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btrfs: Init io_lock after cloning btrfs device struct
[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 <asm/div64.h>
30 #include "compat.h"
31 #include "ctree.h"
32 #include "extent_map.h"
33 #include "disk-io.h"
34 #include "transaction.h"
35 #include "print-tree.h"
36 #include "volumes.h"
37 #include "raid56.h"
38 #include "async-thread.h"
39 #include "check-integrity.h"
40 #include "rcu-string.h"
41 #include "math.h"
42 #include "dev-replace.h"
43
44 static int init_first_rw_device(struct btrfs_trans_handle *trans,
45 struct btrfs_root *root,
46 struct btrfs_device *device);
47 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
48 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
49 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
50
51 static DEFINE_MUTEX(uuid_mutex);
52 static LIST_HEAD(fs_uuids);
53
54 static void lock_chunks(struct btrfs_root *root)
55 {
56 mutex_lock(&root->fs_info->chunk_mutex);
57 }
58
59 static void unlock_chunks(struct btrfs_root *root)
60 {
61 mutex_unlock(&root->fs_info->chunk_mutex);
62 }
63
64 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
65 {
66 struct btrfs_device *device;
67 WARN_ON(fs_devices->opened);
68 while (!list_empty(&fs_devices->devices)) {
69 device = list_entry(fs_devices->devices.next,
70 struct btrfs_device, dev_list);
71 list_del(&device->dev_list);
72 rcu_string_free(device->name);
73 kfree(device);
74 }
75 kfree(fs_devices);
76 }
77
78 static void btrfs_kobject_uevent(struct block_device *bdev,
79 enum kobject_action action)
80 {
81 int ret;
82
83 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
84 if (ret)
85 pr_warn("Sending event '%d' to kobject: '%s' (%p): failed\n",
86 action,
87 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
88 &disk_to_dev(bdev->bd_disk)->kobj);
89 }
90
91 void btrfs_cleanup_fs_uuids(void)
92 {
93 struct btrfs_fs_devices *fs_devices;
94
95 while (!list_empty(&fs_uuids)) {
96 fs_devices = list_entry(fs_uuids.next,
97 struct btrfs_fs_devices, list);
98 list_del(&fs_devices->list);
99 free_fs_devices(fs_devices);
100 }
101 }
102
103 static noinline struct btrfs_device *__find_device(struct list_head *head,
104 u64 devid, u8 *uuid)
105 {
106 struct btrfs_device *dev;
107
108 list_for_each_entry(dev, head, dev_list) {
109 if (dev->devid == devid &&
110 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
111 return dev;
112 }
113 }
114 return NULL;
115 }
116
117 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
118 {
119 struct btrfs_fs_devices *fs_devices;
120
121 list_for_each_entry(fs_devices, &fs_uuids, list) {
122 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
123 return fs_devices;
124 }
125 return NULL;
126 }
127
128 static int
129 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
130 int flush, struct block_device **bdev,
131 struct buffer_head **bh)
132 {
133 int ret;
134
135 *bdev = blkdev_get_by_path(device_path, flags, holder);
136
137 if (IS_ERR(*bdev)) {
138 ret = PTR_ERR(*bdev);
139 printk(KERN_INFO "btrfs: open %s failed\n", device_path);
140 goto error;
141 }
142
143 if (flush)
144 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
145 ret = set_blocksize(*bdev, 4096);
146 if (ret) {
147 blkdev_put(*bdev, flags);
148 goto error;
149 }
150 invalidate_bdev(*bdev);
151 *bh = btrfs_read_dev_super(*bdev);
152 if (!*bh) {
153 ret = -EINVAL;
154 blkdev_put(*bdev, flags);
155 goto error;
156 }
157
158 return 0;
159
160 error:
161 *bdev = NULL;
162 *bh = NULL;
163 return ret;
164 }
165
166 static void requeue_list(struct btrfs_pending_bios *pending_bios,
167 struct bio *head, struct bio *tail)
168 {
169
170 struct bio *old_head;
171
172 old_head = pending_bios->head;
173 pending_bios->head = head;
174 if (pending_bios->tail)
175 tail->bi_next = old_head;
176 else
177 pending_bios->tail = tail;
178 }
179
180 /*
181 * we try to collect pending bios for a device so we don't get a large
182 * number of procs sending bios down to the same device. This greatly
183 * improves the schedulers ability to collect and merge the bios.
184 *
185 * But, it also turns into a long list of bios to process and that is sure
186 * to eventually make the worker thread block. The solution here is to
187 * make some progress and then put this work struct back at the end of
188 * the list if the block device is congested. This way, multiple devices
189 * can make progress from a single worker thread.
190 */
191 static noinline void run_scheduled_bios(struct btrfs_device *device)
192 {
193 struct bio *pending;
194 struct backing_dev_info *bdi;
195 struct btrfs_fs_info *fs_info;
196 struct btrfs_pending_bios *pending_bios;
197 struct bio *tail;
198 struct bio *cur;
199 int again = 0;
200 unsigned long num_run;
201 unsigned long batch_run = 0;
202 unsigned long limit;
203 unsigned long last_waited = 0;
204 int force_reg = 0;
205 int sync_pending = 0;
206 struct blk_plug plug;
207
208 /*
209 * this function runs all the bios we've collected for
210 * a particular device. We don't want to wander off to
211 * another device without first sending all of these down.
212 * So, setup a plug here and finish it off before we return
213 */
214 blk_start_plug(&plug);
215
216 bdi = blk_get_backing_dev_info(device->bdev);
217 fs_info = device->dev_root->fs_info;
218 limit = btrfs_async_submit_limit(fs_info);
219 limit = limit * 2 / 3;
220
221 loop:
222 spin_lock(&device->io_lock);
223
224 loop_lock:
225 num_run = 0;
226
227 /* take all the bios off the list at once and process them
228 * later on (without the lock held). But, remember the
229 * tail and other pointers so the bios can be properly reinserted
230 * into the list if we hit congestion
231 */
232 if (!force_reg && device->pending_sync_bios.head) {
233 pending_bios = &device->pending_sync_bios;
234 force_reg = 1;
235 } else {
236 pending_bios = &device->pending_bios;
237 force_reg = 0;
238 }
239
240 pending = pending_bios->head;
241 tail = pending_bios->tail;
242 WARN_ON(pending && !tail);
243
244 /*
245 * if pending was null this time around, no bios need processing
246 * at all and we can stop. Otherwise it'll loop back up again
247 * and do an additional check so no bios are missed.
248 *
249 * device->running_pending is used to synchronize with the
250 * schedule_bio code.
251 */
252 if (device->pending_sync_bios.head == NULL &&
253 device->pending_bios.head == NULL) {
254 again = 0;
255 device->running_pending = 0;
256 } else {
257 again = 1;
258 device->running_pending = 1;
259 }
260
261 pending_bios->head = NULL;
262 pending_bios->tail = NULL;
263
264 spin_unlock(&device->io_lock);
265
266 while (pending) {
267
268 rmb();
269 /* we want to work on both lists, but do more bios on the
270 * sync list than the regular list
271 */
272 if ((num_run > 32 &&
273 pending_bios != &device->pending_sync_bios &&
274 device->pending_sync_bios.head) ||
275 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
276 device->pending_bios.head)) {
277 spin_lock(&device->io_lock);
278 requeue_list(pending_bios, pending, tail);
279 goto loop_lock;
280 }
281
282 cur = pending;
283 pending = pending->bi_next;
284 cur->bi_next = NULL;
285
286 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
287 waitqueue_active(&fs_info->async_submit_wait))
288 wake_up(&fs_info->async_submit_wait);
289
290 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
291
292 /*
293 * if we're doing the sync list, record that our
294 * plug has some sync requests on it
295 *
296 * If we're doing the regular list and there are
297 * sync requests sitting around, unplug before
298 * we add more
299 */
300 if (pending_bios == &device->pending_sync_bios) {
301 sync_pending = 1;
302 } else if (sync_pending) {
303 blk_finish_plug(&plug);
304 blk_start_plug(&plug);
305 sync_pending = 0;
306 }
307
308 btrfsic_submit_bio(cur->bi_rw, cur);
309 num_run++;
310 batch_run++;
311 if (need_resched())
312 cond_resched();
313
314 /*
315 * we made progress, there is more work to do and the bdi
316 * is now congested. Back off and let other work structs
317 * run instead
318 */
319 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
320 fs_info->fs_devices->open_devices > 1) {
321 struct io_context *ioc;
322
323 ioc = current->io_context;
324
325 /*
326 * the main goal here is that we don't want to
327 * block if we're going to be able to submit
328 * more requests without blocking.
329 *
330 * This code does two great things, it pokes into
331 * the elevator code from a filesystem _and_
332 * it makes assumptions about how batching works.
333 */
334 if (ioc && ioc->nr_batch_requests > 0 &&
335 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
336 (last_waited == 0 ||
337 ioc->last_waited == last_waited)) {
338 /*
339 * we want to go through our batch of
340 * requests and stop. So, we copy out
341 * the ioc->last_waited time and test
342 * against it before looping
343 */
344 last_waited = ioc->last_waited;
345 if (need_resched())
346 cond_resched();
347 continue;
348 }
349 spin_lock(&device->io_lock);
350 requeue_list(pending_bios, pending, tail);
351 device->running_pending = 1;
352
353 spin_unlock(&device->io_lock);
354 btrfs_requeue_work(&device->work);
355 goto done;
356 }
357 /* unplug every 64 requests just for good measure */
358 if (batch_run % 64 == 0) {
359 blk_finish_plug(&plug);
360 blk_start_plug(&plug);
361 sync_pending = 0;
362 }
363 }
364
365 cond_resched();
366 if (again)
367 goto loop;
368
369 spin_lock(&device->io_lock);
370 if (device->pending_bios.head || device->pending_sync_bios.head)
371 goto loop_lock;
372 spin_unlock(&device->io_lock);
373
374 done:
375 blk_finish_plug(&plug);
376 }
377
378 static void pending_bios_fn(struct btrfs_work *work)
379 {
380 struct btrfs_device *device;
381
382 device = container_of(work, struct btrfs_device, work);
383 run_scheduled_bios(device);
384 }
385
386 static noinline int device_list_add(const char *path,
387 struct btrfs_super_block *disk_super,
388 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
389 {
390 struct btrfs_device *device;
391 struct btrfs_fs_devices *fs_devices;
392 struct rcu_string *name;
393 u64 found_transid = btrfs_super_generation(disk_super);
394
395 fs_devices = find_fsid(disk_super->fsid);
396 if (!fs_devices) {
397 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
398 if (!fs_devices)
399 return -ENOMEM;
400 INIT_LIST_HEAD(&fs_devices->devices);
401 INIT_LIST_HEAD(&fs_devices->alloc_list);
402 list_add(&fs_devices->list, &fs_uuids);
403 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
404 fs_devices->latest_devid = devid;
405 fs_devices->latest_trans = found_transid;
406 mutex_init(&fs_devices->device_list_mutex);
407 device = NULL;
408 } else {
409 device = __find_device(&fs_devices->devices, devid,
410 disk_super->dev_item.uuid);
411 }
412 if (!device) {
413 if (fs_devices->opened)
414 return -EBUSY;
415
416 device = kzalloc(sizeof(*device), GFP_NOFS);
417 if (!device) {
418 /* we can safely leave the fs_devices entry around */
419 return -ENOMEM;
420 }
421 device->devid = devid;
422 device->dev_stats_valid = 0;
423 device->work.func = pending_bios_fn;
424 memcpy(device->uuid, disk_super->dev_item.uuid,
425 BTRFS_UUID_SIZE);
426 spin_lock_init(&device->io_lock);
427
428 name = rcu_string_strdup(path, GFP_NOFS);
429 if (!name) {
430 kfree(device);
431 return -ENOMEM;
432 }
433 rcu_assign_pointer(device->name, name);
434 INIT_LIST_HEAD(&device->dev_alloc_list);
435
436 /* init readahead state */
437 spin_lock_init(&device->reada_lock);
438 device->reada_curr_zone = NULL;
439 atomic_set(&device->reada_in_flight, 0);
440 device->reada_next = 0;
441 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
442 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
443
444 mutex_lock(&fs_devices->device_list_mutex);
445 list_add_rcu(&device->dev_list, &fs_devices->devices);
446 mutex_unlock(&fs_devices->device_list_mutex);
447
448 device->fs_devices = fs_devices;
449 fs_devices->num_devices++;
450 } else if (!device->name || strcmp(device->name->str, path)) {
451 name = rcu_string_strdup(path, GFP_NOFS);
452 if (!name)
453 return -ENOMEM;
454 rcu_string_free(device->name);
455 rcu_assign_pointer(device->name, name);
456 if (device->missing) {
457 fs_devices->missing_devices--;
458 device->missing = 0;
459 }
460 }
461
462 if (found_transid > fs_devices->latest_trans) {
463 fs_devices->latest_devid = devid;
464 fs_devices->latest_trans = found_transid;
465 }
466 *fs_devices_ret = fs_devices;
467 return 0;
468 }
469
470 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
471 {
472 struct btrfs_fs_devices *fs_devices;
473 struct btrfs_device *device;
474 struct btrfs_device *orig_dev;
475
476 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
477 if (!fs_devices)
478 return ERR_PTR(-ENOMEM);
479
480 INIT_LIST_HEAD(&fs_devices->devices);
481 INIT_LIST_HEAD(&fs_devices->alloc_list);
482 INIT_LIST_HEAD(&fs_devices->list);
483 mutex_init(&fs_devices->device_list_mutex);
484 fs_devices->latest_devid = orig->latest_devid;
485 fs_devices->latest_trans = orig->latest_trans;
486 fs_devices->total_devices = orig->total_devices;
487 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
488
489 /* We have held the volume lock, it is safe to get the devices. */
490 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
491 struct rcu_string *name;
492
493 device = kzalloc(sizeof(*device), GFP_NOFS);
494 if (!device)
495 goto error;
496
497 /*
498 * This is ok to do without rcu read locked because we hold the
499 * uuid mutex so nothing we touch in here is going to disappear.
500 */
501 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
502 if (!name) {
503 kfree(device);
504 goto error;
505 }
506 rcu_assign_pointer(device->name, name);
507
508 device->devid = orig_dev->devid;
509 device->work.func = pending_bios_fn;
510 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
511 spin_lock_init(&device->io_lock);
512 INIT_LIST_HEAD(&device->dev_list);
513 INIT_LIST_HEAD(&device->dev_alloc_list);
514
515 list_add(&device->dev_list, &fs_devices->devices);
516 device->fs_devices = fs_devices;
517 fs_devices->num_devices++;
518 }
519 return fs_devices;
520 error:
521 free_fs_devices(fs_devices);
522 return ERR_PTR(-ENOMEM);
523 }
524
525 void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
526 struct btrfs_fs_devices *fs_devices, int step)
527 {
528 struct btrfs_device *device, *next;
529
530 struct block_device *latest_bdev = NULL;
531 u64 latest_devid = 0;
532 u64 latest_transid = 0;
533
534 mutex_lock(&uuid_mutex);
535 again:
536 /* This is the initialized path, it is safe to release the devices. */
537 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
538 if (device->in_fs_metadata) {
539 if (!device->is_tgtdev_for_dev_replace &&
540 (!latest_transid ||
541 device->generation > latest_transid)) {
542 latest_devid = device->devid;
543 latest_transid = device->generation;
544 latest_bdev = device->bdev;
545 }
546 continue;
547 }
548
549 if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
550 /*
551 * In the first step, keep the device which has
552 * the correct fsid and the devid that is used
553 * for the dev_replace procedure.
554 * In the second step, the dev_replace state is
555 * read from the device tree and it is known
556 * whether the procedure is really active or
557 * not, which means whether this device is
558 * used or whether it should be removed.
559 */
560 if (step == 0 || device->is_tgtdev_for_dev_replace) {
561 continue;
562 }
563 }
564 if (device->bdev) {
565 blkdev_put(device->bdev, device->mode);
566 device->bdev = NULL;
567 fs_devices->open_devices--;
568 }
569 if (device->writeable) {
570 list_del_init(&device->dev_alloc_list);
571 device->writeable = 0;
572 if (!device->is_tgtdev_for_dev_replace)
573 fs_devices->rw_devices--;
574 }
575 list_del_init(&device->dev_list);
576 fs_devices->num_devices--;
577 rcu_string_free(device->name);
578 kfree(device);
579 }
580
581 if (fs_devices->seed) {
582 fs_devices = fs_devices->seed;
583 goto again;
584 }
585
586 fs_devices->latest_bdev = latest_bdev;
587 fs_devices->latest_devid = latest_devid;
588 fs_devices->latest_trans = latest_transid;
589
590 mutex_unlock(&uuid_mutex);
591 }
592
593 static void __free_device(struct work_struct *work)
594 {
595 struct btrfs_device *device;
596
597 device = container_of(work, struct btrfs_device, rcu_work);
598
599 if (device->bdev)
600 blkdev_put(device->bdev, device->mode);
601
602 rcu_string_free(device->name);
603 kfree(device);
604 }
605
606 static void free_device(struct rcu_head *head)
607 {
608 struct btrfs_device *device;
609
610 device = container_of(head, struct btrfs_device, rcu);
611
612 INIT_WORK(&device->rcu_work, __free_device);
613 schedule_work(&device->rcu_work);
614 }
615
616 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
617 {
618 struct btrfs_device *device;
619
620 if (--fs_devices->opened > 0)
621 return 0;
622
623 mutex_lock(&fs_devices->device_list_mutex);
624 list_for_each_entry(device, &fs_devices->devices, dev_list) {
625 struct btrfs_device *new_device;
626 struct rcu_string *name;
627
628 if (device->bdev)
629 fs_devices->open_devices--;
630
631 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
632 list_del_init(&device->dev_alloc_list);
633 fs_devices->rw_devices--;
634 }
635
636 if (device->can_discard)
637 fs_devices->num_can_discard--;
638
639 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
640 BUG_ON(!new_device); /* -ENOMEM */
641 memcpy(new_device, device, sizeof(*new_device));
642
643 /* Safe because we are under uuid_mutex */
644 if (device->name) {
645 name = rcu_string_strdup(device->name->str, GFP_NOFS);
646 BUG_ON(device->name && !name); /* -ENOMEM */
647 rcu_assign_pointer(new_device->name, name);
648 }
649 new_device->bdev = NULL;
650 new_device->writeable = 0;
651 new_device->in_fs_metadata = 0;
652 new_device->can_discard = 0;
653 spin_lock_init(&new_device->io_lock);
654 list_replace_rcu(&device->dev_list, &new_device->dev_list);
655
656 call_rcu(&device->rcu, free_device);
657 }
658 mutex_unlock(&fs_devices->device_list_mutex);
659
660 WARN_ON(fs_devices->open_devices);
661 WARN_ON(fs_devices->rw_devices);
662 fs_devices->opened = 0;
663 fs_devices->seeding = 0;
664
665 return 0;
666 }
667
668 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
669 {
670 struct btrfs_fs_devices *seed_devices = NULL;
671 int ret;
672
673 mutex_lock(&uuid_mutex);
674 ret = __btrfs_close_devices(fs_devices);
675 if (!fs_devices->opened) {
676 seed_devices = fs_devices->seed;
677 fs_devices->seed = NULL;
678 }
679 mutex_unlock(&uuid_mutex);
680
681 while (seed_devices) {
682 fs_devices = seed_devices;
683 seed_devices = fs_devices->seed;
684 __btrfs_close_devices(fs_devices);
685 free_fs_devices(fs_devices);
686 }
687 return ret;
688 }
689
690 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
691 fmode_t flags, void *holder)
692 {
693 struct request_queue *q;
694 struct block_device *bdev;
695 struct list_head *head = &fs_devices->devices;
696 struct btrfs_device *device;
697 struct block_device *latest_bdev = NULL;
698 struct buffer_head *bh;
699 struct btrfs_super_block *disk_super;
700 u64 latest_devid = 0;
701 u64 latest_transid = 0;
702 u64 devid;
703 int seeding = 1;
704 int ret = 0;
705
706 flags |= FMODE_EXCL;
707
708 list_for_each_entry(device, head, dev_list) {
709 if (device->bdev)
710 continue;
711 if (!device->name)
712 continue;
713
714 ret = btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
715 &bdev, &bh);
716 if (ret)
717 continue;
718
719 disk_super = (struct btrfs_super_block *)bh->b_data;
720 devid = btrfs_stack_device_id(&disk_super->dev_item);
721 if (devid != device->devid)
722 goto error_brelse;
723
724 if (memcmp(device->uuid, disk_super->dev_item.uuid,
725 BTRFS_UUID_SIZE))
726 goto error_brelse;
727
728 device->generation = btrfs_super_generation(disk_super);
729 if (!latest_transid || device->generation > latest_transid) {
730 latest_devid = devid;
731 latest_transid = device->generation;
732 latest_bdev = bdev;
733 }
734
735 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
736 device->writeable = 0;
737 } else {
738 device->writeable = !bdev_read_only(bdev);
739 seeding = 0;
740 }
741
742 q = bdev_get_queue(bdev);
743 if (blk_queue_discard(q)) {
744 device->can_discard = 1;
745 fs_devices->num_can_discard++;
746 }
747
748 device->bdev = bdev;
749 device->in_fs_metadata = 0;
750 device->mode = flags;
751
752 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
753 fs_devices->rotating = 1;
754
755 fs_devices->open_devices++;
756 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
757 fs_devices->rw_devices++;
758 list_add(&device->dev_alloc_list,
759 &fs_devices->alloc_list);
760 }
761 brelse(bh);
762 continue;
763
764 error_brelse:
765 brelse(bh);
766 blkdev_put(bdev, flags);
767 continue;
768 }
769 if (fs_devices->open_devices == 0) {
770 ret = -EINVAL;
771 goto out;
772 }
773 fs_devices->seeding = seeding;
774 fs_devices->opened = 1;
775 fs_devices->latest_bdev = latest_bdev;
776 fs_devices->latest_devid = latest_devid;
777 fs_devices->latest_trans = latest_transid;
778 fs_devices->total_rw_bytes = 0;
779 out:
780 return ret;
781 }
782
783 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
784 fmode_t flags, void *holder)
785 {
786 int ret;
787
788 mutex_lock(&uuid_mutex);
789 if (fs_devices->opened) {
790 fs_devices->opened++;
791 ret = 0;
792 } else {
793 ret = __btrfs_open_devices(fs_devices, flags, holder);
794 }
795 mutex_unlock(&uuid_mutex);
796 return ret;
797 }
798
799 /*
800 * Look for a btrfs signature on a device. This may be called out of the mount path
801 * and we are not allowed to call set_blocksize during the scan. The superblock
802 * is read via pagecache
803 */
804 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
805 struct btrfs_fs_devices **fs_devices_ret)
806 {
807 struct btrfs_super_block *disk_super;
808 struct block_device *bdev;
809 struct page *page;
810 void *p;
811 int ret = -EINVAL;
812 u64 devid;
813 u64 transid;
814 u64 total_devices;
815 u64 bytenr;
816 pgoff_t index;
817
818 /*
819 * we would like to check all the supers, but that would make
820 * a btrfs mount succeed after a mkfs from a different FS.
