stripe = &chunk->stripe;
4319 for (i = 0; i < map->num_stripes; i++) {
4320 device = map->stripes[i].dev;
4321 dev_offset = map->stripes[i].physical;
4322
4323 btrfs_set_stack_stripe_devid(stripe, device->devid);
4324 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4325 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4326 stripe++;
4327 }
4328
4329 btrfs_set_stack_chunk_length(chunk, chunk_size);
4330 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4331 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4332 btrfs_set_stack_chunk_type(chunk, map->type);
4333 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4334 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4335 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4336 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4337 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4338
4339 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4340 key.type = BTRFS_CHUNK_ITEM_KEY;
4341 key.offset = chunk_offset;
4342
4343 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4344 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4345 /*
4346 * TODO: Cleanup of inserted chunk root in case of
4347 * failure.
4348 */
4349 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4350 item_size);
4351 }
4352
4353 out:
4354 kfree(chunk);
4355 free_extent_map(em);
4356 return ret;
4357 }
4358
4359 /*
4360 * Chunk allocation falls into two parts. The first part does works
4361 * that make the new allocated chunk useable, but not do any operation
4362 * that modifies the chunk tree. The second part does the works that
4363 * require modifying the chunk tree. This division is important for the
4364 * bootstrap process of adding storage to a seed btrfs.
4365 */
4366 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4367 struct btrfs_root *extent_root, u64 type)
4368 {
4369 u64 chunk_offset;
4370
4371 chunk_offset = find_next_chunk(extent_root->fs_info);
4372 return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
4373 }
4374
4375 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4376 struct btrfs_root *root,
4377 struct btrfs_device *device)
4378 {
4379 u64 chunk_offset;
4380 u64 sys_chunk_offset;
4381 u64 alloc_profile;
4382 struct btrfs_fs_info *fs_info = root->fs_info;
4383 struct btrfs_root *extent_root = fs_info->extent_root;
4384 int ret;
4385
4386 chunk_offset = find_next_chunk(fs_info);
4387 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4388 ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
4389 alloc_profile);
4390 if (ret)
4391 return ret;
4392
4393 sys_chunk_offset = find_next_chunk(root->fs_info);
4394 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4395 ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
4396 alloc_profile);
4397 if (ret) {
4398 btrfs_abort_transaction(trans, root, ret);
4399 goto out;
4400 }
4401
4402 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4403 if (ret)
4404 btrfs_abort_transaction(trans, root, ret);
4405 out:
4406 return ret;
4407 }
4408
4409 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4410 {
4411 struct extent_map *em;
4412 struct map_lookup *map;
4413 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4414 int readonly = 0;
4415 int i;
4416
4417 read_lock(&map_tree->map_tree.lock);
4418 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4419 read_unlock(&map_tree->map_tree.lock);
4420 if (!em)
4421 return 1;
4422
4423 if (btrfs_test_opt(root, DEGRADED)) {
4424 free_extent_map(em);
4425 return 0;
4426 }
4427
4428 map = (struct map_lookup *)em->bdev;
4429 for (i = 0; i < map->num_stripes; i++) {
4430 if (!map->stripes[i].dev->writeable) {
4431 readonly = 1;
4432 break;
4433 }
4434 }
4435 free_extent_map(em);
4436 return readonly;
4437 }
4438
4439 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4440 {
4441 extent_map_tree_init(&tree->map_tree);
4442 }
4443
4444 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4445 {
4446 struct extent_map *em;
4447
4448 while (1) {
4449 write_lock(&tree->map_tree.lock);
4450 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4451 if (em)
4452 remove_extent_mapping(&tree->map_tree, em);
4453 write_unlock(&tree->map_tree.lock);
4454 if (!em)
4455 break;
4456 kfree(em->bdev);
4457 /* once for us */
4458 free_extent_map(em);
4459 /* once for the tree */
4460 free_extent_map(em);
4461 }
4462 }
4463
4464 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4465 {
4466 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4467 struct extent_map *em;
4468 struct map_lookup *map;
4469 struct extent_map_tree *em_tree = &map_tree->map_tree;
4470 int ret;
4471
4472 read_lock(&em_tree->lock);
4473 em = lookup_extent_mapping(em_tree, logical, len);
4474 read_unlock(&em_tree->lock);
4475
4476 /*
4477 * We could return errors for these cases, but that could get ugly and
4478 * we'd probably do the same thing which is just not do anything else
4479 * and exit, so return 1 so the callers don't try to use other copies.
4480 */
4481 if (!em) {
4482 btrfs_crit(fs_info, "No mapping for %Lu-%Lu\n", logical,
4483 logical+len);
4484 return 1;
4485 }
4486
4487 if (em->start > logical || em->start + em->len < logical) {
4488 btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got "
4489 "%Lu-%Lu\n", logical, logical+len, em->start,
4490 em->start + em->len);
4491 return 1;
4492 }
4493
4494 map = (struct map_lookup *)em->bdev;
4495 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4496 ret = map->num_stripes;
4497 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4498 ret = map->sub_stripes;
4499 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4500 ret = 2;
4501 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4502 ret = 3;
4503 else
4504 ret = 1;
4505 free_extent_map(em);
4506
4507 btrfs_dev_replace_lock(&fs_info->dev_replace);
4508 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4509 ret++;
4510 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4511
4512 return ret;
4513 }
4514
4515 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4516 struct btrfs_mapping_tree *map_tree,
4517 u64 logical)
4518 {
4519 struct extent_map *em;
4520 struct map_lookup *map;
4521 struct extent_map_tree *em_tree = &map_tree->map_tree;
4522 unsigned long len = root->sectorsize;
4523
4524 read_lock(&em_tree->lock);
4525 em = lookup_extent_mapping(em_tree, logical, len);
4526 read_unlock(&em_tree->lock);
4527 BUG_ON(!em);
4528
4529 BUG_ON(em->start > logical || em->start + em->len < logical);
4530 map = (struct map_lookup *)em->bdev;
4531 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4532 BTRFS_BLOCK_GROUP_RAID6)) {
4533 len = map->stripe_len * nr_data_stripes(map);
4534 }
4535 free_extent_map(em);
4536 return len;
4537 }
4538
4539 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4540 u64 logical, u64 len, int mirror_num)
4541 {
4542 struct extent_map *em;
4543 struct map_lookup *map;
4544 struct extent_map_tree *em_tree = &map_tree->map_tree;
4545 int ret = 0;
4546
4547 read_lock(&em_tree->lock);
4548 em = lookup_extent_mapping(em_tree, logical, len);
4549 read_unlock(&em_tree->lock);
4550 BUG_ON(!em);
4551
4552 BUG_ON(em->start > logical || em->start + em->len < logical);
4553 map = (struct map_lookup *)em->bdev;
4554 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4555 BTRFS_BLOCK_GROUP_RAID6))
