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Btrfs: do not add replace target to the alloc_list
[deliverable/linux.git] / fs / btrfs / volumes.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <linux/ratelimit.h>
27 #include <linux/kthread.h>
28 #include <linux/raid/pq.h>
29 #include <linux/semaphore.h>
30 #include <asm/div64.h>
31 #include "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 "device label %s ", disk_super->label);
916 } else {
917 printk(KERN_INFO "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 list_del_rcu(&srcdev->dev_list);
1720 list_del_rcu(&srcdev->dev_alloc_list);
1721 fs_info->fs_devices->num_devices--;
1722 if (srcdev->missing) {
1723 fs_info->fs_devices->missing_devices--;
1724 fs_info->fs_devices->rw_devices++;
1725 }
1726 if (srcdev->can_discard)
1727 fs_info->fs_devices->num_can_discard--;
1728 if (srcdev->bdev)
1729 fs_info->fs_devices->open_devices--;
1730
1731 call_rcu(&srcdev->rcu, free_device);
1732 }
1733
1734 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1735 struct btrfs_device *tgtdev)
1736 {
1737 struct btrfs_device *next_device;
1738
1739 WARN_ON(!tgtdev);
1740 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1741 if (tgtdev->bdev) {
1742 btrfs_scratch_superblock(tgtdev);
1743 fs_info->fs_devices->open_devices--;
1744 }
1745 fs_info->fs_devices->num_devices--;
1746 if (tgtdev->can_discard)
1747 fs_info->fs_devices->num_can_discard++;
1748
1749 next_device = list_entry(fs_info->fs_devices->devices.next,
1750 struct btrfs_device, dev_list);
1751 if (tgtdev->bdev == fs_info->sb->s_bdev)
1752 fs_info->sb->s_bdev = next_device->bdev;
1753 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1754 fs_info->fs_devices->latest_bdev = next_device->bdev;
1755 list_del_rcu(&tgtdev->dev_list);
1756
1757 call_rcu(&tgtdev->rcu, free_device);
1758
1759 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1760 }
1761
1762 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1763 struct btrfs_device **device)
1764 {
1765 int ret = 0;
1766 struct btrfs_super_block *disk_super;
1767 u64 devid;
1768 u8 *dev_uuid;
1769 struct block_device *bdev;
1770 struct buffer_head *bh;
1771
1772 *device = NULL;
1773 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1774 root->fs_info->bdev_holder, 0, &bdev, &bh);
1775 if (ret)
1776 return ret;
1777 disk_super = (struct btrfs_super_block *)bh->b_data;
1778 devid = btrfs_stack_device_id(&disk_super->dev_item);
1779 dev_uuid = disk_super->dev_item.uuid;
1780 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1781 disk_super->fsid);
1782 brelse(bh);
1783 if (!*device)
1784 ret = -ENOENT;
1785 blkdev_put(bdev, FMODE_READ);
1786 return ret;
1787 }
1788
1789 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1790 char *device_path,
1791 struct btrfs_device **device)
1792 {
1793 *device = NULL;
1794 if (strcmp(device_path, "missing") == 0) {
1795 struct list_head *devices;
1796 struct btrfs_device *tmp;
1797
1798 devices = &root->fs_info->fs_devices->devices;
1799 /*
1800 * It is safe to read the devices since the volume_mutex
1801 * is held by the caller.
1802 */
1803 list_for_each_entry(tmp, devices, dev_list) {
1804 if (tmp->in_fs_metadata && !tmp->bdev) {
1805 *device = tmp;
1806 break;
1807 }
1808 }
1809
1810 if (!*device) {
1811 pr_err("btrfs: no missing device found\n");
1812 return -ENOENT;
1813 }
1814
1815 return 0;
1816 } else {
1817 return btrfs_find_device_by_path(root, device_path, device);
1818 }
1819 }
1820
1821 /*
1822 * does all the dirty work required for changing file system's UUID.
1823 */
1824 static int btrfs_prepare_sprout(struct btrfs_root *root)
1825 {
1826 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1827 struct btrfs_fs_devices *old_devices;
1828 struct btrfs_fs_devices *seed_devices;
1829 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1830 struct btrfs_device *device;
1831 u64 super_flags;
1832
1833 BUG_ON(!mutex_is_locked(&uuid_mutex));
1834 if (!fs_devices->seeding)
1835 return -EINVAL;
1836
1837 seed_devices = __alloc_fs_devices();
1838 if (IS_ERR(seed_devices))
1839 return PTR_ERR(seed_devices);
1840
1841 old_devices = clone_fs_devices(fs_devices);
1842 if (IS_ERR(old_devices)) {
1843 kfree(seed_devices);
1844 return PTR_ERR(old_devices);
1845 }
1846
1847 list_add(&old_devices->list, &fs_uuids);
1848
1849 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1850 seed_devices->opened = 1;
1851 INIT_LIST_HEAD(&seed_devices->devices);
1852 INIT_LIST_HEAD(&seed_devices->alloc_list);
1853 mutex_init(&seed_devices->device_list_mutex);
1854
1855 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1856 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1857 synchronize_rcu);
1858
1859 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1860 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1861 device->fs_devices = seed_devices;
1862 }
1863
1864 fs_devices->seeding = 0;
1865 fs_devices->num_devices = 0;
1866 fs_devices->open_devices = 0;
1867 fs_devices->total_devices = 0;
1868 fs_devices->seed = seed_devices;
1869
1870 generate_random_uuid(fs_devices->fsid);
1871 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1872 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1873 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1874
1875 super_flags = btrfs_super_flags(disk_super) &
1876 ~BTRFS_SUPER_FLAG_SEEDING;
1877 btrfs_set_super_flags(disk_super, super_flags);
1878
1879 return 0;
1880 }
1881
1882 /*
1883 * strore the expected generation for seed devices in device items.
1884 */
1885 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1886 struct btrfs_root *root)
1887 {
1888 struct btrfs_path *path;
1889 struct extent_buffer *leaf;
1890 struct btrfs_dev_item *dev_item;
1891 struct btrfs_device *device;
1892 struct btrfs_key key;
1893 u8 fs_uuid[BTRFS_UUID_SIZE];
1894 u8 dev_uuid[BTRFS_UUID_SIZE];
1895 u64 devid;
1896 int ret;
1897
1898 path = btrfs_alloc_path();
1899 if (!path)
1900 return -ENOMEM;
1901
1902 root = root->fs_info->chunk_root;
1903 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1904 key.offset = 0;
1905 key.type = BTRFS_DEV_ITEM_KEY;
1906
1907 while (1) {
1908 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1909 if (ret < 0)
1910 goto error;
1911
1912 leaf = path->nodes[0];
1913 next_slot:
1914 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1915 ret = btrfs_next_leaf(root, path);
1916 if (ret > 0)
1917 break;
1918 if (ret < 0)
1919 goto error;
1920 leaf = path->nodes[0];
1921 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1922 btrfs_release_path(path);
1923 continue;
1924 }
1925
1926 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1927 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1928 key.type != BTRFS_DEV_ITEM_KEY)
1929 break;
1930
1931 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1932 struct btrfs_dev_item);
1933 devid = btrfs_device_id(leaf, dev_item);
1934 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
1935 BTRFS_UUID_SIZE);
1936 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
1937 BTRFS_UUID_SIZE);
1938 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1939 fs_uuid);
1940 BUG_ON(!device); /* Logic error */
1941
1942 if (device->fs_devices->seeding) {
1943 btrfs_set_device_generation(leaf, dev_item,
1944 device->generation);
1945 btrfs_mark_buffer_dirty(leaf);
1946 }
1947
1948 path->slots[0]++;
1949 goto next_slot;
1950 }
1951 ret = 0;
1952 error:
1953 btrfs_free_path(path);
1954 return ret;
1955 }
1956
1957 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1958 {
1959 struct request_queue *q;
1960 struct btrfs_trans_handle *trans;
1961 struct btrfs_device *device;
1962 struct block_device *bdev;
1963 struct list_head *devices;
1964 struct super_block *sb = root->fs_info->sb;
1965 struct rcu_string *name;
1966 u64 total_bytes;
1967 int seeding_dev = 0;
1968 int ret = 0;
1969
1970 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1971 return -EROFS;
1972
1973 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1974 root->fs_info->bdev_holder);
1975 if (IS_ERR(bdev))
1976 return PTR_ERR(bdev);
1977
1978 if (root->fs_info->fs_devices->seeding) {
1979 seeding_dev = 1;
1980 down_write(&sb->s_umount);
1981 mutex_lock(&uuid_mutex);
1982 }
1983
1984 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1985
1986 devices = &root->fs_info->fs_devices->devices;
1987
1988 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1989 list_for_each_entry(device, devices, dev_list) {
1990 if (device->bdev == bdev) {
1991 ret = -EEXIST;
1992 mutex_unlock(
1993 &root->fs_info->fs_devices->device_list_mutex);
1994 goto error;
1995 }
1996 }
1997 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1998
1999 device = btrfs_alloc_device(root->fs_info, NULL, NULL);
2000 if (IS_ERR(device)) {
2001 /* we can safely leave the fs_devices entry around */
2002 ret = PTR_ERR(device);
2003 goto error;
2004 }
2005
2006 name = rcu_string_strdup(device_path, GFP_NOFS);
2007 if (!name) {
2008 kfree(device);
2009 ret = -ENOMEM;
2010 goto error;
2011 }
2012 rcu_assign_pointer(device->name, name);
2013
2014 trans = btrfs_start_transaction(root, 0);
2015 if (IS_ERR(trans)) {
2016 rcu_string_free(device->name);
2017 kfree(device);
2018 ret = PTR_ERR(trans);
2019 goto error;
2020 }
2021
2022 lock_chunks(root);
2023
2024 q = bdev_get_queue(bdev);
2025 if (blk_queue_discard(q))
2026 device->can_discard = 1;
2027 device->writeable = 1;
2028 device->generation = trans->transid;
2029 device->io_width = root->sectorsize;
2030 device->io_align = root->sectorsize;
2031 device->sector_size = root->sectorsize;
2032 device->total_bytes = i_size_read(bdev->bd_inode);
2033 device->disk_total_bytes = device->total_bytes;
2034 device->dev_root = root->fs_info->dev_root;
2035 device->bdev = bdev;
2036 device->in_fs_metadata = 1;
2037 device->is_tgtdev_for_dev_replace = 0;
2038 device->mode = FMODE_EXCL;
2039 set_blocksize(device->bdev, 4096);
2040
2041 if (seeding_dev) {
2042 sb->s_flags &= ~MS_RDONLY;
2043 ret = btrfs_prepare_sprout(root);
2044 BUG_ON(ret); /* -ENOMEM */
2045 }
2046
2047 device->fs_devices = root->fs_info->fs_devices;
2048
2049 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2050 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2051 list_add(&device->dev_alloc_list,
2052 &root->fs_info->fs_devices->alloc_list);
2053 root->fs_info->fs_devices->num_devices++;
2054 root->fs_info->fs_devices->open_devices++;
2055 root->fs_info->fs_devices->rw_devices++;
2056 root->fs_info->fs_devices->total_devices++;
2057 if (device->can_discard)
2058 root->fs_info->fs_devices->num_can_discard++;
2059 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2060
2061 spin_lock(&root->fs_info->free_chunk_lock);
2062 root->fs_info->free_chunk_space += device->total_bytes;
2063 spin_unlock(&root->fs_info->free_chunk_lock);
2064
2065 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2066 root->fs_info->fs_devices->rotating = 1;
2067
2068 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2069 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2070 total_bytes + device->total_bytes);
2071
2072 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2073 btrfs_set_super_num_devices(root->fs_info->super_copy,
2074 total_bytes + 1);
2075 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2076
2077 if (seeding_dev) {
2078 ret = init_first_rw_device(trans, root, device);
2079 if (ret) {
2080 btrfs_abort_transaction(trans, root, ret);
2081 goto error_trans;
2082 }
2083 ret = btrfs_finish_sprout(trans, root);
2084 if (ret) {
2085 btrfs_abort_transaction(trans, root, ret);
2086 goto error_trans;
2087 }
2088 } else {
2089 ret = btrfs_add_device(trans, root, device);
2090 if (ret) {
2091 btrfs_abort_transaction(trans, root, ret);
2092 goto error_trans;
2093 }
2094 }
2095
2096 /*
2097 * we've got more storage, clear any full flags on the space
2098 * infos
2099 */
2100 btrfs_clear_space_info_full(root->fs_info);
2101
2102 unlock_chunks(root);
2103 root->fs_info->num_tolerated_disk_barrier_failures =
2104 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2105 ret = btrfs_commit_transaction(trans, root);
2106
2107 if (seeding_dev) {
2108 mutex_unlock(&uuid_mutex);
2109 up_write(&sb->s_umount);
2110
2111 if (ret) /* transaction commit */
2112 return ret;
2113
2114 ret = btrfs_relocate_sys_chunks(root);
2115 if (ret < 0)
2116 btrfs_error(root->fs_info, ret,
2117 "Failed to relocate sys chunks after "
2118 "device initialization. This can be fixed "
2119 "using the \"btrfs balance\" command.");
2120 trans = btrfs_attach_transaction(root);
2121 if (IS_ERR(trans)) {
2122 if (PTR_ERR(trans) == -ENOENT)
2123 return 0;
2124 return PTR_ERR(trans);
2125 }
2126 ret = btrfs_commit_transaction(trans, root);
2127 }
2128
2129 return ret;
2130
2131 error_trans:
2132 unlock_chunks(root);
2133 btrfs_end_transaction(trans, root);
2134 rcu_string_free(device->name);
2135 kfree(device);
2136 error:
2137 blkdev_put(bdev, FMODE_EXCL);
2138 if (seeding_dev) {
2139 mutex_unlock(&uuid_mutex);
2140 up_write(&sb->s_umount);
2141 }
2142 return ret;
2143 }
2144
2145 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2146 struct btrfs_device **device_out)
2147 {
2148 struct request_queue *q;
2149 struct btrfs_device *device;
2150 struct block_device *bdev;
2151 struct btrfs_fs_info *fs_info = root->fs_info;
2152 struct list_head *devices;
2153 struct rcu_string *name;
2154 u64 devid = BTRFS_DEV_REPLACE_DEVID;
2155 int ret = 0;
2156
2157 *device_out = NULL;
2158 if (fs_info->fs_devices->seeding)
2159 return -EINVAL;
2160
2161 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2162 fs_info->bdev_holder);
2163 if (IS_ERR(bdev))
2164 return PTR_ERR(bdev);
2165
2166 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2167
2168 devices = &fs_info->fs_devices->devices;
2169 list_for_each_entry(device, devices, dev_list) {
2170 if (device->bdev == bdev) {
2171 ret = -EEXIST;
2172 goto error;
2173 }
2174 }
2175
2176 device = btrfs_alloc_device(NULL, &devid, NULL);
2177 if (IS_ERR(device)) {
2178 ret = PTR_ERR(device);
2179 goto error;
2180 }
2181
2182 name = rcu_string_strdup(device_path, GFP_NOFS);
2183 if (!name) {
2184 kfree(device);
2185 ret = -ENOMEM;
2186 goto error;
2187 }
2188 rcu_assign_pointer(device->name, name);
2189
2190 q = bdev_get_queue(bdev);
2191 if (blk_queue_discard(q))
2192 device->can_discard = 1;
2193 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2194 device->writeable = 1;
2195 device->generation = 0;
2196 device->io_width = root->sectorsize;
2197 device->io_align = root->sectorsize;
2198 device->sector_size = root->sectorsize;
2199 device->total_bytes = i_size_read(bdev->bd_inode);
2200 device->disk_total_bytes = device->total_bytes;