821 * So, we need to add a special mount option to scan for
822 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
823 */
824 bytenr = btrfs_sb_offset(0);
825 flags |= FMODE_EXCL;
826 mutex_lock(&uuid_mutex);
827
828 bdev = blkdev_get_by_path(path, flags, holder);
829
830 if (IS_ERR(bdev)) {
831 ret = PTR_ERR(bdev);
832 printk(KERN_INFO "btrfs: open %s failed\n", path);
833 goto error;
834 }
835
836 /* make sure our super fits in the device */
837 if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
838 goto error_bdev_put;
839
840 /* make sure our super fits in the page */
841 if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
842 goto error_bdev_put;
843
844 /* make sure our super doesn't straddle pages on disk */
845 index = bytenr >> PAGE_CACHE_SHIFT;
846 if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
847 goto error_bdev_put;
848
849 /* pull in the page with our super */
850 page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
851 index, GFP_NOFS);
852
853 if (IS_ERR_OR_NULL(page))
854 goto error_bdev_put;
855
856 p = kmap(page);
857
858 /* align our pointer to the offset of the super block */
859 disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
860
861 if (btrfs_super_bytenr(disk_super) != bytenr ||
862 disk_super->magic != cpu_to_le64(BTRFS_MAGIC))
863 goto error_unmap;
864
865 devid = btrfs_stack_device_id(&disk_super->dev_item);
866 transid = btrfs_super_generation(disk_super);
867 total_devices = btrfs_super_num_devices(disk_super);
868
869 if (disk_super->label[0]) {
870 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
871 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
872 printk(KERN_INFO "device label %s ", disk_super->label);
873 } else {
874 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
875 }
876
877 printk(KERN_CONT "devid %llu transid %llu %s\n",
878 (unsigned long long)devid, (unsigned long long)transid, path);
879
880 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
881 if (!ret && fs_devices_ret)
882 (*fs_devices_ret)->total_devices = total_devices;
883
884 error_unmap:
885 kunmap(page);
886 page_cache_release(page);
887
888 error_bdev_put:
889 blkdev_put(bdev, flags);
890 error:
891 mutex_unlock(&uuid_mutex);
892 return ret;
893 }
894
895 /* helper to account the used device space in the range */
896 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
897 u64 end, u64 *length)
898 {
899 struct btrfs_key key;
900 struct btrfs_root *root = device->dev_root;
901 struct btrfs_dev_extent *dev_extent;
902 struct btrfs_path *path;
903 u64 extent_end;
904 int ret;
905 int slot;
906 struct extent_buffer *l;
907
908 *length = 0;
909
910 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
911 return 0;
912
913 path = btrfs_alloc_path();
914 if (!path)
915 return -ENOMEM;
916 path->reada = 2;
917
918 key.objectid = device->devid;
919 key.offset = start;
920 key.type = BTRFS_DEV_EXTENT_KEY;
921
922 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
923 if (ret < 0)
924 goto out;
925 if (ret > 0) {
926 ret = btrfs_previous_item(root, path, key.objectid, key.type);
927 if (ret < 0)
928 goto out;
929 }
930
931 while (1) {
932 l = path->nodes[0];
933 slot = path->slots[0];
934 if (slot >= btrfs_header_nritems(l)) {
935 ret = btrfs_next_leaf(root, path);
936 if (ret == 0)
937 continue;
938 if (ret < 0)
939 goto out;
940
941 break;
942 }
943 btrfs_item_key_to_cpu(l, &key, slot);
944
945 if (key.objectid < device->devid)
946 goto next;
947
948 if (key.objectid > device->devid)
949 break;
950
951 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
952 goto next;
953
954 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
955 extent_end = key.offset + btrfs_dev_extent_length(l,
956 dev_extent);
957 if (key.offset <= start && extent_end > end) {
958 *length = end - start + 1;
959 break;
960 } else if (key.offset <= start && extent_end > start)
961 *length += extent_end - start;
962 else if (key.offset > start && extent_end <= end)
963 *length += extent_end - key.offset;
964 else if (key.offset > start && key.offset <= end) {
965 *length += end - key.offset + 1;
966 break;
967 } else if (key.offset > end)
968 break;
969
970 next:
971 path->slots[0]++;
972 }
973 ret = 0;
974 out:
975 btrfs_free_path(path);
976 return ret;
977 }
978
979 /*
980 * find_free_dev_extent - find free space in the specified device
981 * @device: the device which we search the free space in
982 * @num_bytes: the size of the free space that we need
983 * @start: store the start of the free space.
984 * @len: the size of the free space. that we find, or the size of the max
985 * free space if we don't find suitable free space
986 *
987 * this uses a pretty simple search, the expectation is that it is
988 * called very infrequently and that a given device has a small number
989 * of extents
990 *
991 * @start is used to store the start of the free space if we find. But if we
992 * don't find suitable free space, it will be used to store the start position
993 * of the max free space.
994 *
995 * @len is used to store the size of the free space that we find.
996 * But if we don't find suitable free space, it is used to store the size of
997 * the max free space.
998 */
999 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
1000 u64 *start, u64 *len)
1001 {
1002 struct btrfs_key key;
1003 struct btrfs_root *root = device->dev_root;
1004 struct btrfs_dev_extent *dev_extent;
1005 struct btrfs_path *path;
1006 u64 hole_size;
1007 u64 max_hole_start;
1008 u64 max_hole_size;
1009 u64 extent_end;
1010 u64 search_start;
1011 u64 search_end = device->total_bytes;
1012 int ret;
1013 int slot;
1014 struct extent_buffer *l;
1015
1016 /* FIXME use last free of some kind */
1017
1018 /* we don't want to overwrite the superblock on the drive,
1019 * so we make sure to start at an offset of at least 1MB
1020 */
1021 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1022
1023 max_hole_start = search_start;
1024 max_hole_size = 0;
1025 hole_size = 0;
1026
1027 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1028 ret = -ENOSPC;
1029 goto error;
1030 }
1031
1032 path = btrfs_alloc_path();
1033 if (!path) {
1034 ret = -ENOMEM;
1035 goto error;
1036 }
1037 path->reada = 2;
1038
1039 key.objectid = device->devid;
1040 key.offset = search_start;
1041 key.type = BTRFS_DEV_EXTENT_KEY;
1042
1043 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1044 if (ret < 0)
1045 goto out;
1046 if (ret > 0) {
1047 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1048 if (ret < 0)
1049 goto out;
1050 }
1051
1052 while (1) {
1053 l = path->nodes[0];
1054 slot = path->slots[0];
1055 if (slot >= btrfs_header_nritems(l)) {
1056 ret = btrfs_next_leaf(root, path);
1057 if (ret == 0)
1058 continue;
1059 if (ret < 0)
1060 goto out;
1061
1062 break;
1063 }
1064 btrfs_item_key_to_cpu(l, &key, slot);
1065
1066 if (key.objectid < device->devid)
1067 goto next;
1068
1069 if (key.objectid > device->devid)
1070 break;
1071
1072 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1073 goto next;
1074
1075 if (key.offset > search_start) {
1076 hole_size = key.offset - search_start;
1077
1078 if (hole_size > max_hole_size) {
1079 max_hole_start = search_start;
1080 max_hole_size = hole_size;
1081 }
1082
1083 /*
1084 * If this free space is greater than which we need,
1085 * it must be the max free space that we have found
1086 * until now, so max_hole_start must point to the start
1087 * of this free space and the length of this free space
1088 * is stored in max_hole_size. Thus, we return
1089 * max_hole_start and max_hole_size and go back to the
1090 * caller.
1091 */
1092 if (hole_size >= num_bytes) {
1093 ret = 0;
1094 goto out;
1095 }
1096 }
1097
1098 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1099 extent_end = key.offset + btrfs_dev_extent_length(l,
1100 dev_extent);
1101 if (extent_end > search_start)
1102 search_start = extent_end;
1103 next:
1104 path->slots[0]++;
1105 cond_resched();
1106 }
1107
1108 /*
1109 * At this point, search_start should be the end of
1110 * allocated dev extents, and when shrinking the device,
1111 * search_end may be smaller than search_start.
1112 */
1113 if (search_end > search_start)
1114 hole_size = search_end - search_start;
1115
1116 if (hole_size > max_hole_size) {
1117 max_hole_start = search_start;
1118 max_hole_size = hole_size;
1119 }
1120
1121 /* See above. */
1122 if (hole_size < num_bytes)
1123 ret = -ENOSPC;
1124 else
1125 ret = 0;
1126
1127 out:
1128 btrfs_free_path(path);
1129 error:
1130 *start = max_hole_start;
1131 if (len)
1132 *len = max_hole_size;
1133 return ret;
1134 }
1135
1136 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1137 struct btrfs_device *device,
1138 u64 start)
1139 {
1140 int ret;
1141 struct btrfs_path *path;
1142 struct btrfs_root *root = device->dev_root;
1143 struct btrfs_key key;
1144 struct btrfs_key found_key;
1145 struct extent_buffer *leaf = NULL;
1146 struct btrfs_dev_extent *extent = NULL;
1147
1148 path = btrfs_alloc_path();
1149 if (!path)
1150 return -ENOMEM;
1151
1152 key.objectid = device->devid;
1153 key.offset = start;
1154 key.type = BTRFS_DEV_EXTENT_KEY;
1155 again:
1156 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1157 if (ret > 0) {
1158 ret = btrfs_previous_item(root, path, key.objectid,
1159 BTRFS_DEV_EXTENT_KEY);
1160 if (ret)
1161 goto out;
1162 leaf = path->nodes[0];
1163 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1164 extent = btrfs_item_ptr(leaf, path->slots[0],
1165 struct btrfs_dev_extent);
1166 BUG_ON(found_key.offset > start || found_key.offset +
1167 btrfs_dev_extent_length(leaf, extent) < start);
1168 key = found_key;
1169 btrfs_release_path(path);
1170 goto again;
1171 } else if (ret == 0) {
1172 leaf = path->nodes[0];
1173 extent = btrfs_item_ptr(leaf, path->slots[0],
1174 struct btrfs_dev_extent);
1175 } else {
1176 btrfs_error(root->fs_info, ret, "Slot search failed");
1177 goto out;
1178 }
1179
1180 if (device->bytes_used > 0) {
1181 u64 len = btrfs_dev_extent_length(leaf, extent);
1182 device->bytes_used -= len;
1183 spin_lock(&root->fs_info->free_chunk_lock);
1184 root->fs_info->free_chunk_space += len;
1185 spin_unlock(&root->fs_info->free_chunk_lock);
1186 }
1187 ret = btrfs_del_item(trans, root, path);
1188 if (ret) {
1189 btrfs_error(root->fs_info, ret,
1190 "Failed to remove dev extent item");
1191 }
1192 out:
1193 btrfs_free_path(path);
1194 return ret;
1195 }
1196
1197 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1198 struct btrfs_device *device,
1199 u64 chunk_tree, u64 chunk_objectid,
1200 u64 chunk_offset, u64 start, u64 num_bytes)
1201 {
1202 int ret;
1203 struct btrfs_path *path;
1204 struct btrfs_root *root = device->dev_root;
1205 struct btrfs_dev_extent *extent;
1206 struct extent_buffer *leaf;
1207 struct btrfs_key key;
1208
1209 WARN_ON(!device->in_fs_metadata);
1210 WARN_ON(device->is_tgtdev_for_dev_replace);
1211 path = btrfs_alloc_path();
1212 if (!path)
1213 return -ENOMEM;
1214
1215 key.objectid = device->devid;
1216 key.offset = start;
1217 key.type = BTRFS_DEV_EXTENT_KEY;
1218 ret = btrfs_insert_empty_item(trans, root, path, &key,
1219 sizeof(*extent));
1220 if (ret)
1221 goto out;
1222
1223 leaf = path->nodes[0];
1224 extent = btrfs_item_ptr(leaf, path->slots[0],
1225 struct btrfs_dev_extent);
1226 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1227 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1228 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1229
1230 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1231 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1232 BTRFS_UUID_SIZE);
1233
1234 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1235 btrfs_mark_buffer_dirty(leaf);
1236 out:
1237 btrfs_free_path(path);
1238 return ret;
1239 }
1240
1241 static noinline int find_next_chunk(struct btrfs_root *root,
1242 u64 objectid, u64 *offset)
1243 {
1244 struct btrfs_path *path;
1245 int ret;
1246 struct btrfs_key key;
1247 struct btrfs_chunk *chunk;
1248 struct btrfs_key found_key;
1249
1250 path = btrfs_alloc_path();
1251 if (!path)
1252 return -ENOMEM;
1253
1254 key.objectid = objectid;
1255 key.offset = (u64)-1;
1256 key.type = BTRFS_CHUNK_ITEM_KEY;
1257
1258 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1259 if (ret < 0)
1260 goto error;
1261
1262 BUG_ON(ret == 0); /* Corruption */
1263
1264 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1265 if (ret) {
1266 *offset = 0;
1267 } else {
1268 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1269 path->slots[0]);
1270 if (found_key.objectid != objectid)
1271 *offset = 0;
1272 else {
1273 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1274 struct btrfs_chunk);
1275 *offset = found_key.offset +
1276 btrfs_chunk_length(path->nodes[0], chunk);
1277 }
1278 }
1279 ret = 0;
1280 error:
1281 btrfs_free_path(path);
1282 return ret;
1283 }
1284
1285 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1286 {
1287 int ret;
1288 struct btrfs_key key;
1289 struct btrfs_key found_key;
1290 struct btrfs_path *path;
1291
1292 root = root->fs_info->chunk_root;
1293
1294 path = btrfs_alloc_path();
1295 if (!path)
1296 return -ENOMEM;
1297
1298 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1299 key.type = BTRFS_DEV_ITEM_KEY;
1300 key.offset = (u64)-1;
1301
1302 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1303 if (ret < 0)
1304 goto error;
1305
1306 BUG_ON(ret == 0); /* Corruption */
1307
1308 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1309 BTRFS_DEV_ITEM_KEY);
1310 if (ret) {
1311 *objectid = 1;
1312 } else {
1313 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1314 path->slots[0]);
1315 *objectid = found_key.offset + 1;
1316 }
1317 ret = 0;
1318 error:
1319 btrfs_free_path(path);
1320 return ret;
1321 }
1322
1323 /*
1324 * the device information is stored in the chunk root
1325 * the btrfs_device struct should be fully filled in
1326 */
1327 int btrfs_add_device(struct btrfs_trans_handle *trans,
1328 struct btrfs_root *root,
1329 struct btrfs_device *device)
1330 {
1331 int ret;
1332 struct btrfs_path *path;
1333 struct btrfs_dev_item *dev_item;
1334 struct extent_buffer *leaf;
1335 struct btrfs_key key;
1336 unsigned long ptr;
1337
1338 root = root->fs_info->chunk_root;
1339
1340 path = btrfs_alloc_path();
1341 if (!path)
1342 return -ENOMEM;
1343
1344 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1345 key.type = BTRFS_DEV_ITEM_KEY;
1346 key.offset = device->devid;
1347
1348 ret = btrfs_insert_empty_item(trans, root, path, &key,
1349 sizeof(*dev_item));
1350 if (ret)
1351 goto out;
1352
1353 leaf = path->nodes[0];
1354 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1355
1356 btrfs_set_device_id(leaf, dev_item, device->devid);
1357 btrfs_set_device_generation(leaf, dev_item, 0);
1358 btrfs_set_device_type(leaf, dev_item, device->type);
1359 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1360 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1361 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1362 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1363 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1364 btrfs_set_device_group(leaf, dev_item, 0);
1365 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1366 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1367 btrfs_set_device_start_offset(leaf, dev_item, 0);
1368
1369 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1370 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1371 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1372 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1373 btrfs_mark_buffer_dirty(leaf);
1374
1375 ret = 0;
1376 out:
1377 btrfs_free_path(path);
1378 return ret;
1379 }
1380
1381 static int btrfs_rm_dev_item(struct btrfs_root *root,
1382 struct btrfs_device *device)
1383 {
1384 int ret;
1385 struct btrfs_path *path;
1386 struct btrfs_key key;
1387 struct btrfs_trans_handle *trans;
1388
1389 root = root->fs_info->chunk_root;
1390
1391 path = btrfs_alloc_path();
1392 if (!path)
1393 return -ENOMEM;
1394
1395 trans = btrfs_start_transaction(root, 0);
1396 if (IS_ERR(trans)) {
1397 btrfs_free_path(path);
1398 return PTR_ERR(trans);
1399 }
1400 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1401 key.type = BTRFS_DEV_ITEM_KEY;
1402 key.offset = device->devid;
1403 lock_chunks(root);
1404
1405 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1406 if (ret < 0)
1407 goto out;
1408
1409 if (ret > 0) {
1410 ret = -ENOENT;
1411 goto out;
1412 }
1413
1414 ret = btrfs_del_item(trans, root, path);
1415 if (ret)
1416 goto out;
1417 out:
1418 btrfs_free_path(path);
1419 unlock_chunks(root);
1420 btrfs_commit_transaction(trans, root);
1421 return ret;
1422 }
1423
1424 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1425 {
1426 struct btrfs_device *device;
1427 struct btrfs_device *next_device;
1428 struct block_device *bdev;
1429 struct buffer_head *bh = NULL;
1430 struct btrfs_super_block *disk_super;
1431 struct btrfs_fs_devices *cur_devices;
1432 u64 all_avail;
1433 u64 devid;
1434 u64 num_devices;
1435 u8 *dev_uuid;
1436 unsigned seq;
1437 int ret = 0;
1438 bool clear_super = false;
1439
1440 mutex_lock(&uuid_mutex);
1441
1442 do {
1443 seq = read_seqbegin(&root->fs_info->profiles_lock);
1444
1445 all_avail = root->fs_info->avail_data_alloc_bits |
1446 root->fs_info->avail_system_alloc_bits |
1447 root->fs_info->avail_metadata_alloc_bits;
1448 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
1449
1450 num_devices = root->fs_info->fs_devices->num_devices;
1451 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1452 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1453 WARN_ON(num_devices < 1);
1454 num_devices--;
1455 }
1456 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1457
1458 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1459 printk(KERN_ERR "btrfs: unable to go below four devices "
1460 "on raid10\n");
1461 ret = -EINVAL;
1462 goto out;
1463 }
1464
1465 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1466 printk(KERN_ERR "btrfs: unable to go below two "
1467 "devices on raid1\n");
1468 ret = -EINVAL;
1469 goto out;
1470 }
1471
1472 if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1473 root->fs_info->fs_devices->rw_devices <= 2) {
1474 printk(KERN_ERR "btrfs: unable to go below two "
1475 "devices on raid5\n");
1476 ret = -EINVAL;
1477 goto out;
1478 }
1479 if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1480 root->fs_info->fs_devices->rw_devices <= 3) {
1481 printk(KERN_ERR "btrfs: unable to go below three "
1482 "devices on raid6\n");
1483 ret = -EINVAL;
1484 goto out;
1485 }
1486
1487 if (strcmp(device_path, "missing") == 0) {
1488 struct list_head *devices;
1489 struct btrfs_device *tmp;
1490
1491 device = NULL;
1492 devices = &root->fs_info->fs_devices->devices;
1493 /*
1494 * It is safe to read the devices since the volume_mutex
1495 * is held.