4556 ret = 1;
4557 free_extent_map(em);
4558 return ret;
4559 }
4560
4561 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4562 struct map_lookup *map, int first, int num,
4563 int optimal, int dev_replace_is_ongoing)
4564 {
4565 int i;
4566 int tolerance;
4567 struct btrfs_device *srcdev;
4568
4569 if (dev_replace_is_ongoing &&
4570 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4571 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4572 srcdev = fs_info->dev_replace.srcdev;
4573 else
4574 srcdev = NULL;
4575
4576 /*
4577 * try to avoid the drive that is the source drive for a
4578 * dev-replace procedure, only choose it if no other non-missing
4579 * mirror is available
4580 */
4581 for (tolerance = 0; tolerance < 2; tolerance++) {
4582 if (map->stripes[optimal].dev->bdev &&
4583 (tolerance || map->stripes[optimal].dev != srcdev))
4584 return optimal;
4585 for (i = first; i < first + num; i++) {
4586 if (map->stripes[i].dev->bdev &&
4587 (tolerance || map->stripes[i].dev != srcdev))
4588 return i;
4589 }
4590 }
4591
4592 /* we couldn't find one that doesn't fail. Just return something
4593 * and the io error handling code will clean up eventually
4594 */
4595 return optimal;
4596 }
4597
4598 static inline int parity_smaller(u64 a, u64 b)
4599 {
4600 return a > b;
4601 }
4602
4603 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4604 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4605 {
4606 struct btrfs_bio_stripe s;
4607 int i;
4608 u64 l;
4609 int again = 1;
4610
4611 while (again) {
4612 again = 0;
4613 for (i = 0; i < bbio->num_stripes - 1; i++) {
4614 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4615 s = bbio->stripes[i];
4616 l = raid_map[i];
4617 bbio->stripes[i] = bbio->stripes[i+1];
4618 raid_map[i] = raid_map[i+1];
4619 bbio->stripes[i+1] = s;
4620 raid_map[i+1] = l;
4621 again = 1;
4622 }
4623 }
4624 }
4625 }
4626
4627 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4628 u64 logical, u64 *length,
4629 struct btrfs_bio **bbio_ret,
4630 int mirror_num, u64 **raid_map_ret)
4631 {
4632 struct extent_map *em;
4633 struct map_lookup *map;
4634 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4635 struct extent_map_tree *em_tree = &map_tree->map_tree;
4636 u64 offset;
4637 u64 stripe_offset;
4638 u64 stripe_end_offset;
4639 u64 stripe_nr;
4640 u64 stripe_nr_orig;
4641 u64 stripe_nr_end;
4642 u64 stripe_len;
4643 u64 *raid_map = NULL;
4644 int stripe_index;
4645 int i;
4646 int ret = 0;
4647 int num_stripes;
4648 int max_errors = 0;
4649 struct btrfs_bio *bbio = NULL;
4650 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4651 int dev_replace_is_ongoing = 0;
4652 int num_alloc_stripes;
4653 int patch_the_first_stripe_for_dev_replace = 0;
4654 u64 physical_to_patch_in_first_stripe = 0;
4655 u64 raid56_full_stripe_start = (u64)-1;
4656
4657 read_lock(&em_tree->lock);
4658 em = lookup_extent_mapping(em_tree, logical, *length);
4659 read_unlock(&em_tree->lock);
4660
4661 if (!em) {
4662 btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4663 logical, *length);
4664 return -EINVAL;
4665 }
4666
4667 if (em->start > logical || em->start + em->len < logical) {
4668 btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4669 "found %Lu-%Lu\n", logical, em->start,
4670 em->start + em->len);
4671 return -EINVAL;
4672 }
4673
4674 map = (struct map_lookup *)em->bdev;
4675 offset = logical - em->start;
4676
4677 stripe_len = map->stripe_len;
4678 stripe_nr = offset;
4679 /*
4680 * stripe_nr counts the total number of stripes we have to stride
4681 * to get to this block
4682 */
4683 do_div(stripe_nr, stripe_len);
4684
4685 stripe_offset = stripe_nr * stripe_len;
4686 BUG_ON(offset < stripe_offset);
4687
4688 /* stripe_offset is the offset of this block in its stripe*/
4689 stripe_offset = offset - stripe_offset;
4690
4691 /* if we're here for raid56, we need to know the stripe aligned start */
4692 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4693 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4694 raid56_full_stripe_start = offset;
4695
4696 /* allow a write of a full stripe, but make sure we don't
4697 * allow straddling of stripes
4698 */
4699 do_div(raid56_full_stripe_start, full_stripe_len);
4700 raid56_full_stripe_start *= full_stripe_len;
4701 }
4702
4703 if (rw & REQ_DISCARD) {
4704 /* we don't discard raid56 yet */
4705 if (map->type &
4706 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4707 ret = -EOPNOTSUPP;
4708 goto out;
4709 }
4710 *length = min_t(u64, em->len - offset, *length);
4711 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4712 u64 max_len;
4713 /* For writes to RAID[56], allow a full stripeset across all disks.
4714 For other RAID types and for RAID[56] reads, just allow a single
4715 stripe (on a single disk). */
4716 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4717 (rw & REQ_WRITE)) {
4718 max_len = stripe_len * nr_data_stripes(map) -
4719 (offset - raid56_full_stripe_start);
4720 } else {
4721 /* we limit the length of each bio to what fits in a stripe */
4722 max_len = stripe_len - stripe_offset;
4723 }
4724 *length = min_t(u64, em->len - offset, max_len);
4725 } else {
4726 *length = em->len - offset;
4727 }
4728
4729 /* This is for when we're called from btrfs_merge_bio_hook() and all
4730 it cares about is the length */
4731 if (!bbio_ret)
4732 goto out;
4733
4734 btrfs_dev_replace_lock(dev_replace);
4735 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4736 if (!dev_replace_is_ongoing)
4737 btrfs_dev_replace_unlock(dev_replace);
4738
4739 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4740 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4741 dev_replace->tgtdev != NULL) {
4742 /*
4743 * in dev-replace case, for repair case (that's the only
4744 * case where the mirror is selected explicitly when
4745 * calling btrfs_map_block), blocks left of the left cursor
4746 * can also be read from the target drive.
4747 * For REQ_GET_READ_MIRRORS, the target drive is added as
4748 * the last one to the array of stripes. For READ, it also
4749 * needs to be supported using the same mirror number.
4750 * If the requested block is not left of the left cursor,
4751 * EIO is returned. This can happen because btrfs_num_copies()
4752 * returns one more in the dev-replace case.
4753 */
4754 u64 tmp_length = *length;
4755 struct btrfs_bio *tmp_bbio = NULL;
4756 int tmp_num_stripes;
4757 u64 srcdev_devid = dev_replace->srcdev->devid;
4758 int index_srcdev = 0;
4759 int found = 0;
4760 u64 physical_of_found = 0;
4761
4762 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4763 logical, &tmp_length, &tmp_bbio, 0, NULL);
4764 if (ret) {
4765 WARN_ON(tmp_bbio != NULL);
4766 goto out;
4767 }
4768
4769 tmp_num_stripes = tmp_bbio->num_stripes;
4770 if (mirror_num > tmp_num_stripes) {
4771 /*
4772 * REQ_GET_READ_MIRRORS does not contain this
4773 * mirror, that means that the requested area
4774 * is not left of the left cursor
4775 */
4776 ret = -EIO;
4777 kfree(tmp_bbio);
4778 goto out;
4779 }
4780
4781 /*
4782 * process the rest of the function using the mirror_num
4783 * of the source drive. Therefore look it up first.
4784 * At the end, patch the device pointer to the one of the
4785 * target drive.