2201 device->dev_root = fs_info->dev_root;
2202 device->bdev = bdev;
2203 device->in_fs_metadata = 1;
2204 device->is_tgtdev_for_dev_replace = 1;
2205 device->mode = FMODE_EXCL;
2206 set_blocksize(device->bdev, 4096);
2207 device->fs_devices = fs_info->fs_devices;
2208 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2209 fs_info->fs_devices->num_devices++;
2210 fs_info->fs_devices->open_devices++;
2211 if (device->can_discard)
2212 fs_info->fs_devices->num_can_discard++;
2213 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2214
2215 *device_out = device;
2216 return ret;
2217
2218 error:
2219 blkdev_put(bdev, FMODE_EXCL);
2220 return ret;
2221 }
2222
2223 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2224 struct btrfs_device *tgtdev)
2225 {
2226 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2227 tgtdev->io_width = fs_info->dev_root->sectorsize;
2228 tgtdev->io_align = fs_info->dev_root->sectorsize;
2229 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2230 tgtdev->dev_root = fs_info->dev_root;
2231 tgtdev->in_fs_metadata = 1;
2232 }
2233
2234 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2235 struct btrfs_device *device)
2236 {
2237 int ret;
2238 struct btrfs_path *path;
2239 struct btrfs_root *root;
2240 struct btrfs_dev_item *dev_item;
2241 struct extent_buffer *leaf;
2242 struct btrfs_key key;
2243
2244 root = device->dev_root->fs_info->chunk_root;
2245
2246 path = btrfs_alloc_path();
2247 if (!path)
2248 return -ENOMEM;
2249
2250 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2251 key.type = BTRFS_DEV_ITEM_KEY;
2252 key.offset = device->devid;
2253
2254 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2255 if (ret < 0)
2256 goto out;
2257
2258 if (ret > 0) {
2259 ret = -ENOENT;
2260 goto out;
2261 }
2262
2263 leaf = path->nodes[0];
2264 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2265
2266 btrfs_set_device_id(leaf, dev_item, device->devid);
2267 btrfs_set_device_type(leaf, dev_item, device->type);
2268 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2269 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2270 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2271 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2272 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2273 btrfs_mark_buffer_dirty(leaf);
2274
2275 out:
2276 btrfs_free_path(path);
2277 return ret;
2278 }
2279
2280 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2281 struct btrfs_device *device, u64 new_size)
2282 {
2283 struct btrfs_super_block *super_copy =
2284 device->dev_root->fs_info->super_copy;
2285 u64 old_total = btrfs_super_total_bytes(super_copy);
2286 u64 diff = new_size - device->total_bytes;
2287
2288 if (!device->writeable)
2289 return -EACCES;
2290 if (new_size <= device->total_bytes ||
2291 device->is_tgtdev_for_dev_replace)
2292 return -EINVAL;
2293
2294 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2295 device->fs_devices->total_rw_bytes += diff;
2296
2297 device->total_bytes = new_size;
2298 device->disk_total_bytes = new_size;
2299 btrfs_clear_space_info_full(device->dev_root->fs_info);
2300
2301 return btrfs_update_device(trans, device);
2302 }
2303
2304 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2305 struct btrfs_device *device, u64 new_size)
2306 {
2307 int ret;
2308 lock_chunks(device->dev_root);
2309 ret = __btrfs_grow_device(trans, device, new_size);
2310 unlock_chunks(device->dev_root);
2311 return ret;
2312 }
2313
2314 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2315 struct btrfs_root *root,
2316 u64 chunk_tree, u64 chunk_objectid,
2317 u64 chunk_offset)
2318 {
2319 int ret;
2320 struct btrfs_path *path;
2321 struct btrfs_key key;
2322
2323 root = root->fs_info->chunk_root;
2324 path = btrfs_alloc_path();
2325 if (!path)
2326 return -ENOMEM;
2327
2328 key.objectid = chunk_objectid;
2329 key.offset = chunk_offset;
2330 key.type = BTRFS_CHUNK_ITEM_KEY;
2331
2332 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2333 if (ret < 0)
2334 goto out;
2335 else if (ret > 0) { /* Logic error or corruption */
2336 btrfs_error(root->fs_info, -ENOENT,
2337 "Failed lookup while freeing chunk.");
2338 ret = -ENOENT;
2339 goto out;
2340 }
2341
2342 ret = btrfs_del_item(trans, root, path);
2343 if (ret < 0)
2344 btrfs_error(root->fs_info, ret,
2345 "Failed to delete chunk item.");
2346 out:
2347 btrfs_free_path(path);
2348 return ret;
2349 }
2350
2351 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2352 chunk_offset)
2353 {
2354 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2355 struct btrfs_disk_key *disk_key;
2356 struct btrfs_chunk *chunk;
2357 u8 *ptr;
2358 int ret = 0;
2359 u32 num_stripes;
2360 u32 array_size;
2361 u32 len = 0;
2362 u32 cur;
2363 struct btrfs_key key;
2364
2365 array_size = btrfs_super_sys_array_size(super_copy);
2366
2367 ptr = super_copy->sys_chunk_array;
2368 cur = 0;
2369
2370 while (cur < array_size) {
2371 disk_key = (struct btrfs_disk_key *)ptr;
2372 btrfs_disk_key_to_cpu(&key, disk_key);
2373
2374 len = sizeof(*disk_key);
2375
2376 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2377 chunk = (struct btrfs_chunk *)(ptr + len);
2378 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2379 len += btrfs_chunk_item_size(num_stripes);
2380 } else {
2381 ret = -EIO;
2382 break;
2383 }
2384 if (key.objectid == chunk_objectid &&
2385 key.offset == chunk_offset) {
2386 memmove(ptr, ptr + len, array_size - (cur + len));
2387 array_size -= len;
2388 btrfs_set_super_sys_array_size(super_copy, array_size);
2389 } else {
2390 ptr += len;
2391 cur += len;
2392 }
2393 }
2394 return ret;
2395 }
2396
2397 static int btrfs_relocate_chunk(struct btrfs_root *root,
2398 u64 chunk_tree, u64 chunk_objectid,
2399 u64 chunk_offset)
2400 {
2401 struct extent_map_tree *em_tree;
2402 struct btrfs_root *extent_root;
2403 struct btrfs_trans_handle *trans;
2404 struct extent_map *em;
2405 struct map_lookup *map;
2406 int ret;
2407 int i;
2408
2409 root = root->fs_info->chunk_root;
2410 extent_root = root->fs_info->extent_root;
2411 em_tree = &root->fs_info->mapping_tree.map_tree;
2412
2413 ret = btrfs_can_relocate(extent_root, chunk_offset);
2414 if (ret)
2415 return -ENOSPC;
2416
2417 /* step one, relocate all the extents inside this chunk */
2418 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2419 if (ret)
2420 return ret;
2421
2422 trans = btrfs_start_transaction(root, 0);
2423 if (IS_ERR(trans)) {
2424 ret = PTR_ERR(trans);
2425 btrfs_std_error(root->fs_info, ret);
2426 return ret;
2427 }
2428
2429 lock_chunks(root);
2430
2431 /*
2432 * step two, delete the device extents and the
2433 * chunk tree entries
2434 */
2435 read_lock(&em_tree->lock);
2436 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2437 read_unlock(&em_tree->lock);
2438
2439 BUG_ON(!em || em->start > chunk_offset ||
2440 em->start + em->len < chunk_offset);
2441 map = (struct map_lookup *)em->bdev;
2442
2443 for (i = 0; i < map->num_stripes; i++) {
2444 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2445 map->stripes[i].physical);
2446 BUG_ON(ret);
2447
2448 if (map->stripes[i].dev) {
2449 ret = btrfs_update_device(trans, map->stripes[i].dev);
2450 BUG_ON(ret);
2451 }
2452 }
2453 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2454 chunk_offset);
2455
2456 BUG_ON(ret);
2457
2458 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2459
2460 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2461 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2462 BUG_ON(ret);
2463 }
2464
2465 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2466 BUG_ON(ret);
2467
2468 write_lock(&em_tree->lock);
2469 remove_extent_mapping(em_tree, em);
2470 write_unlock(&em_tree->lock);
2471
2472 kfree(map);
2473 em->bdev = NULL;
2474
2475 /* once for the tree */
2476 free_extent_map(em);
2477 /* once for us */
2478 free_extent_map(em);
2479
2480 unlock_chunks(root);
2481 btrfs_end_transaction(trans, root);
2482 return 0;
2483 }
2484
2485 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2486 {
2487 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2488 struct btrfs_path *path;
2489 struct extent_buffer *leaf;
2490 struct btrfs_chunk *chunk;
2491 struct btrfs_key key;
2492 struct btrfs_key found_key;
2493 u64 chunk_tree = chunk_root->root_key.objectid;
2494 u64 chunk_type;
2495 bool retried = false;
2496 int failed = 0;
2497 int ret;
2498
2499 path = btrfs_alloc_path();
2500 if (!path)
2501 return -ENOMEM;
2502
2503 again:
2504 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2505 key.offset = (u64)-1;
2506 key.type = BTRFS_CHUNK_ITEM_KEY;
2507
2508 while (1) {
2509 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2510 if (ret < 0)
2511 goto error;
2512 BUG_ON(ret == 0); /* Corruption */
2513
2514 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2515 key.type);
2516 if (ret < 0)
2517 goto error;
2518 if (ret > 0)
2519 break;
2520
2521 leaf = path->nodes[0];
2522 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2523
2524 chunk = btrfs_item_ptr(leaf, path->slots[0],
2525 struct btrfs_chunk);
2526 chunk_type = btrfs_chunk_type(leaf, chunk);
2527 btrfs_release_path(path);
2528
2529 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2530 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2531 found_key.objectid,
2532 found_key.offset);
2533 if (ret == -ENOSPC)
2534 failed++;
2535 else if (ret)
2536 BUG();
2537 }
2538
2539 if (found_key.offset == 0)
2540 break;
2541 key.offset = found_key.offset - 1;
2542 }
2543 ret = 0;
2544 if (failed && !retried) {
2545 failed = 0;
2546 retried = true;
2547 goto again;
2548 } else if (failed && retried) {
2549 WARN_ON(1);
2550 ret = -ENOSPC;
2551 }
2552 error:
2553 btrfs_free_path(path);
2554 return ret;
2555 }
2556
2557 static int insert_balance_item(struct btrfs_root *root,
2558 struct btrfs_balance_control *bctl)
2559 {
2560 struct btrfs_trans_handle *trans;
2561 struct btrfs_balance_item *item;
2562 struct btrfs_disk_balance_args disk_bargs;
2563 struct btrfs_path *path;
2564 struct extent_buffer *leaf;
2565 struct btrfs_key key;
2566 int ret, err;
2567
2568 path = btrfs_alloc_path();
2569 if (!path)
2570 return -ENOMEM;
2571
2572 trans = btrfs_start_transaction(root, 0);
2573 if (IS_ERR(trans)) {
2574 btrfs_free_path(path);
2575 return PTR_ERR(trans);
2576 }
2577
2578 key.objectid = BTRFS_BALANCE_OBJECTID;
2579 key.type = BTRFS_BALANCE_ITEM_KEY;
2580 key.offset = 0;
2581
2582 ret = btrfs_insert_empty_item(trans, root, path, &key,
2583 sizeof(*item));
2584 if (ret)
2585 goto out;
2586
2587 leaf = path->nodes[0];
2588 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2589
2590 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2591
2592 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2593 btrfs_set_balance_data(leaf, item, &disk_bargs);
2594 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2595 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2596 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2597 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2598
2599 btrfs_set_balance_flags(leaf, item, bctl->flags);
2600
2601 btrfs_mark_buffer_dirty(leaf);
2602 out:
2603 btrfs_free_path(path);
2604 err = btrfs_commit_transaction(trans, root);
2605 if (err && !ret)
2606 ret = err;
2607 return ret;
2608 }
2609
2610 static int del_balance_item(struct btrfs_root *root)
2611 {
2612 struct btrfs_trans_handle *trans;
2613 struct btrfs_path *path;
2614 struct btrfs_key key;
2615 int ret, err;
2616
2617 path = btrfs_alloc_path();
2618 if (!path)
2619 return -ENOMEM;
2620
2621 trans = btrfs_start_transaction(root, 0);
2622 if (IS_ERR(trans)) {
2623 btrfs_free_path(path);
2624 return PTR_ERR(trans);
2625 }
2626
2627 key.objectid = BTRFS_BALANCE_OBJECTID;
2628 key.type = BTRFS_BALANCE_ITEM_KEY;
2629 key.offset = 0;
2630
2631 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2632 if (ret < 0)
2633 goto out;
2634 if (ret > 0) {
2635 ret = -ENOENT;
2636 goto out;
2637 }
2638
2639 ret = btrfs_del_item(trans, root, path);
2640 out:
2641 btrfs_free_path(path);
2642 err = btrfs_commit_transaction(trans, root);
2643 if (err && !ret)
2644 ret = err;
2645 return ret;
2646 }
2647
2648 /*
2649 * This is a heuristic used to reduce the number of chunks balanced on
2650 * resume after balance was interrupted.
2651 */
2652 static void update_balance_args(struct btrfs_balance_control *bctl)
2653 {
2654 /*
2655 * Turn on soft mode for chunk types that were being converted.
2656 */
2657 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2658 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2659 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2660 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2661 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2662 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2663
2664 /*
2665 * Turn on usage filter if is not already used. The idea is
2666 * that chunks that we have already balanced should be
2667 * reasonably full. Don't do it for chunks that are being
2668 * converted - that will keep us from relocating unconverted
2669 * (albeit full) chunks.
2670 */
2671 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2672 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2673 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2674 bctl->data.usage = 90;
2675 }
2676 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2677 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2678 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2679 bctl->sys.usage = 90;
2680 }
2681 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2682 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2683 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2684 bctl->meta.usage = 90;
2685 }
2686 }
2687
2688 /*
2689 * Should be called with both balance and volume mutexes held to
2690 * serialize other volume operations (add_dev/rm_dev/resize) with
2691 * restriper. Same goes for unset_balance_control.
2692 */
2693 static void set_balance_control(struct btrfs_balance_control *bctl)
2694 {
2695 struct btrfs_fs_info *fs_info = bctl->fs_info;
2696
2697 BUG_ON(fs_info->balance_ctl);
2698
2699 spin_lock(&fs_info->balance_lock);
2700 fs_info->balance_ctl = bctl;
2701 spin_unlock(&fs_info->balance_lock);
2702 }
2703
2704 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2705 {
2706 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2707
2708 BUG_ON(!fs_info->balance_ctl);
2709
2710 spin_lock(&fs_info->balance_lock);
2711 fs_info->balance_ctl = NULL;
2712 spin_unlock(&fs_info->balance_lock);
2713
2714 kfree(bctl);
2715 }
2716
2717 /*
2718 * Balance filters. Return 1 if chunk should be filtered out
2719 * (should not be balanced).