1496 */
1497 list_for_each_entry(tmp, devices, dev_list) {
1498 if (tmp->in_fs_metadata &&
1499 !tmp->is_tgtdev_for_dev_replace &&
1500 !tmp->bdev) {
1501 device = tmp;
1502 break;
1503 }
1504 }
1505 bdev = NULL;
1506 bh = NULL;
1507 disk_super = NULL;
1508 if (!device) {
1509 printk(KERN_ERR "btrfs: no missing devices found to "
1510 "remove\n");
1511 goto out;
1512 }
1513 } else {
1514 ret = btrfs_get_bdev_and_sb(device_path,
1515 FMODE_WRITE | FMODE_EXCL,
1516 root->fs_info->bdev_holder, 0,
1517 &bdev, &bh);
1518 if (ret)
1519 goto out;
1520 disk_super = (struct btrfs_super_block *)bh->b_data;
1521 devid = btrfs_stack_device_id(&disk_super->dev_item);
1522 dev_uuid = disk_super->dev_item.uuid;
1523 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1524 disk_super->fsid);
1525 if (!device) {
1526 ret = -ENOENT;
1527 goto error_brelse;
1528 }
1529 }
1530
1531 if (device->is_tgtdev_for_dev_replace) {
1532 pr_err("btrfs: unable to remove the dev_replace target dev\n");
1533 ret = -EINVAL;
1534 goto error_brelse;
1535 }
1536
1537 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1538 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1539 "device\n");
1540 ret = -EINVAL;
1541 goto error_brelse;
1542 }
1543
1544 if (device->writeable) {
1545 lock_chunks(root);
1546 list_del_init(&device->dev_alloc_list);
1547 unlock_chunks(root);
1548 root->fs_info->fs_devices->rw_devices--;
1549 clear_super = true;
1550 }
1551
1552 ret = btrfs_shrink_device(device, 0);
1553 if (ret)
1554 goto error_undo;
1555
1556 /*
1557 * TODO: the superblock still includes this device in its num_devices
1558 * counter although write_all_supers() is not locked out. This
1559 * could give a filesystem state which requires a degraded mount.
1560 */
1561 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1562 if (ret)
1563 goto error_undo;
1564
1565 spin_lock(&root->fs_info->free_chunk_lock);
1566 root->fs_info->free_chunk_space = device->total_bytes -
1567 device->bytes_used;
1568 spin_unlock(&root->fs_info->free_chunk_lock);
1569
1570 device->in_fs_metadata = 0;
1571 btrfs_scrub_cancel_dev(root->fs_info, device);
1572
1573 /*
1574 * the device list mutex makes sure that we don't change
1575 * the device list while someone else is writing out all
1576 * the device supers.
1577 */
1578
1579 cur_devices = device->fs_devices;
1580 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1581 list_del_rcu(&device->dev_list);
1582
1583 device->fs_devices->num_devices--;
1584 device->fs_devices->total_devices--;
1585
1586 if (device->missing)
1587 root->fs_info->fs_devices->missing_devices--;
1588
1589 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1590 struct btrfs_device, dev_list);
1591 if (device->bdev == root->fs_info->sb->s_bdev)
1592 root->fs_info->sb->s_bdev = next_device->bdev;
1593 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1594 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1595
1596 if (device->bdev)
1597 device->fs_devices->open_devices--;
1598
1599 call_rcu(&device->rcu, free_device);
1600 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1601
1602 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1603 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1604
1605 if (cur_devices->open_devices == 0) {
1606 struct btrfs_fs_devices *fs_devices;
1607 fs_devices = root->fs_info->fs_devices;
1608 while (fs_devices) {
1609 if (fs_devices->seed == cur_devices)
1610 break;
1611 fs_devices = fs_devices->seed;
1612 }
1613 fs_devices->seed = cur_devices->seed;
1614 cur_devices->seed = NULL;
1615 lock_chunks(root);
1616 __btrfs_close_devices(cur_devices);
1617 unlock_chunks(root);
1618 free_fs_devices(cur_devices);
1619 }
1620
1621 root->fs_info->num_tolerated_disk_barrier_failures =
1622 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1623
1624 /*
1625 * at this point, the device is zero sized. We want to
1626 * remove it from the devices list and zero out the old super
1627 */
1628 if (clear_super && disk_super) {
1629 /* make sure this device isn't detected as part of
1630 * the FS anymore
1631 */
1632 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1633 set_buffer_dirty(bh);
1634 sync_dirty_buffer(bh);
1635 }
1636
1637 ret = 0;
1638
1639 /* Notify udev that device has changed */
1640 if (bdev)
1641 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1642
1643 error_brelse:
1644 brelse(bh);
1645 if (bdev)
1646 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1647 out:
1648 mutex_unlock(&uuid_mutex);
1649 return ret;
1650 error_undo:
1651 if (device->writeable) {
1652 lock_chunks(root);
1653 list_add(&device->dev_alloc_list,
1654 &root->fs_info->fs_devices->alloc_list);
1655 unlock_chunks(root);
1656 root->fs_info->fs_devices->rw_devices++;
1657 }
1658 goto error_brelse;
1659 }
1660
1661 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1662 struct btrfs_device *srcdev)
1663 {
1664 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1665 list_del_rcu(&srcdev->dev_list);
1666 list_del_rcu(&srcdev->dev_alloc_list);
1667 fs_info->fs_devices->num_devices--;
1668 if (srcdev->missing) {
1669 fs_info->fs_devices->missing_devices--;
1670 fs_info->fs_devices->rw_devices++;
1671 }
1672 if (srcdev->can_discard)
1673 fs_info->fs_devices->num_can_discard--;
1674 if (srcdev->bdev)
1675 fs_info->fs_devices->open_devices--;
1676
1677 call_rcu(&srcdev->rcu, free_device);
1678 }
1679
1680 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1681 struct btrfs_device *tgtdev)
1682 {
1683 struct btrfs_device *next_device;
1684
1685 WARN_ON(!tgtdev);
1686 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1687 if (tgtdev->bdev) {
1688 btrfs_scratch_superblock(tgtdev);
1689 fs_info->fs_devices->open_devices--;
1690 }
1691 fs_info->fs_devices->num_devices--;
1692 if (tgtdev->can_discard)
1693 fs_info->fs_devices->num_can_discard++;
1694
1695 next_device = list_entry(fs_info->fs_devices->devices.next,
1696 struct btrfs_device, dev_list);
1697 if (tgtdev->bdev == fs_info->sb->s_bdev)
1698 fs_info->sb->s_bdev = next_device->bdev;
1699 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1700 fs_info->fs_devices->latest_bdev = next_device->bdev;
1701 list_del_rcu(&tgtdev->dev_list);
1702
1703 call_rcu(&tgtdev->rcu, free_device);
1704
1705 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1706 }
1707
1708 int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1709 struct btrfs_device **device)
1710 {
1711 int ret = 0;
1712 struct btrfs_super_block *disk_super;
1713 u64 devid;
1714 u8 *dev_uuid;
1715 struct block_device *bdev;
1716 struct buffer_head *bh;
1717
1718 *device = NULL;
1719 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1720 root->fs_info->bdev_holder, 0, &bdev, &bh);
1721 if (ret)
1722 return ret;
1723 disk_super = (struct btrfs_super_block *)bh->b_data;
1724 devid = btrfs_stack_device_id(&disk_super->dev_item);
1725 dev_uuid = disk_super->dev_item.uuid;
1726 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1727 disk_super->fsid);
1728 brelse(bh);
1729 if (!*device)
1730 ret = -ENOENT;
1731 blkdev_put(bdev, FMODE_READ);
1732 return ret;
1733 }
1734
1735 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1736 char *device_path,
1737 struct btrfs_device **device)
1738 {
1739 *device = NULL;
1740 if (strcmp(device_path, "missing") == 0) {
1741 struct list_head *devices;
1742 struct btrfs_device *tmp;
1743
1744 devices = &root->fs_info->fs_devices->devices;
1745 /*
1746 * It is safe to read the devices since the volume_mutex
1747 * is held by the caller.
1748 */
1749 list_for_each_entry(tmp, devices, dev_list) {
1750 if (tmp->in_fs_metadata && !tmp->bdev) {
1751 *device = tmp;
1752 break;
1753 }
1754 }
1755
1756 if (!*device) {
1757 pr_err("btrfs: no missing device found\n");
1758 return -ENOENT;
1759 }
1760
1761 return 0;
1762 } else {
1763 return btrfs_find_device_by_path(root, device_path, device);
1764 }
1765 }
1766
1767 /*
1768 * does all the dirty work required for changing file system's UUID.
1769 */
1770 static int btrfs_prepare_sprout(struct btrfs_root *root)
1771 {
1772 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1773 struct btrfs_fs_devices *old_devices;
1774 struct btrfs_fs_devices *seed_devices;
1775 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1776 struct btrfs_device *device;
1777 u64 super_flags;
1778
1779 BUG_ON(!mutex_is_locked(&uuid_mutex));
1780 if (!fs_devices->seeding)
1781 return -EINVAL;
1782
1783 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1784 if (!seed_devices)
1785 return -ENOMEM;
1786
1787 old_devices = clone_fs_devices(fs_devices);
1788 if (IS_ERR(old_devices)) {
1789 kfree(seed_devices);
1790 return PTR_ERR(old_devices);
1791 }
1792
1793 list_add(&old_devices->list, &fs_uuids);
1794
1795 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1796 seed_devices->opened = 1;
1797 INIT_LIST_HEAD(&seed_devices->devices);
1798 INIT_LIST_HEAD(&seed_devices->alloc_list);
1799 mutex_init(&seed_devices->device_list_mutex);
1800
1801 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1802 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1803 synchronize_rcu);
1804 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1805
1806 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1807 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1808 device->fs_devices = seed_devices;
1809 }
1810
1811 fs_devices->seeding = 0;
1812 fs_devices->num_devices = 0;
1813 fs_devices->open_devices = 0;
1814 fs_devices->total_devices = 0;
1815 fs_devices->seed = seed_devices;
1816
1817 generate_random_uuid(fs_devices->fsid);
1818 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1819 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1820 super_flags = btrfs_super_flags(disk_super) &
1821 ~BTRFS_SUPER_FLAG_SEEDING;
1822 btrfs_set_super_flags(disk_super, super_flags);
1823
1824 return 0;
1825 }
1826
1827 /*
1828 * strore the expected generation for seed devices in device items.
1829 */
1830 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1831 struct btrfs_root *root)
1832 {
1833 struct btrfs_path *path;
1834 struct extent_buffer *leaf;
1835 struct btrfs_dev_item *dev_item;
1836 struct btrfs_device *device;
1837 struct btrfs_key key;
1838 u8 fs_uuid[BTRFS_UUID_SIZE];
1839 u8 dev_uuid[BTRFS_UUID_SIZE];
1840 u64 devid;
1841 int ret;
1842
1843 path = btrfs_alloc_path();
1844 if (!path)
1845 return -ENOMEM;
1846
1847 root = root->fs_info->chunk_root;
1848 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1849 key.offset = 0;
1850 key.type = BTRFS_DEV_ITEM_KEY;
1851
1852 while (1) {
1853 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1854 if (ret < 0)
1855 goto error;
1856
1857 leaf = path->nodes[0];
1858 next_slot:
1859 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1860 ret = btrfs_next_leaf(root, path);
1861 if (ret > 0)
1862 break;
1863 if (ret < 0)
1864 goto error;
1865 leaf = path->nodes[0];
1866 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1867 btrfs_release_path(path);
1868 continue;
1869 }
1870
1871 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1872 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1873 key.type != BTRFS_DEV_ITEM_KEY)
1874 break;
1875
1876 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1877 struct btrfs_dev_item);
1878 devid = btrfs_device_id(leaf, dev_item);
1879 read_extent_buffer(leaf, dev_uuid,
1880 (unsigned long)btrfs_device_uuid(dev_item),
1881 BTRFS_UUID_SIZE);
1882 read_extent_buffer(leaf, fs_uuid,
1883 (unsigned long)btrfs_device_fsid(dev_item),
1884 BTRFS_UUID_SIZE);
1885 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1886 fs_uuid);
1887 BUG_ON(!device); /* Logic error */
1888
1889 if (device->fs_devices->seeding) {
1890 btrfs_set_device_generation(leaf, dev_item,
1891 device->generation);
1892 btrfs_mark_buffer_dirty(leaf);
1893 }
1894
1895 path->slots[0]++;
1896 goto next_slot;
1897 }
1898 ret = 0;
1899 error:
1900 btrfs_free_path(path);
1901 return ret;
1902 }
1903
1904 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1905 {
1906 struct request_queue *q;
1907 struct btrfs_trans_handle *trans;
1908 struct btrfs_device *device;
1909 struct block_device *bdev;
1910 struct list_head *devices;
1911 struct super_block *sb = root->fs_info->sb;
1912 struct rcu_string *name;
1913 u64 total_bytes;
1914 int seeding_dev = 0;
1915 int ret = 0;
1916
1917 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1918 return -EROFS;
1919
1920 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1921 root->fs_info->bdev_holder);
1922 if (IS_ERR(bdev))
1923 return PTR_ERR(bdev);
1924
1925 if (root->fs_info->fs_devices->seeding) {
1926 seeding_dev = 1;
1927 down_write(&sb->s_umount);
1928 mutex_lock(&uuid_mutex);
1929 }
1930
1931 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1932
1933 devices = &root->fs_info->fs_devices->devices;
1934
1935 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1936 list_for_each_entry(device, devices, dev_list) {
1937 if (device->bdev == bdev) {
1938 ret = -EEXIST;
1939 mutex_unlock(
1940 &root->fs_info->fs_devices->device_list_mutex);
1941 goto error;
1942 }
1943 }
1944 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1945
1946 device = kzalloc(sizeof(*device), GFP_NOFS);
1947 if (!device) {
1948 /* we can safely leave the fs_devices entry around */
1949 ret = -ENOMEM;
1950 goto error;
1951 }
1952
1953 name = rcu_string_strdup(device_path, GFP_NOFS);
1954 if (!name) {
1955 kfree(device);
1956 ret = -ENOMEM;
1957 goto error;
1958 }
1959 rcu_assign_pointer(device->name, name);
1960
1961 ret = find_next_devid(root, &device->devid);
1962 if (ret) {
1963 rcu_string_free(device->name);
1964 kfree(device);
1965 goto error;
1966 }
1967
1968 trans = btrfs_start_transaction(root, 0);
1969 if (IS_ERR(trans)) {
1970 rcu_string_free(device->name);
1971 kfree(device);
1972 ret = PTR_ERR(trans);
1973 goto error;
1974 }
1975
1976 lock_chunks(root);
1977
1978 q = bdev_get_queue(bdev);
1979 if (blk_queue_discard(q))
1980 device->can_discard = 1;
1981 device->writeable = 1;
1982 device->work.func = pending_bios_fn;
1983 generate_random_uuid(device->uuid);
1984 spin_lock_init(&device->io_lock);
1985 device->generation = trans->transid;
1986 device->io_width = root->sectorsize;
1987 device->io_align = root->sectorsize;
1988 device->sector_size = root->sectorsize;
1989 device->total_bytes = i_size_read(bdev->bd_inode);
1990 device->disk_total_bytes = device->total_bytes;
1991 device->dev_root = root->fs_info->dev_root;
1992 device->bdev = bdev;
1993 device->in_fs_metadata = 1;
1994 device->is_tgtdev_for_dev_replace = 0;
1995 device->mode = FMODE_EXCL;
1996 set_blocksize(device->bdev, 4096);
1997
1998 if (seeding_dev) {
1999 sb->s_flags &= ~MS_RDONLY;
2000 ret = btrfs_prepare_sprout(root);
2001 BUG_ON(ret); /* -ENOMEM */
2002 }
2003
2004 device->fs_devices = root->fs_info->fs_devices;
2005
2006 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2007 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2008 list_add(&device->dev_alloc_list,
2009 &root->fs_info->fs_devices->alloc_list);
2010 root->fs_info->fs_devices->num_devices++;
2011 root->fs_info->fs_devices->open_devices++;
2012 root->fs_info->fs_devices->rw_devices++;
2013 root->fs_info->fs_devices->total_devices++;
2014 if (device->can_discard)
2015 root->fs_info->fs_devices->num_can_discard++;
2016 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2017
2018 spin_lock(&root->fs_info->free_chunk_lock);
2019 root->fs_info->free_chunk_space += device->total_bytes;
2020 spin_unlock(&root->fs_info->free_chunk_lock);
2021
2022 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2023 root->fs_info->fs_devices->rotating = 1;
2024
2025 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2026 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2027 total_bytes + device->total_bytes);
2028
2029 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2030 btrfs_set_super_num_devices(root->fs_info->super_copy,
2031 total_bytes + 1);
2032 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2033
2034 if (seeding_dev) {
2035 ret = init_first_rw_device(trans, root, device);
2036 if (ret) {
2037 btrfs_abort_transaction(trans, root, ret);
2038 goto error_trans;
2039 }
2040 ret = btrfs_finish_sprout(trans, root);
2041 if (ret) {
2042 btrfs_abort_transaction(trans, root, ret);
2043 goto error_trans;
2044 }
2045 } else {
2046 ret = btrfs_add_device(trans, root, device);
2047 if (ret) {
2048 btrfs_abort_transaction(trans, root, ret);
2049 goto error_trans;
2050 }
2051 }
2052
2053 /*
2054 * we've got more storage, clear any full flags on the space
2055 * infos
2056 */
2057 btrfs_clear_space_info_full(root->fs_info);
2058
2059 unlock_chunks(root);
2060 root->fs_info->num_tolerated_disk_barrier_failures =
2061 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2062 ret = btrfs_commit_transaction(trans, root);
2063
2064 if (seeding_dev) {
2065 mutex_unlock(&uuid_mutex);
2066 up_write(&sb->s_umount);
2067
2068 if (ret) /* transaction commit */
2069 return ret;
2070
2071 ret = btrfs_relocate_sys_chunks(root);
2072 if (ret < 0)