4786 */
4787 for (i = 0; i < tmp_num_stripes; i++) {
4788 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4789 /*
4790 * In case of DUP, in order to keep it
4791 * simple, only add the mirror with the
4792 * lowest physical address
4793 */
4794 if (found &&
4795 physical_of_found <=
4796 tmp_bbio->stripes[i].physical)
4797 continue;
4798 index_srcdev = i;
4799 found = 1;
4800 physical_of_found =
4801 tmp_bbio->stripes[i].physical;
4802 }
4803 }
4804
4805 if (found) {
4806 mirror_num = index_srcdev + 1;
4807 patch_the_first_stripe_for_dev_replace = 1;
4808 physical_to_patch_in_first_stripe = physical_of_found;
4809 } else {
4810 WARN_ON(1);
4811 ret = -EIO;
4812 kfree(tmp_bbio);
4813 goto out;
4814 }
4815
4816 kfree(tmp_bbio);
4817 } else if (mirror_num > map->num_stripes) {
4818 mirror_num = 0;
4819 }
4820
4821 num_stripes = 1;
4822 stripe_index = 0;
4823 stripe_nr_orig = stripe_nr;
4824 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
4825 do_div(stripe_nr_end, map->stripe_len);
4826 stripe_end_offset = stripe_nr_end * map->stripe_len -
4827 (offset + *length);
4828
4829 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4830 if (rw & REQ_DISCARD)
4831 num_stripes = min_t(u64, map->num_stripes,
4832 stripe_nr_end - stripe_nr_orig);
4833 stripe_index = do_div(stripe_nr, map->num_stripes);
4834 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4835 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4836 num_stripes = map->num_stripes;
4837 else if (mirror_num)
4838 stripe_index = mirror_num - 1;
4839 else {
4840 stripe_index = find_live_mirror(fs_info, map, 0,
4841 map->num_stripes,
4842 current->pid % map->num_stripes,
4843 dev_replace_is_ongoing);
4844 mirror_num = stripe_index + 1;
4845 }
4846
4847 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4848 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4849 num_stripes = map->num_stripes;
4850 } else if (mirror_num) {
4851 stripe_index = mirror_num - 1;
4852 } else {
4853 mirror_num = 1;
4854 }
4855
4856 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4857 int factor = map->num_stripes / map->sub_stripes;
4858
4859 stripe_index = do_div(stripe_nr, factor);
4860 stripe_index *= map->sub_stripes;
4861
4862 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4863 num_stripes = map->sub_stripes;
4864 else if (rw & REQ_DISCARD)
4865 num_stripes = min_t(u64, map->sub_stripes *
4866 (stripe_nr_end - stripe_nr_orig),
4867 map->num_stripes);
4868 else if (mirror_num)
4869 stripe_index += mirror_num - 1;
4870 else {
4871 int old_stripe_index = stripe_index;
4872 stripe_index = find_live_mirror(fs_info, map,
4873 stripe_index,
4874 map->sub_stripes, stripe_index +
4875 current->pid % map->sub_stripes,
4876 dev_replace_is_ongoing);
4877 mirror_num = stripe_index - old_stripe_index + 1;
4878 }
4879
4880 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4881 BTRFS_BLOCK_GROUP_RAID6)) {
4882 u64 tmp;
4883
4884 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4885 && raid_map_ret) {
4886 int i, rot;
4887
4888 /* push stripe_nr back to the start of the full stripe */
4889 stripe_nr = raid56_full_stripe_start;
4890 do_div(stripe_nr, stripe_len);
4891
4892 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4893
4894 /* RAID[56] write or recovery. Return all stripes */
4895 num_stripes = map->num_stripes;
4896 max_errors = nr_parity_stripes(map);
4897
4898 raid_map = kmalloc(sizeof(u64) * num_stripes,
4899 GFP_NOFS);
4900 if (!raid_map) {
4901 ret = -ENOMEM;
4902 goto out;
4903 }
4904
4905 /* Work out the disk rotation on this stripe-set */
4906 tmp = stripe_nr;
4907 rot = do_div(tmp, num_stripes);
4908
4909 /* Fill in the logical address of each stripe */
4910 tmp = stripe_nr * nr_data_stripes(map);
4911 for (i = 0; i < nr_data_stripes(map); i++)
4912 raid_map[(i+rot) % num_stripes] =
4913 em->start + (tmp + i) * map->stripe_len;
4914
4915 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4916 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4917 raid_map[(i+rot+1) % num_stripes] =
4918 RAID6_Q_STRIPE;
4919
4920 *length = map->stripe_len;
4921 stripe_index = 0;
4922 stripe_offset = 0;
4923 } else {
4924 /*
4925 * Mirror #0 or #1 means the original data block.
4926 * Mirror #2 is RAID5 parity block.
4927 * Mirror #3 is RAID6 Q block.
4928 */
4929 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4930 if (mirror_num > 1)
4931 stripe_index = nr_data_stripes(map) +
4932 mirror_num - 2;
4933
4934 /* We distribute the parity blocks across stripes */
4935 tmp = stripe_nr + stripe_index;
4936 stripe_index = do_div(tmp, map->num_stripes);
4937 }
4938 } else {
4939 /*
4940 * after this do_div call, stripe_nr is the number of stripes
4941 * on this device we have to walk to find the data, and
4942 * stripe_index is the number of our device in the stripe array
4943 */
4944 stripe_index = do_div(stripe_nr, map->num_stripes);
4945 mirror_num = stripe_index + 1;
4946 }
4947 BUG_ON(stripe_index >= map->num_stripes);
4948
4949 num_alloc_stripes = num_stripes;
4950 if (dev_replace_is_ongoing) {
4951 if (rw & (REQ_WRITE | REQ_DISCARD))
4952 num_alloc_stripes <<= 1;
4953 if (rw & REQ_GET_READ_MIRRORS)
4954 num_alloc_stripes++;
4955 }
4956 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4957 if (!bbio) {
4958 kfree(raid_map);
4959 ret = -ENOMEM;
4960 goto out;
4961 }
4962 atomic_set(&bbio->error, 0);
4963
4964 if (rw & REQ_DISCARD) {
4965 int factor = 0;
4966 int sub_stripes = 0;
4967 u64 stripes_per_dev = 0;
4968 u32 remaining_stripes = 0;
4969 u32 last_stripe = 0;
4970
4971 if (map->type &
4972 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4973 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4974 sub_stripes = 1;
4975 else
4976 sub_stripes = map->sub_stripes;
4977
4978 factor = map->num_stripes / sub_stripes;
4979 stripes_per_dev = div_u64_rem(stripe_nr_end -
4980 stripe_nr_orig,
4981 factor,
4982 &remaining_stripes);
4983 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4984 last_stripe *= sub_stripes;
4985 }
4986
4987 for (i = 0; i < num_stripes; i++) {
4988 bbio->stripes[i].physical =
4989 map->stripes[stripe_index].physical +
4990 stripe_offset + stripe_nr * map->stripe_len;
4991 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4992
4993 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4994 BTRFS_BLOCK_GROUP_RAID10)) {
4995 bbio->stripes[i].length = stripes_per_dev *
4996 map->stripe_len;
4997
4998 if (i / sub_stripes < remaining_stripes)
4999 bbio->stripes[i].length +=
5000 map->stripe_len;
5001
5002 /*
5003 * Special for the first stripe and
5004 * the last stripe:
5005 *
5006 * |-------|...|-------|
5007 * |----------|
5008 * off end_off
5009 */
5010 if (i < sub_stripes)
5011 bbio->stripes[i].length -=
5012 stripe_offset;
5013
5014 if (stripe_index >= last_stripe &&
5015 stripe_index <= (last_stripe +
5016 sub_stripes - 1))
5017 bbio->stripes[i].length -=
5018 stripe_end_offset;
5019
5020 if (i == sub_stripes - 1)
5021 stripe_offset = 0;
5022 } else
5023 bbio->stripes[i].length = *length;
5024
5025 stripe_index++;
5026 if (stripe_index == map->num_stripes) {
5027 /* This could only happen for RAID0/10 */
5028 stripe_index = 0;
5029 stripe_nr++;
5030 }
5031 }
5032 } else {
5033 for (i = 0; i < num_stripes; i++) {
5034 bbio->stripes[i].physical =
5035 map->stripes[stripe_index].physical +
5036 stripe_offset +
5037 stripe_nr * map->stripe_len;
5038 bbio->stripes[i].dev =
5039 map->stripes[stripe_index].dev;
5040 stripe_index++;
5041 }
5042 }
5043
5044 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
5045 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
5046 BTRFS_BLOCK_GROUP_RAID10 |
5047 BTRFS_BLOCK_GROUP_RAID5 |
5048 BTRFS_BLOCK_GROUP_DUP)) {
5049 max_errors = 1;
5050 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
5051 max_errors = 2;
5052 }
5053 }
5054
5055 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
5056 dev_replace->tgtdev != NULL) {
5057 int index_where_to_add;
5058 u64 srcdev_devid = dev_replace->srcdev->devid;
5059
5060 /*
5061 * duplicate the write operations while the dev replace
5062 * procedure is running. Since the copying of the old disk
5063 * to the new disk takes place at run time while the
5064 * filesystem is mounted writable, the regular write
5065 * operations to the old disk have to be duplicated to go
5066 * to the new disk as well.