2720 */
2721 static int chunk_profiles_filter(u64 chunk_type,
2722 struct btrfs_balance_args *bargs)
2723 {
2724 chunk_type = chunk_to_extended(chunk_type) &
2725 BTRFS_EXTENDED_PROFILE_MASK;
2726
2727 if (bargs->profiles & chunk_type)
2728 return 0;
2729
2730 return 1;
2731 }
2732
2733 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2734 struct btrfs_balance_args *bargs)
2735 {
2736 struct btrfs_block_group_cache *cache;
2737 u64 chunk_used, user_thresh;
2738 int ret = 1;
2739
2740 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2741 chunk_used = btrfs_block_group_used(&cache->item);
2742
2743 if (bargs->usage == 0)
2744 user_thresh = 1;
2745 else if (bargs->usage > 100)
2746 user_thresh = cache->key.offset;
2747 else
2748 user_thresh = div_factor_fine(cache->key.offset,
2749 bargs->usage);
2750
2751 if (chunk_used < user_thresh)
2752 ret = 0;
2753
2754 btrfs_put_block_group(cache);
2755 return ret;
2756 }
2757
2758 static int chunk_devid_filter(struct extent_buffer *leaf,
2759 struct btrfs_chunk *chunk,
2760 struct btrfs_balance_args *bargs)
2761 {
2762 struct btrfs_stripe *stripe;
2763 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2764 int i;
2765
2766 for (i = 0; i < num_stripes; i++) {
2767 stripe = btrfs_stripe_nr(chunk, i);
2768 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2769 return 0;
2770 }
2771
2772 return 1;
2773 }
2774
2775 /* [pstart, pend) */
2776 static int chunk_drange_filter(struct extent_buffer *leaf,
2777 struct btrfs_chunk *chunk,
2778 u64 chunk_offset,
2779 struct btrfs_balance_args *bargs)
2780 {
2781 struct btrfs_stripe *stripe;
2782 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2783 u64 stripe_offset;
2784 u64 stripe_length;
2785 int factor;
2786 int i;
2787
2788 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2789 return 0;
2790
2791 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2792 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2793 factor = num_stripes / 2;
2794 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2795 factor = num_stripes - 1;
2796 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2797 factor = num_stripes - 2;
2798 } else {
2799 factor = num_stripes;
2800 }
2801
2802 for (i = 0; i < num_stripes; i++) {
2803 stripe = btrfs_stripe_nr(chunk, i);
2804 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2805 continue;
2806
2807 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2808 stripe_length = btrfs_chunk_length(leaf, chunk);
2809 do_div(stripe_length, factor);
2810
2811 if (stripe_offset < bargs->pend &&
2812 stripe_offset + stripe_length > bargs->pstart)
2813 return 0;
2814 }
2815
2816 return 1;
2817 }
2818
2819 /* [vstart, vend) */
2820 static int chunk_vrange_filter(struct extent_buffer *leaf,
2821 struct btrfs_chunk *chunk,
2822 u64 chunk_offset,
2823 struct btrfs_balance_args *bargs)
2824 {
2825 if (chunk_offset < bargs->vend &&
2826 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2827 /* at least part of the chunk is inside this vrange */
2828 return 0;
2829
2830 return 1;
2831 }
2832
2833 static int chunk_soft_convert_filter(u64 chunk_type,
2834 struct btrfs_balance_args *bargs)
2835 {
2836 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2837 return 0;
2838
2839 chunk_type = chunk_to_extended(chunk_type) &
2840 BTRFS_EXTENDED_PROFILE_MASK;
2841
2842 if (bargs->target == chunk_type)
2843 return 1;
2844
2845 return 0;
2846 }
2847
2848 static int should_balance_chunk(struct btrfs_root *root,
2849 struct extent_buffer *leaf,
2850 struct btrfs_chunk *chunk, u64 chunk_offset)
2851 {
2852 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2853 struct btrfs_balance_args *bargs = NULL;
2854 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2855
2856 /* type filter */
2857 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2858 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2859 return 0;
2860 }
2861
2862 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2863 bargs = &bctl->data;
2864 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2865 bargs = &bctl->sys;
2866 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2867 bargs = &bctl->meta;
2868
2869 /* profiles filter */
2870 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2871 chunk_profiles_filter(chunk_type, bargs)) {
2872 return 0;
2873 }
2874
2875 /* usage filter */
2876 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2877 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2878 return 0;
2879 }
2880
2881 /* devid filter */
2882 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2883 chunk_devid_filter(leaf, chunk, bargs)) {
2884 return 0;
2885 }
2886
2887 /* drange filter, makes sense only with devid filter */
2888 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2889 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2890 return 0;
2891 }
2892
2893 /* vrange filter */
2894 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2895 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2896 return 0;
2897 }
2898
2899 /* soft profile changing mode */
2900 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2901 chunk_soft_convert_filter(chunk_type, bargs)) {
2902 return 0;
2903 }
2904
2905 return 1;
2906 }
2907
2908 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2909 {
2910 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2911 struct btrfs_root *chunk_root = fs_info->chunk_root;
2912 struct btrfs_root *dev_root = fs_info->dev_root;
2913 struct list_head *devices;
2914 struct btrfs_device *device;
2915 u64 old_size;
2916 u64 size_to_free;
2917 struct btrfs_chunk *chunk;
2918 struct btrfs_path *path;
2919 struct btrfs_key key;
2920 struct btrfs_key found_key;
2921 struct btrfs_trans_handle *trans;
2922 struct extent_buffer *leaf;
2923 int slot;
2924 int ret;
2925 int enospc_errors = 0;
2926 bool counting = true;
2927
2928 /* step one make some room on all the devices */
2929 devices = &fs_info->fs_devices->devices;
2930 list_for_each_entry(device, devices, dev_list) {
2931 old_size = device->total_bytes;
2932 size_to_free = div_factor(old_size, 1);
2933 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2934 if (!device->writeable ||
2935 device->total_bytes - device->bytes_used > size_to_free ||
2936 device->is_tgtdev_for_dev_replace)
2937 continue;
2938
2939 ret = btrfs_shrink_device(device, old_size - size_to_free);
2940 if (ret == -ENOSPC)
2941 break;
2942 BUG_ON(ret);
2943
2944 trans = btrfs_start_transaction(dev_root, 0);
2945 BUG_ON(IS_ERR(trans));
2946
2947 ret = btrfs_grow_device(trans, device, old_size);
2948 BUG_ON(ret);
2949
2950 btrfs_end_transaction(trans, dev_root);
2951 }
2952
2953 /* step two, relocate all the chunks */
2954 path = btrfs_alloc_path();
2955 if (!path) {
2956 ret = -ENOMEM;
2957 goto error;
2958 }
2959
2960 /* zero out stat counters */
2961 spin_lock(&fs_info->balance_lock);
2962 memset(&bctl->stat, 0, sizeof(bctl->stat));
2963 spin_unlock(&fs_info->balance_lock);
2964 again:
2965 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2966 key.offset = (u64)-1;
2967 key.type = BTRFS_CHUNK_ITEM_KEY;
2968
2969 while (1) {
2970 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2971 atomic_read(&fs_info->balance_cancel_req)) {
2972 ret = -ECANCELED;
2973 goto error;
2974 }
2975
2976 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2977 if (ret < 0)
2978 goto error;
2979
2980 /*
2981 * this shouldn't happen, it means the last relocate
2982 * failed
2983 */
2984 if (ret == 0)
2985 BUG(); /* FIXME break ? */
2986
2987 ret = btrfs_previous_item(chunk_root, path, 0,
2988 BTRFS_CHUNK_ITEM_KEY);
2989 if (ret) {
2990 ret = 0;
2991 break;
2992 }
2993
2994 leaf = path->nodes[0];
2995 slot = path->slots[0];
2996 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2997
2998 if (found_key.objectid != key.objectid)
2999 break;
3000
3001 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3002
3003 if (!counting) {
3004 spin_lock(&fs_info->balance_lock);
3005 bctl->stat.considered++;
3006 spin_unlock(&fs_info->balance_lock);
3007 }
3008
3009 ret = should_balance_chunk(chunk_root, leaf, chunk,
3010 found_key.offset);
3011 btrfs_release_path(path);
3012 if (!ret)
3013 goto loop;
3014
3015 if (counting) {
3016 spin_lock(&fs_info->balance_lock);
3017 bctl->stat.expected++;
3018 spin_unlock(&fs_info->balance_lock);
3019 goto loop;
3020 }
3021
3022 ret = btrfs_relocate_chunk(chunk_root,
3023 chunk_root->root_key.objectid,
3024 found_key.objectid,
3025 found_key.offset);
3026 if (ret && ret != -ENOSPC)
3027 goto error;
3028 if (ret == -ENOSPC) {
3029 enospc_errors++;
3030 } else {
3031 spin_lock(&fs_info->balance_lock);
3032 bctl->stat.completed++;
3033 spin_unlock(&fs_info->balance_lock);
3034 }
3035 loop:
3036 if (found_key.offset == 0)
3037 break;
3038 key.offset = found_key.offset - 1;
3039 }
3040
3041 if (counting) {
3042 btrfs_release_path(path);
3043 counting = false;
3044 goto again;
3045 }
3046 error:
3047 btrfs_free_path(path);
3048 if (enospc_errors) {
3049 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
3050 enospc_errors);
3051 if (!ret)
3052 ret = -ENOSPC;
3053 }
3054
3055 return ret;
3056 }
3057
3058 /**
3059 * alloc_profile_is_valid - see if a given profile is valid and reduced
3060 * @flags: profile to validate
3061 * @extended: if true @flags is treated as an extended profile
3062 */
3063 static int alloc_profile_is_valid(u64 flags, int extended)
3064 {
3065 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3066 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3067
3068 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3069
3070 /* 1) check that all other bits are zeroed */
3071 if (flags & ~mask)
3072 return 0;
3073
3074 /* 2) see if profile is reduced */
3075 if (flags == 0)
3076 return !extended; /* "0" is valid for usual profiles */
3077
3078 /* true if exactly one bit set */
3079 return (flags & (flags - 1)) == 0;
3080 }
3081
3082 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3083 {
3084 /* cancel requested || normal exit path */
3085 return atomic_read(&fs_info->balance_cancel_req) ||
3086 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3087 atomic_read(&fs_info->balance_cancel_req) == 0);
3088 }
3089
3090 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3091 {
3092 int ret;
3093
3094 unset_balance_control(fs_info);
3095 ret = del_balance_item(fs_info->tree_root);
3096 if (ret)
3097 btrfs_std_error(fs_info, ret);
3098
3099 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3100 }
3101
3102 /*
3103 * Should be called with both balance and volume mutexes held
3104 */
3105 int btrfs_balance(struct btrfs_balance_control *bctl,
3106 struct btrfs_ioctl_balance_args *bargs)
3107 {
3108 struct btrfs_fs_info *fs_info = bctl->fs_info;
3109 u64 allowed;
3110 int mixed = 0;
3111 int ret;
3112 u64 num_devices;
3113 unsigned seq;
3114
3115 if (btrfs_fs_closing(fs_info) ||
3116 atomic_read(&fs_info->balance_pause_req) ||
3117 atomic_read(&fs_info->balance_cancel_req)) {
3118 ret = -EINVAL;
3119 goto out;
3120 }
3121
3122 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3123 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3124 mixed = 1;
3125
3126 /*
3127 * In case of mixed groups both data and meta should be picked,
3128 * and identical options should be given for both of them.
3129 */
3130 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3131 if (mixed && (bctl->flags & allowed)) {
3132 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3133 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3134 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3135 printk(KERN_ERR "btrfs: with mixed groups data and "
3136 "metadata balance options must be the same\n");
3137 ret = -EINVAL;
3138 goto out;
3139 }
3140 }
3141
3142 num_devices = fs_info->fs_devices->num_devices;
3143 btrfs_dev_replace_lock(&fs_info->dev_replace);
3144 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3145 BUG_ON(num_devices < 1);
3146 num_devices--;
3147 }
3148 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3149 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3150 if (num_devices == 1)
3151 allowed |= BTRFS_BLOCK_GROUP_DUP;
3152 else if (num_devices > 1)
3153 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3154 if (num_devices > 2)
3155 allowed |= BTRFS_BLOCK_GROUP_RAID5;
3156 if (num_devices > 3)
3157 allowed |= (BTRFS_BLOCK_GROUP_RAID10 |
3158 BTRFS_BLOCK_GROUP_RAID6);
3159 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3160 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3161 (bctl->data.target & ~allowed))) {
3162 printk(KERN_ERR "btrfs: unable to start balance with target "
3163 "data profile %llu\n",
3164 bctl->data.target);
3165 ret = -EINVAL;
3166 goto out;
3167 }
3168 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3169 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3170 (bctl->meta.target & ~allowed))) {
3171 printk(KERN_ERR "btrfs: unable to start balance with target "
3172 "metadata profile %llu\n",
3173 bctl->meta.target);
3174 ret = -EINVAL;
3175 goto out;
3176 }
3177 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3178 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3179 (bctl->sys.target & ~allowed))) {
3180 printk(KERN_ERR "btrfs: unable to start balance with target "
3181 "system profile %llu\n",
3182 bctl->sys.target);
3183 ret = -EINVAL;
3184 goto out;
3185 }
3186
3187 /* allow dup'ed data chunks only in mixed mode */
3188 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3189 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3190 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3191 ret = -EINVAL;
3192 goto out;
3193 }
3194
3195 /* allow to reduce meta or sys integrity only if force set */
3196 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3197 BTRFS_BLOCK_GROUP_RAID10 |
3198 BTRFS_BLOCK_GROUP_RAID5 |
3199 BTRFS_BLOCK_GROUP_RAID6;
3200 do {
3201 seq = read_seqbegin(&fs_info->profiles_lock);
3202
3203 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3204 (fs_info->avail_system_alloc_bits & allowed) &&
3205 !(bctl->sys.target & allowed)) ||
3206 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3207 (fs_info->avail_metadata_alloc_bits & allowed) &&
3208 !(bctl->meta.target & allowed))) {
3209 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3210 printk(KERN_INFO "btrfs: force reducing metadata "
3211 "integrity\n");
3212 } else {
3213 printk(KERN_ERR "btrfs: balance will reduce metadata "
3214 "integrity, use force if you want this\n");
3215 ret = -EINVAL;
3216 goto out;
3217 }
3218 }
3219 } while (read_seqretry(&fs_info->profiles_lock, seq));
3220
3221 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3222 int num_tolerated_disk_barrier_failures;
3223 u64 target = bctl->sys.target;
3224
3225 num_tolerated_disk_barrier_failures =
3226 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3227 if (num_tolerated_disk_barrier_failures > 0 &&
3228 (target &
3229 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3230 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3231 num_tolerated_disk_barrier_failures = 0;
3232 else if (num_tolerated_disk_barrier_failures > 1 &&
3233 (target &
3234 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3235 num_tolerated_disk_barrier_failures = 1;
3236
3237 fs_info->num_tolerated_disk_barrier_failures =
3238 num_tolerated_disk_barrier_failures;
3239 }
3240
3241 ret = insert_balance_item(fs_info->tree_root, bctl);
3242 if (ret && ret != -EEXIST)
3243 goto out;
3244
3245 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3246 BUG_ON(ret == -EEXIST);
3247 set_balance_control(bctl);
3248 } else {
3249 BUG_ON(ret != -EEXIST);
3250 spin_lock(&fs_info->balance_lock);
3251 update_balance_args(bctl);
3252 spin_unlock(&fs_info->balance_lock);
3253 }
3254
3255 atomic_inc(&fs_info->balance_running);
3256 mutex_unlock(&fs_info->balance_mutex);
3257
3258 ret = __btrfs_balance(fs_info);
3259
3260 mutex_lock(&fs_info->balance_mutex);
3261 atomic_dec(&fs_info->balance_running);
3262
3263 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3264 fs_info->num_tolerated_disk_barrier_failures =
3265 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3266 }
3267
3268 if (bargs) {
3269 memset(bargs, 0, sizeof(*bargs));
3270 update_ioctl_balance_args(fs_info, 0, bargs);
3271 }
3272
3273 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3274 balance_need_close(fs_info)) {
3275 __cancel_balance(fs_info);
3276 }
3277
3278 wake_up(&fs_info->balance_wait_q);
3279
3280 return ret;
3281 out:
3282 if (bctl->flags & BTRFS_BALANCE_RESUME)
3283 __cancel_balance(fs_info);
3284 else {
3285 kfree(bctl);
3286 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3287 }
3288 return ret;
3289 }
3290
3291 static int balance_kthread(void *data)
3292 {
3293 struct btrfs_fs_info *fs_info = data;
3294 int ret = 0;
3295
3296 mutex_lock(&fs_info->volume_mutex);
3297 mutex_lock(&fs_info->balance_mutex);
3298
3299 if (fs_info->balance_ctl) {
3300 printk(KERN_INFO "btrfs: continuing balance\n");
3301 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3302 }
3303
3304 mutex_unlock(&fs_info->balance_mutex);
3305 mutex_unlock(&fs_info->volume_mutex);
3306
3307 return ret;
3308 }
3309
3310 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3311 {
3312 struct task_struct *tsk;
3313
3314 spin_lock(&fs_info->balance_lock);
3315 if (!fs_info->balance_ctl) {
3316 spin_unlock(&fs_info->balance_lock);
3317 return 0;
3318 }
3319 spin_unlock(&fs_info->balance_lock);
3320
3321 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3322 printk(KERN_INFO "btrfs: force skipping balance\n");
3323 return 0;
3324 }
3325
3326 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3327 return PTR_RET(tsk);
3328 }
3329
3330 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3331 {
3332 struct btrfs_balance_control *bctl;
3333 struct btrfs_balance_item *item;
3334 struct btrfs_disk_balance_args disk_bargs;
3335 struct btrfs_path *path;
3336 struct extent_buffer *leaf;
3337 struct btrfs_key key;
3338 int ret;
3339
3340 path = btrfs_alloc_path();
3341 if (!path)
3342 return -ENOMEM;
3343
3344 key.objectid = BTRFS_BALANCE_OBJECTID;
3345 key.type = BTRFS_BALANCE_ITEM_KEY;
3346 key.offset = 0;
3347
3348 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3349 if (ret < 0)
3350 goto out;
3351 if (ret > 0) { /* ret = -ENOENT; */
3352 ret = 0;
3353 goto out;
3354 }
3355
3356 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3357 if (!bctl) {
3358 ret = -ENOMEM;
3359 goto out;
3360 }
3361
3362 leaf = path->nodes[0];
3363 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3364
3365 bctl->fs_info = fs_info;
3366 bctl->flags = btrfs_balance_flags(leaf, item);
3367 bctl->flags |= BTRFS_BALANCE_RESUME;
3368
3369 btrfs_balance_data(leaf, item, &disk_bargs);
3370 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3371 btrfs_balance_meta(leaf, item, &disk_bargs);
3372 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3373 btrfs_balance_sys(leaf, item, &disk_bargs);
3374 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3375
3376 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3377
3378 mutex_lock(&fs_info->volume_mutex);
3379 mutex_lock(&fs_info->balance_mutex);
3380
3381 set_balance_control(bctl);
3382
3383 mutex_unlock(&fs_info->balance_mutex);
3384 mutex_unlock(&fs_info->volume_mutex);
3385 out:
3386 btrfs_free_path(path);
3387 return ret;
3388 }
3389
3390 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3391 {
3392 int ret = 0;
3393
3394 mutex_lock(&fs_info->balance_mutex);
3395 if (!fs_info->balance_ctl) {
3396 mutex_unlock(&fs_info->balance_mutex);
3397 return -ENOTCONN;
3398 }
3399
3400 if (atomic_read(&fs_info->balance_running)) {
3401 atomic_inc(&fs_info->balance_pause_req);
3402 mutex_unlock(&fs_info->balance_mutex);
3403
3404 wait_event(fs_info->balance_wait_q,
3405 atomic_read(&fs_info->balance_running) == 0);
3406
3407 mutex_lock(&fs_info->balance_mutex);
3408 /* we are good with balance_ctl ripped off from under us */
3409 BUG_ON(atomic_read(&fs_info->balance_running));
3410 atomic_dec(&fs_info->balance_pause_req);
3411 } else {
3412 ret = -ENOTCONN;
3413 }
3414
3415 mutex_unlock(&fs_info->balance_mutex);
3416 return ret;
3417 }
3418
3419 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3420 {
3421 mutex_lock(&fs_info->balance_mutex);
3422 if (!fs_info->balance_ctl) {
3423 mutex_unlock(&fs_info->balance_mutex);
3424 return -ENOTCONN;
3425 }
3426
3427 atomic_inc(&fs_info->balance_cancel_req);
3428 /*
3429 * if we are running just wait and return, balance item is
3430 * deleted in btrfs_balance in this case
3431 */
3432 if (atomic_read(&fs_info->balance_running)) {
3433 mutex_unlock(&fs_info->balance_mutex);
3434 wait_event(fs_info->balance_wait_q,
3435 atomic_read(&fs_info->balance_running) == 0);
3436 mutex_lock(&fs_info->balance_mutex);
3437 } else {
3438 /* __cancel_balance needs volume_mutex */
3439 mutex_unlock(&fs_info->balance_mutex);
3440 mutex_lock(&fs_info->volume_mutex);
3441 mutex_lock(&fs_info->balance_mutex);
3442
3443 if (fs_info->balance_ctl)
3444 __cancel_balance(fs_info);
3445
3446 mutex_unlock(&fs_info->volume_mutex);
3447 }
3448
3449 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3450 atomic_dec(&fs_info->balance_cancel_req);
3451 mutex_unlock(&fs_info->balance_mutex);
3452 return 0;
3453 }
3454
3455 static int btrfs_uuid_scan_kthread(void *data)
3456 {
3457 struct btrfs_fs_info *fs_info = data;
3458 struct btrfs_root *root = fs_info->tree_root;
3459 struct btrfs_key key;
3460 struct btrfs_key max_key;
3461 struct btrfs_path *path = NULL;
3462 int ret = 0;
3463 struct extent_buffer *eb;
3464 int slot;
3465 struct btrfs_root_item root_item;
3466 u32 item_size;
3467 struct btrfs_trans_handle *trans = NULL;
3468
3469 path = btrfs_alloc_path();
3470 if (!path) {
3471 ret = -ENOMEM;
3472 goto out;
3473 }
3474
3475 key.objectid = 0;
3476 key.type = BTRFS_ROOT_ITEM_KEY;
3477 key.offset = 0;
3478
3479 max_key.objectid = (u64)-1;
3480 max_key.type = BTRFS_ROOT_ITEM_KEY;
3481 max_key.offset = (u64)-1;
3482
3483 path->keep_locks = 1;
3484
3485 while (1) {
3486 ret = btrfs_search_forward(root, &key, &max_key, path, 0);
3487 if (ret) {
3488 if (ret > 0)
3489 ret = 0;
3490 break;
3491 }
3492
3493 if (key.type != BTRFS_ROOT_ITEM_KEY ||
3494 (key.objectid < BTRFS_FIRST_FREE_OBJECTID &&
3495 key.objectid != BTRFS_FS_TREE_OBJECTID) ||
3496 key.objectid > BTRFS_LAST_FREE_OBJECTID)
3497 goto skip;
3498
3499 eb = path->nodes[0];
3500 slot = path->slots[0];
3501 item_size = btrfs_item_size_nr(eb, slot);
3502 if (item_size < sizeof(root_item))
3503 goto skip;
3504
3505 read_extent_buffer(eb, &root_item,
3506 btrfs_item_ptr_offset(eb, slot),
3507 (int)sizeof(root_item));
3508 if (btrfs_root_refs(&root_item) == 0)
3509 goto skip;
3510
3511 if (!btrfs_is_empty_uuid(root_item.uuid) ||
3512 !btrfs_is_empty_uuid(root_item.received_uuid)) {
3513 if (trans)
3514 goto update_tree;
3515
3516 btrfs_release_path(path);
3517 /*
3518 * 1 - subvol uuid item
3519 * 1 - received_subvol uuid item
3520 */
3521 trans = btrfs_start_transaction(fs_info->uuid_root, 2);
3522 if (IS_ERR(trans)) {
3523 ret = PTR_ERR(trans);
3524 break;
3525 }
3526 continue;
3527 } else {
3528 goto skip;
3529 }
3530 update_tree:
3531 if (!btrfs_is_empty_uuid(root_item.uuid)) {
3532 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3533 root_item.uuid,
3534 BTRFS_UUID_KEY_SUBVOL,
3535 key.objectid);
3536 if (ret < 0) {
3537 pr_warn("btrfs: uuid_tree_add failed %d\n",
3538 ret);
3539 break;
3540 }
3541 }
3542
3543 if (!btrfs_is_empty_uuid(root_item.received_uuid)) {
3544 ret = btrfs_uuid_tree_add(trans, fs_info->uuid_root,
3545 root_item.received_uuid,
3546 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
3547 key.objectid);
3548 if (ret < 0) {
3549 pr_warn("btrfs: uuid_tree_add failed %d\n",
3550 ret);
3551 break;
3552 }
3553 }
3554
3555 skip:
3556 if (trans) {
3557 ret = btrfs_end_transaction(trans, fs_info->uuid_root);
3558 trans = NULL;
3559 if (ret)
3560 break;
3561 }
3562
3563 btrfs_release_path(path);
3564 if (key.offset < (u64)-1) {
3565 key.offset++;
3566 } else if (key.type < BTRFS_ROOT_ITEM_KEY) {
3567 key.offset = 0;
3568 key.type = BTRFS_ROOT_ITEM_KEY;
3569 } else if (key.objectid < (u64)-1) {
3570 key.offset = 0;
3571 key.type = BTRFS_ROOT_ITEM_KEY;
3572 key.objectid++;
3573 } else {
3574 break;
3575 }
3576 cond_resched();
3577 }
3578
3579 out:
3580 btrfs_free_path(path);
3581 if (trans && !IS_ERR(trans))
3582 btrfs_end_transaction(trans, fs_info->uuid_root);
3583 if (ret)
3584 pr_warn("btrfs: btrfs_uuid_scan_kthread failed %d\n", ret);
3585 else
3586 fs_info->update_uuid_tree_gen = 1;
3587 up(&fs_info->uuid_tree_rescan_sem);
3588 return 0;
3589 }
3590
3591 /*
3592 * Callback for btrfs_uuid_tree_iterate().