2073 btrfs_error(root->fs_info, ret,
2074 "Failed to relocate sys chunks after "
2075 "device initialization. This can be fixed "
2076 "using the \"btrfs balance\" command.");
2077 trans = btrfs_attach_transaction(root);
2078 if (IS_ERR(trans)) {
2079 if (PTR_ERR(trans) == -ENOENT)
2080 return 0;
2081 return PTR_ERR(trans);
2082 }
2083 ret = btrfs_commit_transaction(trans, root);
2084 }
2085
2086 return ret;
2087
2088 error_trans:
2089 unlock_chunks(root);
2090 btrfs_end_transaction(trans, root);
2091 rcu_string_free(device->name);
2092 kfree(device);
2093 error:
2094 blkdev_put(bdev, FMODE_EXCL);
2095 if (seeding_dev) {
2096 mutex_unlock(&uuid_mutex);
2097 up_write(&sb->s_umount);
2098 }
2099 return ret;
2100 }
2101
2102 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2103 struct btrfs_device **device_out)
2104 {
2105 struct request_queue *q;
2106 struct btrfs_device *device;
2107 struct block_device *bdev;
2108 struct btrfs_fs_info *fs_info = root->fs_info;
2109 struct list_head *devices;
2110 struct rcu_string *name;
2111 int ret = 0;
2112
2113 *device_out = NULL;
2114 if (fs_info->fs_devices->seeding)
2115 return -EINVAL;
2116
2117 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2118 fs_info->bdev_holder);
2119 if (IS_ERR(bdev))
2120 return PTR_ERR(bdev);
2121
2122 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2123
2124 devices = &fs_info->fs_devices->devices;
2125 list_for_each_entry(device, devices, dev_list) {
2126 if (device->bdev == bdev) {
2127 ret = -EEXIST;
2128 goto error;
2129 }
2130 }
2131
2132 device = kzalloc(sizeof(*device), GFP_NOFS);
2133 if (!device) {
2134 ret = -ENOMEM;
2135 goto error;
2136 }
2137
2138 name = rcu_string_strdup(device_path, GFP_NOFS);
2139 if (!name) {
2140 kfree(device);
2141 ret = -ENOMEM;
2142 goto error;
2143 }
2144 rcu_assign_pointer(device->name, name);
2145
2146 q = bdev_get_queue(bdev);
2147 if (blk_queue_discard(q))
2148 device->can_discard = 1;
2149 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2150 device->writeable = 1;
2151 device->work.func = pending_bios_fn;
2152 generate_random_uuid(device->uuid);
2153 device->devid = BTRFS_DEV_REPLACE_DEVID;
2154 spin_lock_init(&device->io_lock);
2155 device->generation = 0;
2156 device->io_width = root->sectorsize;
2157 device->io_align = root->sectorsize;
2158 device->sector_size = root->sectorsize;
2159 device->total_bytes = i_size_read(bdev->bd_inode);
2160 device->disk_total_bytes = device->total_bytes;
2161 device->dev_root = fs_info->dev_root;
2162 device->bdev = bdev;
2163 device->in_fs_metadata = 1;
2164 device->is_tgtdev_for_dev_replace = 1;
2165 device->mode = FMODE_EXCL;
2166 set_blocksize(device->bdev, 4096);
2167 device->fs_devices = fs_info->fs_devices;
2168 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2169 fs_info->fs_devices->num_devices++;
2170 fs_info->fs_devices->open_devices++;
2171 if (device->can_discard)
2172 fs_info->fs_devices->num_can_discard++;
2173 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2174
2175 *device_out = device;
2176 return ret;
2177
2178 error:
2179 blkdev_put(bdev, FMODE_EXCL);
2180 return ret;
2181 }
2182
2183 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2184 struct btrfs_device *tgtdev)
2185 {
2186 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2187 tgtdev->io_width = fs_info->dev_root->sectorsize;
2188 tgtdev->io_align = fs_info->dev_root->sectorsize;
2189 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2190 tgtdev->dev_root = fs_info->dev_root;
2191 tgtdev->in_fs_metadata = 1;
2192 }
2193
2194 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2195 struct btrfs_device *device)
2196 {
2197 int ret;
2198 struct btrfs_path *path;
2199 struct btrfs_root *root;
2200 struct btrfs_dev_item *dev_item;
2201 struct extent_buffer *leaf;
2202 struct btrfs_key key;
2203
2204 root = device->dev_root->fs_info->chunk_root;
2205
2206 path = btrfs_alloc_path();
2207 if (!path)
2208 return -ENOMEM;
2209
2210 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2211 key.type = BTRFS_DEV_ITEM_KEY;
2212 key.offset = device->devid;
2213
2214 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2215 if (ret < 0)
2216 goto out;
2217
2218 if (ret > 0) {
2219 ret = -ENOENT;
2220 goto out;
2221 }
2222
2223 leaf = path->nodes[0];
2224 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2225
2226 btrfs_set_device_id(leaf, dev_item, device->devid);
2227 btrfs_set_device_type(leaf, dev_item, device->type);
2228 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2229 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2230 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2231 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2232 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2233 btrfs_mark_buffer_dirty(leaf);
2234
2235 out:
2236 btrfs_free_path(path);
2237 return ret;
2238 }
2239
2240 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2241 struct btrfs_device *device, u64 new_size)
2242 {
2243 struct btrfs_super_block *super_copy =
2244 device->dev_root->fs_info->super_copy;
2245 u64 old_total = btrfs_super_total_bytes(super_copy);
2246 u64 diff = new_size - device->total_bytes;
2247
2248 if (!device->writeable)
2249 return -EACCES;
2250 if (new_size <= device->total_bytes ||
2251 device->is_tgtdev_for_dev_replace)
2252 return -EINVAL;
2253
2254 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2255 device->fs_devices->total_rw_bytes += diff;
2256
2257 device->total_bytes = new_size;
2258 device->disk_total_bytes = new_size;
2259 btrfs_clear_space_info_full(device->dev_root->fs_info);
2260
2261 return btrfs_update_device(trans, device);
2262 }
2263
2264 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2265 struct btrfs_device *device, u64 new_size)
2266 {
2267 int ret;
2268 lock_chunks(device->dev_root);
2269 ret = __btrfs_grow_device(trans, device, new_size);
2270 unlock_chunks(device->dev_root);
2271 return ret;
2272 }
2273
2274 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2275 struct btrfs_root *root,
2276 u64 chunk_tree, u64 chunk_objectid,
2277 u64 chunk_offset)
2278 {
2279 int ret;
2280 struct btrfs_path *path;
2281 struct btrfs_key key;
2282
2283 root = root->fs_info->chunk_root;
2284 path = btrfs_alloc_path();
2285 if (!path)
2286 return -ENOMEM;
2287
2288 key.objectid = chunk_objectid;
2289 key.offset = chunk_offset;
2290 key.type = BTRFS_CHUNK_ITEM_KEY;
2291
2292 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2293 if (ret < 0)
2294 goto out;
2295 else if (ret > 0) { /* Logic error or corruption */
2296 btrfs_error(root->fs_info, -ENOENT,
2297 "Failed lookup while freeing chunk.");
2298 ret = -ENOENT;
2299 goto out;
2300 }
2301
2302 ret = btrfs_del_item(trans, root, path);
2303 if (ret < 0)
2304 btrfs_error(root->fs_info, ret,
2305 "Failed to delete chunk item.");
2306 out:
2307 btrfs_free_path(path);
2308 return ret;
2309 }
2310
2311 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2312 chunk_offset)
2313 {
2314 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2315 struct btrfs_disk_key *disk_key;
2316 struct btrfs_chunk *chunk;
2317 u8 *ptr;
2318 int ret = 0;
2319 u32 num_stripes;
2320 u32 array_size;
2321 u32 len = 0;
2322 u32 cur;
2323 struct btrfs_key key;
2324
2325 array_size = btrfs_super_sys_array_size(super_copy);
2326
2327 ptr = super_copy->sys_chunk_array;
2328 cur = 0;
2329
2330 while (cur < array_size) {
2331 disk_key = (struct btrfs_disk_key *)ptr;
2332 btrfs_disk_key_to_cpu(&key, disk_key);
2333
2334 len = sizeof(*disk_key);
2335
2336 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2337 chunk = (struct btrfs_chunk *)(ptr + len);
2338 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2339 len += btrfs_chunk_item_size(num_stripes);
2340 } else {
2341 ret = -EIO;
2342 break;
2343 }
2344 if (key.objectid == chunk_objectid &&
2345 key.offset == chunk_offset) {
2346 memmove(ptr, ptr + len, array_size - (cur + len));
2347 array_size -= len;
2348 btrfs_set_super_sys_array_size(super_copy, array_size);
2349 } else {
2350 ptr += len;
2351 cur += len;
2352 }
2353 }
2354 return ret;
2355 }
2356
2357 static int btrfs_relocate_chunk(struct btrfs_root *root,
2358 u64 chunk_tree, u64 chunk_objectid,
2359 u64 chunk_offset)
2360 {
2361 struct extent_map_tree *em_tree;
2362 struct btrfs_root *extent_root;
2363 struct btrfs_trans_handle *trans;
2364 struct extent_map *em;
2365 struct map_lookup *map;
2366 int ret;
2367 int i;
2368
2369 root = root->fs_info->chunk_root;
2370 extent_root = root->fs_info->extent_root;
2371 em_tree = &root->fs_info->mapping_tree.map_tree;
2372
2373 ret = btrfs_can_relocate(extent_root, chunk_offset);
2374 if (ret)
2375 return -ENOSPC;
2376
2377 /* step one, relocate all the extents inside this chunk */
2378 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2379 if (ret)
2380 return ret;
2381
2382 trans = btrfs_start_transaction(root, 0);
2383 BUG_ON(IS_ERR(trans));
2384
2385 lock_chunks(root);
2386
2387 /*
2388 * step two, delete the device extents and the
2389 * chunk tree entries
2390 */
2391 read_lock(&em_tree->lock);
2392 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2393 read_unlock(&em_tree->lock);
2394
2395 BUG_ON(!em || em->start > chunk_offset ||
2396 em->start + em->len < chunk_offset);
2397 map = (struct map_lookup *)em->bdev;
2398
2399 for (i = 0; i < map->num_stripes; i++) {
2400 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2401 map->stripes[i].physical);
2402 BUG_ON(ret);
2403
2404 if (map->stripes[i].dev) {
2405 ret = btrfs_update_device(trans, map->stripes[i].dev);
2406 BUG_ON(ret);
2407 }
2408 }
2409 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2410 chunk_offset);
2411
2412 BUG_ON(ret);
2413
2414 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2415
2416 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2417 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2418 BUG_ON(ret);
2419 }
2420
2421 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2422 BUG_ON(ret);
2423
2424 write_lock(&em_tree->lock);
2425 remove_extent_mapping(em_tree, em);
2426 write_unlock(&em_tree->lock);
2427
2428 kfree(map);
2429 em->bdev = NULL;
2430
2431 /* once for the tree */
2432 free_extent_map(em);
2433 /* once for us */
2434 free_extent_map(em);
2435
2436 unlock_chunks(root);
2437 btrfs_end_transaction(trans, root);
2438 return 0;
2439 }
2440
2441 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2442 {
2443 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2444 struct btrfs_path *path;
2445 struct extent_buffer *leaf;
2446 struct btrfs_chunk *chunk;
2447 struct btrfs_key key;
2448 struct btrfs_key found_key;
2449 u64 chunk_tree = chunk_root->root_key.objectid;
2450 u64 chunk_type;
2451 bool retried = false;
2452 int failed = 0;
2453 int ret;
2454
2455 path = btrfs_alloc_path();
2456 if (!path)
2457 return -ENOMEM;
2458
2459 again:
2460 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2461 key.offset = (u64)-1;
2462 key.type = BTRFS_CHUNK_ITEM_KEY;
2463
2464 while (1) {
2465 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2466 if (ret < 0)
2467 goto error;
2468 BUG_ON(ret == 0); /* Corruption */
2469
2470 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2471 key.type);
2472 if (ret < 0)
2473 goto error;
2474 if (ret > 0)
2475 break;
2476
2477 leaf = path->nodes[0];
2478 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2479
2480 chunk = btrfs_item_ptr(leaf, path->slots[0],
2481 struct btrfs_chunk);
2482 chunk_type = btrfs_chunk_type(leaf, chunk);
2483 btrfs_release_path(path);
2484
2485 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2486 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2487 found_key.objectid,
2488 found_key.offset);
2489 if (ret == -ENOSPC)
2490 failed++;
2491 else if (ret)
2492 BUG();
2493 }
2494
2495 if (found_key.offset == 0)
2496 break;
2497 key.offset = found_key.offset - 1;
2498 }
2499 ret = 0;
2500 if (failed && !retried) {
2501 failed = 0;
2502 retried = true;
2503 goto again;
2504 } else if (failed && retried) {
2505 WARN_ON(1);
2506 ret = -ENOSPC;
2507 }
2508 error:
2509 btrfs_free_path(path);
2510 return ret;
2511 }
2512
2513 static int insert_balance_item(struct btrfs_root *root,
2514 struct btrfs_balance_control *bctl)
2515 {
2516 struct btrfs_trans_handle *trans;
2517 struct btrfs_balance_item *item;
2518 struct btrfs_disk_balance_args disk_bargs;
2519 struct btrfs_path *path;
2520 struct extent_buffer *leaf;
2521 struct btrfs_key key;
2522 int ret, err;
2523
2524 path = btrfs_alloc_path();
2525 if (!path)
2526 return -ENOMEM;
2527
2528 trans = btrfs_start_transaction(root, 0);
2529 if (IS_ERR(trans)) {
2530 btrfs_free_path(path);
2531 return PTR_ERR(trans);
2532 }
2533
2534 key.objectid = BTRFS_BALANCE_OBJECTID;
2535 key.type = BTRFS_BALANCE_ITEM_KEY;
2536 key.offset = 0;
2537
2538 ret = btrfs_insert_empty_item(trans, root, path, &key,
2539 sizeof(*item));
2540 if (ret)
2541 goto out;
2542
2543 leaf = path->nodes[0];
2544 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2545
2546 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2547
2548 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2549 btrfs_set_balance_data(leaf, item, &disk_bargs);
2550 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2551 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2552 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2553 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2554
2555 btrfs_set_balance_flags(leaf, item, bctl->flags);
2556
2557 btrfs_mark_buffer_dirty(leaf);
2558 out:
2559 btrfs_free_path(path);
2560 err = btrfs_commit_transaction(trans, root);
2561 if (err && !ret)
2562 ret = err;
2563 return ret;
2564 }
2565
2566 static int del_balance_item(struct btrfs_root *root)
2567 {
2568 struct btrfs_trans_handle *trans;
2569 struct btrfs_path *path;
2570 struct btrfs_key key;
2571 int ret, err;
2572
2573 path = btrfs_alloc_path();
2574 if (!path)
2575 return -ENOMEM;
2576
2577 trans = btrfs_start_transaction(root, 0);
2578 if (IS_ERR(trans)) {
2579 btrfs_free_path(path);
2580 return PTR_ERR(trans);
2581 }
2582
2583 key.objectid = BTRFS_BALANCE_OBJECTID;
2584 key.type = BTRFS_BALANCE_ITEM_KEY;
2585 key.offset = 0;
2586
2587 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2588 if (ret < 0)
2589 goto out;
2590 if (ret > 0) {
2591 ret = -ENOENT;
2592 goto out;
2593 }
2594
2595 ret = btrfs_del_item(trans, root, path);
2596 out:
2597 btrfs_free_path(path);
2598 err = btrfs_commit_transaction(trans, root);
2599 if (err && !ret)
2600 ret = err;
2601 return ret;
2602 }
2603
2604 /*
2605 * This is a heuristic used to reduce the number of chunks balanced on
2606 * resume after balance was interrupted.
2607 */
2608 static void update_balance_args(struct btrfs_balance_control *bctl)
2609 {
2610 /*
2611 * Turn on soft mode for chunk types that were being converted.
2612 */
2613 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2614 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2615 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2616 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2617 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2618 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2619
2620 /*
2621 * Turn on usage filter if is not already used. The idea is
2622 * that chunks that we have already balanced should be
2623 * reasonably full. Don't do it for chunks that are being
2624 * converted - that will keep us from relocating unconverted
2625 * (albeit full) chunks.
2626 */
2627 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2628 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2629 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2630 bctl->data.usage = 90;
2631 }
2632 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2633 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2634 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2635 bctl->sys.usage = 90;
2636 }
2637 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2638 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2639 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2640 bctl->meta.usage = 90;
2641 }
2642 }
2643
2644 /*
2645 * Should be called with both balance and volume mutexes held to
2646 * serialize other volume operations (add_dev/rm_dev/resize) with
2647 * restriper. Same goes for unset_balance_control.
2648 */
2649 static void set_balance_control(struct btrfs_balance_control *bctl)
2650 {
2651 struct btrfs_fs_info *fs_info = bctl->fs_info;
2652
2653 BUG_ON(fs_info->balance_ctl);
2654
2655 spin_lock(&fs_info->balance_lock);
2656 fs_info->balance_ctl = bctl;
2657 spin_unlock(&fs_info->balance_lock);
2658 }
2659
2660 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2661 {
2662 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2663
2664 BUG_ON(!fs_info->balance_ctl);
2665
2666 spin_lock(&fs_info->balance_lock);
2667 fs_info->balance_ctl = NULL;
2668 spin_unlock(&fs_info->balance_lock);
2669
2670 kfree(bctl);
2671 }
2672
2673 /*
2674 * Balance filters. Return 1 if chunk should be filtered out
2675 * (should not be balanced).