5067 * Note that device->missing is handled by the caller, and
5068 * that the write to the old disk is already set up in the
5069 * stripes array.
5070 */
5071 index_where_to_add = num_stripes;
5072 for (i = 0; i < num_stripes; i++) {
5073 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5074 /* write to new disk, too */
5075 struct btrfs_bio_stripe *new =
5076 bbio->stripes + index_where_to_add;
5077 struct btrfs_bio_stripe *old =
5078 bbio->stripes + i;
5079
5080 new->physical = old->physical;
5081 new->length = old->length;
5082 new->dev = dev_replace->tgtdev;
5083 index_where_to_add++;
5084 max_errors++;
5085 }
5086 }
5087 num_stripes = index_where_to_add;
5088 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
5089 dev_replace->tgtdev != NULL) {
5090 u64 srcdev_devid = dev_replace->srcdev->devid;
5091 int index_srcdev = 0;
5092 int found = 0;
5093 u64 physical_of_found = 0;
5094
5095 /*
5096 * During the dev-replace procedure, the target drive can
5097 * also be used to read data in case it is needed to repair
5098 * a corrupt block elsewhere. This is possible if the
5099 * requested area is left of the left cursor. In this area,
5100 * the target drive is a full copy of the source drive.
5101 */
5102 for (i = 0; i < num_stripes; i++) {
5103 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5104 /*
5105 * In case of DUP, in order to keep it
5106 * simple, only add the mirror with the
5107 * lowest physical address
5108 */
5109 if (found &&
5110 physical_of_found <=
5111 bbio->stripes[i].physical)
5112 continue;
5113 index_srcdev = i;
5114 found = 1;
5115 physical_of_found = bbio->stripes[i].physical;
5116 }
5117 }
5118 if (found) {
5119 u64 length = map->stripe_len;
5120
5121 if (physical_of_found + length <=
5122 dev_replace->cursor_left) {
5123 struct btrfs_bio_stripe *tgtdev_stripe =
5124 bbio->stripes + num_stripes;
5125
5126 tgtdev_stripe->physical = physical_of_found;
5127 tgtdev_stripe->length =
5128 bbio->stripes[index_srcdev].length;
5129 tgtdev_stripe->dev = dev_replace->tgtdev;
5130
5131 num_stripes++;
5132 }
5133 }
5134 }
5135
5136 *bbio_ret = bbio;
5137 bbio->num_stripes = num_stripes;
5138 bbio->max_errors = max_errors;
5139 bbio->mirror_num = mirror_num;
5140
5141 /*
5142 * this is the case that REQ_READ && dev_replace_is_ongoing &&
5143 * mirror_num == num_stripes + 1 && dev_replace target drive is
5144 * available as a mirror
5145 */
5146 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
5147 WARN_ON(num_stripes > 1);
5148 bbio->stripes[0].dev = dev_replace->tgtdev;
5149 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
5150 bbio->mirror_num = map->num_stripes + 1;
5151 }
5152 if (raid_map) {
5153 sort_parity_stripes(bbio, raid_map);
5154 *raid_map_ret = raid_map;
5155 }
5156 out:
5157 if (dev_replace_is_ongoing)
5158 btrfs_dev_replace_unlock(dev_replace);
5159 free_extent_map(em);
5160 return ret;
5161 }
5162
5163 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
5164 u64 logical, u64 *length,
5165 struct btrfs_bio **bbio_ret, int mirror_num)
5166 {
5167 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
5168 mirror_num, NULL);
5169 }
5170
5171 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
5172 u64 chunk_start, u64 physical, u64 devid,
5173 u64 **logical, int *naddrs, int *stripe_len)
5174 {
5175 struct extent_map_tree *em_tree = &map_tree->map_tree;
5176 struct extent_map *em;
5177 struct map_lookup *map;
5178 u64 *buf;
5179 u64 bytenr;
5180 u64 length;
5181 u64 stripe_nr;
5182 u64 rmap_len;
5183 int i, j, nr = 0;
5184
5185 read_lock(&em_tree->lock);
5186 em = lookup_extent_mapping(em_tree, chunk_start, 1);
5187 read_unlock(&em_tree->lock);
5188
5189 if (!em) {
5190 printk(KERN_ERR "btrfs: couldn't find em for chunk %Lu\n",
5191 chunk_start);
5192 return -EIO;
5193 }
5194
5195 if (em->start != chunk_start) {
5196 printk(KERN_ERR "btrfs: bad chunk start, em=%Lu, wanted=%Lu\n",
5197 em->start, chunk_start);
5198 free_extent_map(em);
5199 return -EIO;
5200 }
5201 map = (struct map_lookup *)em->bdev;
5202
5203 length = em->len;
5204 rmap_len = map->stripe_len;
5205
5206 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
5207 do_div(length, map->num_stripes / map->sub_stripes);
5208 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
5209 do_div(length, map->num_stripes);
5210 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
5211 BTRFS_BLOCK_GROUP_RAID6)) {
5212 do_div(length, nr_data_stripes(map));
5213 rmap_len = map->stripe_len * nr_data_stripes(map);
5214 }
5215
5216 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
5217 BUG_ON(!buf); /* -ENOMEM */
5218
5219 for (i = 0; i < map->num_stripes; i++) {
5220 if (devid && map->stripes[i].dev->devid != devid)
5221 continue;
5222 if (map->stripes[i].physical > physical ||
5223 map->stripes[i].physical + length <= physical)
5224 continue;
5225
5226 stripe_nr = physical - map->stripes[i].physical;
5227 do_div(stripe_nr, map->stripe_len);
5228
5229 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
5230 stripe_nr = stripe_nr * map->num_stripes + i;
5231 do_div(stripe_nr, map->sub_stripes);
5232 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
5233 stripe_nr = stripe_nr * map->num_stripes + i;
5234 } /* else if RAID[56], multiply by nr_data_stripes().