3593 * returns:
3594 * 0 check succeeded, the entry is not outdated.
3595 * < 0 if an error occured.
3596 * > 0 if the check failed, which means the caller shall remove the entry.
3597 */
3598 static int btrfs_check_uuid_tree_entry(struct btrfs_fs_info *fs_info,
3599 u8 *uuid, u8 type, u64 subid)
3600 {
3601 struct btrfs_key key;
3602 int ret = 0;
3603 struct btrfs_root *subvol_root;
3604
3605 if (type != BTRFS_UUID_KEY_SUBVOL &&
3606 type != BTRFS_UUID_KEY_RECEIVED_SUBVOL)
3607 goto out;
3608
3609 key.objectid = subid;
3610 key.type = BTRFS_ROOT_ITEM_KEY;
3611 key.offset = (u64)-1;
3612 subvol_root = btrfs_read_fs_root_no_name(fs_info, &key);
3613 if (IS_ERR(subvol_root)) {
3614 ret = PTR_ERR(subvol_root);
3615 if (ret == -ENOENT)
3616 ret = 1;
3617 goto out;
3618 }
3619
3620 switch (type) {
3621 case BTRFS_UUID_KEY_SUBVOL:
3622 if (memcmp(uuid, subvol_root->root_item.uuid, BTRFS_UUID_SIZE))
3623 ret = 1;
3624 break;
3625 case BTRFS_UUID_KEY_RECEIVED_SUBVOL:
3626 if (memcmp(uuid, subvol_root->root_item.received_uuid,
3627 BTRFS_UUID_SIZE))
3628 ret = 1;
3629 break;
3630 }
3631
3632 out:
3633 return ret;
3634 }
3635
3636 static int btrfs_uuid_rescan_kthread(void *data)
3637 {
3638 struct btrfs_fs_info *fs_info = (struct btrfs_fs_info *)data;
3639 int ret;
3640
3641 /*
3642 * 1st step is to iterate through the existing UUID tree and
3643 * to delete all entries that contain outdated data.
3644 * 2nd step is to add all missing entries to the UUID tree.
3645 */
3646 ret = btrfs_uuid_tree_iterate(fs_info, btrfs_check_uuid_tree_entry);
3647 if (ret < 0) {
3648 pr_warn("btrfs: iterating uuid_tree failed %d\n", ret);
3649 up(&fs_info->uuid_tree_rescan_sem);
3650 return ret;
3651 }
3652 return btrfs_uuid_scan_kthread(data);
3653 }
3654
3655 int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info)
3656 {
3657 struct btrfs_trans_handle *trans;
3658 struct btrfs_root *tree_root = fs_info->tree_root;
3659 struct btrfs_root *uuid_root;
3660 struct task_struct *task;
3661 int ret;
3662
3663 /*
3664 * 1 - root node
3665 * 1 - root item
3666 */
3667 trans = btrfs_start_transaction(tree_root, 2);
3668 if (IS_ERR(trans))
3669 return PTR_ERR(trans);
3670
3671 uuid_root = btrfs_create_tree(trans, fs_info,
3672 BTRFS_UUID_TREE_OBJECTID);
3673 if (IS_ERR(uuid_root)) {
3674 btrfs_abort_transaction(trans, tree_root,
3675 PTR_ERR(uuid_root));
3676 return PTR_ERR(uuid_root);
3677 }
3678
3679 fs_info->uuid_root = uuid_root;
3680
3681 ret = btrfs_commit_transaction(trans, tree_root);
3682 if (ret)
3683 return ret;
3684
3685 down(&fs_info->uuid_tree_rescan_sem);
3686 task = kthread_run(btrfs_uuid_scan_kthread, fs_info, "btrfs-uuid");
3687 if (IS_ERR(task)) {
3688 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3689 pr_warn("btrfs: failed to start uuid_scan task\n");
3690 up(&fs_info->uuid_tree_rescan_sem);
3691 return PTR_ERR(task);
3692 }
3693
3694 return 0;
3695 }
3696
3697 int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info)
3698 {
3699 struct task_struct *task;
3700
3701 down(&fs_info->uuid_tree_rescan_sem);
3702 task = kthread_run(btrfs_uuid_rescan_kthread, fs_info, "btrfs-uuid");
3703 if (IS_ERR(task)) {
3704 /* fs_info->update_uuid_tree_gen remains 0 in all error case */
3705 pr_warn("btrfs: failed to start uuid_rescan task\n");
3706 up(&fs_info->uuid_tree_rescan_sem);
3707 return PTR_ERR(task);
3708 }
3709
3710 return 0;
3711 }
3712
3713 /*
3714 * shrinking a device means finding all of the device extents past
3715 * the new size, and then following the back refs to the chunks.
3716 * The chunk relocation code actually frees the device extent
3717 */
3718 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3719 {
3720 struct btrfs_trans_handle *trans;
3721 struct btrfs_root *root = device->dev_root;
3722 struct btrfs_dev_extent *dev_extent = NULL;
3723 struct btrfs_path *path;
3724 u64 length;
3725 u64 chunk_tree;
3726 u64 chunk_objectid;
3727 u64 chunk_offset;
3728 int ret;
3729 int slot;
3730 int failed = 0;
3731 bool retried = false;
3732 struct extent_buffer *l;
3733 struct btrfs_key key;
3734 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3735 u64 old_total = btrfs_super_total_bytes(super_copy);
3736 u64 old_size = device->total_bytes;
3737 u64 diff = device->total_bytes - new_size;
3738
3739 if (device->is_tgtdev_for_dev_replace)
3740 return -EINVAL;
3741
3742 path = btrfs_alloc_path();
3743 if (!path)
3744 return -ENOMEM;
3745
3746 path->reada = 2;
3747
3748 lock_chunks(root);
3749
3750 device->total_bytes = new_size;
3751 if (device->writeable) {
3752 device->fs_devices->total_rw_bytes -= diff;
3753 spin_lock(&root->fs_info->free_chunk_lock);
3754 root->fs_info->free_chunk_space -= diff;
3755 spin_unlock(&root->fs_info->free_chunk_lock);
3756 }
3757 unlock_chunks(root);
3758
3759 again:
3760 key.objectid = device->devid;
3761 key.offset = (u64)-1;
3762 key.type = BTRFS_DEV_EXTENT_KEY;
3763
3764 do {
3765 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3766 if (ret < 0)
3767 goto done;
3768
3769 ret = btrfs_previous_item(root, path, 0, key.type);
3770 if (ret < 0)
3771 goto done;
3772 if (ret) {
3773 ret = 0;
3774 btrfs_release_path(path);
3775 break;
3776 }
3777
3778 l = path->nodes[0];
3779 slot = path->slots[0];
3780 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3781
3782 if (key.objectid != device->devid) {
3783 btrfs_release_path(path);
3784 break;
3785 }
3786
3787 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3788 length = btrfs_dev_extent_length(l, dev_extent);
3789
3790 if (key.offset + length <= new_size) {
3791 btrfs_release_path(path);
3792 break;
3793 }
3794
3795 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3796 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3797 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3798 btrfs_release_path(path);
3799
3800 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3801 chunk_offset);
3802 if (ret && ret != -ENOSPC)
3803 goto done;
3804 if (ret == -ENOSPC)
3805 failed++;
3806 } while (key.offset-- > 0);
3807
3808 if (failed && !retried) {
3809 failed = 0;
3810 retried = true;
3811 goto again;
3812 } else if (failed && retried) {
3813 ret = -ENOSPC;
3814 lock_chunks(root);
3815
3816 device->total_bytes = old_size;
3817 if (device->writeable)
3818 device->fs_devices->total_rw_bytes += diff;
3819 spin_lock(&root->fs_info->free_chunk_lock);
3820 root->fs_info->free_chunk_space += diff;
3821 spin_unlock(&root->fs_info->free_chunk_lock);
3822 unlock_chunks(root);
3823 goto done;
3824 }
3825
3826 /* Shrinking succeeded, else we would be at "done". */
3827 trans = btrfs_start_transaction(root, 0);
3828 if (IS_ERR(trans)) {
3829 ret = PTR_ERR(trans);
3830 goto done;
3831 }
3832
3833 lock_chunks(root);
3834
3835 device->disk_total_bytes = new_size;
3836 /* Now btrfs_update_device() will change the on-disk size. */
3837 ret = btrfs_update_device(trans, device);
3838 if (ret) {
3839 unlock_chunks(root);
3840 btrfs_end_transaction(trans, root);
3841 goto done;
3842 }
3843 WARN_ON(diff > old_total);
3844 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3845 unlock_chunks(root);
3846 btrfs_end_transaction(trans, root);
3847 done:
3848 btrfs_free_path(path);
3849 return ret;
3850 }
3851
3852 static int btrfs_add_system_chunk(struct btrfs_root *root,
3853 struct btrfs_key *key,
3854 struct btrfs_chunk *chunk, int item_size)
3855 {
3856 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3857 struct btrfs_disk_key disk_key;
3858 u32 array_size;
3859 u8 *ptr;
3860
3861 array_size = btrfs_super_sys_array_size(super_copy);
3862 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3863 return -EFBIG;
3864
3865 ptr = super_copy->sys_chunk_array + array_size;
3866 btrfs_cpu_key_to_disk(&disk_key, key);
3867 memcpy(ptr, &disk_key, sizeof(disk_key));
3868 ptr += sizeof(disk_key);
3869 memcpy(ptr, chunk, item_size);
3870 item_size += sizeof(disk_key);
3871 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3872 return 0;
3873 }
3874
3875 /*
3876 * sort the devices in descending order by max_avail, total_avail
3877 */
3878 static int btrfs_cmp_device_info(const void *a, const void *b)
3879 {
3880 const struct btrfs_device_info *di_a = a;
3881 const struct btrfs_device_info *di_b = b;
3882
3883 if (di_a->max_avail > di_b->max_avail)
3884 return -1;
3885 if (di_a->max_avail < di_b->max_avail)
3886 return 1;
3887 if (di_a->total_avail > di_b->total_avail)
3888 return -1;
3889 if (di_a->total_avail < di_b->total_avail)
3890 return 1;
3891 return 0;
3892 }
3893
3894 static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3895 [BTRFS_RAID_RAID10] = {
3896 .sub_stripes = 2,
3897 .dev_stripes = 1,
3898 .devs_max = 0, /* 0 == as many as possible */
3899 .devs_min = 4,
3900 .devs_increment = 2,
3901 .ncopies = 2,
3902 },
3903 [BTRFS_RAID_RAID1] = {
3904 .sub_stripes = 1,
3905 .dev_stripes = 1,
3906 .devs_max = 2,
3907 .devs_min = 2,
3908 .devs_increment = 2,
3909 .ncopies = 2,
3910 },
3911 [BTRFS_RAID_DUP] = {
3912 .sub_stripes = 1,
3913 .dev_stripes = 2,
3914 .devs_max = 1,
3915 .devs_min = 1,
3916 .devs_increment = 1,
3917 .ncopies = 2,
3918 },
3919 [BTRFS_RAID_RAID0] = {
3920 .sub_stripes = 1,
3921 .dev_stripes = 1,
3922 .devs_max = 0,
3923 .devs_min = 2,
3924 .devs_increment = 1,
3925 .ncopies = 1,
3926 },
3927 [BTRFS_RAID_SINGLE] = {
3928 .sub_stripes = 1,
3929 .dev_stripes = 1,
3930 .devs_max = 1,
3931 .devs_min = 1,
3932 .devs_increment = 1,
3933 .ncopies = 1,
3934 },
3935 [BTRFS_RAID_RAID5] = {
3936 .sub_stripes = 1,
3937 .dev_stripes = 1,
3938 .devs_max = 0,
3939 .devs_min = 2,
3940 .devs_increment = 1,
3941 .ncopies = 2,
3942 },
3943 [BTRFS_RAID_RAID6] = {
3944 .sub_stripes = 1,
3945 .dev_stripes = 1,
3946 .devs_max = 0,
3947 .devs_min = 3,
3948 .devs_increment = 1,
3949 .ncopies = 3,
3950 },
3951 };
3952
3953 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3954 {
3955 /* TODO allow them to set a preferred stripe size */
3956 return 64 * 1024;
3957 }
3958
3959 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3960 {
3961 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3962 return;
3963
3964 btrfs_set_fs_incompat(info, RAID56);
3965 }
3966
3967 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3968 struct btrfs_root *extent_root, u64 start,
3969 u64 type)
3970 {
3971 struct btrfs_fs_info *info = extent_root->fs_info;
3972 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3973 struct list_head *cur;
3974 struct map_lookup *map = NULL;
3975 struct extent_map_tree *em_tree;
3976 struct extent_map *em;
3977 struct btrfs_device_info *devices_info = NULL;
3978 u64 total_avail;
3979 int num_stripes; /* total number of stripes to allocate */
3980 int data_stripes; /* number of stripes that count for
3981 block group size */
3982 int sub_stripes; /* sub_stripes info for map */
3983 int dev_stripes; /* stripes per dev */
3984 int devs_max; /* max devs to use */
3985 int devs_min; /* min devs needed */
3986 int devs_increment; /* ndevs has to be a multiple of this */
3987 int ncopies; /* how many copies to data has */
3988 int ret;
3989 u64 max_stripe_size;
3990 u64 max_chunk_size;
3991 u64 stripe_size;
3992 u64 num_bytes;
3993 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
3994 int ndevs;
3995 int i;
3996 int j;
3997 int index;
3998
3999 BUG_ON(!alloc_profile_is_valid(type, 0));
4000
4001 if (list_empty(&fs_devices->alloc_list))
4002 return -ENOSPC;
4003
4004 index = __get_raid_index(type);
4005
4006 sub_stripes = btrfs_raid_array[index].sub_stripes;
4007 dev_stripes = btrfs_raid_array[index].dev_stripes;
4008 devs_max = btrfs_raid_array[index].devs_max;
4009 devs_min = btrfs_raid_array[index].devs_min;
4010 devs_increment = btrfs_raid_array[index].devs_increment;
4011 ncopies = btrfs_raid_array[index].ncopies;
4012
4013 if (type & BTRFS_BLOCK_GROUP_DATA) {
4014 max_stripe_size = 1024 * 1024 * 1024;
4015 max_chunk_size = 10 * max_stripe_size;
4016 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
4017 /* for larger filesystems, use larger metadata chunks */
4018 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
4019 max_stripe_size = 1024 * 1024 * 1024;
4020 else
4021 max_stripe_size = 256 * 1024 * 1024;
4022 max_chunk_size = max_stripe_size;
4023 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
4024 max_stripe_size = 32 * 1024 * 1024;
4025 max_chunk_size = 2 * max_stripe_size;
4026 } else {
4027 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
4028 type);
4029 BUG_ON(1);
4030 }
4031
4032 /* we don't want a chunk larger than 10% of writeable space */
4033 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
4034 max_chunk_size);
4035
4036 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
4037 GFP_NOFS);
4038 if (!devices_info)
4039 return -ENOMEM;
4040
4041 cur = fs_devices->alloc_list.next;
4042
4043 /*
4044 * in the first pass through the devices list, we gather information
4045 * about the available holes on each device.