2676 */
2677 static int chunk_profiles_filter(u64 chunk_type,
2678 struct btrfs_balance_args *bargs)
2679 {
2680 chunk_type = chunk_to_extended(chunk_type) &
2681 BTRFS_EXTENDED_PROFILE_MASK;
2682
2683 if (bargs->profiles & chunk_type)
2684 return 0;
2685
2686 return 1;
2687 }
2688
2689 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2690 struct btrfs_balance_args *bargs)
2691 {
2692 struct btrfs_block_group_cache *cache;
2693 u64 chunk_used, user_thresh;
2694 int ret = 1;
2695
2696 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2697 chunk_used = btrfs_block_group_used(&cache->item);
2698
2699 if (bargs->usage == 0)
2700 user_thresh = 1;
2701 else if (bargs->usage > 100)
2702 user_thresh = cache->key.offset;
2703 else
2704 user_thresh = div_factor_fine(cache->key.offset,
2705 bargs->usage);
2706
2707 if (chunk_used < user_thresh)
2708 ret = 0;
2709
2710 btrfs_put_block_group(cache);
2711 return ret;
2712 }
2713
2714 static int chunk_devid_filter(struct extent_buffer *leaf,
2715 struct btrfs_chunk *chunk,
2716 struct btrfs_balance_args *bargs)
2717 {
2718 struct btrfs_stripe *stripe;
2719 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2720 int i;
2721
2722 for (i = 0; i < num_stripes; i++) {
2723 stripe = btrfs_stripe_nr(chunk, i);
2724 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2725 return 0;
2726 }
2727
2728 return 1;
2729 }
2730
2731 /* [pstart, pend) */
2732 static int chunk_drange_filter(struct extent_buffer *leaf,
2733 struct btrfs_chunk *chunk,
2734 u64 chunk_offset,
2735 struct btrfs_balance_args *bargs)
2736 {
2737 struct btrfs_stripe *stripe;
2738 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2739 u64 stripe_offset;
2740 u64 stripe_length;
2741 int factor;
2742 int i;
2743
2744 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2745 return 0;
2746
2747 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2748 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2749 factor = num_stripes / 2;
2750 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2751 factor = num_stripes - 1;
2752 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2753 factor = num_stripes - 2;
2754 } else {
2755 factor = num_stripes;
2756 }
2757
2758 for (i = 0; i < num_stripes; i++) {
2759 stripe = btrfs_stripe_nr(chunk, i);
2760 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2761 continue;
2762
2763 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2764 stripe_length = btrfs_chunk_length(leaf, chunk);
2765 do_div(stripe_length, factor);
2766
2767 if (stripe_offset < bargs->pend &&
2768 stripe_offset + stripe_length > bargs->pstart)
2769 return 0;
2770 }
2771
2772 return 1;
2773 }
2774
2775 /* [vstart, vend) */
2776 static int chunk_vrange_filter(struct extent_buffer *leaf,
2777 struct btrfs_chunk *chunk,
2778 u64 chunk_offset,
2779 struct btrfs_balance_args *bargs)
2780 {
2781 if (chunk_offset < bargs->vend &&
2782 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2783 /* at least part of the chunk is inside this vrange */
2784 return 0;
2785
2786 return 1;
2787 }
2788
2789 static int chunk_soft_convert_filter(u64 chunk_type,
2790 struct btrfs_balance_args *bargs)
2791 {
2792 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2793 return 0;
2794
2795 chunk_type = chunk_to_extended(chunk_type) &
2796 BTRFS_EXTENDED_PROFILE_MASK;
2797
2798 if (bargs->target == chunk_type)
2799 return 1;
2800
2801 return 0;
2802 }
2803
2804 static int should_balance_chunk(struct btrfs_root *root,
2805 struct extent_buffer *leaf,
2806 struct btrfs_chunk *chunk, u64 chunk_offset)
2807 {
2808 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2809 struct btrfs_balance_args *bargs = NULL;
2810 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2811
2812 /* type filter */
2813 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2814 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2815 return 0;
2816 }
2817
2818 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2819 bargs = &bctl->data;
2820 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2821 bargs = &bctl->sys;
2822 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2823 bargs = &bctl->meta;
2824
2825 /* profiles filter */
2826 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2827 chunk_profiles_filter(chunk_type, bargs)) {
2828 return 0;
2829 }
2830
2831 /* usage filter */
2832 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2833 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2834 return 0;
2835 }
2836
2837 /* devid filter */
2838 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2839 chunk_devid_filter(leaf, chunk, bargs)) {
2840 return 0;
2841 }
2842
2843 /* drange filter, makes sense only with devid filter */
2844 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2845 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2846 return 0;
2847 }
2848
2849 /* vrange filter */
2850 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2851 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2852 return 0;
2853 }
2854
2855 /* soft profile changing mode */
2856 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2857 chunk_soft_convert_filter(chunk_type, bargs)) {
2858 return 0;
2859 }
2860
2861 return 1;
2862 }
2863
2864 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2865 {
2866 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2867 struct btrfs_root *chunk_root = fs_info->chunk_root;
2868 struct btrfs_root *dev_root = fs_info->dev_root;
2869 struct list_head *devices;
2870 struct btrfs_device *device;
2871 u64 old_size;
2872 u64 size_to_free;
2873 struct btrfs_chunk *chunk;
2874 struct btrfs_path *path;
2875 struct btrfs_key key;
2876 struct btrfs_key found_key;
2877 struct btrfs_trans_handle *trans;
2878 struct extent_buffer *leaf;
2879 int slot;
2880 int ret;
2881 int enospc_errors = 0;
2882 bool counting = true;
2883
2884 /* step one make some room on all the devices */
2885 devices = &fs_info->fs_devices->devices;
2886 list_for_each_entry(device, devices, dev_list) {
2887 old_size = device->total_bytes;
2888 size_to_free = div_factor(old_size, 1);
2889 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2890 if (!device->writeable ||
2891 device->total_bytes - device->bytes_used > size_to_free ||
2892 device->is_tgtdev_for_dev_replace)
2893 continue;
2894
2895 ret = btrfs_shrink_device(device, old_size - size_to_free);
2896 if (ret == -ENOSPC)
2897 break;
2898 BUG_ON(ret);
2899
2900 trans = btrfs_start_transaction(dev_root, 0);
2901 BUG_ON(IS_ERR(trans));
2902
2903 ret = btrfs_grow_device(trans, device, old_size);
2904 BUG_ON(ret);
2905
2906 btrfs_end_transaction(trans, dev_root);
2907 }
2908
2909 /* step two, relocate all the chunks */
2910 path = btrfs_alloc_path();
2911 if (!path) {
2912 ret = -ENOMEM;
2913 goto error;
2914 }
2915
2916 /* zero out stat counters */
2917 spin_lock(&fs_info->balance_lock);
2918 memset(&bctl->stat, 0, sizeof(bctl->stat));
2919 spin_unlock(&fs_info->balance_lock);
2920 again:
2921 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2922 key.offset = (u64)-1;
2923 key.type = BTRFS_CHUNK_ITEM_KEY;
2924
2925 while (1) {
2926 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2927 atomic_read(&fs_info->balance_cancel_req)) {
2928 ret = -ECANCELED;
2929 goto error;
2930 }
2931
2932 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2933 if (ret < 0)
2934 goto error;
2935
2936 /*
2937 * this shouldn't happen, it means the last relocate
2938 * failed
2939 */
2940 if (ret == 0)
2941 BUG(); /* FIXME break ? */
2942
2943 ret = btrfs_previous_item(chunk_root, path, 0,
2944 BTRFS_CHUNK_ITEM_KEY);
2945 if (ret) {
2946 ret = 0;
2947 break;
2948 }
2949
2950 leaf = path->nodes[0];
2951 slot = path->slots[0];
2952 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2953
2954 if (found_key.objectid != key.objectid)
2955 break;
2956
2957 /* chunk zero is special */
2958 if (found_key.offset == 0)
2959 break;
2960
2961 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2962
2963 if (!counting) {
2964 spin_lock(&fs_info->balance_lock);
2965 bctl->stat.considered++;
2966 spin_unlock(&fs_info->balance_lock);
2967 }
2968
2969 ret = should_balance_chunk(chunk_root, leaf, chunk,
2970 found_key.offset);
2971 btrfs_release_path(path);
2972 if (!ret)
2973 goto loop;
2974
2975 if (counting) {
2976 spin_lock(&fs_info->balance_lock);
2977 bctl->stat.expected++;
2978 spin_unlock(&fs_info->balance_lock);
2979 goto loop;
2980 }
2981
2982 ret = btrfs_relocate_chunk(chunk_root,
2983 chunk_root->root_key.objectid,
2984 found_key.objectid,
2985 found_key.offset);
2986 if (ret && ret != -ENOSPC)
2987 goto error;
2988 if (ret == -ENOSPC) {
2989 enospc_errors++;
2990 } else {
2991 spin_lock(&fs_info->balance_lock);
2992 bctl->stat.completed++;
2993 spin_unlock(&fs_info->balance_lock);
2994 }
2995 loop:
2996 key.offset = found_key.offset - 1;
2997 }
2998
2999 if (counting) {
3000 btrfs_release_path(path);
3001 counting = false;
3002 goto again;
3003 }
3004 error:
3005 btrfs_free_path(path);
3006 if (enospc_errors) {
3007 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
3008 enospc_errors);
3009 if (!ret)
3010 ret = -ENOSPC;
3011 }
3012
3013 return ret;
3014 }
3015
3016 /**
3017 * alloc_profile_is_valid - see if a given profile is valid and reduced
3018 * @flags: profile to validate
3019 * @extended: if true @flags is treated as an extended profile
3020 */
3021 static int alloc_profile_is_valid(u64 flags, int extended)
3022 {
3023 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3024 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3025
3026 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3027
3028 /* 1) check that all other bits are zeroed */
3029 if (flags & ~mask)
3030 return 0;
3031
3032 /* 2) see if profile is reduced */
3033 if (flags == 0)
3034 return !extended; /* "0" is valid for usual profiles */
3035
3036 /* true if exactly one bit set */
3037 return (flags & (flags - 1)) == 0;
3038 }
3039
3040 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3041 {
3042 /* cancel requested || normal exit path */
3043 return atomic_read(&fs_info->balance_cancel_req) ||
3044 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3045 atomic_read(&fs_info->balance_cancel_req) == 0);
3046 }
3047
3048 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3049 {
3050 int ret;
3051
3052 unset_balance_control(fs_info);
3053 ret = del_balance_item(fs_info->tree_root);
3054 BUG_ON(ret);
3055
3056 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3057 }
3058
3059 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3060 struct btrfs_ioctl_balance_args *bargs);
3061
3062 /*
3063 * Should be called with both balance and volume mutexes held
3064 */
3065 int btrfs_balance(struct btrfs_balance_control *bctl,
3066 struct btrfs_ioctl_balance_args *bargs)
3067 {
3068 struct btrfs_fs_info *fs_info = bctl->fs_info;
3069 u64 allowed;
3070 int mixed = 0;
3071 int ret;
3072 u64 num_devices;
3073 unsigned seq;
3074
3075 if (btrfs_fs_closing(fs_info) ||
3076 atomic_read(&fs_info->balance_pause_req) ||
3077 atomic_read(&fs_info->balance_cancel_req)) {
3078 ret = -EINVAL;
3079 goto out;
3080 }
3081
3082 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3083 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3084 mixed = 1;
3085
3086 /*
3087 * In case of mixed groups both data and meta should be picked,
3088 * and identical options should be given for both of them.
3089 */
3090 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3091 if (mixed && (bctl->flags & allowed)) {
3092 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3093 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3094 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3095 printk(KERN_ERR "btrfs: with mixed groups data and "
3096 "metadata balance options must be the same\n");
3097 ret = -EINVAL;
3098 goto out;
3099 }
3100 }
3101
3102 num_devices = fs_info->fs_devices->num_devices;
3103 btrfs_dev_replace_lock(&fs_info->dev_replace);
3104 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3105 BUG_ON(num_devices < 1);
3106 num_devices--;
3107 }
3108 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3109 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3110 if (num_devices == 1)
3111 allowed |= BTRFS_BLOCK_GROUP_DUP;
3112 else if (num_devices < 4)
3113 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3114 else
3115 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
3116 BTRFS_BLOCK_GROUP_RAID10 |
3117 BTRFS_BLOCK_GROUP_RAID5 |
3118 BTRFS_BLOCK_GROUP_RAID6);
3119
3120 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3121 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3122 (bctl->data.target & ~allowed))) {
3123 printk(KERN_ERR "btrfs: unable to start balance with target "
3124 "data profile %llu\n",
3125 (unsigned long long)bctl->data.target);
3126 ret = -EINVAL;
3127 goto out;
3128 }
3129 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3130 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3131 (bctl->meta.target & ~allowed))) {
3132 printk(KERN_ERR "btrfs: unable to start balance with target "
3133 "metadata profile %llu\n",
3134 (unsigned long long)bctl->meta.target);
3135 ret = -EINVAL;
3136 goto out;
3137 }
3138 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3139 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3140 (bctl->sys.target & ~allowed))) {
3141 printk(KERN_ERR "btrfs: unable to start balance with target "
3142 "system profile %llu\n",
3143 (unsigned long long)bctl->sys.target);
3144 ret = -EINVAL;
3145 goto out;
3146 }
3147
3148 /* allow dup'ed data chunks only in mixed mode */
3149 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3150 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3151 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3152 ret = -EINVAL;
3153 goto out;
3154 }
3155
3156 /* allow to reduce meta or sys integrity only if force set */
3157 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3158 BTRFS_BLOCK_GROUP_RAID10 |
3159 BTRFS_BLOCK_GROUP_RAID5 |
3160 BTRFS_BLOCK_GROUP_RAID6;
3161 do {
3162 seq = read_seqbegin(&fs_info->profiles_lock);
3163
3164 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3165 (fs_info->avail_system_alloc_bits & allowed) &&
3166 !(bctl->sys.target & allowed)) ||
3167 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3168 (fs_info->avail_metadata_alloc_bits & allowed) &&
3169 !(bctl->meta.target & allowed))) {
3170 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3171 printk(KERN_INFO "btrfs: force reducing metadata "
3172 "integrity\n");
3173 } else {
3174 printk(KERN_ERR "btrfs: balance will reduce metadata "
3175 "integrity, use force if you want this\n");
3176 ret = -EINVAL;
3177 goto out;
3178 }
3179 }
3180 } while (read_seqretry(&fs_info->profiles_lock, seq));
3181
3182 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3183 int num_tolerated_disk_barrier_failures;
3184 u64 target = bctl->sys.target;
3185
3186 num_tolerated_disk_barrier_failures =
3187 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3188 if (num_tolerated_disk_barrier_failures > 0 &&
3189 (target &
3190 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3191 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3192 num_tolerated_disk_barrier_failures = 0;
3193 else if (num_tolerated_disk_barrier_failures > 1 &&
3194 (target &
3195 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3196 num_tolerated_disk_barrier_failures = 1;
3197
3198 fs_info->num_tolerated_disk_barrier_failures =
3199 num_tolerated_disk_barrier_failures;
3200 }
3201
3202 ret = insert_balance_item(fs_info->tree_root, bctl);
3203 if (ret && ret != -EEXIST)
3204 goto out;
3205
3206 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3207 BUG_ON(ret == -EEXIST);
3208 set_balance_control(bctl);
3209 } else {
3210 BUG_ON(ret != -EEXIST);
3211 spin_lock(&fs_info->balance_lock);
3212 update_balance_args(bctl);
3213 spin_unlock(&fs_info->balance_lock);
3214 }
3215
3216 atomic_inc(&fs_info->balance_running);
3217 mutex_unlock(&fs_info->balance_mutex);
3218
3219 ret = __btrfs_balance(fs_info);
3220
3221 mutex_lock(&fs_info->balance_mutex);
3222 atomic_dec(&fs_info->balance_running);
3223
3224 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3225 fs_info->num_tolerated_disk_barrier_failures =
3226 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3227 }
3228
3229 if (bargs) {
3230 memset(bargs, 0, sizeof(*bargs));
3231 update_ioctl_balance_args(fs_info, 0, bargs);
3232 }
3233
3234 wake_up(&fs_info->balance_wait_q);
3235
3236 return ret;
3237 out:
3238 if (bctl->flags & BTRFS_BALANCE_RESUME)
3239 __cancel_balance(fs_info);
3240 else {
3241 kfree(bctl);
3242 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3243 }
3244 return ret;
3245 }
3246
3247 static int balance_kthread(void *data)
3248 {
3249 struct btrfs_fs_info *fs_info = data;
3250 int ret = 0;
3251
3252 mutex_lock(&fs_info->volume_mutex);
3253 mutex_lock(&fs_info->balance_mutex);
3254
3255 if (fs_info->balance_ctl) {
3256 printk(KERN_INFO "btrfs: continuing balance\n");
3257 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3258 }
3259
3260 mutex_unlock(&fs_info->balance_mutex);
3261 mutex_unlock(&fs_info->volume_mutex);
3262
3263 return ret;
3264 }
3265
3266 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3267 {
3268 struct task_struct *tsk;
3269
3270 spin_lock(&fs_info->balance_lock);
3271 if (!fs_info->balance_ctl) {
3272 spin_unlock(&fs_info->balance_lock);
3273 return 0;
3274 }
3275 spin_unlock(&fs_info->balance_lock);
3276
3277 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3278 printk(KERN_INFO "btrfs: force skipping balance\n");
3279 return 0;
3280 }
3281
3282 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3283 if (IS_ERR(tsk))
3284 return PTR_ERR(tsk);
3285
3286 return 0;
3287 }
3288
3289 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3290 {
3291 struct btrfs_balance_control *bctl;
3292 struct btrfs_balance_item *item;
3293 struct btrfs_disk_balance_args disk_bargs;
3294 struct btrfs_path *path;
3295 struct extent_buffer *leaf;
3296 struct btrfs_key key;
3297 int ret;
3298
3299 path = btrfs_alloc_path();
3300 if (!path)
3301 return -ENOMEM;
3302
3303 key.objectid = BTRFS_BALANCE_OBJECTID;
3304 key.type = BTRFS_BALANCE_ITEM_KEY;
3305 key.offset = 0;
3306
3307 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3308 if (ret < 0)
3309 goto out;
3310 if (ret > 0) { /* ret = -ENOENT; */
3311 ret = 0;
3312 goto out;
3313 }
3314
3315 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3316 if (!bctl) {
3317 ret = -ENOMEM;
3318 goto out;
3319 }
3320
3321 leaf = path->nodes[0];
3322 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3323
3324 bctl->fs_info = fs_info;
3325 bctl->flags = btrfs_balance_flags(leaf, item);
3326 bctl->flags |= BTRFS_BALANCE_RESUME;
3327
3328 btrfs_balance_data(leaf, item, &disk_bargs);
3329 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3330 btrfs_balance_meta(leaf, item, &disk_bargs);
3331 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3332 btrfs_balance_sys(leaf, item, &disk_bargs);
3333 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3334
3335 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3336
3337 mutex_lock(&fs_info->volume_mutex);
3338 mutex_lock(&fs_info->balance_mutex);
3339
3340 set_balance_control(bctl);
3341
3342 mutex_unlock(&fs_info->balance_mutex);
3343 mutex_unlock(&fs_info->volume_mutex);
3344 out:
3345 btrfs_free_path(path);
3346 return ret;
3347 }
3348
3349 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3350 {
3351 int ret = 0;
3352
3353 mutex_lock(&fs_info->balance_mutex);
3354 if (!fs_info->balance_ctl) {
3355 mutex_unlock(&fs_info->balance_mutex);
3356 return -ENOTCONN;
3357 }
3358
3359 if (atomic_read(&fs_info->balance_running)) {
3360 atomic_inc(&fs_info->balance_pause_req);
3361 mutex_unlock(&fs_info->balance_mutex);
3362
3363 wait_event(fs_info->balance_wait_q,
3364 atomic_read(&fs_info->balance_running) == 0);
3365
3366 mutex_lock(&fs_info->balance_mutex);
3367 /* we are good with balance_ctl ripped off from under us */
3368 BUG_ON(atomic_read(&fs_info->balance_running));
3369 atomic_dec(&fs_info->balance_pause_req);
3370 } else {
3371 ret = -ENOTCONN;
3372 }
3373
3374 mutex_unlock(&fs_info->balance_mutex);
3375 return ret;
3376 }
3377
3378 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3379 {
3380 mutex_lock(&fs_info->balance_mutex);
3381 if (!fs_info->balance_ctl) {
3382 mutex_unlock(&fs_info->balance_mutex);
3383 return -ENOTCONN;
3384 }
3385
3386 atomic_inc(&fs_info->balance_cancel_req);
3387 /*
3388 * if we are running just wait and return, balance item is
3389 * deleted in btrfs_balance in this case
3390 */
3391 if (atomic_read(&fs_info->balance_running)) {
3392 mutex_unlock(&fs_info->balance_mutex);
3393 wait_event(fs_info->balance_wait_q,
3394 atomic_read(&fs_info->balance_running) == 0);
3395 mutex_lock(&fs_info->balance_mutex);
3396 } else {
3397 /* __cancel_balance needs volume_mutex */
3398 mutex_unlock(&fs_info->balance_mutex);
3399 mutex_lock(&fs_info->volume_mutex);
3400 mutex_lock(&fs_info->balance_mutex);
3401
3402 if (fs_info->balance_ctl)
3403 __cancel_balance(fs_info);
3404
3405 mutex_unlock(&fs_info->volume_mutex);
3406 }
3407
3408 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3409 atomic_dec(&fs_info->balance_cancel_req);
3410 mutex_unlock(&fs_info->balance_mutex);
3411 return 0;
3412 }
3413
3414 /*
3415 * shrinking a device means finding all of the device extents past
3416 * the new size, and then following the back refs to the chunks.