5235 * Alternatively, just use rmap_len below instead of
5236 * map->stripe_len */
5237
5238 bytenr = chunk_start + stripe_nr * rmap_len;
5239 WARN_ON(nr >= map->num_stripes);
5240 for (j = 0; j < nr; j++) {
5241 if (buf[j] == bytenr)
5242 break;
5243 }
5244 if (j == nr) {
5245 WARN_ON(nr >= map->num_stripes);
5246 buf[nr++] = bytenr;
5247 }
5248 }
5249
5250 *logical = buf;
5251 *naddrs = nr;
5252 *stripe_len = rmap_len;
5253
5254 free_extent_map(em);
5255 return 0;
5256 }
5257
5258 static void btrfs_end_bio(struct bio *bio, int err)
5259 {
5260 struct btrfs_bio *bbio = bio->bi_private;
5261 int is_orig_bio = 0;
5262
5263 if (err) {
5264 atomic_inc(&bbio->error);
5265 if (err == -EIO || err == -EREMOTEIO) {
5266 unsigned int stripe_index =
5267 btrfs_io_bio(bio)->stripe_index;
5268 struct btrfs_device *dev;
5269
5270 BUG_ON(stripe_index >= bbio->num_stripes);
5271 dev = bbio->stripes[stripe_index].dev;
5272 if (dev->bdev) {
5273 if (bio->bi_rw & WRITE)
5274 btrfs_dev_stat_inc(dev,
5275 BTRFS_DEV_STAT_WRITE_ERRS);
5276 else
5277 btrfs_dev_stat_inc(dev,
5278 BTRFS_DEV_STAT_READ_ERRS);
5279 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5280 btrfs_dev_stat_inc(dev,
5281 BTRFS_DEV_STAT_FLUSH_ERRS);
5282 btrfs_dev_stat_print_on_error(dev);
5283 }
5284 }
5285 }
5286
5287 if (bio == bbio->orig_bio)
5288 is_orig_bio = 1;
5289
5290 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5291 if (!is_orig_bio) {
5292 bio_put(bio);
5293 bio = bbio->orig_bio;
5294 }
5295 bio->bi_private = bbio->private;
5296 bio->bi_end_io = bbio->end_io;
5297 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5298 /* only send an error to the higher layers if it is
5299 * beyond the tolerance of the btrfs bio
5300 */
5301 if (atomic_read(&bbio->error) > bbio->max_errors) {
5302 err = -EIO;
5303 } else {
5304 /*
5305 * this bio is actually up to date, we didn't
5306 * go over the max number of errors
5307 */
5308 set_bit(BIO_UPTODATE, &bio->bi_flags);
5309 err = 0;
5310 }
5311 kfree(bbio);
5312
5313 bio_endio(bio, err);
5314 } else if (!is_orig_bio) {
5315 bio_put(bio);
5316 }
5317 }
5318
5319 struct async_sched {
5320 struct bio *bio;
5321 int rw;
5322 struct btrfs_fs_info *info;
5323 struct btrfs_work work;
5324 };
5325
5326 /*
5327 * see run_scheduled_bios for a description of why bios are collected for
5328 * async submit.
5329 *
5330 * This will add one bio to the pending list for a device and make sure
5331 * the work struct is scheduled.
5332 */
5333 static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5334 struct btrfs_device *device,
5335 int rw, struct bio *bio)
5336 {
5337 int should_queue = 1;
5338 struct btrfs_pending_bios *pending_bios;
5339
5340 if (device->missing || !device->bdev) {
5341 bio_endio(bio, -EIO);
5342 return;
5343 }
5344
5345 /* don't bother with additional async steps for reads, right now */
5346 if (!(rw & REQ_WRITE)) {
5347 bio_get(bio);
5348 btrfsic_submit_bio(rw, bio);
5349 bio_put(bio);
5350 return;
5351 }
5352
5353 /*
5354 * nr_async_bios allows us to reliably return congestion to the
5355 * higher layers. Otherwise, the async bio makes it appear we have
5356 * made progress against dirty pages when we've really just put it
5357 * on a queue for later
5358 */
5359 atomic_inc(&root->fs_info->nr_async_bios);
5360 WARN_ON(bio->bi_next);
5361 bio->bi_next = NULL;
5362 bio->bi_rw |= rw;
5363
5364 spin_lock(&device->io_lock);
5365 if (bio->bi_rw & REQ_SYNC)
5366 pending_bios = &device->pending_sync_bios;
5367 else
5368 pending_bios = &device->pending_bios;
5369
5370 if (pending_bios->tail)
5371 pending_bios->tail->bi_next = bio;
5372
5373 pending_bios->tail = bio;
5374 if (!pending_bios->head)
5375 pending_bios->head = bio;
5376 if (device->running_pending)
5377 should_queue = 0;
5378
5379 spin_unlock(&device->io_lock);
5380
5381 if (should_queue)
5382 btrfs_queue_worker(&root->fs_info->submit_workers,
5383 &device->work);
5384 }
5385
5386 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5387 sector_t sector)
5388 {
5389 struct bio_vec *prev;
5390 struct request_queue *q = bdev_get_queue(bdev);
5391 unsigned short max_sectors = queue_max_sectors(q);
5392 struct bvec_merge_data bvm = {
5393 .bi_bdev = bdev,
5394 .bi_sector = sector,
5395 .bi_rw = bio->bi_rw,
5396 };
5397
5398 if (bio->bi_vcnt == 0) {
5399 WARN_ON(1);
5400 return 1;
5401 }
5402
5403 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5404 if (bio_sectors(bio) > max_sectors)
5405 return 0;
5406
5407 if (!q->merge_bvec_fn)
5408 return 1;
5409
5410 bvm.bi_size = bio->bi_size - prev->bv_len;
5411 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5412 return 0;
5413 return 1;
5414 }
5415
5416 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5417 struct bio *bio, u64 physical, int dev_nr,
5418 int rw, int async)
5419 {
5420 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5421
5422 bio->bi_private = bbio;
5423 btrfs_io_bio(bio)->stripe_index = dev_nr;
5424 bio->bi_end_io = btrfs_end_bio;
5425 bio->bi_sector = physical >> 9;
5426 #ifdef DEBUG
5427 {
5428 struct rcu_string *name;
5429
5430 rcu_read_lock();
5431 name = rcu_dereference(dev->name);
5432 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5433 "(%s id %llu), size=%u\n", rw,
5434 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5435 name->str, dev->devid, bio->bi_size);
5436 rcu_read_unlock();
5437 }
5438 #endif
5439 bio->bi_bdev = dev->bdev;
5440 if (async)
5441 btrfs_schedule_bio(root, dev, rw, bio);
5442 else
5443 btrfsic_submit_bio(rw, bio);
5444 }
5445
5446 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5447 struct bio *first_bio, struct btrfs_device *dev,
5448 int dev_nr, int rw, int async)
5449 {
5450 struct bio_vec *bvec = first_bio->bi_io_vec;
5451 struct bio *bio;
5452 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5453 u64 physical = bbio->stripes[dev_nr].physical;
5454
5455 again:
5456 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5457 if (!bio)
5458 return -ENOMEM;
5459
5460 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5461 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5462 bvec->bv_offset) < bvec->bv_len) {
5463 u64 len = bio->bi_size;
5464
5465 atomic_inc(&bbio->stripes_pending);
5466 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5467 rw, async);
5468 physical += len;
5469 goto again;
5470 }
5471 bvec++;
5472 }
5473
5474 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5475 return 0;
5476 }
5477
5478 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5479 {
5480 atomic_inc(&bbio->error);
5481 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5482 bio->bi_private = bbio->private;
5483 bio->bi_end_io = bbio->end_io;
5484 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5485 bio->bi_sector = logical >> 9;
5486 kfree(bbio);
5487 bio_endio(bio, -EIO);
5488 }
5489 }
5490
5491 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5492 int mirror_num, int async_submit)
5493 {
5494 struct btrfs_device *dev;
5495 struct bio *first_bio = bio;
5496 u64 logical = (u64)bio->bi_sector << 9;
5497 u64 length = 0;
5498 u64 map_length;
5499 u64 *raid_map = NULL;
5500 int ret;
5501 int dev_nr = 0;
5502 int total_devs = 1;
5503 struct btrfs_bio *bbio = NULL;
5504
5505 length = bio->bi_size;
5506 map_length = length;
5507
5508 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5509 mirror_num, &raid_map);
5510 if (ret) /* -ENOMEM */
5511 return ret;
5512
5513 total_devs = bbio->num_stripes;
5514 bbio->orig_bio = first_bio;
5515 bbio->private = first_bio->bi_private;
5516 bbio->end_io = first_bio->bi_end_io;
5517 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5518
5519 if (raid_map) {
5520 /* In this case, map_length has been set to the length of
5521 a single stripe; not the whole write */
5522 if (rw & WRITE) {
5523 return raid56_parity_write(root, bio, bbio,
5524 raid_map, map_length);
5525 } else {
5526 return raid56_parity_recover(root, bio, bbio,
5527 raid_map, map_length,
5528 mirror_num);
5529 }
5530 }
5531
5532 if (map_length < length) {
5533 btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5534 logical, length, map_length);
5535 BUG();
5536 }
5537
5538 while (dev_nr < total_devs) {
5539 dev = bbio->stripes[dev_nr].dev;
5540 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5541 bbio_error(bbio, first_bio, logical);
5542 dev_nr++;
5543 continue;
5544 }
5545
5546 /*
5547 * Check and see if we're ok with this bio based on it's size
5548 * and offset with the given device.