4046 */
4047 ndevs = 0;
4048 while (cur != &fs_devices->alloc_list) {
4049 struct btrfs_device *device;
4050 u64 max_avail;
4051 u64 dev_offset;
4052
4053 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
4054
4055 cur = cur->next;
4056
4057 if (!device->writeable) {
4058 WARN(1, KERN_ERR
4059 "btrfs: read-only device in alloc_list\n");
4060 continue;
4061 }
4062
4063 if (!device->in_fs_metadata ||
4064 device->is_tgtdev_for_dev_replace)
4065 continue;
4066
4067 if (device->total_bytes > device->bytes_used)
4068 total_avail = device->total_bytes - device->bytes_used;
4069 else
4070 total_avail = 0;
4071
4072 /* If there is no space on this device, skip it. */
4073 if (total_avail == 0)
4074 continue;
4075
4076 ret = find_free_dev_extent(trans, device,
4077 max_stripe_size * dev_stripes,
4078 &dev_offset, &max_avail);
4079 if (ret && ret != -ENOSPC)
4080 goto error;
4081
4082 if (ret == 0)
4083 max_avail = max_stripe_size * dev_stripes;
4084
4085 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
4086 continue;
4087
4088 if (ndevs == fs_devices->rw_devices) {
4089 WARN(1, "%s: found more than %llu devices\n",
4090 __func__, fs_devices->rw_devices);
4091 break;
4092 }
4093 devices_info[ndevs].dev_offset = dev_offset;
4094 devices_info[ndevs].max_avail = max_avail;
4095 devices_info[ndevs].total_avail = total_avail;
4096 devices_info[ndevs].dev = device;
4097 ++ndevs;
4098 }
4099
4100 /*
4101 * now sort the devices by hole size / available space
4102 */
4103 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
4104 btrfs_cmp_device_info, NULL);
4105
4106 /* round down to number of usable stripes */
4107 ndevs -= ndevs % devs_increment;
4108
4109 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
4110 ret = -ENOSPC;
4111 goto error;
4112 }
4113
4114 if (devs_max && ndevs > devs_max)
4115 ndevs = devs_max;
4116 /*
4117 * the primary goal is to maximize the number of stripes, so use as many
4118 * devices as possible, even if the stripes are not maximum sized.
4119 */
4120 stripe_size = devices_info[ndevs-1].max_avail;
4121 num_stripes = ndevs * dev_stripes;
4122
4123 /*
4124 * this will have to be fixed for RAID1 and RAID10 over
4125 * more drives
4126 */
4127 data_stripes = num_stripes / ncopies;
4128
4129 if (type & BTRFS_BLOCK_GROUP_RAID5) {
4130 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
4131 btrfs_super_stripesize(info->super_copy));
4132 data_stripes = num_stripes - 1;
4133 }
4134 if (type & BTRFS_BLOCK_GROUP_RAID6) {
4135 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
4136 btrfs_super_stripesize(info->super_copy));
4137 data_stripes = num_stripes - 2;
4138 }
4139
4140 /*
4141 * Use the number of data stripes to figure out how big this chunk
4142 * is really going to be in terms of logical address space,
4143 * and compare that answer with the max chunk size
4144 */
4145 if (stripe_size * data_stripes > max_chunk_size) {
4146 u64 mask = (1ULL << 24) - 1;
4147 stripe_size = max_chunk_size;
4148 do_div(stripe_size, data_stripes);
4149
4150 /* bump the answer up to a 16MB boundary */
4151 stripe_size = (stripe_size + mask) & ~mask;
4152
4153 /* but don't go higher than the limits we found
4154 * while searching for free extents
4155 */
4156 if (stripe_size > devices_info[ndevs-1].max_avail)
4157 stripe_size = devices_info[ndevs-1].max_avail;
4158 }
4159
4160 do_div(stripe_size, dev_stripes);
4161
4162 /* align to BTRFS_STRIPE_LEN */
4163 do_div(stripe_size, raid_stripe_len);
4164 stripe_size *= raid_stripe_len;
4165
4166 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4167 if (!map) {
4168 ret = -ENOMEM;
4169 goto error;
4170 }
4171 map->num_stripes = num_stripes;
4172
4173 for (i = 0; i < ndevs; ++i) {
4174 for (j = 0; j < dev_stripes; ++j) {
4175 int s = i * dev_stripes + j;
4176 map->stripes[s].dev = devices_info[i].dev;
4177 map->stripes[s].physical = devices_info[i].dev_offset +
4178 j * stripe_size;
4179 }
4180 }
4181 map->sector_size = extent_root->sectorsize;
4182 map->stripe_len = raid_stripe_len;
4183 map->io_align = raid_stripe_len;
4184 map->io_width = raid_stripe_len;
4185 map->type = type;
4186 map->sub_stripes = sub_stripes;
4187
4188 num_bytes = stripe_size * data_stripes;
4189
4190 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
4191
4192 em = alloc_extent_map();
4193 if (!em) {
4194 ret = -ENOMEM;
4195 goto error;
4196 }
4197 em->bdev = (struct block_device *)map;
4198 em->start = start;
4199 em->len = num_bytes;
4200 em->block_start = 0;
4201 em->block_len = em->len;
4202 em->orig_block_len = stripe_size;
4203
4204 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4205 write_lock(&em_tree->lock);
4206 ret = add_extent_mapping(em_tree, em, 0);
4207 if (!ret) {
4208 list_add_tail(&em->list, &trans->transaction->pending_chunks);
4209 atomic_inc(&em->refs);
4210 }
4211 write_unlock(&em_tree->lock);
4212 if (ret) {
4213 free_extent_map(em);
4214 goto error;
4215 }
4216
4217 ret = btrfs_make_block_group(trans, extent_root, 0, type,
4218 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4219 start, num_bytes);
4220 if (ret)
4221 goto error_del_extent;
4222
4223 free_extent_map(em);
4224 check_raid56_incompat_flag(extent_root->fs_info, type);
4225
4226 kfree(devices_info);
4227 return 0;
4228
4229 error_del_extent:
4230 write_lock(&em_tree->lock);
4231 remove_extent_mapping(em_tree, em);
4232 write_unlock(&em_tree->lock);
4233
4234 /* One for our allocation */
4235 free_extent_map(em);
4236 /* One for the tree reference */
4237 free_extent_map(em);
4238 error:
4239 kfree(map);
4240 kfree(devices_info);
4241 return ret;
4242 }
4243
4244 int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
4245 struct btrfs_root *extent_root,
4246 u64 chunk_offset, u64 chunk_size)
4247 {
4248 struct btrfs_key key;
4249 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4250 struct btrfs_device *device;
4251 struct btrfs_chunk *chunk;
4252 struct btrfs_stripe *stripe;
4253 struct extent_map_tree *em_tree;
4254 struct extent_map *em;
4255 struct map_lookup *map;
4256 size_t item_size;
4257 u64 dev_offset;
4258 u64 stripe_size;
4259 int i = 0;
4260 int ret;
4261
4262 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
4263 read_lock(&em_tree->lock);
4264 em = lookup_extent_mapping(em_tree, chunk_offset, chunk_size);
4265 read_unlock(&em_tree->lock);
4266
4267 if (!em) {
4268 btrfs_crit(extent_root->fs_info, "unable to find logical "
4269 "%Lu len %Lu", chunk_offset, chunk_size);
4270 return -EINVAL;
4271 }
4272
4273 if (em->start != chunk_offset || em->len != chunk_size) {
4274 btrfs_crit(extent_root->fs_info, "found a bad mapping, wanted"
4275 " %Lu-%Lu, found %Lu-%Lu\n", chunk_offset,
4276 chunk_size, em->start, em->len);
4277 free_extent_map(em);
4278 return -EINVAL;
4279 }
4280
4281 map = (struct map_lookup *)em->bdev;
4282 item_size = btrfs_chunk_item_size(map->num_stripes);
4283 stripe_size = em->orig_block_len;
4284
4285 chunk = kzalloc(item_size, GFP_NOFS);
4286 if (!chunk) {
4287 ret = -ENOMEM;
4288 goto out;
4289 }
4290
4291 for (i = 0; i < map->num_stripes; i++) {
4292 device = map->stripes[i].dev;
4293 dev_offset = map->stripes[i].physical;
4294
4295 device->bytes_used += stripe_size;
4296 ret = btrfs_update_device(trans, device);
4297 if (ret)
4298 goto out;
4299 ret = btrfs_alloc_dev_extent(trans, device,
4300 chunk_root->root_key.objectid,
4301 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4302 chunk_offset, dev_offset,
4303 stripe_size);
4304 if (ret)
4305 goto out;
4306 }
4307
4308 spin_lock(&extent_root->fs_info->free_chunk_lock);
4309 extent_root->fs_info->free_chunk_space -= (stripe_size *
4310 map->num_stripes);
4311 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4312
4313 stripe = &chunk->stripe;
4314 for (i = 0; i < map->num_stripes; i++) {
4315 device = map->stripes[i].dev;
4316 dev_offset = map->stripes[i].physical;
4317
4318 btrfs_set_stack_stripe_devid(stripe, device->devid);
4319 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4320 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4321 stripe++;
4322 }
4323
4324 btrfs_set_stack_chunk_length(chunk, chunk_size);
4325 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4326 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4327 btrfs_set_stack_chunk_type(chunk, map->type);
4328 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4329 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4330 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4331 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4332 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4333
4334 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4335 key.type = BTRFS_CHUNK_ITEM_KEY;
4336 key.offset = chunk_offset;
4337
4338 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4339 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4340 /*
4341 * TODO: Cleanup of inserted chunk root in case of
4342 * failure.
4343 */
4344 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4345 item_size);
4346 }
4347
4348 out:
4349 kfree(chunk);
4350 free_extent_map(em);
4351 return ret;
4352 }
4353
4354 /*
4355 * Chunk allocation falls into two parts. The first part does works
4356 * that make the new allocated chunk useable, but not do any operation
4357 * that modifies the chunk tree. The second part does the works that
4358 * require modifying the chunk tree. This division is important for the
4359 * bootstrap process of adding storage to a seed btrfs.
4360 */
4361 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4362 struct btrfs_root *extent_root, u64 type)
4363 {
4364 u64 chunk_offset;
4365
4366 chunk_offset = find_next_chunk(extent_root->fs_info);
4367 return __btrfs_alloc_chunk(trans, extent_root, chunk_offset, type);
4368 }
4369
4370 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4371 struct btrfs_root *root,
4372 struct btrfs_device *device)
4373 {
4374 u64 chunk_offset;
4375 u64 sys_chunk_offset;
4376 u64 alloc_profile;
4377 struct btrfs_fs_info *fs_info = root->fs_info;
4378 struct btrfs_root *extent_root = fs_info->extent_root;
4379 int ret;
4380
4381 chunk_offset = find_next_chunk(fs_info);
4382 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4383 ret = __btrfs_alloc_chunk(trans, extent_root, chunk_offset,
4384 alloc_profile);
4385 if (ret)
4386 return ret;
4387
4388 sys_chunk_offset = find_next_chunk(root->fs_info);
4389 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4390 ret = __btrfs_alloc_chunk(trans, extent_root, sys_chunk_offset,
4391 alloc_profile);
4392 if (ret) {
4393 btrfs_abort_transaction(trans, root, ret);
4394 goto out;
4395 }
4396
4397 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4398 if (ret)
4399 btrfs_abort_transaction(trans, root, ret);
4400 out:
4401 return ret;
4402 }
4403
4404 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4405 {
4406 struct extent_map *em;
4407 struct map_lookup *map;
4408 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4409 int readonly = 0;
4410 int i;
4411
4412 read_lock(&map_tree->map_tree.lock);
4413 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4414 read_unlock(&map_tree->map_tree.lock);
4415 if (!em)
4416 return 1;
4417
4418 if (btrfs_test_opt(root, DEGRADED)) {
4419 free_extent_map(em);
4420 return 0;
4421 }
4422
4423 map = (struct map_lookup *)em->bdev;
4424 for (i = 0; i < map->num_stripes; i++) {
4425 if (!map->stripes[i].dev->writeable) {
4426 readonly = 1;
4427 break;
4428 }
4429 }
4430 free_extent_map(em);
4431 return readonly;
4432 }
4433
4434 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4435 {
4436 extent_map_tree_init(&tree->map_tree);
4437 }
4438
4439 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4440 {
4441 struct extent_map *em;
4442
4443 while (1) {
4444 write_lock(&tree->map_tree.lock);
4445 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4446 if (em)
4447 remove_extent_mapping(&tree->map_tree, em);
4448 write_unlock(&tree->map_tree.lock);
4449 if (!em)
4450 break;
4451 kfree(em->bdev);
4452 /* once for us */
4453 free_extent_map(em);
4454 /* once for the tree */
4455 free_extent_map(em);
4456 }
4457 }
4458
4459 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4460 {
4461 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4462 struct extent_map *em;
4463 struct map_lookup *map;
4464 struct extent_map_tree *em_tree = &map_tree->map_tree;
4465 int ret;
4466
4467 read_lock(&em_tree->lock);
4468 em = lookup_extent_mapping(em_tree, logical, len);
4469 read_unlock(&em_tree->lock);
4470
4471 /*
4472 * We could return errors for these cases, but that could get ugly and
4473 * we'd probably do the same thing which is just not do anything else
4474 * and exit, so return 1 so the callers don't try to use other copies.