3417 * The chunk relocation code actually frees the device extent
3418 */
3419 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3420 {
3421 struct btrfs_trans_handle *trans;
3422 struct btrfs_root *root = device->dev_root;
3423 struct btrfs_dev_extent *dev_extent = NULL;
3424 struct btrfs_path *path;
3425 u64 length;
3426 u64 chunk_tree;
3427 u64 chunk_objectid;
3428 u64 chunk_offset;
3429 int ret;
3430 int slot;
3431 int failed = 0;
3432 bool retried = false;
3433 struct extent_buffer *l;
3434 struct btrfs_key key;
3435 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3436 u64 old_total = btrfs_super_total_bytes(super_copy);
3437 u64 old_size = device->total_bytes;
3438 u64 diff = device->total_bytes - new_size;
3439
3440 if (device->is_tgtdev_for_dev_replace)
3441 return -EINVAL;
3442
3443 path = btrfs_alloc_path();
3444 if (!path)
3445 return -ENOMEM;
3446
3447 path->reada = 2;
3448
3449 lock_chunks(root);
3450
3451 device->total_bytes = new_size;
3452 if (device->writeable) {
3453 device->fs_devices->total_rw_bytes -= diff;
3454 spin_lock(&root->fs_info->free_chunk_lock);
3455 root->fs_info->free_chunk_space -= diff;
3456 spin_unlock(&root->fs_info->free_chunk_lock);
3457 }
3458 unlock_chunks(root);
3459
3460 again:
3461 key.objectid = device->devid;
3462 key.offset = (u64)-1;
3463 key.type = BTRFS_DEV_EXTENT_KEY;
3464
3465 do {
3466 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3467 if (ret < 0)
3468 goto done;
3469
3470 ret = btrfs_previous_item(root, path, 0, key.type);
3471 if (ret < 0)
3472 goto done;
3473 if (ret) {
3474 ret = 0;
3475 btrfs_release_path(path);
3476 break;
3477 }
3478
3479 l = path->nodes[0];
3480 slot = path->slots[0];
3481 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3482
3483 if (key.objectid != device->devid) {
3484 btrfs_release_path(path);
3485 break;
3486 }
3487
3488 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3489 length = btrfs_dev_extent_length(l, dev_extent);
3490
3491 if (key.offset + length <= new_size) {
3492 btrfs_release_path(path);
3493 break;
3494 }
3495
3496 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3497 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3498 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3499 btrfs_release_path(path);
3500
3501 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3502 chunk_offset);
3503 if (ret && ret != -ENOSPC)
3504 goto done;
3505 if (ret == -ENOSPC)
3506 failed++;
3507 } while (key.offset-- > 0);
3508
3509 if (failed && !retried) {
3510 failed = 0;
3511 retried = true;
3512 goto again;
3513 } else if (failed && retried) {
3514 ret = -ENOSPC;
3515 lock_chunks(root);
3516
3517 device->total_bytes = old_size;
3518 if (device->writeable)
3519 device->fs_devices->total_rw_bytes += diff;
3520 spin_lock(&root->fs_info->free_chunk_lock);
3521 root->fs_info->free_chunk_space += diff;
3522 spin_unlock(&root->fs_info->free_chunk_lock);
3523 unlock_chunks(root);
3524 goto done;
3525 }
3526
3527 /* Shrinking succeeded, else we would be at "done". */
3528 trans = btrfs_start_transaction(root, 0);
3529 if (IS_ERR(trans)) {
3530 ret = PTR_ERR(trans);
3531 goto done;
3532 }
3533
3534 lock_chunks(root);
3535
3536 device->disk_total_bytes = new_size;
3537 /* Now btrfs_update_device() will change the on-disk size. */
3538 ret = btrfs_update_device(trans, device);
3539 if (ret) {
3540 unlock_chunks(root);
3541 btrfs_end_transaction(trans, root);
3542 goto done;
3543 }
3544 WARN_ON(diff > old_total);
3545 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3546 unlock_chunks(root);
3547 btrfs_end_transaction(trans, root);
3548 done:
3549 btrfs_free_path(path);
3550 return ret;
3551 }
3552
3553 static int btrfs_add_system_chunk(struct btrfs_root *root,
3554 struct btrfs_key *key,
3555 struct btrfs_chunk *chunk, int item_size)
3556 {
3557 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3558 struct btrfs_disk_key disk_key;
3559 u32 array_size;
3560 u8 *ptr;
3561
3562 array_size = btrfs_super_sys_array_size(super_copy);
3563 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3564 return -EFBIG;
3565
3566 ptr = super_copy->sys_chunk_array + array_size;
3567 btrfs_cpu_key_to_disk(&disk_key, key);
3568 memcpy(ptr, &disk_key, sizeof(disk_key));
3569 ptr += sizeof(disk_key);
3570 memcpy(ptr, chunk, item_size);
3571 item_size += sizeof(disk_key);
3572 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3573 return 0;
3574 }
3575
3576 /*
3577 * sort the devices in descending order by max_avail, total_avail
3578 */
3579 static int btrfs_cmp_device_info(const void *a, const void *b)
3580 {
3581 const struct btrfs_device_info *di_a = a;
3582 const struct btrfs_device_info *di_b = b;
3583
3584 if (di_a->max_avail > di_b->max_avail)
3585 return -1;
3586 if (di_a->max_avail < di_b->max_avail)
3587 return 1;
3588 if (di_a->total_avail > di_b->total_avail)
3589 return -1;
3590 if (di_a->total_avail < di_b->total_avail)
3591 return 1;
3592 return 0;
3593 }
3594
3595 struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3596 [BTRFS_RAID_RAID10] = {
3597 .sub_stripes = 2,
3598 .dev_stripes = 1,
3599 .devs_max = 0, /* 0 == as many as possible */
3600 .devs_min = 4,
3601 .devs_increment = 2,
3602 .ncopies = 2,
3603 },
3604 [BTRFS_RAID_RAID1] = {
3605 .sub_stripes = 1,
3606 .dev_stripes = 1,
3607 .devs_max = 2,
3608 .devs_min = 2,
3609 .devs_increment = 2,
3610 .ncopies = 2,
3611 },
3612 [BTRFS_RAID_DUP] = {
3613 .sub_stripes = 1,
3614 .dev_stripes = 2,
3615 .devs_max = 1,
3616 .devs_min = 1,
3617 .devs_increment = 1,
3618 .ncopies = 2,
3619 },
3620 [BTRFS_RAID_RAID0] = {
3621 .sub_stripes = 1,
3622 .dev_stripes = 1,
3623 .devs_max = 0,
3624 .devs_min = 2,
3625 .devs_increment = 1,
3626 .ncopies = 1,
3627 },
3628 [BTRFS_RAID_SINGLE] = {
3629 .sub_stripes = 1,
3630 .dev_stripes = 1,
3631 .devs_max = 1,
3632 .devs_min = 1,
3633 .devs_increment = 1,
3634 .ncopies = 1,
3635 },
3636 [BTRFS_RAID_RAID5] = {
3637 .sub_stripes = 1,
3638 .dev_stripes = 1,
3639 .devs_max = 0,
3640 .devs_min = 2,
3641 .devs_increment = 1,
3642 .ncopies = 2,
3643 },
3644 [BTRFS_RAID_RAID6] = {
3645 .sub_stripes = 1,
3646 .dev_stripes = 1,
3647 .devs_max = 0,
3648 .devs_min = 3,
3649 .devs_increment = 1,
3650 .ncopies = 3,
3651 },
3652 };
3653
3654 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3655 {
3656 /* TODO allow them to set a preferred stripe size */
3657 return 64 * 1024;
3658 }
3659
3660 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3661 {
3662 u64 features;
3663
3664 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3665 return;
3666
3667 features = btrfs_super_incompat_flags(info->super_copy);
3668 if (features & BTRFS_FEATURE_INCOMPAT_RAID56)
3669 return;
3670
3671 features |= BTRFS_FEATURE_INCOMPAT_RAID56;
3672 btrfs_set_super_incompat_flags(info->super_copy, features);
3673 printk(KERN_INFO "btrfs: setting RAID5/6 feature flag\n");
3674 }
3675
3676 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3677 struct btrfs_root *extent_root,
3678 struct map_lookup **map_ret,
3679 u64 *num_bytes_out, u64 *stripe_size_out,
3680 u64 start, u64 type)
3681 {
3682 struct btrfs_fs_info *info = extent_root->fs_info;
3683 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3684 struct list_head *cur;
3685 struct map_lookup *map = NULL;
3686 struct extent_map_tree *em_tree;
3687 struct extent_map *em;
3688 struct btrfs_device_info *devices_info = NULL;
3689 u64 total_avail;
3690 int num_stripes; /* total number of stripes to allocate */
3691 int data_stripes; /* number of stripes that count for
3692 block group size */
3693 int sub_stripes; /* sub_stripes info for map */
3694 int dev_stripes; /* stripes per dev */
3695 int devs_max; /* max devs to use */
3696 int devs_min; /* min devs needed */
3697 int devs_increment; /* ndevs has to be a multiple of this */
3698 int ncopies; /* how many copies to data has */
3699 int ret;
3700 u64 max_stripe_size;
3701 u64 max_chunk_size;
3702 u64 stripe_size;
3703 u64 num_bytes;
3704 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
3705 int ndevs;
3706 int i;
3707 int j;
3708 int index;
3709
3710 BUG_ON(!alloc_profile_is_valid(type, 0));
3711
3712 if (list_empty(&fs_devices->alloc_list))
3713 return -ENOSPC;
3714
3715 index = __get_raid_index(type);
3716
3717 sub_stripes = btrfs_raid_array[index].sub_stripes;
3718 dev_stripes = btrfs_raid_array[index].dev_stripes;
3719 devs_max = btrfs_raid_array[index].devs_max;
3720 devs_min = btrfs_raid_array[index].devs_min;
3721 devs_increment = btrfs_raid_array[index].devs_increment;
3722 ncopies = btrfs_raid_array[index].ncopies;
3723
3724 if (type & BTRFS_BLOCK_GROUP_DATA) {
3725 max_stripe_size = 1024 * 1024 * 1024;
3726 max_chunk_size = 10 * max_stripe_size;
3727 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3728 /* for larger filesystems, use larger metadata chunks */
3729 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3730 max_stripe_size = 1024 * 1024 * 1024;
3731 else
3732 max_stripe_size = 256 * 1024 * 1024;
3733 max_chunk_size = max_stripe_size;
3734 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3735 max_stripe_size = 32 * 1024 * 1024;
3736 max_chunk_size = 2 * max_stripe_size;
3737 } else {
3738 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3739 type);
3740 BUG_ON(1);
3741 }
3742
3743 /* we don't want a chunk larger than 10% of writeable space */
3744 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3745 max_chunk_size);
3746
3747 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3748 GFP_NOFS);
3749 if (!devices_info)
3750 return -ENOMEM;
3751
3752 cur = fs_devices->alloc_list.next;
3753
3754 /*
3755 * in the first pass through the devices list, we gather information
3756 * about the available holes on each device.
3757 */
3758 ndevs = 0;
3759 while (cur != &fs_devices->alloc_list) {
3760 struct btrfs_device *device;
3761 u64 max_avail;
3762 u64 dev_offset;
3763
3764 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3765
3766 cur = cur->next;
3767
3768 if (!device->writeable) {
3769 WARN(1, KERN_ERR
3770 "btrfs: read-only device in alloc_list\n");
3771 continue;
3772 }
3773
3774 if (!device->in_fs_metadata ||
3775 device->is_tgtdev_for_dev_replace)
3776 continue;
3777
3778 if (device->total_bytes > device->bytes_used)
3779 total_avail = device->total_bytes - device->bytes_used;
3780 else
3781 total_avail = 0;
3782
3783 /* If there is no space on this device, skip it. */
3784 if (total_avail == 0)
3785 continue;
3786
3787 ret = find_free_dev_extent(device,
3788 max_stripe_size * dev_stripes,
3789 &dev_offset, &max_avail);
3790 if (ret && ret != -ENOSPC)
3791 goto error;
3792
3793 if (ret == 0)
3794 max_avail = max_stripe_size * dev_stripes;
3795
3796 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3797 continue;
3798
3799 if (ndevs == fs_devices->rw_devices) {
3800 WARN(1, "%s: found more than %llu devices\n",
3801 __func__, fs_devices->rw_devices);
3802 break;
3803 }
3804 devices_info[ndevs].dev_offset = dev_offset;
3805 devices_info[ndevs].max_avail = max_avail;
3806 devices_info[ndevs].total_avail = total_avail;
3807 devices_info[ndevs].dev = device;
3808 ++ndevs;
3809 }
3810
3811 /*
3812 * now sort the devices by hole size / available space
3813 */
3814 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3815 btrfs_cmp_device_info, NULL);
3816
3817 /* round down to number of usable stripes */
3818 ndevs -= ndevs % devs_increment;
3819
3820 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3821 ret = -ENOSPC;
3822 goto error;
3823 }
3824
3825 if (devs_max && ndevs > devs_max)
3826 ndevs = devs_max;
3827 /*
3828 * the primary goal is to maximize the number of stripes, so use as many
3829 * devices as possible, even if the stripes are not maximum sized.
3830 */
3831 stripe_size = devices_info[ndevs-1].max_avail;
3832 num_stripes = ndevs * dev_stripes;
3833
3834 /*
3835 * this will have to be fixed for RAID1 and RAID10 over
3836 * more drives
3837 */
3838 data_stripes = num_stripes / ncopies;
3839
3840 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3841 stripe_size = max_chunk_size * ncopies;
3842 do_div(stripe_size, ndevs);
3843 }
3844 if (type & BTRFS_BLOCK_GROUP_RAID5) {
3845 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
3846 btrfs_super_stripesize(info->super_copy));
3847 data_stripes = num_stripes - 1;
3848 }
3849 if (type & BTRFS_BLOCK_GROUP_RAID6) {
3850 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
3851 btrfs_super_stripesize(info->super_copy));
3852 data_stripes = num_stripes - 2;
3853 }
3854 do_div(stripe_size, dev_stripes);
3855
3856 /* align to BTRFS_STRIPE_LEN */
3857 do_div(stripe_size, raid_stripe_len);
3858 stripe_size *= raid_stripe_len;
3859
3860 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3861 if (!map) {
3862 ret = -ENOMEM;
3863 goto error;
3864 }
3865 map->num_stripes = num_stripes;
3866
3867 for (i = 0; i < ndevs; ++i) {
3868 for (j = 0; j < dev_stripes; ++j) {
3869 int s = i * dev_stripes + j;
3870 map->stripes[s].dev = devices_info[i].dev;
3871 map->stripes[s].physical = devices_info[i].dev_offset +
3872 j * stripe_size;
3873 }
3874 }
3875 map->sector_size = extent_root->sectorsize;
3876 map->stripe_len = raid_stripe_len;
3877 map->io_align = raid_stripe_len;
3878 map->io_width = raid_stripe_len;
3879 map->type = type;
3880 map->sub_stripes = sub_stripes;
3881
3882 *map_ret = map;
3883 num_bytes = stripe_size * data_stripes;
3884
3885 *stripe_size_out = stripe_size;
3886 *num_bytes_out = num_bytes;
3887
3888 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3889
3890 em = alloc_extent_map();
3891 if (!em) {
3892 ret = -ENOMEM;
3893 goto error;
3894 }
3895 em->bdev = (struct block_device *)map;
3896 em->start = start;
3897 em->len = num_bytes;
3898 em->block_start = 0;
3899 em->block_len = em->len;
3900
3901 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3902 write_lock(&em_tree->lock);
3903 ret = add_extent_mapping(em_tree, em);
3904 write_unlock(&em_tree->lock);
3905 if (ret) {
3906 free_extent_map(em);
3907 goto error;
3908 }
3909
3910 for (i = 0; i < map->num_stripes; ++i) {
3911 struct btrfs_device *device;
3912 u64 dev_offset;
3913
3914 device = map->stripes[i].dev;
3915 dev_offset = map->stripes[i].physical;
3916
3917 ret = btrfs_alloc_dev_extent(trans, device,
3918 info->chunk_root->root_key.objectid,
3919 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3920 start, dev_offset, stripe_size);
3921 if (ret)
3922 goto error_dev_extent;
3923 }
3924
3925 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3926 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3927 start, num_bytes);
3928 if (ret) {
3929 i = map->num_stripes - 1;
3930 goto error_dev_extent;
3931 }
3932
3933 free_extent_map(em);
3934 check_raid56_incompat_flag(extent_root->fs_info, type);
3935
3936 kfree(devices_info);
3937 return 0;
3938
3939 error_dev_extent:
3940 for (; i >= 0; i--) {
3941 struct btrfs_device *device;
3942 int err;
3943
3944 device = map->stripes[i].dev;
3945 err = btrfs_free_dev_extent(trans, device, start);
3946 if (err) {
3947 btrfs_abort_transaction(trans, extent_root, err);
3948 break;
3949 }
3950 }
3951 write_lock(&em_tree->lock);
3952 remove_extent_mapping(em_tree, em);
3953 write_unlock(&em_tree->lock);
3954
3955 /* One for our allocation */
3956 free_extent_map(em);
3957 /* One for the tree reference */
3958 free_extent_map(em);
3959 error:
3960 kfree(map);
3961 kfree(devices_info);
3962 return ret;
3963 }
3964
3965 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3966 struct btrfs_root *extent_root,
3967 struct map_lookup *map, u64 chunk_offset,
3968 u64 chunk_size, u64 stripe_size)
3969 {
3970 u64 dev_offset;
3971 struct btrfs_key key;
3972 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3973 struct btrfs_device *device;
3974 struct btrfs_chunk *chunk;
3975 struct btrfs_stripe *stripe;
3976 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3977 int index = 0;
3978 int ret;
3979
3980 chunk = kzalloc(item_size, GFP_NOFS);
3981 if (!chunk)
3982 return -ENOMEM;
3983
3984 index = 0;
3985 while (index < map->num_stripes) {
3986 device = map->stripes[index].dev;
3987 device->bytes_used += stripe_size;
3988 ret = btrfs_update_device(trans, device);
3989 if (ret)
3990 goto out_free;
3991 index++;
3992 }
3993
3994 spin_lock(&extent_root->fs_info->free_chunk_lock);
3995 extent_root->fs_info->free_chunk_space -= (stripe_size *
3996 map->num_stripes);
3997 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3998
3999 index = 0;
4000 stripe = &chunk->stripe;
4001 while (index < map->num_stripes) {
4002 device = map->stripes[index].dev;
4003 dev_offset = map->stripes[index].physical;
4004
4005 btrfs_set_stack_stripe_devid(stripe, device->devid);
4006 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4007 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4008 stripe++;
4009 index++;
4010 }
4011
4012 btrfs_set_stack_chunk_length(chunk, chunk_size);
4013 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4014 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4015 btrfs_set_stack_chunk_type(chunk, map->type);
4016 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4017 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4018 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4019 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4020 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4021
4022 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4023 key.type = BTRFS_CHUNK_ITEM_KEY;
4024 key.offset = chunk_offset;
4025
4026 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4027
4028 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4029 /*
4030 * TODO: Cleanup of inserted chunk root in case of
4031 * failure.
4032 */
4033 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4034 item_size);
4035 }
4036
4037 out_free:
4038 kfree(chunk);
4039 return ret;
4040 }
4041
4042 /*
4043 * Chunk allocation falls into two parts. The first part does works
4044 * that make the new allocated chunk useable, but not do any operation
4045 * that modifies the chunk tree. The second part does the works that
4046 * require modifying the chunk tree. This division is important for the
4047 * bootstrap process of adding storage to a seed btrfs.