5549 */
5550 if (!bio_size_ok(dev->bdev, first_bio,
5551 bbio->stripes[dev_nr].physical >> 9)) {
5552 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5553 dev_nr, rw, async_submit);
5554 BUG_ON(ret);
5555 dev_nr++;
5556 continue;
5557 }
5558
5559 if (dev_nr < total_devs - 1) {
5560 bio = btrfs_bio_clone(first_bio, GFP_NOFS);
5561 BUG_ON(!bio); /* -ENOMEM */
5562 } else {
5563 bio = first_bio;
5564 }
5565
5566 submit_stripe_bio(root, bbio, bio,
5567 bbio->stripes[dev_nr].physical, dev_nr, rw,
5568 async_submit);
5569 dev_nr++;
5570 }
5571 return 0;
5572 }
5573
5574 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5575 u8 *uuid, u8 *fsid)
5576 {
5577 struct btrfs_device *device;
5578 struct btrfs_fs_devices *cur_devices;
5579
5580 cur_devices = fs_info->fs_devices;
5581 while (cur_devices) {
5582 if (!fsid ||
5583 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5584 device = __find_device(&cur_devices->devices,
5585 devid, uuid);
5586 if (device)
5587 return device;
5588 }
5589 cur_devices = cur_devices->seed;
5590 }
5591 return NULL;
5592 }
5593
5594 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5595 u64 devid, u8 *dev_uuid)
5596 {
5597 struct btrfs_device *device;
5598 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5599
5600 device = btrfs_alloc_device(NULL, &devid, dev_uuid);
5601 if (IS_ERR(device))
5602 return NULL;
5603
5604 list_add(&device->dev_list, &fs_devices->devices);
5605 device->fs_devices = fs_devices;
5606 fs_devices->num_devices++;
5607
5608 device->missing = 1;
5609 fs_devices->missing_devices++;
5610
5611 return device;
5612 }
5613
5614 /**
5615 * btrfs_alloc_device - allocate struct btrfs_device
5616 * @fs_info: used only for generating a new devid, can be NULL if
5617 * devid is provided (i.e. @devid != NULL).
5618 * @devid: a pointer to devid for this device. If NULL a new devid
5619 * is generated.
5620 * @uuid: a pointer to UUID for this device. If NULL a new UUID
5621 * is generated.
5622 *
5623 * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
5624 * on error. Returned struct is not linked onto any lists and can be
5625 * destroyed with kfree() right away.
5626 */
5627 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
5628 const u64 *devid,
5629 const u8 *uuid)
5630 {
5631 struct btrfs_device *dev;
5632 u64 tmp;
5633
5634 if (!devid && !fs_info) {
5635 WARN_ON(1);
5636 return ERR_PTR(-EINVAL);
5637 }
5638
5639 dev = __alloc_device();
5640 if (IS_ERR(dev))
5641 return dev;
5642
5643 if (devid)
5644 tmp = *devid;
5645 else {
5646 int ret;
5647
5648 ret = find_next_devid(fs_info, &tmp);
5649 if (ret) {
5650 kfree(dev);
5651 return ERR_PTR(ret);
5652 }
5653 }
5654 dev->devid = tmp;
5655
5656 if (uuid)
5657 memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
5658 else
5659 generate_random_uuid(dev->uuid);
5660
5661 dev->work.func = pending_bios_fn;
5662
5663 return dev;
5664 }
5665
5666 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5667 struct extent_buffer *leaf,
5668 struct btrfs_chunk *chunk)
5669 {
5670 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5671 struct map_lookup *map;
5672 struct extent_map *em;
5673 u64 logical;
5674 u64 length;
5675 u64 devid;
5676 u8 uuid[BTRFS_UUID_SIZE];
5677 int num_stripes;
5678 int ret;
5679 int i;
5680
5681 logical = key->offset;
5682 length = btrfs_chunk_length(leaf, chunk);
5683
5684 read_lock(&map_tree->map_tree.lock);
5685 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5686 read_unlock(&map_tree->map_tree.lock);
5687
5688 /* already mapped? */
5689 if (em && em->start <= logical && em->start + em->len > logical) {
5690 free_extent_map(em);
5691 return 0;
5692 } else if (em) {
5693 free_extent_map(em);
5694 }
5695
5696 em = alloc_extent_map();
5697 if (!em)
5698 return -ENOMEM;
5699 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5700 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5701 if (!map) {
5702 free_extent_map(em);
5703 return -ENOMEM;
5704 }
5705
5706 em->bdev = (struct block_device *)map;
5707 em->start = logical;
5708 em->len = length;
5709 em->orig_start = 0;
5710 em->block_start = 0;
5711 em->block_len = em->len;
5712
5713 map->num_stripes = num_stripes;
5714 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5715 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5716 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5717 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5718 map->type = btrfs_chunk_type(leaf, chunk);
5719 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5720 for (i = 0; i < num_stripes; i++) {
5721 map->stripes[i].physical =
5722 btrfs_stripe_offset_nr(leaf, chunk, i);
5723 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5724 read_extent_buffer(leaf, uuid, (unsigned long)
5725 btrfs_stripe_dev_uuid_nr(chunk, i),
5726 BTRFS_UUID_SIZE);
5727 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5728 uuid, NULL);
5729 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5730 kfree(map);
5731 free_extent_map(em);
5732 return -EIO;
5733 }
5734 if (!map->stripes[i].dev) {
5735 map->stripes[i].dev =
5736 add_missing_dev(root, devid, uuid);
5737 if (!map->stripes[i].dev) {
5738 kfree(map);
5739 free_extent_map(em);
5740 return -EIO;
5741 }
5742 }
5743 map->stripes[i].dev->in_fs_metadata = 1;
5744 }
5745
5746 write_lock(&map_tree->map_tree.lock);
5747 ret = add_extent_mapping(&map_tree->map_tree, em, 0);
5748 write_unlock(&map_tree->map_tree.lock);
5749 BUG_ON(ret); /* Tree corruption */
5750 free_extent_map(em);
5751
5752 return 0;
5753 }
5754
5755 static void fill_device_from_item(struct extent_buffer *leaf,
5756 struct btrfs_dev_item *dev_item,
5757 struct btrfs_device *device)
5758 {
5759 unsigned long ptr;
5760
5761 device->devid = btrfs_device_id(leaf, dev_item);
5762 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5763 device->total_bytes = device->disk_total_bytes;
5764 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5765 device->type = btrfs_device_type(leaf, dev_item);
5766 device->io_align = btrfs_device_io_align(leaf, dev_item);
5767 device->io_width = btrfs_device_io_width(leaf, dev_item);
5768 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5769 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5770 device->is_tgtdev_for_dev_replace = 0;
5771
5772 ptr = btrfs_device_uuid(dev_item);
5773 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5774 }
5775
5776 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5777 {
5778 struct btrfs_fs_devices *fs_devices;
5779 int ret;
5780
5781 BUG_ON(!mutex_is_locked(&uuid_mutex));
5782
5783 fs_devices = root->fs_info->fs_devices->seed;
5784 while (fs_devices) {
5785 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5786 ret = 0;
5787 goto out;
5788 }
5789 fs_devices = fs_devices->seed;
5790 }
5791
5792 fs_devices = find_fsid(fsid);
5793 if (!fs_devices) {
5794 ret = -ENOENT;
5795 goto out;
5796 }
5797
5798 fs_devices = clone_fs_devices(fs_devices);
5799 if (IS_ERR(fs_devices)) {
5800 ret = PTR_ERR(fs_devices);
5801 goto out;
5802 }
5803
5804 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5805 root->fs_info->bdev_holder);