4475 */
4476 if (!em) {
4477 btrfs_crit(fs_info, "No mapping for %Lu-%Lu\n", logical,
4478 logical+len);
4479 return 1;
4480 }
4481
4482 if (em->start > logical || em->start + em->len < logical) {
4483 btrfs_crit(fs_info, "Invalid mapping for %Lu-%Lu, got "
4484 "%Lu-%Lu\n", logical, logical+len, em->start,
4485 em->start + em->len);
4486 return 1;
4487 }
4488
4489 map = (struct map_lookup *)em->bdev;
4490 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4491 ret = map->num_stripes;
4492 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4493 ret = map->sub_stripes;
4494 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4495 ret = 2;
4496 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4497 ret = 3;
4498 else
4499 ret = 1;
4500 free_extent_map(em);
4501
4502 btrfs_dev_replace_lock(&fs_info->dev_replace);
4503 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4504 ret++;
4505 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4506
4507 return ret;
4508 }
4509
4510 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4511 struct btrfs_mapping_tree *map_tree,
4512 u64 logical)
4513 {
4514 struct extent_map *em;
4515 struct map_lookup *map;
4516 struct extent_map_tree *em_tree = &map_tree->map_tree;
4517 unsigned long len = root->sectorsize;
4518
4519 read_lock(&em_tree->lock);
4520 em = lookup_extent_mapping(em_tree, logical, len);
4521 read_unlock(&em_tree->lock);
4522 BUG_ON(!em);
4523
4524 BUG_ON(em->start > logical || em->start + em->len < logical);
4525 map = (struct map_lookup *)em->bdev;
4526 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4527 BTRFS_BLOCK_GROUP_RAID6)) {
4528 len = map->stripe_len * nr_data_stripes(map);
4529 }
4530 free_extent_map(em);
4531 return len;
4532 }
4533
4534 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4535 u64 logical, u64 len, int mirror_num)
4536 {
4537 struct extent_map *em;
4538 struct map_lookup *map;
4539 struct extent_map_tree *em_tree = &map_tree->map_tree;
4540 int ret = 0;
4541
4542 read_lock(&em_tree->lock);
4543 em = lookup_extent_mapping(em_tree, logical, len);
4544 read_unlock(&em_tree->lock);
4545 BUG_ON(!em);
4546
4547 BUG_ON(em->start > logical || em->start + em->len < logical);
4548 map = (struct map_lookup *)em->bdev;
4549 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4550 BTRFS_BLOCK_GROUP_RAID6))
4551 ret = 1;
4552 free_extent_map(em);
4553 return ret;
4554 }
4555
4556 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4557 struct map_lookup *map, int first, int num,
4558 int optimal, int dev_replace_is_ongoing)
4559 {
4560 int i;
4561 int tolerance;
4562 struct btrfs_device *srcdev;
4563
4564 if (dev_replace_is_ongoing &&
4565 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4566 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4567 srcdev = fs_info->dev_replace.srcdev;
4568 else
4569 srcdev = NULL;
4570
4571 /*
4572 * try to avoid the drive that is the source drive for a
4573 * dev-replace procedure, only choose it if no other non-missing
4574 * mirror is available
4575 */
4576 for (tolerance = 0; tolerance < 2; tolerance++) {
4577 if (map->stripes[optimal].dev->bdev &&
4578 (tolerance || map->stripes[optimal].dev != srcdev))
4579 return optimal;
4580 for (i = first; i < first + num; i++) {
4581 if (map->stripes[i].dev->bdev &&
4582 (tolerance || map->stripes[i].dev != srcdev))
4583 return i;
4584 }
4585 }
4586
4587 /* we couldn't find one that doesn't fail. Just return something
4588 * and the io error handling code will clean up eventually
4589 */
4590 return optimal;
4591 }
4592
4593 static inline int parity_smaller(u64 a, u64 b)
4594 {
4595 return a > b;
4596 }
4597
4598 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4599 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4600 {
4601 struct btrfs_bio_stripe s;
4602 int i;
4603 u64 l;
4604 int again = 1;
4605
4606 while (again) {
4607 again = 0;
4608 for (i = 0; i < bbio->num_stripes - 1; i++) {
4609 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4610 s = bbio->stripes[i];
4611 l = raid_map[i];
4612 bbio->stripes[i] = bbio->stripes[i+1];
4613 raid_map[i] = raid_map[i+1];
4614 bbio->stripes[i+1] = s;
4615 raid_map[i+1] = l;
4616 again = 1;
4617 }
4618 }
4619 }
4620 }
4621
4622 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4623 u64 logical, u64 *length,
4624 struct btrfs_bio **bbio_ret,
4625 int mirror_num, u64 **raid_map_ret)
4626 {
4627 struct extent_map *em;
4628 struct map_lookup *map;
4629 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4630 struct extent_map_tree *em_tree = &map_tree->map_tree;
4631 u64 offset;
4632 u64 stripe_offset;
4633 u64 stripe_end_offset;
4634 u64 stripe_nr;
4635 u64 stripe_nr_orig;
4636 u64 stripe_nr_end;
4637 u64 stripe_len;
4638 u64 *raid_map = NULL;
4639 int stripe_index;
4640 int i;
4641 int ret = 0;
4642 int num_stripes;
4643 int max_errors = 0;
4644 struct btrfs_bio *bbio = NULL;
4645 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4646 int dev_replace_is_ongoing = 0;
4647 int num_alloc_stripes;
4648 int patch_the_first_stripe_for_dev_replace = 0;
4649 u64 physical_to_patch_in_first_stripe = 0;
4650 u64 raid56_full_stripe_start = (u64)-1;
4651
4652 read_lock(&em_tree->lock);
4653 em = lookup_extent_mapping(em_tree, logical, *length);
4654 read_unlock(&em_tree->lock);
4655
4656 if (!em) {
4657 btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4658 logical, *length);
4659 return -EINVAL;
4660 }
4661
4662 if (em->start > logical || em->start + em->len < logical) {
4663 btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4664 "found %Lu-%Lu\n", logical, em->start,
4665 em->start + em->len);
4666 return -EINVAL;
4667 }
4668
4669 map = (struct map_lookup *)em->bdev;
4670 offset = logical - em->start;
4671
4672 stripe_len = map->stripe_len;
4673 stripe_nr = offset;
4674 /*
4675 * stripe_nr counts the total number of stripes we have to stride
4676 * to get to this block
4677 */
4678 do_div(stripe_nr, stripe_len);
4679
4680 stripe_offset = stripe_nr * stripe_len;
4681 BUG_ON(offset < stripe_offset);
4682
4683 /* stripe_offset is the offset of this block in its stripe*/
4684 stripe_offset = offset - stripe_offset;
4685
4686 /* if we're here for raid56, we need to know the stripe aligned start */
4687 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4688 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4689 raid56_full_stripe_start = offset;
4690
4691 /* allow a write of a full stripe, but make sure we don't
4692 * allow straddling of stripes
4693 */
4694 do_div(raid56_full_stripe_start, full_stripe_len);
4695 raid56_full_stripe_start *= full_stripe_len;
4696 }
4697
4698 if (rw & REQ_DISCARD) {
4699 /* we don't discard raid56 yet */
4700 if (map->type &
4701 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4702 ret = -EOPNOTSUPP;
4703 goto out;
4704 }
4705 *length = min_t(u64, em->len - offset, *length);
4706 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4707 u64 max_len;
4708 /* For writes to RAID[56], allow a full stripeset across all disks.
4709 For other RAID types and for RAID[56] reads, just allow a single
4710 stripe (on a single disk). */
4711 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4712 (rw & REQ_WRITE)) {
4713 max_len = stripe_len * nr_data_stripes(map) -
4714 (offset - raid56_full_stripe_start);
4715 } else {
4716 /* we limit the length of each bio to what fits in a stripe */
4717 max_len = stripe_len - stripe_offset;
4718 }
4719 *length = min_t(u64, em->len - offset, max_len);
4720 } else {
4721 *length = em->len - offset;
4722 }
4723
4724 /* This is for when we're called from btrfs_merge_bio_hook() and all
4725 it cares about is the length */
4726 if (!bbio_ret)
4727 goto out;
4728
4729 btrfs_dev_replace_lock(dev_replace);
4730 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4731 if (!dev_replace_is_ongoing)
4732 btrfs_dev_replace_unlock(dev_replace);
4733
4734 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4735 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4736 dev_replace->tgtdev != NULL) {
4737 /*
4738 * in dev-replace case, for repair case (that's the only
4739 * case where the mirror is selected explicitly when
4740 * calling btrfs_map_block), blocks left of the left cursor
4741 * can also be read from the target drive.
4742 * For REQ_GET_READ_MIRRORS, the target drive is added as
4743 * the last one to the array of stripes. For READ, it also
4744 * needs to be supported using the same mirror number.
4745 * If the requested block is not left of the left cursor,
4746 * EIO is returned. This can happen because btrfs_num_copies()
4747 * returns one more in the dev-replace case.
4748 */
4749 u64 tmp_length = *length;
4750 struct btrfs_bio *tmp_bbio = NULL;
4751 int tmp_num_stripes;
4752 u64 srcdev_devid = dev_replace->srcdev->devid;
4753 int index_srcdev = 0;
4754 int found = 0;
4755 u64 physical_of_found = 0;
4756
4757 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4758 logical, &tmp_length, &tmp_bbio, 0, NULL);
4759 if (ret) {
4760 WARN_ON(tmp_bbio != NULL);
4761 goto out;
4762 }
4763
4764 tmp_num_stripes = tmp_bbio->num_stripes;
4765 if (mirror_num > tmp_num_stripes) {
4766 /*
4767 * REQ_GET_READ_MIRRORS does not contain this
4768 * mirror, that means that the requested area
4769 * is not left of the left cursor
4770 */
4771 ret = -EIO;
4772 kfree(tmp_bbio);
4773 goto out;
4774 }
4775
4776 /*
4777 * process the rest of the function using the mirror_num
4778 * of the source drive. Therefore look it up first.
4779 * At the end, patch the device pointer to the one of the
4780 * target drive.
4781 */
4782 for (i = 0; i < tmp_num_stripes; i++) {
4783 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4784 /*
4785 * In case of DUP, in order to keep it
4786 * simple, only add the mirror with the
4787 * lowest physical address
4788 */
4789 if (found &&
4790 physical_of_found <=
4791 tmp_bbio->stripes[i].physical)
4792 continue;
4793 index_srcdev = i;
4794 found = 1;
4795 physical_of_found =
4796 tmp_bbio->stripes[i].physical;
4797 }
4798 }
4799
4800 if (found) {
4801 mirror_num = index_srcdev + 1;
4802 patch_the_first_stripe_for_dev_replace = 1;
4803 physical_to_patch_in_first_stripe = physical_of_found;
4804 } else {
4805 WARN_ON(1);
4806 ret = -EIO;
4807 kfree(tmp_bbio);
4808 goto out;
4809 }
4810
4811 kfree(tmp_bbio);
4812 } else if (mirror_num > map->num_stripes) {
4813 mirror_num = 0;
4814 }
4815
4816 num_stripes = 1;
4817 stripe_index = 0;
4818 stripe_nr_orig = stripe_nr;
4819 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
4820 do_div(stripe_nr_end, map->stripe_len);
4821 stripe_end_offset = stripe_nr_end * map->stripe_len -
4822 (offset + *length);
4823
4824 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4825 if (rw & REQ_DISCARD)
4826 num_stripes = min_t(u64, map->num_stripes,
4827 stripe_nr_end - stripe_nr_orig);
4828 stripe_index = do_div(stripe_nr, map->num_stripes);
4829 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4830 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4831 num_stripes = map->num_stripes;
4832 else if (mirror_num)
4833 stripe_index = mirror_num - 1;
4834 else {
4835 stripe_index = find_live_mirror(fs_info, map, 0,
4836 map->num_stripes,
4837 current->pid % map->num_stripes,
4838 dev_replace_is_ongoing);
4839 mirror_num = stripe_index + 1;
4840 }
4841
4842 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4843 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4844 num_stripes = map->num_stripes;
4845 } else if (mirror_num) {
4846 stripe_index = mirror_num - 1;
4847 } else {
4848 mirror_num = 1;
4849 }
4850
4851 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4852 int factor = map->num_stripes / map->sub_stripes;
4853
4854 stripe_index = do_div(stripe_nr, factor);
4855 stripe_index *= map->sub_stripes;
4856
4857 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4858 num_stripes = map->sub_stripes;
4859 else if (rw & REQ_DISCARD)
4860 num_stripes = min_t(u64, map->sub_stripes *
4861 (stripe_nr_end - stripe_nr_orig),
4862 map->num_stripes);
4863 else if (mirror_num)
4864 stripe_index += mirror_num - 1;
4865 else {
4866 int old_stripe_index = stripe_index;
4867 stripe_index = find_live_mirror(fs_info, map,
4868 stripe_index,
4869 map->sub_stripes, stripe_index +
4870 current->pid % map->sub_stripes,
4871 dev_replace_is_ongoing);
4872 mirror_num = stripe_index - old_stripe_index + 1;
4873 }
4874
4875 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4876 BTRFS_BLOCK_GROUP_RAID6)) {
4877 u64 tmp;
4878
4879 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4880 && raid_map_ret) {
4881 int i, rot;
4882
4883 /* push stripe_nr back to the start of the full stripe */
4884 stripe_nr = raid56_full_stripe_start;
4885 do_div(stripe_nr, stripe_len);
4886
4887 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4888
4889 /* RAID[56] write or recovery. Return all stripes */
4890 num_stripes = map->num_stripes;
4891 max_errors = nr_parity_stripes(map);
4892
4893 raid_map = kmalloc(sizeof(u64) * num_stripes,
4894 GFP_NOFS);
4895 if (!raid_map) {
4896 ret = -ENOMEM;
4897 goto out;
4898 }
4899
4900 /* Work out the disk rotation on this stripe-set */
4901 tmp = stripe_nr;
4902 rot = do_div(tmp, num_stripes);
4903
4904 /* Fill in the logical address of each stripe */
4905 tmp = stripe_nr * nr_data_stripes(map);
4906 for (i = 0; i < nr_data_stripes(map); i++)
4907 raid_map[(i+rot) % num_stripes] =
4908 em->start + (tmp + i) * map->stripe_len;
4909
4910 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4911 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4912 raid_map[(i+rot+1) % num_stripes] =
4913 RAID6_Q_STRIPE;
4914
4915 *length = map->stripe_len;
4916 stripe_index = 0;
4917 stripe_offset = 0;
4918 } else {
4919 /*
4920 * Mirror #0 or #1 means the original data block.
4921 * Mirror #2 is RAID5 parity block.
4922 * Mirror #3 is RAID6 Q block.
4923 */
4924 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4925 if (mirror_num > 1)
4926 stripe_index = nr_data_stripes(map) +
4927 mirror_num - 2;
4928
4929 /* We distribute the parity blocks across stripes */
4930 tmp = stripe_nr + stripe_index;
4931 stripe_index = do_div(tmp, map->num_stripes);
4932 }
4933 } else {
4934 /*
4935 * after this do_div call, stripe_nr is the number of stripes
4936 * on this device we have to walk to find the data, and
4937 * stripe_index is the number of our device in the stripe array
4938 */
4939 stripe_index = do_div(stripe_nr, map->num_stripes);
4940 mirror_num = stripe_index + 1;
4941 }
4942 BUG_ON(stripe_index >= map->num_stripes);
4943
4944 num_alloc_stripes = num_stripes;
4945 if (dev_replace_is_ongoing) {
4946 if (rw & (REQ_WRITE | REQ_DISCARD))
4947 num_alloc_stripes <<= 1;
4948 if (rw & REQ_GET_READ_MIRRORS)
4949 num_alloc_stripes++;
4950 }
4951 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4952 if (!bbio) {
4953 kfree(raid_map);
4954 ret = -ENOMEM;
4955 goto out;
4956 }
4957 atomic_set(&bbio->error, 0);
4958
4959 if (rw & REQ_DISCARD) {
4960 int factor = 0;
4961 int sub_stripes = 0;
4962 u64 stripes_per_dev = 0;
4963 u32 remaining_stripes = 0;
4964 u32 last_stripe = 0;
4965
4966 if (map->type &
4967 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4968 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4969 sub_stripes = 1;
4970 else
4971 sub_stripes = map->sub_stripes;
4972
4973 factor = map->num_stripes / sub_stripes;
4974 stripes_per_dev = div_u64_rem(stripe_nr_end -
4975 stripe_nr_orig,
4976 factor,
4977 &remaining_stripes);
4978 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4979 last_stripe *= sub_stripes;
4980 }
4981
4982 for (i = 0; i < num_stripes; i++) {
4983 bbio->stripes[i].physical =
4984 map->stripes[stripe_index].physical +
4985 stripe_offset + stripe_nr * map->stripe_len;
4986 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4987
4988 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4989 BTRFS_BLOCK_GROUP_RAID10)) {
4990 bbio->stripes[i].length = stripes_per_dev *
4991 map->stripe_len;
4992
4993 if (i / sub_stripes < remaining_stripes)
4994 bbio->stripes[i].length +=
4995 map->stripe_len;
4996
4997 /*
4998 * Special for the first stripe and
4999 * the last stripe:
5000 *
5001 * |-------|...|-------|
5002 * |----------|
5003 * off end_off
5004 */
5005 if (i < sub_stripes)
5006 bbio->stripes[i].length -=
5007 stripe_offset;
5008
5009 if (stripe_index >= last_stripe &&
5010 stripe_index <= (last_stripe +
5011 sub_stripes - 1))
5012 bbio->stripes[i].length -=
5013 stripe_end_offset;
5014
5015 if (i == sub_stripes - 1)
5016 stripe_offset = 0;
5017 } else
5018 bbio->stripes[i].length = *length;
5019
5020 stripe_index++;
5021 if (stripe_index == map->num_stripes) {
5022 /* This could only happen for RAID0/10 */
5023 stripe_index = 0;
5024 stripe_nr++;
5025 }
5026 }
5027 } else {
5028 for (i = 0; i < num_stripes; i++) {
5029 bbio->stripes[i].physical =
5030 map->stripes[stripe_index].physical +
5031 stripe_offset +
5032 stripe_nr * map->stripe_len;
5033 bbio->stripes[i].dev =
5034 map->stripes[stripe_index].dev;
5035 stripe_index++;
5036 }
5037 }
5038
5039 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
5040 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
5041 BTRFS_BLOCK_GROUP_RAID10 |
5042 BTRFS_BLOCK_GROUP_RAID5 |
5043 BTRFS_BLOCK_GROUP_DUP)) {
5044 max_errors = 1;
5045 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
5046 max_errors = 2;
5047 }
5048 }
5049
5050 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
5051 dev_replace->tgtdev != NULL) {
5052 int index_where_to_add;
5053 u64 srcdev_devid = dev_replace->srcdev->devid;
5054
5055 /*
5056 * duplicate the write operations while the dev replace
5057 * procedure is running. Since the copying of the old disk
5058 * to the new disk takes place at run time while the
5059 * filesystem is mounted writable, the regular write
5060 * operations to the old disk have to be duplicated to go
5061 * to the new disk as well.
5062 * Note that device->missing is handled by the caller, and
5063 * that the write to the old disk is already set up in the
5064 * stripes array.
5065 */
5066 index_where_to_add = num_stripes;
5067 for (i = 0; i < num_stripes; i++) {
5068 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5069 /* write to new disk, too */
5070 struct btrfs_bio_stripe *new =
5071 bbio->stripes + index_where_to_add;
5072 struct btrfs_bio_stripe *old =
5073 bbio->stripes + i;
5074
5075 new->physical = old->physical;
5076 new->length = old->length;
5077 new->dev = dev_replace->tgtdev;
5078 index_where_to_add++;
5079 max_errors++;
5080 }
5081 }
5082 num_stripes = index_where_to_add;
5083 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
5084 dev_replace->tgtdev != NULL) {
5085 u64 srcdev_devid = dev_replace->srcdev->devid;
5086 int index_srcdev = 0;
5087 int found = 0;
5088 u64 physical_of_found = 0;
5089
5090 /*
5091 * During the dev-replace procedure, the target drive can
5092 * also be used to read data in case it is needed to repair
5093 * a corrupt block elsewhere. This is possible if the
5094 * requested area is left of the left cursor. In this area,
5095 * the target drive is a full copy of the source drive.