4048 */
4049 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4050 struct btrfs_root *extent_root, u64 type)
4051 {
4052 u64 chunk_offset;
4053 u64 chunk_size;
4054 u64 stripe_size;
4055 struct map_lookup *map;
4056 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4057 int ret;
4058
4059 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4060 &chunk_offset);
4061 if (ret)
4062 return ret;
4063
4064 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
4065 &stripe_size, chunk_offset, type);
4066 if (ret)
4067 return ret;
4068
4069 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
4070 chunk_size, stripe_size);
4071 if (ret)
4072 return ret;
4073 return 0;
4074 }
4075
4076 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4077 struct btrfs_root *root,
4078 struct btrfs_device *device)
4079 {
4080 u64 chunk_offset;
4081 u64 sys_chunk_offset;
4082 u64 chunk_size;
4083 u64 sys_chunk_size;
4084 u64 stripe_size;
4085 u64 sys_stripe_size;
4086 u64 alloc_profile;
4087 struct map_lookup *map;
4088 struct map_lookup *sys_map;
4089 struct btrfs_fs_info *fs_info = root->fs_info;
4090 struct btrfs_root *extent_root = fs_info->extent_root;
4091 int ret;
4092
4093 ret = find_next_chunk(fs_info->chunk_root,
4094 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
4095 if (ret)
4096 return ret;
4097
4098 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4099 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
4100 &stripe_size, chunk_offset, alloc_profile);
4101 if (ret)
4102 return ret;
4103
4104 sys_chunk_offset = chunk_offset + chunk_size;
4105
4106 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4107 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
4108 &sys_chunk_size, &sys_stripe_size,
4109 sys_chunk_offset, alloc_profile);
4110 if (ret) {
4111 btrfs_abort_transaction(trans, root, ret);
4112 goto out;
4113 }
4114
4115 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4116 if (ret) {
4117 btrfs_abort_transaction(trans, root, ret);
4118 goto out;
4119 }
4120
4121 /*
4122 * Modifying chunk tree needs allocating new blocks from both
4123 * system block group and metadata block group. So we only can
4124 * do operations require modifying the chunk tree after both
4125 * block groups were created.
4126 */
4127 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
4128 chunk_size, stripe_size);
4129 if (ret) {
4130 btrfs_abort_transaction(trans, root, ret);
4131 goto out;
4132 }
4133
4134 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
4135 sys_chunk_offset, sys_chunk_size,
4136 sys_stripe_size);
4137 if (ret)
4138 btrfs_abort_transaction(trans, root, ret);
4139
4140 out:
4141
4142 return ret;
4143 }
4144
4145 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4146 {
4147 struct extent_map *em;
4148 struct map_lookup *map;
4149 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4150 int readonly = 0;
4151 int i;
4152
4153 read_lock(&map_tree->map_tree.lock);
4154 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4155 read_unlock(&map_tree->map_tree.lock);
4156 if (!em)
4157 return 1;
4158
4159 if (btrfs_test_opt(root, DEGRADED)) {
4160 free_extent_map(em);
4161 return 0;
4162 }
4163
4164 map = (struct map_lookup *)em->bdev;
4165 for (i = 0; i < map->num_stripes; i++) {
4166 if (!map->stripes[i].dev->writeable) {
4167 readonly = 1;
4168 break;
4169 }
4170 }
4171 free_extent_map(em);
4172 return readonly;
4173 }
4174
4175 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4176 {
4177 extent_map_tree_init(&tree->map_tree);
4178 }
4179
4180 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4181 {
4182 struct extent_map *em;
4183
4184 while (1) {
4185 write_lock(&tree->map_tree.lock);
4186 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4187 if (em)
4188 remove_extent_mapping(&tree->map_tree, em);
4189 write_unlock(&tree->map_tree.lock);
4190 if (!em)
4191 break;
4192 kfree(em->bdev);
4193 /* once for us */
4194 free_extent_map(em);
4195 /* once for the tree */
4196 free_extent_map(em);
4197 }
4198 }
4199
4200 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4201 {
4202 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4203 struct extent_map *em;
4204 struct map_lookup *map;
4205 struct extent_map_tree *em_tree = &map_tree->map_tree;
4206 int ret;
4207
4208 read_lock(&em_tree->lock);
4209 em = lookup_extent_mapping(em_tree, logical, len);
4210 read_unlock(&em_tree->lock);
4211 BUG_ON(!em);
4212
4213 BUG_ON(em->start > logical || em->start + em->len < logical);
4214 map = (struct map_lookup *)em->bdev;
4215 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4216 ret = map->num_stripes;
4217 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4218 ret = map->sub_stripes;
4219 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4220 ret = 2;
4221 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4222 ret = 3;
4223 else
4224 ret = 1;
4225 free_extent_map(em);
4226
4227 btrfs_dev_replace_lock(&fs_info->dev_replace);
4228 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4229 ret++;
4230 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4231
4232 return ret;
4233 }
4234
4235 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4236 struct btrfs_mapping_tree *map_tree,
4237 u64 logical)
4238 {
4239 struct extent_map *em;
4240 struct map_lookup *map;
4241 struct extent_map_tree *em_tree = &map_tree->map_tree;
4242 unsigned long len = root->sectorsize;
4243
4244 read_lock(&em_tree->lock);
4245 em = lookup_extent_mapping(em_tree, logical, len);
4246 read_unlock(&em_tree->lock);
4247 BUG_ON(!em);
4248
4249 BUG_ON(em->start > logical || em->start + em->len < logical);
4250 map = (struct map_lookup *)em->bdev;
4251 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4252 BTRFS_BLOCK_GROUP_RAID6)) {
4253 len = map->stripe_len * nr_data_stripes(map);
4254 }
4255 free_extent_map(em);
4256 return len;
4257 }
4258
4259 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4260 u64 logical, u64 len, int mirror_num)
4261 {
4262 struct extent_map *em;
4263 struct map_lookup *map;
4264 struct extent_map_tree *em_tree = &map_tree->map_tree;
4265 int ret = 0;
4266
4267 read_lock(&em_tree->lock);
4268 em = lookup_extent_mapping(em_tree, logical, len);
4269 read_unlock(&em_tree->lock);
4270 BUG_ON(!em);
4271
4272 BUG_ON(em->start > logical || em->start + em->len < logical);
4273 map = (struct map_lookup *)em->bdev;
4274 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4275 BTRFS_BLOCK_GROUP_RAID6))
4276 ret = 1;
4277 free_extent_map(em);
4278 return ret;
4279 }
4280
4281 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4282 struct map_lookup *map, int first, int num,
4283 int optimal, int dev_replace_is_ongoing)
4284 {
4285 int i;
4286 int tolerance;
4287 struct btrfs_device *srcdev;
4288
4289 if (dev_replace_is_ongoing &&
4290 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4291 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4292 srcdev = fs_info->dev_replace.srcdev;
4293 else
4294 srcdev = NULL;
4295
4296 /*
4297 * try to avoid the drive that is the source drive for a
4298 * dev-replace procedure, only choose it if no other non-missing
4299 * mirror is available
4300 */
4301 for (tolerance = 0; tolerance < 2; tolerance++) {
4302 if (map->stripes[optimal].dev->bdev &&
4303 (tolerance || map->stripes[optimal].dev != srcdev))
4304 return optimal;
4305 for (i = first; i < first + num; i++) {
4306 if (map->stripes[i].dev->bdev &&
4307 (tolerance || map->stripes[i].dev != srcdev))
4308 return i;
4309 }
4310 }
4311
4312 /* we couldn't find one that doesn't fail. Just return something
4313 * and the io error handling code will clean up eventually
4314 */
4315 return optimal;
4316 }
4317
4318 static inline int parity_smaller(u64 a, u64 b)
4319 {
4320 return a > b;
4321 }
4322
4323 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4324 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4325 {
4326 struct btrfs_bio_stripe s;
4327 int i;
4328 u64 l;
4329 int again = 1;
4330
4331 while (again) {
4332 again = 0;
4333 for (i = 0; i < bbio->num_stripes - 1; i++) {
4334 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4335 s = bbio->stripes[i];
4336 l = raid_map[i];
4337 bbio->stripes[i] = bbio->stripes[i+1];
4338 raid_map[i] = raid_map[i+1];
4339 bbio->stripes[i+1] = s;
4340 raid_map[i+1] = l;
4341 again = 1;
4342 }
4343 }
4344 }
4345 }
4346
4347 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4348 u64 logical, u64 *length,
4349 struct btrfs_bio **bbio_ret,
4350 int mirror_num, u64 **raid_map_ret)
4351 {
4352 struct extent_map *em;
4353 struct map_lookup *map;
4354 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4355 struct extent_map_tree *em_tree = &map_tree->map_tree;
4356 u64 offset;
4357 u64 stripe_offset;
4358 u64 stripe_end_offset;
4359 u64 stripe_nr;
4360 u64 stripe_nr_orig;
4361 u64 stripe_nr_end;
4362 u64 stripe_len;
4363 u64 *raid_map = NULL;
4364 int stripe_index;
4365 int i;
4366 int ret = 0;
4367 int num_stripes;
4368 int max_errors = 0;
4369 struct btrfs_bio *bbio = NULL;
4370 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4371 int dev_replace_is_ongoing = 0;
4372 int num_alloc_stripes;
4373 int patch_the_first_stripe_for_dev_replace = 0;
4374 u64 physical_to_patch_in_first_stripe = 0;
4375 u64 raid56_full_stripe_start = (u64)-1;
4376
4377 read_lock(&em_tree->lock);
4378 em = lookup_extent_mapping(em_tree, logical, *length);
4379 read_unlock(&em_tree->lock);
4380
4381 if (!em) {
4382 printk(KERN_CRIT "btrfs: unable to find logical %llu len %llu\n",
4383 (unsigned long long)logical,
4384 (unsigned long long)*length);
4385 BUG();
4386 }
4387
4388 BUG_ON(em->start > logical || em->start + em->len < logical);
4389 map = (struct map_lookup *)em->bdev;
4390 offset = logical - em->start;
4391
4392 if (mirror_num > map->num_stripes)
4393 mirror_num = 0;
4394
4395 stripe_len = map->stripe_len;
4396 stripe_nr = offset;
4397 /*
4398 * stripe_nr counts the total number of stripes we have to stride
4399 * to get to this block
4400 */
4401 do_div(stripe_nr, stripe_len);
4402
4403 stripe_offset = stripe_nr * stripe_len;
4404 BUG_ON(offset < stripe_offset);
4405
4406 /* stripe_offset is the offset of this block in its stripe*/
4407 stripe_offset = offset - stripe_offset;
4408
4409 /* if we're here for raid56, we need to know the stripe aligned start */
4410 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4411 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4412 raid56_full_stripe_start = offset;
4413
4414 /* allow a write of a full stripe, but make sure we don't
4415 * allow straddling of stripes
4416 */
4417 do_div(raid56_full_stripe_start, full_stripe_len);
4418 raid56_full_stripe_start *= full_stripe_len;
4419 }
4420
4421 if (rw & REQ_DISCARD) {
4422 /* we don't discard raid56 yet */
4423 if (map->type &
4424 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4425 ret = -EOPNOTSUPP;
4426 goto out;
4427 }
4428 *length = min_t(u64, em->len - offset, *length);
4429 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4430 u64 max_len;
4431 /* For writes to RAID[56], allow a full stripeset across all disks.
4432 For other RAID types and for RAID[56] reads, just allow a single
4433 stripe (on a single disk). */
4434 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4435 (rw & REQ_WRITE)) {
4436 max_len = stripe_len * nr_data_stripes(map) -
4437 (offset - raid56_full_stripe_start);
4438 } else {
4439 /* we limit the length of each bio to what fits in a stripe */
4440 max_len = stripe_len - stripe_offset;
4441 }
4442 *length = min_t(u64, em->len - offset, max_len);
4443 } else {
4444 *length = em->len - offset;
4445 }
4446
4447 /* This is for when we're called from btrfs_merge_bio_hook() and all
4448 it cares about is the length */
4449 if (!bbio_ret)
4450 goto out;
4451
4452 btrfs_dev_replace_lock(dev_replace);
4453 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4454 if (!dev_replace_is_ongoing)
4455 btrfs_dev_replace_unlock(dev_replace);
4456
4457 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4458 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4459 dev_replace->tgtdev != NULL) {
4460 /*
4461 * in dev-replace case, for repair case (that's the only
4462 * case where the mirror is selected explicitly when
4463 * calling btrfs_map_block), blocks left of the left cursor
4464 * can also be read from the target drive.
4465 * For REQ_GET_READ_MIRRORS, the target drive is added as
4466 * the last one to the array of stripes. For READ, it also
4467 * needs to be supported using the same mirror number.
4468 * If the requested block is not left of the left cursor,
4469 * EIO is returned. This can happen because btrfs_num_copies()
4470 * returns one more in the dev-replace case.
4471 */
4472 u64 tmp_length = *length;
4473 struct btrfs_bio *tmp_bbio = NULL;
4474 int tmp_num_stripes;
4475 u64 srcdev_devid = dev_replace->srcdev->devid;
4476 int index_srcdev = 0;
4477 int found = 0;
4478 u64 physical_of_found = 0;
4479
4480 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4481 logical, &tmp_length, &tmp_bbio, 0, NULL);
4482 if (ret) {
4483 WARN_ON(tmp_bbio != NULL);
4484 goto out;
4485 }
4486
4487 tmp_num_stripes = tmp_bbio->num_stripes;
4488 if (mirror_num > tmp_num_stripes) {
4489 /*
4490 * REQ_GET_READ_MIRRORS does not contain this
4491 * mirror, that means that the requested area
4492 * is not left of the left cursor
4493 */
4494 ret = -EIO;
4495 kfree(tmp_bbio);
4496 goto out;
4497 }
4498
4499 /*
4500 * process the rest of the function using the mirror_num
4501 * of the source drive. Therefore look it up first.
4502 * At the end, patch the device pointer to the one of the
4503 * target drive.
4504 */
4505 for (i = 0; i < tmp_num_stripes; i++) {
4506 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4507 /*
4508 * In case of DUP, in order to keep it
4509 * simple, only add the mirror with the
4510 * lowest physical address
4511 */
4512 if (found &&
4513 physical_of_found <=
4514 tmp_bbio->stripes[i].physical)
4515 continue;
4516 index_srcdev = i;
4517 found = 1;
4518 physical_of_found =
4519 tmp_bbio->stripes[i].physical;
4520 }
4521 }
4522
4523 if (found) {
4524 mirror_num = index_srcdev + 1;
4525 patch_the_first_stripe_for_dev_replace = 1;
4526 physical_to_patch_in_first_stripe = physical_of_found;
4527 } else {
4528 WARN_ON(1);
4529 ret = -EIO;
4530 kfree(tmp_bbio);
4531 goto out;
4532 }
4533
4534 kfree(tmp_bbio);
4535 } else if (mirror_num > map->num_stripes) {
4536 mirror_num = 0;
4537 }
4538
4539 num_stripes = 1;
4540 stripe_index = 0;
4541 stripe_nr_orig = stripe_nr;
4542 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
4543 (~(map->stripe_len - 1));
4544 do_div(stripe_nr_end, map->stripe_len);
4545 stripe_end_offset = stripe_nr_end * map->stripe_len -
4546 (offset + *length);
4547
4548 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4549 if (rw & REQ_DISCARD)
4550 num_stripes = min_t(u64, map->num_stripes,
4551 stripe_nr_end - stripe_nr_orig);
4552 stripe_index = do_div(stripe_nr, map->num_stripes);
4553 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4554 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4555 num_stripes = map->num_stripes;
4556 else if (mirror_num)
4557 stripe_index = mirror_num - 1;
4558 else {
4559 stripe_index = find_live_mirror(fs_info, map, 0,
4560 map->num_stripes,
4561 current->pid % map->num_stripes,
4562 dev_replace_is_ongoing);
4563 mirror_num = stripe_index + 1;
4564 }
4565
4566 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4567 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4568 num_stripes = map->num_stripes;
4569 } else if (mirror_num) {
4570 stripe_index = mirror_num - 1;
4571 } else {
4572 mirror_num = 1;
4573 }
4574
4575 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4576 int factor = map->num_stripes / map->sub_stripes;
4577
4578 stripe_index = do_div(stripe_nr, factor);
4579 stripe_index *= map->sub_stripes;
4580
4581 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4582 num_stripes = map->sub_stripes;
4583 else if (rw & REQ_DISCARD)
4584 num_stripes = min_t(u64, map->sub_stripes *
4585 (stripe_nr_end - stripe_nr_orig),
4586 map->num_stripes);
4587 else if (mirror_num)
4588 stripe_index += mirror_num - 1;
4589 else {
4590 int old_stripe_index = stripe_index;
4591 stripe_index = find_live_mirror(fs_info, map,
4592 stripe_index,
4593 map->sub_stripes, stripe_index +
4594 current->pid % map->sub_stripes,
4595 dev_replace_is_ongoing);
4596 mirror_num = stripe_index - old_stripe_index + 1;
4597 }
4598
4599 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4600 BTRFS_BLOCK_GROUP_RAID6)) {
4601 u64 tmp;
4602
4603 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4604 && raid_map_ret) {
4605 int i, rot;
4606
4607 /* push stripe_nr back to the start of the full stripe */
4608 stripe_nr = raid56_full_stripe_start;
4609 do_div(stripe_nr, stripe_len);
4610
4611 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4612
4613 /* RAID[56] write or recovery. Return all stripes */
4614 num_stripes = map->num_stripes;
4615 max_errors = nr_parity_stripes(map);
4616
4617 raid_map = kmalloc(sizeof(u64) * num_stripes,
4618 GFP_NOFS);
4619 if (!raid_map) {
4620 ret = -ENOMEM;
4621 goto out;
4622 }
4623
4624 /* Work out the disk rotation on this stripe-set */
4625 tmp = stripe_nr;
4626 rot = do_div(tmp, num_stripes);
4627
4628 /* Fill in the logical address of each stripe */
4629 tmp = stripe_nr * nr_data_stripes(map);
4630 for (i = 0; i < nr_data_stripes(map); i++)
4631 raid_map[(i+rot) % num_stripes] =
4632 em->start + (tmp + i) * map->stripe_len;
4633
4634 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4635 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4636 raid_map[(i+rot+1) % num_stripes] =
4637 RAID6_Q_STRIPE;
4638
4639 *length = map->stripe_len;
4640 stripe_index = 0;
4641 stripe_offset = 0;
4642 } else {
4643 /*
4644 * Mirror #0 or #1 means the original data block.
4645 * Mirror #2 is RAID5 parity block.
4646 * Mirror #3 is RAID6 Q block.