5806 if (ret) {
5807 free_fs_devices(fs_devices);
5808 goto out;
5809 }
5810
5811 if (!fs_devices->seeding) {
5812 __btrfs_close_devices(fs_devices);
5813 free_fs_devices(fs_devices);
5814 ret = -EINVAL;
5815 goto out;
5816 }
5817
5818 fs_devices->seed = root->fs_info->fs_devices->seed;
5819 root->fs_info->fs_devices->seed = fs_devices;
5820 out:
5821 return ret;
5822 }
5823
5824 static int read_one_dev(struct btrfs_root *root,
5825 struct extent_buffer *leaf,
5826 struct btrfs_dev_item *dev_item)
5827 {
5828 struct btrfs_device *device;
5829 u64 devid;
5830 int ret;
5831 u8 fs_uuid[BTRFS_UUID_SIZE];
5832 u8 dev_uuid[BTRFS_UUID_SIZE];
5833
5834 devid = btrfs_device_id(leaf, dev_item);
5835 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
5836 BTRFS_UUID_SIZE);
5837 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
5838 BTRFS_UUID_SIZE);
5839
5840 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5841 ret = open_seed_devices(root, fs_uuid);
5842 if (ret && !btrfs_test_opt(root, DEGRADED))
5843 return ret;
5844 }
5845
5846 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5847 if (!device || !device->bdev) {
5848 if (!btrfs_test_opt(root, DEGRADED))
5849 return -EIO;
5850
5851 if (!device) {
5852 btrfs_warn(root->fs_info, "devid %llu missing", devid);
5853 device = add_missing_dev(root, devid, dev_uuid);
5854 if (!device)
5855 return -ENOMEM;
5856 } else if (!device->missing) {
5857 /*
5858 * this happens when a device that was properly setup
5859 * in the device info lists suddenly goes bad.
5860 * device->bdev is NULL, and so we have to set
5861 * device->missing to one here
5862 */
5863 root->fs_info->fs_devices->missing_devices++;
5864 device->missing = 1;
5865 }
5866 }
5867
5868 if (device->fs_devices != root->fs_info->fs_devices) {
5869 BUG_ON(device->writeable);
5870 if (device->generation !=
5871 btrfs_device_generation(leaf, dev_item))
5872 return -EINVAL;
5873 }
5874
5875 fill_device_from_item(leaf, dev_item, device);
5876 device->in_fs_metadata = 1;
5877 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5878 device->fs_devices->total_rw_bytes += device->total_bytes;
5879 spin_lock(&root->fs_info->free_chunk_lock);
5880 root->fs_info->free_chunk_space += device->total_bytes -
5881 device->bytes_used;
5882 spin_unlock(&root->fs_info->free_chunk_lock);
5883 }
5884 ret = 0;
5885 return ret;
5886 }
5887
5888 int btrfs_read_sys_array(struct btrfs_root *root)
5889 {
5890 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5891 struct extent_buffer *sb;
5892 struct btrfs_disk_key *disk_key;
5893 struct btrfs_chunk *chunk;
5894 u8 *ptr;
5895 unsigned long sb_ptr;
5896 int ret = 0;
5897 u32 num_stripes;
5898 u32 array_size;
5899 u32 len = 0;
5900 u32 cur;
5901 struct btrfs_key key;
5902
5903 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5904 BTRFS_SUPER_INFO_SIZE);
5905 if (!sb)
5906 return -ENOMEM;
5907 btrfs_set_buffer_uptodate(sb);
5908 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5909 /*
5910 * The sb extent buffer is artifical and just used to read the system array.
5911 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5912 * pages up-to-date when the page is larger: extent does not cover the
5913 * whole page and consequently check_page_uptodate does not find all
5914 * the page's extents up-to-date (the hole beyond sb),
5915 * write_extent_buffer then triggers a WARN_ON.
5916 *
5917 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5918 * but sb spans only this function. Add an explicit SetPageUptodate call
5919 * to silence the warning eg. on PowerPC 64.
5920 */
5921 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5922 SetPageUptodate(sb->pages[0]);
5923
5924 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5925 array_size = btrfs_super_sys_array_size(super_copy);
5926
5927 ptr = super_copy->sys_chunk_array;
5928 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5929 cur = 0;
5930
5931 while (cur < array_size) {
5932 disk_key = (struct btrfs_disk_key *)ptr;
5933 btrfs_disk_key_to_cpu(&key, disk_key);
5934
5935 len = sizeof(*disk_key); ptr += len;
5936 sb_ptr += len;
5937 cur += len;
5938
5939 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5940 chunk = (struct btrfs_chunk *)sb_ptr;
5941 ret = read_one_chunk(root, &key, sb, chunk);
5942 if (ret)
5943 break;
5944 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5945 len = btrfs_chunk_item_size(num_stripes);
5946 } else {
5947 ret = -EIO;
5948 break;
5949 }
5950 ptr += len;
5951 sb_ptr += len;
5952 cur += len;
5953 }
5954 free_extent_buffer(sb);
5955 return ret;
5956 }
5957
5958 int btrfs_read_chunk_tree(struct btrfs_root *root)
5959 {
5960 struct btrfs_path *path;
5961 struct extent_buffer *leaf;
5962 struct btrfs_key key;
5963 struct btrfs_key found_key;
5964 int ret;
5965 int slot;
5966
5967 root = root->fs_info->chunk_root;
5968
5969 path = btrfs_alloc_path();
5970 if (!path)
5971 return -ENOMEM;
5972
5973 mutex_lock(&uuid_mutex);
5974 lock_chunks(root);
5975
5976 /*
5977 * Read all device items, and then all the chunk items. All
5978 * device items are found before any chunk item (their object id
5979 * is smaller than the lowest possible object id for a chunk
5980 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
5981 */
5982 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5983 key.offset = 0;
5984 key.type = 0;
5985 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5986 if (ret < 0)
5987 goto error;
5988 while (1) {
5989 leaf = path->nodes[0];
5990 slot = path->slots[0];
5991 if (slot >= btrfs_header_nritems(leaf)) {
5992 ret = btrfs_next_leaf(root, path);
5993 if (ret == 0)
5994 continue;
5995 if (ret < 0)
5996 goto error;
5997 break;
5998 }
5999 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6000 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
6001 struct btrfs_dev_item *dev_item;
6002 dev_item = btrfs_item_ptr(leaf, slot,
6003 struct btrfs_dev_item);
6004 ret = read_one_dev(root, leaf, dev_item);
6005 if (ret)
6006 goto error;
6007 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
6008 struct btrfs_chunk *chunk;
6009 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
6010 ret = read_one_chunk(root, &found_key, leaf, chunk);
6011 if (ret)
6012 goto error;
6013 }
6014 path->slots[0]++;
6015 }
6016 ret = 0;
6017 error:
6018 unlock_chunks(root);
6019 mutex_unlock(&uuid_mutex);
6020
6021 btrfs_free_path(path);
6022 return ret;
6023 }
6024
6025 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
6026 {
6027 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6028 struct btrfs_device *device;
6029
6030 mutex_lock(&fs_devices->device_list_mutex);
6031 list_for_each_entry(device, &fs_devices->devices, dev_list)
6032 device->dev_root = fs_info->dev_root;
6033 mutex_unlock(&fs_devices->device_list_mutex);
6034 }
6035
6036 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
6037 {
6038 int i;
6039
6040 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6041 btrfs_dev_stat_reset(dev, i);
6042 }
6043
6044 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
6045 {
6046 struct btrfs_key key;