5096 */
5097 for (i = 0; i < num_stripes; i++) {
5098 if (bbio->stripes[i].dev->devid == srcdev_devid) {
5099 /*
5100 * In case of DUP, in order to keep it
5101 * simple, only add the mirror with the
5102 * lowest physical address
5103 */
5104 if (found &&
5105 physical_of_found <=
5106 bbio->stripes[i].physical)
5107 continue;
5108 index_srcdev = i;
5109 found = 1;
5110 physical_of_found = bbio->stripes[i].physical;
5111 }
5112 }
5113 if (found) {
5114 u64 length = map->stripe_len;
5115
5116 if (physical_of_found + length <=
5117 dev_replace->cursor_left) {
5118 struct btrfs_bio_stripe *tgtdev_stripe =
5119 bbio->stripes + num_stripes;
5120
5121 tgtdev_stripe->physical = physical_of_found;
5122 tgtdev_stripe->length =
5123 bbio->stripes[index_srcdev].length;
5124 tgtdev_stripe->dev = dev_replace->tgtdev;
5125
5126 num_stripes++;
5127 }
5128 }
5129 }
5130
5131 *bbio_ret = bbio;
5132 bbio->num_stripes = num_stripes;
5133 bbio->max_errors = max_errors;
5134 bbio->mirror_num = mirror_num;
5135
5136 /*
5137 * this is the case that REQ_READ && dev_replace_is_ongoing &&
5138 * mirror_num == num_stripes + 1 && dev_replace target drive is
5139 * available as a mirror
5140 */
5141 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
5142 WARN_ON(num_stripes > 1);
5143 bbio->stripes[0].dev = dev_replace->tgtdev;
5144 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
5145 bbio->mirror_num = map->num_stripes + 1;
5146 }
5147 if (raid_map) {
5148 sort_parity_stripes(bbio, raid_map);
5149 *raid_map_ret = raid_map;
5150 }
5151 out:
5152 if (dev_replace_is_ongoing)
5153 btrfs_dev_replace_unlock(dev_replace);
5154 free_extent_map(em);
5155 return ret;
5156 }
5157
5158 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
5159 u64 logical, u64 *length,
5160 struct btrfs_bio **bbio_ret, int mirror_num)
5161 {
5162 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
5163 mirror_num, NULL);
5164 }
5165
5166 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
5167 u64 chunk_start, u64 physical, u64 devid,
5168 u64 **logical, int *naddrs, int *stripe_len)
5169 {
5170 struct extent_map_tree *em_tree = &map_tree->map_tree;
5171 struct extent_map *em;
5172 struct map_lookup *map;
5173 u64 *buf;
5174 u64 bytenr;
5175 u64 length;
5176 u64 stripe_nr;
5177 u64 rmap_len;
5178 int i, j, nr = 0;
5179
5180 read_lock(&em_tree->lock);
5181 em = lookup_extent_mapping(em_tree, chunk_start, 1);
5182 read_unlock(&em_tree->lock);
5183
5184 if (!em) {
5185 printk(KERN_ERR "btrfs: couldn't find em for chunk %Lu\n",
5186 chunk_start);
5187 return -EIO;
5188 }
5189
5190 if (em->start != chunk_start) {
5191 printk(KERN_ERR "btrfs: bad chunk start, em=%Lu, wanted=%Lu\n",
5192 em->start, chunk_start);
5193 free_extent_map(em);
5194 return -EIO;
5195 }
5196 map = (struct map_lookup *)em->bdev;
5197
5198 length = em->len;
5199 rmap_len = map->stripe_len;
5200
5201 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
5202 do_div(length, map->num_stripes / map->sub_stripes);
5203 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
5204 do_div(length, map->num_stripes);
5205 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
5206 BTRFS_BLOCK_GROUP_RAID6)) {
5207 do_div(length, nr_data_stripes(map));
5208 rmap_len = map->stripe_len * nr_data_stripes(map);
5209 }
5210
5211 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
5212 BUG_ON(!buf); /* -ENOMEM */
5213
5214 for (i = 0; i < map->num_stripes; i++) {
5215 if (devid && map->stripes[i].dev->devid != devid)
5216 continue;
5217 if (map->stripes[i].physical > physical ||
5218 map->stripes[i].physical + length <= physical)
5219 continue;
5220
5221 stripe_nr = physical - map->stripes[i].physical;
5222 do_div(stripe_nr, map->stripe_len);
5223
5224 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
5225 stripe_nr = stripe_nr * map->num_stripes + i;
5226 do_div(stripe_nr, map->sub_stripes);
5227 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
5228 stripe_nr = stripe_nr * map->num_stripes + i;
5229 } /* else if RAID[56], multiply by nr_data_stripes().
5230 * Alternatively, just use rmap_len below instead of
5231 * map->stripe_len */
5232
5233 bytenr = chunk_start + stripe_nr * rmap_len;
5234 WARN_ON(nr >= map->num_stripes);
5235 for (j = 0; j < nr; j++) {
5236 if (buf[j] == bytenr)
5237 break;
5238 }
5239 if (j == nr) {
5240 WARN_ON(nr >= map->num_stripes);
5241 buf[nr++] = bytenr;
5242 }
5243 }
5244
5245 *logical = buf;
5246 *naddrs = nr;
5247 *stripe_len = rmap_len;
5248
5249 free_extent_map(em);
5250 return 0;
5251 }
5252
5253 static void btrfs_end_bio(struct bio *bio, int err)
5254 {
5255 struct btrfs_bio *bbio = bio->bi_private;
5256 int is_orig_bio = 0;
5257
5258 if (err) {
5259 atomic_inc(&bbio->error);
5260 if (err == -EIO || err == -EREMOTEIO) {
5261 unsigned int stripe_index =
5262 btrfs_io_bio(bio)->stripe_index;
5263 struct btrfs_device *dev;
5264
5265 BUG_ON(stripe_index >= bbio->num_stripes);
5266 dev = bbio->stripes[stripe_index].dev;
5267 if (dev->bdev) {
5268 if (bio->bi_rw & WRITE)
5269 btrfs_dev_stat_inc(dev,
5270 BTRFS_DEV_STAT_WRITE_ERRS);
5271 else
5272 btrfs_dev_stat_inc(dev,
5273 BTRFS_DEV_STAT_READ_ERRS);
5274 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5275 btrfs_dev_stat_inc(dev,
5276 BTRFS_DEV_STAT_FLUSH_ERRS);
5277 btrfs_dev_stat_print_on_error(dev);
5278 }
5279 }
5280 }
5281
5282 if (bio == bbio->orig_bio)
5283 is_orig_bio = 1;
5284
5285 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5286 if (!is_orig_bio) {
5287 bio_put(bio);
5288 bio = bbio->orig_bio;
5289 }
5290 bio->bi_private = bbio->private;
5291 bio->bi_end_io = bbio->end_io;
5292 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5293 /* only send an error to the higher layers if it is
5294 * beyond the tolerance of the btrfs bio
5295 */
5296 if (atomic_read(&bbio->error) > bbio->max_errors) {
5297 err = -EIO;
5298 } else {
5299 /*
5300 * this bio is actually up to date, we didn't
5301 * go over the max number of errors
5302 */
5303 set_bit(BIO_UPTODATE, &bio->bi_flags);
5304 err = 0;
5305 }
5306 kfree(bbio);
5307
5308 bio_endio(bio, err);
5309 } else if (!is_orig_bio) {
5310 bio_put(bio);
5311 }
5312 }
5313
5314 struct async_sched {
5315 struct bio *bio;
5316 int rw;
5317 struct btrfs_fs_info *info;
5318 struct btrfs_work work;
5319 };
5320
5321 /*
5322 * see run_scheduled_bios for a description of why bios are collected for
5323 * async submit.
5324 *
5325 * This will add one bio to the pending list for a device and make sure
5326 * the work struct is scheduled.
5327 */
5328 static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5329 struct btrfs_device *device,
5330 int rw, struct bio *bio)
5331 {
5332 int should_queue = 1;
5333 struct btrfs_pending_bios *pending_bios;
5334
5335 if (device->missing || !device->bdev) {
5336 bio_endio(bio, -EIO);
5337 return;
5338 }
5339
5340 /* don't bother with additional async steps for reads, right now */
5341 if (!(rw & REQ_WRITE)) {
5342 bio_get(bio);
5343 btrfsic_submit_bio(rw, bio);
5344 bio_put(bio);
5345 return;
5346 }
5347
5348 /*
5349 * nr_async_bios allows us to reliably return congestion to the
5350 * higher layers. Otherwise, the async bio makes it appear we have
5351 * made progress against dirty pages when we've really just put it
5352 * on a queue for later
5353 */
5354 atomic_inc(&root->fs_info->nr_async_bios);
5355 WARN_ON(bio->bi_next);
5356 bio->bi_next = NULL;
5357 bio->bi_rw |= rw;
5358
5359 spin_lock(&device->io_lock);
5360 if (bio->bi_rw & REQ_SYNC)
5361 pending_bios = &device->pending_sync_bios;
5362 else
5363 pending_bios = &device->pending_bios;
5364
5365 if (pending_bios->tail)
5366 pending_bios->tail->bi_next = bio;
5367
5368 pending_bios->tail = bio;
5369 if (!pending_bios->head)
5370 pending_bios->head = bio;
5371 if (device->running_pending)
5372 should_queue = 0;
5373
5374 spin_unlock(&device->io_lock);
5375
5376 if (should_queue)
5377 btrfs_queue_worker(&root->fs_info->submit_workers,
5378 &device->work);
5379 }
5380
5381 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5382 sector_t sector)
5383 {
5384 struct bio_vec *prev;
5385 struct request_queue *q = bdev_get_queue(bdev);
5386 unsigned short max_sectors = queue_max_sectors(q);
5387 struct bvec_merge_data bvm = {
5388 .bi_bdev = bdev,
5389 .bi_sector = sector,
5390 .bi_rw = bio->bi_rw,
5391 };
5392
5393 if (bio->bi_vcnt == 0) {
5394 WARN_ON(1);
5395 return 1;
5396 }
5397
5398 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5399 if (bio_sectors(bio) > max_sectors)
5400 return 0;
5401
5402 if (!q->merge_bvec_fn)
5403 return 1;
5404
5405 bvm.bi_size = bio->bi_size - prev->bv_len;
5406 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5407 return 0;
5408 return 1;
5409 }
5410
5411 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5412 struct bio *bio, u64 physical, int dev_nr,
5413 int rw, int async)
5414 {
5415 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5416
5417 bio->bi_private = bbio;
5418 btrfs_io_bio(bio)->stripe_index = dev_nr;
5419 bio->bi_end_io = btrfs_end_bio;
5420 bio->bi_sector = physical >> 9;
5421 #ifdef DEBUG
5422 {
5423 struct rcu_string *name;
5424
5425 rcu_read_lock();
5426 name = rcu_dereference(dev->name);
5427 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5428 "(%s id %llu), size=%u\n", rw,
5429 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5430 name->str, dev->devid, bio->bi_size);
5431 rcu_read_unlock();
5432 }
5433 #endif
5434 bio->bi_bdev = dev->bdev;
5435 if (async)
5436 btrfs_schedule_bio(root, dev, rw, bio);
5437 else
5438 btrfsic_submit_bio(rw, bio);
5439 }
5440
5441 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5442 struct bio *first_bio, struct btrfs_device *dev,
5443 int dev_nr, int rw, int async)
5444 {
5445 struct bio_vec *bvec = first_bio->bi_io_vec;
5446 struct bio *bio;
5447 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5448 u64 physical = bbio->stripes[dev_nr].physical;
5449
5450 again:
5451 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5452 if (!bio)
5453 return -ENOMEM;
5454
5455 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5456 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5457 bvec->bv_offset) < bvec->bv_len) {
5458 u64 len = bio->bi_size;
5459
5460 atomic_inc(&bbio->stripes_pending);
5461 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5462 rw, async);
5463 physical += len;
5464 goto again;
5465 }
5466 bvec++;
5467 }
5468
5469 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5470 return 0;
5471 }
5472
5473 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5474 {
5475 atomic_inc(&bbio->error);
5476 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5477 bio->bi_private = bbio->private;
5478 bio->bi_end_io = bbio->end_io;
5479 btrfs_io_bio(bio)->mirror_num = bbio->mirror_num;
5480 bio->bi_sector = logical >> 9;
5481 kfree(bbio);
5482 bio_endio(bio, -EIO);
5483 }
5484 }
5485
5486 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5487 int mirror_num, int async_submit)
5488 {
5489 struct btrfs_device *dev;
5490 struct bio *first_bio = bio;
5491 u64 logical = (u64)bio->bi_sector << 9;
5492 u64 length = 0;
5493 u64 map_length;
5494 u64 *raid_map = NULL;
5495 int ret;
5496 int dev_nr = 0;
5497 int total_devs = 1;
5498 struct btrfs_bio *bbio = NULL;
5499
5500 length = bio->bi_size;
5501 map_length = length;
5502
5503 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5504 mirror_num, &raid_map);
5505 if (ret) /* -ENOMEM */
5506 return ret;
5507
5508 total_devs = bbio->num_stripes;
5509 bbio->orig_bio = first_bio;
5510 bbio->private = first_bio->bi_private;
5511 bbio->end_io = first_bio->bi_end_io;
5512 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5513
5514 if (raid_map) {
5515 /* In this case, map_length has been set to the length of
5516 a single stripe; not the whole write */
5517 if (rw & WRITE) {
5518 return raid56_parity_write(root, bio, bbio,
5519 raid_map, map_length);
5520 } else {
5521 return raid56_parity_recover(root, bio, bbio,
5522 raid_map, map_length,
5523 mirror_num);
5524 }
5525 }
5526
5527 if (map_length < length) {
5528 btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5529 logical, length, map_length);
5530 BUG();
5531 }
5532
5533 while (dev_nr < total_devs) {
5534 dev = bbio->stripes[dev_nr].dev;
5535 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5536 bbio_error(bbio, first_bio, logical);
5537 dev_nr++;
5538 continue;
5539 }
5540
5541 /*
5542 * Check and see if we're ok with this bio based on it's size
5543 * and offset with the given device.
5544 */
5545 if (!bio_size_ok(dev->bdev, first_bio,
5546 bbio->stripes[dev_nr].physical >> 9)) {
5547 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5548 dev_nr, rw, async_submit);
5549 BUG_ON(ret);
5550 dev_nr++;
5551 continue;
5552 }
5553
5554 if (dev_nr < total_devs - 1) {
5555 bio = btrfs_bio_clone(first_bio, GFP_NOFS);
5556 BUG_ON(!bio); /* -ENOMEM */
5557 } else {
5558 bio = first_bio;
5559 }
5560
5561 submit_stripe_bio(root, bbio, bio,
5562 bbio->stripes[dev_nr].physical, dev_nr, rw,
5563 async_submit);
5564 dev_nr++;
5565 }
5566 return 0;
5567 }
5568
5569 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5570 u8 *uuid, u8 *fsid)
5571 {
5572 struct btrfs_device *device;
5573 struct btrfs_fs_devices *cur_devices;
5574
5575 cur_devices = fs_info->fs_devices;
5576 while (cur_devices) {
5577 if (!fsid ||
5578 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5579 device = __find_device(&cur_devices->devices,
5580 devid, uuid);
5581 if (device)
5582 return device;
5583 }
5584 cur_devices = cur_devices->seed;
5585 }
5586 return NULL;
5587 }
5588
5589 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5590 u64 devid, u8 *dev_uuid)
5591 {
5592 struct btrfs_device *device;
5593 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5594
5595 device = btrfs_alloc_device(NULL, &devid, dev_uuid);
5596 if (IS_ERR(device))
5597 return NULL;
5598
5599 list_add(&device->dev_list, &fs_devices->devices);
5600 device->fs_devices = fs_devices;
5601 fs_devices->num_devices++;
5602
5603 device->missing = 1;
5604 fs_devices->missing_devices++;
5605
5606 return device;
5607 }
5608
5609 /**
5610 * btrfs_alloc_device - allocate struct btrfs_device
5611 * @fs_info: used only for generating a new devid, can be NULL if
5612 * devid is provided (i.e. @devid != NULL).
5613 * @devid: a pointer to devid for this device. If NULL a new devid
5614 * is generated.
5615 * @uuid: a pointer to UUID for this device. If NULL a new UUID
5616 * is generated.
5617 *
5618 * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR()
5619 * on error. Returned struct is not linked onto any lists and can be
5620 * destroyed with kfree() right away.