6047 struct btrfs_key found_key;
6048 struct btrfs_root *dev_root = fs_info->dev_root;
6049 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6050 struct extent_buffer *eb;
6051 int slot;
6052 int ret = 0;
6053 struct btrfs_device *device;
6054 struct btrfs_path *path = NULL;
6055 int i;
6056
6057 path = btrfs_alloc_path();
6058 if (!path) {
6059 ret = -ENOMEM;
6060 goto out;
6061 }
6062
6063 mutex_lock(&fs_devices->device_list_mutex);
6064 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6065 int item_size;
6066 struct btrfs_dev_stats_item *ptr;
6067
6068 key.objectid = 0;
6069 key.type = BTRFS_DEV_STATS_KEY;
6070 key.offset = device->devid;
6071 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
6072 if (ret) {
6073 __btrfs_reset_dev_stats(device);
6074 device->dev_stats_valid = 1;
6075 btrfs_release_path(path);
6076 continue;
6077 }
6078 slot = path->slots[0];
6079 eb = path->nodes[0];
6080 btrfs_item_key_to_cpu(eb, &found_key, slot);
6081 item_size = btrfs_item_size_nr(eb, slot);
6082
6083 ptr = btrfs_item_ptr(eb, slot,
6084 struct btrfs_dev_stats_item);
6085
6086 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6087 if (item_size >= (1 + i) * sizeof(__le64))
6088 btrfs_dev_stat_set(device, i,
6089 btrfs_dev_stats_value(eb, ptr, i));
6090 else
6091 btrfs_dev_stat_reset(device, i);
6092 }
6093
6094 device->dev_stats_valid = 1;
6095 btrfs_dev_stat_print_on_load(device);
6096 btrfs_release_path(path);
6097 }
6098 mutex_unlock(&fs_devices->device_list_mutex);
6099
6100 out:
6101 btrfs_free_path(path);
6102 return ret < 0 ? ret : 0;
6103 }
6104
6105 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
6106 struct btrfs_root *dev_root,
6107 struct btrfs_device *device)
6108 {
6109 struct btrfs_path *path;
6110 struct btrfs_key key;
6111 struct extent_buffer *eb;
6112 struct btrfs_dev_stats_item *ptr;
6113 int ret;
6114 int i;
6115
6116 key.objectid = 0;
6117 key.type = BTRFS_DEV_STATS_KEY;
6118 key.offset = device->devid;
6119
6120 path = btrfs_alloc_path();
6121 BUG_ON(!path);
6122 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
6123 if (ret < 0) {
6124 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
6125 ret, rcu_str_deref(device->name));
6126 goto out;
6127 }
6128
6129 if (ret == 0 &&
6130 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
6131 /* need to delete old one and insert a new one */
6132 ret = btrfs_del_item(trans, dev_root, path);
6133 if (ret != 0) {
6134 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
6135 rcu_str_deref(device->name), ret);
6136 goto out;
6137 }
6138 ret = 1;
6139 }
6140
6141 if (ret == 1) {
6142 /* need to insert a new item */
6143 btrfs_release_path(path);
6144 ret = btrfs_insert_empty_item(trans, dev_root, path,
6145 &key, sizeof(*ptr));
6146 if (ret < 0) {
6147 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
6148 rcu_str_deref(device->name), ret);
6149 goto out;
6150 }
6151 }
6152
6153 eb = path->nodes[0];
6154 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
6155 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6156 btrfs_set_dev_stats_value(eb, ptr, i,
6157 btrfs_dev_stat_read(device, i));
6158 btrfs_mark_buffer_dirty(eb);
6159
6160 out:
6161 btrfs_free_path(path);
6162 return ret;
6163 }
6164
6165 /*
6166 * called from commit_transaction. Writes all changed device stats to disk.
6167 */
6168 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
6169 struct btrfs_fs_info *fs_info)
6170 {
6171 struct btrfs_root *dev_root = fs_info->dev_root;
6172 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6173 struct btrfs_device *device;
6174 int ret = 0;
6175
6176 mutex_lock(&fs_devices->device_list_mutex);
6177 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6178 if (!device->dev_stats_valid || !device->dev_stats_dirty)
6179 continue;
6180
6181 ret = update_dev_stat_item(trans, dev_root, device);
6182 if (!ret)
6183 device->dev_stats_dirty = 0;
6184 }
6185 mutex_unlock(&fs_devices->device_list_mutex);
6186
6187 return ret;
6188 }
6189
6190 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
6191 {
6192 btrfs_dev_stat_inc(dev, index);
6193 btrfs_dev_stat_print_on_error(dev);
6194 }
6195
6196 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
6197 {
6198 if (!dev->dev_stats_valid)
6199 return;
6200 printk_ratelimited_in_rcu(KERN_ERR
6201 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6202 rcu_str_deref(dev->name),
6203 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6204 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6205 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6206 btrfs_dev_stat_read(dev,
6207 BTRFS_DEV_STAT_CORRUPTION_ERRS),
6208 btrfs_dev_stat_read(dev,
6209 BTRFS_DEV_STAT_GENERATION_ERRS));
6210 }
6211
6212 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
6213 {
6214 int i;
6215
6216 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6217 if (btrfs_dev_stat_read(dev, i) != 0)
6218 break;
6219 if (i == BTRFS_DEV_STAT_VALUES_MAX)
6220 return; /* all values == 0, suppress message */
6221
6222 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6223 rcu_str_deref(dev->name),
6224 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6225 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6226 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6227 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6228 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6229 }
6230
6231 int btrfs_get_dev_stats(struct btrfs_root *root,
6232 struct btrfs_ioctl_get_dev_stats *stats)
6233 {
6234 struct btrfs_device *dev;
6235 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6236 int i;
6237
6238 mutex_lock(&fs_devices->device_list_mutex);
6239 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
6240 mutex_unlock(&fs_devices->device_list_mutex);
6241
6242 if (!dev) {
6243 printk(KERN_WARNING
6244 "btrfs: get dev_stats failed, device not found\n");
6245 return -ENODEV;
6246 } else if (!dev->dev_stats_valid) {
6247 printk(KERN_WARNING
6248 "btrfs: get dev_stats failed, not yet valid\n");
6249 return -ENODEV;
6250 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
6251 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6252 if (stats->nr_items > i)
6253 stats->values[i] =
6254 btrfs_dev_stat_read_and_reset(dev, i);
6255 else
6256 btrfs_dev_stat_reset(dev, i);
6257 }
6258 } else {
6259 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6260 if (stats->nr_items > i)
6261 stats->values[i] = btrfs_dev_stat_read(dev, i);
6262 }
6263 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
6264 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
6265 return 0;
6266 }
6267
6268 int btrfs_scratch_superblock(struct btrfs_device *device)
6269 {
6270 struct buffer_head *bh;
6271 struct btrfs_super_block *disk_super;
6272
6273 bh = btrfs_read_dev_super(device->bdev);
6274 if (!bh)
6275 return -EINVAL;
6276 disk_super = (struct btrfs_super_block *)bh->b_data;
6277
6278 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
6279 set_buffer_dirty(bh);
6280 sync_dirty_buffer(bh);
6281 brelse(bh);
6282
6283 return 0;
6284 }
Linux with added FPC-III support