5621 */
5622 struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
5623 const u64 *devid,
5624 const u8 *uuid)
5625 {
5626 struct btrfs_device *dev;
5627 u64 tmp;
5628
5629 if (!devid && !fs_info) {
5630 WARN_ON(1);
5631 return ERR_PTR(-EINVAL);
5632 }
5633
5634 dev = __alloc_device();
5635 if (IS_ERR(dev))
5636 return dev;
5637
5638 if (devid)
5639 tmp = *devid;
5640 else {
5641 int ret;
5642
5643 ret = find_next_devid(fs_info, &tmp);
5644 if (ret) {
5645 kfree(dev);
5646 return ERR_PTR(ret);
5647 }
5648 }
5649 dev->devid = tmp;
5650
5651 if (uuid)
5652 memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE);
5653 else
5654 generate_random_uuid(dev->uuid);
5655
5656 dev->work.func = pending_bios_fn;
5657
5658 return dev;
5659 }
5660
5661 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5662 struct extent_buffer *leaf,
5663 struct btrfs_chunk *chunk)
5664 {
5665 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5666 struct map_lookup *map;
5667 struct extent_map *em;
5668 u64 logical;
5669 u64 length;
5670 u64 devid;
5671 u8 uuid[BTRFS_UUID_SIZE];
5672 int num_stripes;
5673 int ret;
5674 int i;
5675
5676 logical = key->offset;
5677 length = btrfs_chunk_length(leaf, chunk);
5678
5679 read_lock(&map_tree->map_tree.lock);
5680 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5681 read_unlock(&map_tree->map_tree.lock);
5682
5683 /* already mapped? */
5684 if (em && em->start <= logical && em->start + em->len > logical) {
5685 free_extent_map(em);
5686 return 0;
5687 } else if (em) {
5688 free_extent_map(em);
5689 }
5690
5691 em = alloc_extent_map();
5692 if (!em)
5693 return -ENOMEM;
5694 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5695 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5696 if (!map) {
5697 free_extent_map(em);
5698 return -ENOMEM;
5699 }
5700
5701 em->bdev = (struct block_device *)map;
5702 em->start = logical;
5703 em->len = length;
5704 em->orig_start = 0;
5705 em->block_start = 0;
5706 em->block_len = em->len;
5707
5708 map->num_stripes = num_stripes;
5709 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5710 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5711 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5712 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5713 map->type = btrfs_chunk_type(leaf, chunk);
5714 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5715 for (i = 0; i < num_stripes; i++) {
5716 map->stripes[i].physical =
5717 btrfs_stripe_offset_nr(leaf, chunk, i);
5718 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5719 read_extent_buffer(leaf, uuid, (unsigned long)
5720 btrfs_stripe_dev_uuid_nr(chunk, i),
5721 BTRFS_UUID_SIZE);
5722 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5723 uuid, NULL);
5724 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5725 kfree(map);
5726 free_extent_map(em);
5727 return -EIO;
5728 }
5729 if (!map->stripes[i].dev) {
5730 map->stripes[i].dev =
5731 add_missing_dev(root, devid, uuid);
5732 if (!map->stripes[i].dev) {
5733 kfree(map);
5734 free_extent_map(em);
5735 return -EIO;
5736 }
5737 }
5738 map->stripes[i].dev->in_fs_metadata = 1;
5739 }
5740
5741 write_lock(&map_tree->map_tree.lock);
5742 ret = add_extent_mapping(&map_tree->map_tree, em, 0);
5743 write_unlock(&map_tree->map_tree.lock);
5744 BUG_ON(ret); /* Tree corruption */
5745 free_extent_map(em);
5746
5747 return 0;
5748 }
5749
5750 static void fill_device_from_item(struct extent_buffer *leaf,
5751 struct btrfs_dev_item *dev_item,
5752 struct btrfs_device *device)
5753 {
5754 unsigned long ptr;
5755
5756 device->devid = btrfs_device_id(leaf, dev_item);
5757 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5758 device->total_bytes = device->disk_total_bytes;
5759 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5760 device->type = btrfs_device_type(leaf, dev_item);
5761 device->io_align = btrfs_device_io_align(leaf, dev_item);
5762 device->io_width = btrfs_device_io_width(leaf, dev_item);
5763 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5764 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5765 device->is_tgtdev_for_dev_replace = 0;
5766
5767 ptr = btrfs_device_uuid(dev_item);
5768 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5769 }
5770
5771 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5772 {
5773 struct btrfs_fs_devices *fs_devices;
5774 int ret;
5775
5776 BUG_ON(!mutex_is_locked(&uuid_mutex));
5777
5778 fs_devices = root->fs_info->fs_devices->seed;
5779 while (fs_devices) {
5780 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5781 ret = 0;
5782 goto out;
5783 }
5784 fs_devices = fs_devices->seed;
5785 }
5786
5787 fs_devices = find_fsid(fsid);
5788 if (!fs_devices) {
5789 ret = -ENOENT;
5790 goto out;
5791 }
5792
5793 fs_devices = clone_fs_devices(fs_devices);
5794 if (IS_ERR(fs_devices)) {
5795 ret = PTR_ERR(fs_devices);
5796 goto out;
5797 }
5798
5799 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5800 root->fs_info->bdev_holder);
5801 if (ret) {
5802 free_fs_devices(fs_devices);
5803 goto out;
5804 }
5805
5806 if (!fs_devices->seeding) {
5807 __btrfs_close_devices(fs_devices);
5808 free_fs_devices(fs_devices);
5809 ret = -EINVAL;
5810 goto out;
5811 }
5812
5813 fs_devices->seed = root->fs_info->fs_devices->seed;
5814 root->fs_info->fs_devices->seed = fs_devices;
5815 out:
5816 return ret;
5817 }
5818
5819 static int read_one_dev(struct btrfs_root *root,
5820 struct extent_buffer *leaf,
5821 struct btrfs_dev_item *dev_item)
5822 {
5823 struct btrfs_device *device;
5824 u64 devid;
5825 int ret;
5826 u8 fs_uuid[BTRFS_UUID_SIZE];
5827 u8 dev_uuid[BTRFS_UUID_SIZE];
5828
5829 devid = btrfs_device_id(leaf, dev_item);
5830 read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item),
5831 BTRFS_UUID_SIZE);
5832 read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
5833 BTRFS_UUID_SIZE);
5834
5835 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5836 ret = open_seed_devices(root, fs_uuid);
5837 if (ret && !btrfs_test_opt(root, DEGRADED))
5838 return ret;
5839 }
5840
5841 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5842 if (!device || !device->bdev) {
5843 if (!btrfs_test_opt(root, DEGRADED))
5844 return -EIO;
5845
5846 if (!device) {
5847 btrfs_warn(root->fs_info, "devid %llu missing", devid);
5848 device = add_missing_dev(root, devid, dev_uuid);
5849 if (!device)
5850 return -ENOMEM;
5851 } else if (!device->missing) {
5852 /*
5853 * this happens when a device that was properly setup
5854 * in the device info lists suddenly goes bad.
5855 * device->bdev is NULL, and so we have to set
5856 * device->missing to one here
5857 */
5858 root->fs_info->fs_devices->missing_devices++;
5859 device->missing = 1;
5860 }
5861 }
5862
5863 if (device->fs_devices != root->fs_info->fs_devices) {
5864 BUG_ON(device->writeable);
5865 if (device->generation !=
5866 btrfs_device_generation(leaf, dev_item))
5867 return -EINVAL;
5868 }
5869
5870 fill_device_from_item(leaf, dev_item, device);
5871 device->in_fs_metadata = 1;
5872 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5873 device->fs_devices->total_rw_bytes += device->total_bytes;
5874 spin_lock(&root->fs_info->free_chunk_lock);
5875 root->fs_info->free_chunk_space += device->total_bytes -
5876 device->bytes_used;
5877 spin_unlock(&root->fs_info->free_chunk_lock);
5878 }
5879 ret = 0;
5880 return ret;
5881 }
5882
5883 int btrfs_read_sys_array(struct btrfs_root *root)
5884 {
5885 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5886 struct extent_buffer *sb;
5887 struct btrfs_disk_key *disk_key;
5888 struct btrfs_chunk *chunk;
5889 u8 *ptr;
5890 unsigned long sb_ptr;
5891 int ret = 0;
5892 u32 num_stripes;
5893 u32 array_size;
5894 u32 len = 0;
5895 u32 cur;
5896 struct btrfs_key key;
5897
5898 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5899 BTRFS_SUPER_INFO_SIZE);
5900 if (!sb)
5901 return -ENOMEM;
5902 btrfs_set_buffer_uptodate(sb);
5903 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5904 /*
5905 * The sb extent buffer is artifical and just used to read the system array.
5906 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5907 * pages up-to-date when the page is larger: extent does not cover the
5908 * whole page and consequently check_page_uptodate does not find all
5909 * the page's extents up-to-date (the hole beyond sb),
5910 * write_extent_buffer then triggers a WARN_ON.
5911 *
5912 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5913 * but sb spans only this function. Add an explicit SetPageUptodate call
5914 * to silence the warning eg. on PowerPC 64.
5915 */
5916 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5917 SetPageUptodate(sb->pages[0]);
5918
5919 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5920 array_size = btrfs_super_sys_array_size(super_copy);
5921
5922 ptr = super_copy->sys_chunk_array;
5923 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5924 cur = 0;
5925
5926 while (cur < array_size) {
5927 disk_key = (struct btrfs_disk_key *)ptr;
5928 btrfs_disk_key_to_cpu(&key, disk_key);
5929
5930 len = sizeof(*disk_key); ptr += len;
5931 sb_ptr += len;
5932 cur += len;
5933
5934 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5935 chunk = (struct btrfs_chunk *)sb_ptr;
5936 ret = read_one_chunk(root, &key, sb, chunk);
5937 if (ret)
5938 break;
5939 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5940 len = btrfs_chunk_item_size(num_stripes);
5941 } else {
5942 ret = -EIO;
5943 break;
5944 }
5945 ptr += len;
5946 sb_ptr += len;
5947 cur += len;
5948 }
5949 free_extent_buffer(sb);
5950 return ret;
5951 }
5952
5953 int btrfs_read_chunk_tree(struct btrfs_root *root)
5954 {
5955 struct btrfs_path *path;
5956 struct extent_buffer *leaf;
5957 struct btrfs_key key;
5958 struct btrfs_key found_key;
5959 int ret;
5960 int slot;
5961
5962 root = root->fs_info->chunk_root;
5963
5964 path = btrfs_alloc_path();
5965 if (!path)
5966 return -ENOMEM;
5967
5968 mutex_lock(&uuid_mutex);
5969 lock_chunks(root);
5970
5971 /*
5972 * Read all device items, and then all the chunk items. All
5973 * device items are found before any chunk item (their object id
5974 * is smaller than the lowest possible object id for a chunk
5975 * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID).
5976 */
5977 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5978 key.offset = 0;
5979 key.type = 0;
5980 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5981 if (ret < 0)
5982 goto error;
5983 while (1) {
5984 leaf = path->nodes[0];
5985 slot = path->slots[0];
5986 if (slot >= btrfs_header_nritems(leaf)) {
5987 ret = btrfs_next_leaf(root, path);
5988 if (ret == 0)
5989 continue;
5990 if (ret < 0)
5991 goto error;
5992 break;
5993 }
5994 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5995 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
5996 struct btrfs_dev_item *dev_item;
5997 dev_item = btrfs_item_ptr(leaf, slot,
5998 struct btrfs_dev_item);
5999 ret = read_one_dev(root, leaf, dev_item);
6000 if (ret)
6001 goto error;
6002 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
6003 struct btrfs_chunk *chunk;
6004 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
6005 ret = read_one_chunk(root, &found_key, leaf, chunk);
6006 if (ret)
6007 goto error;
6008 }
6009 path->slots[0]++;
6010 }
6011 ret = 0;
6012 error:
6013 unlock_chunks(root);
6014 mutex_unlock(&uuid_mutex);
6015
6016 btrfs_free_path(path);
6017 return ret;
6018 }
6019
6020 void btrfs_init_devices_late(struct btrfs_fs_info *fs_info)
6021 {
6022 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6023 struct btrfs_device *device;
6024
6025 mutex_lock(&fs_devices->device_list_mutex);
6026 list_for_each_entry(device, &fs_devices->devices, dev_list)
6027 device->dev_root = fs_info->dev_root;
6028 mutex_unlock(&fs_devices->device_list_mutex);
6029 }
6030
6031 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
6032 {
6033 int i;
6034
6035 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6036 btrfs_dev_stat_reset(dev, i);
6037 }
6038
6039 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
6040 {
6041 struct btrfs_key key;
6042 struct btrfs_key found_key;
6043 struct btrfs_root *dev_root = fs_info->dev_root;
6044 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6045 struct extent_buffer *eb;
6046 int slot;
6047 int ret = 0;
6048 struct btrfs_device *device;
6049 struct btrfs_path *path = NULL;
6050 int i;
6051
6052 path = btrfs_alloc_path();
6053 if (!path) {
6054 ret = -ENOMEM;
6055 goto out;
6056 }
6057
6058 mutex_lock(&fs_devices->device_list_mutex);
6059 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6060 int item_size;
6061 struct btrfs_dev_stats_item *ptr;
6062
6063 key.objectid = 0;
6064 key.type = BTRFS_DEV_STATS_KEY;
6065 key.offset = device->devid;
6066 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
6067 if (ret) {
6068 __btrfs_reset_dev_stats(device);
6069 device->dev_stats_valid = 1;
6070 btrfs_release_path(path);
6071 continue;
6072 }
6073 slot = path->slots[0];
6074 eb = path->nodes[0];
6075 btrfs_item_key_to_cpu(eb, &found_key, slot);
6076 item_size = btrfs_item_size_nr(eb, slot);
6077
6078 ptr = btrfs_item_ptr(eb, slot,
6079 struct btrfs_dev_stats_item);
6080
6081 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6082 if (item_size >= (1 + i) * sizeof(__le64))
6083 btrfs_dev_stat_set(device, i,
6084 btrfs_dev_stats_value(eb, ptr, i));
6085 else
6086 btrfs_dev_stat_reset(device, i);
6087 }
6088
6089 device->dev_stats_valid = 1;
6090 btrfs_dev_stat_print_on_load(device);
6091 btrfs_release_path(path);
6092 }
6093 mutex_unlock(&fs_devices->device_list_mutex);
6094
6095 out:
6096 btrfs_free_path(path);
6097 return ret < 0 ? ret : 0;
6098 }
6099
6100 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
6101 struct btrfs_root *dev_root,
6102 struct btrfs_device *device)
6103 {
6104 struct btrfs_path *path;
6105 struct btrfs_key key;
6106 struct extent_buffer *eb;
6107 struct btrfs_dev_stats_item *ptr;
6108 int ret;
6109 int i;
6110
6111 key.objectid = 0;
6112 key.type = BTRFS_DEV_STATS_KEY;
6113 key.offset = device->devid;
6114
6115 path = btrfs_alloc_path();
6116 BUG_ON(!path);
6117 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
6118 if (ret < 0) {
6119 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
6120 ret, rcu_str_deref(device->name));
6121 goto out;
6122 }
6123
6124 if (ret == 0 &&
6125 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
6126 /* need to delete old one and insert a new one */
6127 ret = btrfs_del_item(trans, dev_root, path);
6128 if (ret != 0) {
6129 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
6130 rcu_str_deref(device->name), ret);
6131 goto out;
6132 }
6133 ret = 1;
6134 }
6135
6136 if (ret == 1) {
6137 /* need to insert a new item */
6138 btrfs_release_path(path);
6139 ret = btrfs_insert_empty_item(trans, dev_root, path,
6140 &key, sizeof(*ptr));
6141 if (ret < 0) {
6142 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
6143 rcu_str_deref(device->name), ret);
6144 goto out;
6145 }
6146 }
6147
6148 eb = path->nodes[0];
6149 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
6150 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6151 btrfs_set_dev_stats_value(eb, ptr, i,
6152 btrfs_dev_stat_read(device, i));
6153 btrfs_mark_buffer_dirty(eb);
6154
6155 out:
6156 btrfs_free_path(path);
6157 return ret;
6158 }
6159
6160 /*
6161 * called from commit_transaction. Writes all changed device stats to disk.
6162 */
6163 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
6164 struct btrfs_fs_info *fs_info)
6165 {
6166 struct btrfs_root *dev_root = fs_info->dev_root;
6167 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
6168 struct btrfs_device *device;
6169 int ret = 0;
6170
6171 mutex_lock(&fs_devices->device_list_mutex);
6172 list_for_each_entry(device, &fs_devices->devices, dev_list) {
6173 if (!device->dev_stats_valid || !device->dev_stats_dirty)
6174 continue;
6175
6176 ret = update_dev_stat_item(trans, dev_root, device);
6177 if (!ret)
6178 device->dev_stats_dirty = 0;
6179 }
6180 mutex_unlock(&fs_devices->device_list_mutex);
6181
6182 return ret;
6183 }
6184
6185 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
6186 {
6187 btrfs_dev_stat_inc(dev, index);
6188 btrfs_dev_stat_print_on_error(dev);
6189 }
6190
6191 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
6192 {
6193 if (!dev->dev_stats_valid)
6194 return;
6195 printk_ratelimited_in_rcu(KERN_ERR
6196 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6197 rcu_str_deref(dev->name),
6198 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6199 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6200 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6201 btrfs_dev_stat_read(dev,
6202 BTRFS_DEV_STAT_CORRUPTION_ERRS),
6203 btrfs_dev_stat_read(dev,
6204 BTRFS_DEV_STAT_GENERATION_ERRS));
6205 }
6206
6207 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
6208 {
6209 int i;
6210
6211 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6212 if (btrfs_dev_stat_read(dev, i) != 0)
6213 break;
6214 if (i == BTRFS_DEV_STAT_VALUES_MAX)
6215 return; /* all values == 0, suppress message */
6216
6217 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
6218 rcu_str_deref(dev->name),
6219 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
6220 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
6221 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
6222 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
6223 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
6224 }
6225
6226 int btrfs_get_dev_stats(struct btrfs_root *root,
6227 struct btrfs_ioctl_get_dev_stats *stats)
6228 {
6229 struct btrfs_device *dev;
6230 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
6231 int i;
6232
6233 mutex_lock(&fs_devices->device_list_mutex);
6234 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
6235 mutex_unlock(&fs_devices->device_list_mutex);
6236
6237 if (!dev) {
6238 printk(KERN_WARNING
6239 "btrfs: get dev_stats failed, device not found\n");
6240 return -ENODEV;
6241 } else if (!dev->dev_stats_valid) {
6242 printk(KERN_WARNING
6243 "btrfs: get dev_stats failed, not yet valid\n");
6244 return -ENODEV;
6245 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
6246 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6247 if (stats->nr_items > i)
6248 stats->values[i] =
6249 btrfs_dev_stat_read_and_reset(dev, i);
6250 else
6251 btrfs_dev_stat_reset(dev, i);
6252 }
6253 } else {
6254 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6255 if (stats->nr_items > i)
6256 stats->values[i] = btrfs_dev_stat_read(dev, i);
6257 }
6258 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
6259 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
6260 return 0;
6261 }
6262
6263 int btrfs_scratch_superblock(struct btrfs_device *device)
6264 {
6265 struct buffer_head *bh;
6266 struct btrfs_super_block *disk_super;
6267
6268 bh = btrfs_read_dev_super(device->bdev);
6269 if (!bh)
6270 return -EINVAL;
6271 disk_super = (struct btrfs_super_block *)bh->b_data;
6272
6273 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
6274 set_buffer_dirty(bh);
6275 sync_dirty_buffer(bh);
6276 brelse(bh);
6277
6278 return 0;
6279 }
Linux kernel - Deliverables
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