4647 */
4648 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4649 if (mirror_num > 1)
4650 stripe_index = nr_data_stripes(map) +
4651 mirror_num - 2;
4652
4653 /* We distribute the parity blocks across stripes */
4654 tmp = stripe_nr + stripe_index;
4655 stripe_index = do_div(tmp, map->num_stripes);
4656 }
4657 } else {
4658 /*
4659 * after this do_div call, stripe_nr is the number of stripes
4660 * on this device we have to walk to find the data, and
4661 * stripe_index is the number of our device in the stripe array
4662 */
4663 stripe_index = do_div(stripe_nr, map->num_stripes);
4664 mirror_num = stripe_index + 1;
4665 }
4666 BUG_ON(stripe_index >= map->num_stripes);
4667
4668 num_alloc_stripes = num_stripes;
4669 if (dev_replace_is_ongoing) {
4670 if (rw & (REQ_WRITE | REQ_DISCARD))
4671 num_alloc_stripes <<= 1;
4672 if (rw & REQ_GET_READ_MIRRORS)
4673 num_alloc_stripes++;
4674 }
4675 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4676 if (!bbio) {
4677 ret = -ENOMEM;
4678 goto out;
4679 }
4680 atomic_set(&bbio->error, 0);
4681
4682 if (rw & REQ_DISCARD) {
4683 int factor = 0;
4684 int sub_stripes = 0;
4685 u64 stripes_per_dev = 0;
4686 u32 remaining_stripes = 0;
4687 u32 last_stripe = 0;
4688
4689 if (map->type &
4690 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4691 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4692 sub_stripes = 1;
4693 else
4694 sub_stripes = map->sub_stripes;
4695
4696 factor = map->num_stripes / sub_stripes;
4697 stripes_per_dev = div_u64_rem(stripe_nr_end -
4698 stripe_nr_orig,
4699 factor,
4700 &remaining_stripes);
4701 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4702 last_stripe *= sub_stripes;
4703 }
4704
4705 for (i = 0; i < num_stripes; i++) {
4706 bbio->stripes[i].physical =
4707 map->stripes[stripe_index].physical +
4708 stripe_offset + stripe_nr * map->stripe_len;
4709 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4710
4711 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4712 BTRFS_BLOCK_GROUP_RAID10)) {
4713 bbio->stripes[i].length = stripes_per_dev *
4714 map->stripe_len;
4715
4716 if (i / sub_stripes < remaining_stripes)
4717 bbio->stripes[i].length +=
4718 map->stripe_len;
4719
4720 /*
4721 * Special for the first stripe and
4722 * the last stripe:
4723 *
4724 * |-------|...|-------|
4725 * |----------|
4726 * off end_off
4727 */
4728 if (i < sub_stripes)
4729 bbio->stripes[i].length -=
4730 stripe_offset;
4731
4732 if (stripe_index >= last_stripe &&
4733 stripe_index <= (last_stripe +
4734 sub_stripes - 1))
4735 bbio->stripes[i].length -=
4736 stripe_end_offset;
4737
4738 if (i == sub_stripes - 1)
4739 stripe_offset = 0;
4740 } else
4741 bbio->stripes[i].length = *length;
4742
4743 stripe_index++;
4744 if (stripe_index == map->num_stripes) {
4745 /* This could only happen for RAID0/10 */
4746 stripe_index = 0;
4747 stripe_nr++;
4748 }
4749 }
4750 } else {
4751 for (i = 0; i < num_stripes; i++) {
4752 bbio->stripes[i].physical =
4753 map->stripes[stripe_index].physical +
4754 stripe_offset +
4755 stripe_nr * map->stripe_len;
4756 bbio->stripes[i].dev =
4757 map->stripes[stripe_index].dev;
4758 stripe_index++;
4759 }
4760 }
4761
4762 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
4763 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4764 BTRFS_BLOCK_GROUP_RAID10 |
4765 BTRFS_BLOCK_GROUP_RAID5 |
4766 BTRFS_BLOCK_GROUP_DUP)) {
4767 max_errors = 1;
4768 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
4769 max_errors = 2;
4770 }
4771 }
4772
4773 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
4774 dev_replace->tgtdev != NULL) {
4775 int index_where_to_add;
4776 u64 srcdev_devid = dev_replace->srcdev->devid;
4777
4778 /*
4779 * duplicate the write operations while the dev replace
4780 * procedure is running. Since the copying of the old disk
4781 * to the new disk takes place at run time while the
4782 * filesystem is mounted writable, the regular write
4783 * operations to the old disk have to be duplicated to go
4784 * to the new disk as well.
4785 * Note that device->missing is handled by the caller, and
4786 * that the write to the old disk is already set up in the
4787 * stripes array.
4788 */
4789 index_where_to_add = num_stripes;
4790 for (i = 0; i < num_stripes; i++) {
4791 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4792 /* write to new disk, too */
4793 struct btrfs_bio_stripe *new =
4794 bbio->stripes + index_where_to_add;
4795 struct btrfs_bio_stripe *old =
4796 bbio->stripes + i;
4797
4798 new->physical = old->physical;
4799 new->length = old->length;
4800 new->dev = dev_replace->tgtdev;
4801 index_where_to_add++;
4802 max_errors++;
4803 }
4804 }
4805 num_stripes = index_where_to_add;
4806 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
4807 dev_replace->tgtdev != NULL) {
4808 u64 srcdev_devid = dev_replace->srcdev->devid;
4809 int index_srcdev = 0;
4810 int found = 0;
4811 u64 physical_of_found = 0;
4812
4813 /*
4814 * During the dev-replace procedure, the target drive can
4815 * also be used to read data in case it is needed to repair
4816 * a corrupt block elsewhere. This is possible if the
4817 * requested area is left of the left cursor. In this area,
4818 * the target drive is a full copy of the source drive.
4819 */
4820 for (i = 0; i < num_stripes; i++) {
4821 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4822 /*
4823 * In case of DUP, in order to keep it
4824 * simple, only add the mirror with the
4825 * lowest physical address
4826 */
4827 if (found &&
4828 physical_of_found <=
4829 bbio->stripes[i].physical)
4830 continue;
4831 index_srcdev = i;
4832 found = 1;
4833 physical_of_found = bbio->stripes[i].physical;
4834 }
4835 }
4836 if (found) {
4837 u64 length = map->stripe_len;
4838
4839 if (physical_of_found + length <=
4840 dev_replace->cursor_left) {
4841 struct btrfs_bio_stripe *tgtdev_stripe =
4842 bbio->stripes + num_stripes;
4843
4844 tgtdev_stripe->physical = physical_of_found;
4845 tgtdev_stripe->length =
4846 bbio->stripes[index_srcdev].length;
4847 tgtdev_stripe->dev = dev_replace->tgtdev;
4848
4849 num_stripes++;
4850 }
4851 }
4852 }
4853
4854 *bbio_ret = bbio;
4855 bbio->num_stripes = num_stripes;
4856 bbio->max_errors = max_errors;
4857 bbio->mirror_num = mirror_num;
4858
4859 /*
4860 * this is the case that REQ_READ && dev_replace_is_ongoing &&
4861 * mirror_num == num_stripes + 1 && dev_replace target drive is
4862 * available as a mirror
4863 */
4864 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
4865 WARN_ON(num_stripes > 1);
4866 bbio->stripes[0].dev = dev_replace->tgtdev;
4867 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
4868 bbio->mirror_num = map->num_stripes + 1;
4869 }
4870 if (raid_map) {
4871 sort_parity_stripes(bbio, raid_map);
4872 *raid_map_ret = raid_map;
4873 }
4874 out:
4875 if (dev_replace_is_ongoing)
4876 btrfs_dev_replace_unlock(dev_replace);
4877 free_extent_map(em);
4878 return ret;
4879 }
4880
4881 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4882 u64 logical, u64 *length,
4883 struct btrfs_bio **bbio_ret, int mirror_num)
4884 {
4885 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
4886 mirror_num, NULL);
4887 }
4888
4889 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4890 u64 chunk_start, u64 physical, u64 devid,
4891 u64 **logical, int *naddrs, int *stripe_len)
4892 {
4893 struct extent_map_tree *em_tree = &map_tree->map_tree;
4894 struct extent_map *em;
4895 struct map_lookup *map;
4896 u64 *buf;
4897 u64 bytenr;
4898 u64 length;
4899 u64 stripe_nr;
4900 u64 rmap_len;
4901 int i, j, nr = 0;
4902
4903 read_lock(&em_tree->lock);
4904 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4905 read_unlock(&em_tree->lock);
4906
4907 BUG_ON(!em || em->start != chunk_start);
4908 map = (struct map_lookup *)em->bdev;
4909
4910 length = em->len;
4911 rmap_len = map->stripe_len;
4912
4913 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4914 do_div(length, map->num_stripes / map->sub_stripes);
4915 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4916 do_div(length, map->num_stripes);
4917 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4918 BTRFS_BLOCK_GROUP_RAID6)) {
4919 do_div(length, nr_data_stripes(map));
4920 rmap_len = map->stripe_len * nr_data_stripes(map);
4921 }
4922
4923 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4924 BUG_ON(!buf); /* -ENOMEM */
4925
4926 for (i = 0; i < map->num_stripes; i++) {
4927 if (devid && map->stripes[i].dev->devid != devid)
4928 continue;
4929 if (map->stripes[i].physical > physical ||
4930 map->stripes[i].physical + length <= physical)
4931 continue;
4932
4933 stripe_nr = physical - map->stripes[i].physical;
4934 do_div(stripe_nr, map->stripe_len);
4935
4936 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4937 stripe_nr = stripe_nr * map->num_stripes + i;
4938 do_div(stripe_nr, map->sub_stripes);
4939 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4940 stripe_nr = stripe_nr * map->num_stripes + i;
4941 } /* else if RAID[56], multiply by nr_data_stripes().
4942 * Alternatively, just use rmap_len below instead of
4943 * map->stripe_len */
4944
4945 bytenr = chunk_start + stripe_nr * rmap_len;
4946 WARN_ON(nr >= map->num_stripes);
4947 for (j = 0; j < nr; j++) {
4948 if (buf[j] == bytenr)
4949 break;
4950 }
4951 if (j == nr) {
4952 WARN_ON(nr >= map->num_stripes);
4953 buf[nr++] = bytenr;
4954 }
4955 }
4956
4957 *logical = buf;
4958 *naddrs = nr;
4959 *stripe_len = rmap_len;
4960
4961 free_extent_map(em);
4962 return 0;
4963 }
4964
4965 static void *merge_stripe_index_into_bio_private(void *bi_private,
4966 unsigned int stripe_index)
4967 {
4968 /*
4969 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4970 * at most 1.
4971 * The alternative solution (instead of stealing bits from the
4972 * pointer) would be to allocate an intermediate structure
4973 * that contains the old private pointer plus the stripe_index.
4974 */
4975 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4976 BUG_ON(stripe_index > 3);
4977 return (void *)(((uintptr_t)bi_private) | stripe_index);
4978 }
4979
4980 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4981 {
4982 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4983 }
4984
4985 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4986 {
4987 return (unsigned int)((uintptr_t)bi_private) & 3;
4988 }
4989
4990 static void btrfs_end_bio(struct bio *bio, int err)
4991 {
4992 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4993 int is_orig_bio = 0;
4994
4995 if (err) {
4996 atomic_inc(&bbio->error);
4997 if (err == -EIO || err == -EREMOTEIO) {
4998 unsigned int stripe_index =
4999 extract_stripe_index_from_bio_private(
5000 bio->bi_private);
5001 struct btrfs_device *dev;
5002
5003 BUG_ON(stripe_index >= bbio->num_stripes);
5004 dev = bbio->stripes[stripe_index].dev;
5005 if (dev->bdev) {
5006 if (bio->bi_rw & WRITE)
5007 btrfs_dev_stat_inc(dev,
5008 BTRFS_DEV_STAT_WRITE_ERRS);
5009 else
5010 btrfs_dev_stat_inc(dev,
5011 BTRFS_DEV_STAT_READ_ERRS);
5012 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5013 btrfs_dev_stat_inc(dev,
5014 BTRFS_DEV_STAT_FLUSH_ERRS);
5015 btrfs_dev_stat_print_on_error(dev);
5016 }
5017 }
5018 }
5019
5020 if (bio == bbio->orig_bio)
5021 is_orig_bio = 1;
5022
5023 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5024 if (!is_orig_bio) {
5025 bio_put(bio);
5026 bio = bbio->orig_bio;
5027 }
5028 bio->bi_private = bbio->private;
5029 bio->bi_end_io = bbio->end_io;
5030 bio->bi_bdev = (struct block_device *)
5031 (unsigned long)bbio->mirror_num;
5032 /* only send an error to the higher layers if it is
5033 * beyond the tolerance of the btrfs bio
5034 */
5035 if (atomic_read(&bbio->error) > bbio->max_errors) {
5036 err = -EIO;
5037 } else {
5038 /*
5039 * this bio is actually up to date, we didn't
5040 * go over the max number of errors
5041 */
5042 set_bit(BIO_UPTODATE, &bio->bi_flags);
5043 err = 0;
5044 }
5045 kfree(bbio);
5046
5047 bio_endio(bio, err);
5048 } else if (!is_orig_bio) {
5049 bio_put(bio);
5050 }
5051 }
5052
5053 struct async_sched {
5054 struct bio *bio;
5055 int rw;
5056 struct btrfs_fs_info *info;
5057 struct btrfs_work work;
5058 };
5059
5060 /*
5061 * see run_scheduled_bios for a description of why bios are collected for
5062 * async submit.
5063 *
5064 * This will add one bio to the pending list for a device and make sure
5065 * the work struct is scheduled.
5066 */
5067 noinline void btrfs_schedule_bio(struct btrfs_root *root,
5068 struct btrfs_device *device,
5069 int rw, struct bio *bio)
5070 {
5071 int should_queue = 1;
5072 struct btrfs_pending_bios *pending_bios;
5073
5074 if (device->missing || !device->bdev) {
5075 bio_endio(bio, -EIO);
5076 return;
5077 }
5078
5079 /* don't bother with additional async steps for reads, right now */
5080 if (!(rw & REQ_WRITE)) {
5081 bio_get(bio);
5082 btrfsic_submit_bio(rw, bio);
5083 bio_put(bio);
5084 return;
5085 }
5086
5087 /*
5088 * nr_async_bios allows us to reliably return congestion to the
5089 * higher layers. Otherwise, the async bio makes it appear we have
5090 * made progress against dirty pages when we've really just put it
5091 * on a queue for later
5092 */
5093 atomic_inc(&root->fs_info->nr_async_bios);
5094 WARN_ON(bio->bi_next);
5095 bio->bi_next = NULL;
5096 bio->bi_rw |= rw;
5097
5098 spin_lock(&device->io_lock);
5099 if (bio->bi_rw & REQ_SYNC)
5100 pending_bios = &device->pending_sync_bios;
5101 else
5102 pending_bios = &device->pending_bios;
5103
5104 if (pending_bios->tail)
5105 pending_bios->tail->bi_next = bio;
5106
5107 pending_bios->tail = bio;
5108 if (!pending_bios->head)
5109 pending_bios->head = bio;
5110 if (device->running_pending)
5111 should_queue = 0;
5112
5113 spin_unlock(&device->io_lock);
5114
5115 if (should_queue)
5116 btrfs_queue_worker(&root->fs_info->submit_workers,
5117 &device->work);
5118 }
5119
5120 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5121 sector_t sector)
5122 {
5123 struct bio_vec *prev;
5124 struct request_queue *q = bdev_get_queue(bdev);
5125 unsigned short max_sectors = queue_max_sectors(q);
5126 struct bvec_merge_data bvm = {
5127 .bi_bdev = bdev,
5128 .bi_sector = sector,
5129 .bi_rw = bio->bi_rw,
5130 };
5131
5132 if (bio->bi_vcnt == 0) {
5133 WARN_ON(1);
5134 return 1;
5135 }
5136
5137 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5138 if ((bio->bi_size >> 9) > max_sectors)
5139 return 0;
5140
5141 if (!q->merge_bvec_fn)
5142 return 1;
5143
5144 bvm.bi_size = bio->bi_size - prev->bv_len;
5145 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5146 return 0;
5147 return 1;
5148 }
5149
5150 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5151 struct bio *bio, u64 physical, int dev_nr,
5152 int rw, int async)
5153 {
5154 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5155
5156 bio->bi_private = bbio;
5157 bio->bi_private = merge_stripe_index_into_bio_private(
5158 bio->bi_private, (unsigned int)dev_nr);
5159 bio->bi_end_io = btrfs_end_bio;
5160 bio->bi_sector = physical >> 9;
5161 #ifdef DEBUG
5162 {
5163 struct rcu_string *name;
5164
5165 rcu_read_lock();
5166 name = rcu_dereference(dev->name);
5167 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5168 "(%s id %llu), size=%u\n", rw,
5169 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5170 name->str, dev->devid, bio->bi_size);
5171 rcu_read_unlock();
5172 }
5173 #endif
5174 bio->bi_bdev = dev->bdev;
5175 if (async)
5176 btrfs_schedule_bio(root, dev, rw, bio);
5177 else
5178 btrfsic_submit_bio(rw, bio);
5179 }
5180
5181 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5182 struct bio *first_bio, struct btrfs_device *dev,
5183 int dev_nr, int rw, int async)
5184 {
5185 struct bio_vec *bvec = first_bio->bi_io_vec;
5186 struct bio *bio;
5187 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5188 u64 physical = bbio->stripes[dev_nr].physical;
5189
5190 again:
5191 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5192 if (!bio)
5193 return -ENOMEM;
5194
5195 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5196 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5197 bvec->bv_offset) < bvec->bv_len) {
5198 u64 len = bio->bi_size;
5199
5200 atomic_inc(&bbio->stripes_pending);
5201 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5202 rw, async);
5203 physical += len;
5204 goto again;
5205 }
5206 bvec++;
5207 }
5208
5209 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5210 return 0;
5211 }
5212
5213 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5214 {
5215 atomic_inc(&bbio->error);
5216 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5217 bio->bi_private = bbio->private;
5218 bio->bi_end_io = bbio->end_io;
5219 bio->bi_bdev = (struct block_device *)
5220 (unsigned long)bbio->mirror_num;
5221 bio->bi_sector = logical >> 9;
5222 kfree(bbio);
5223 bio_endio(bio, -EIO);
5224 }
5225 }
5226
5227 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5228 int mirror_num, int async_submit)
5229 {
5230 struct btrfs_device *dev;
5231 struct bio *first_bio = bio;
5232 u64 logical = (u64)bio->bi_sector << 9;
5233 u64 length = 0;
5234 u64 map_length;
5235 u64 *raid_map = NULL;
5236 int ret;
5237 int dev_nr = 0;
5238 int total_devs = 1;
5239 struct btrfs_bio *bbio = NULL;
5240
5241 length = bio->bi_size;
5242 map_length = length;
5243
5244 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5245 mirror_num, &raid_map);
5246 if (ret) /* -ENOMEM */
5247 return ret;
5248
5249 total_devs = bbio->num_stripes;
5250 bbio->orig_bio = first_bio;
5251 bbio->private = first_bio->bi_private;
5252 bbio->end_io = first_bio->bi_end_io;
5253 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5254
5255 if (raid_map) {
5256 /* In this case, map_length has been set to the length of
5257 a single stripe; not the whole write */
5258 if (rw & WRITE) {
5259 return raid56_parity_write(root, bio, bbio,
5260 raid_map, map_length);
5261 } else {
5262 return raid56_parity_recover(root, bio, bbio,
5263 raid_map, map_length,
5264 mirror_num);
5265 }
5266 }
5267
5268 if (map_length < length) {
5269 printk(KERN_CRIT "btrfs: mapping failed logical %llu bio len %llu "
5270 "len %llu\n", (unsigned long long)logical,
5271 (unsigned long long)length,
5272 (unsigned long long)map_length);
5273 BUG();
5274 }
5275
5276 while (dev_nr < total_devs) {
5277 dev = bbio->stripes[dev_nr].dev;
5278 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5279 bbio_error(bbio, first_bio, logical);
5280 dev_nr++;
5281 continue;
5282 }
5283
5284 /*
5285 * Check and see if we're ok with this bio based on it's size
5286 * and offset with the given device.
5287 */
5288 if (!bio_size_ok(dev->bdev, first_bio,
5289 bbio->stripes[dev_nr].physical >> 9)) {
5290 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5291 dev_nr, rw, async_submit);
5292 BUG_ON(ret);
5293 dev_nr++;
5294 continue;
5295 }
5296
5297 if (dev_nr < total_devs - 1) {
5298 bio = bio_clone(first_bio, GFP_NOFS);
5299 BUG_ON(!bio); /* -ENOMEM */
5300 } else {
5301 bio = first_bio;
5302 }
5303
5304 submit_stripe_bio(root, bbio, bio,
5305 bbio->stripes[dev_nr].physical, dev_nr, rw,
5306 async_submit);
5307 dev_nr++;
5308 }
5309 return 0;
5310 }
5311
5312 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5313 u8 *uuid, u8 *fsid)
5314 {
5315 struct btrfs_device *device;
5316 struct btrfs_fs_devices *cur_devices;
5317
5318 cur_devices = fs_info->fs_devices;
5319 while (cur_devices) {
5320 if (!fsid ||
5321 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5322 device = __find_device(&cur_devices->devices,
5323 devid, uuid);
5324 if (device)
5325 return device;
5326 }
5327 cur_devices = cur_devices->seed;
5328 }
5329 return NULL;
5330 }
5331
5332 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5333 u64 devid, u8 *dev_uuid)
5334 {
5335 struct btrfs_device *device;
5336 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5337
5338 device = kzalloc(sizeof(*device), GFP_NOFS);
5339 if (!device)
5340 return NULL;
5341 list_add(&device->dev_list,
5342 &fs_devices->devices);
5343 device->dev_root = root->fs_info->dev_root;
5344 device->devid = devid;
5345 device->work.func = pending_bios_fn;
5346 device->fs_devices = fs_devices;
5347 device->missing = 1;
5348 fs_devices->num_devices++;
5349 fs_devices->missing_devices++;
5350 spin_lock_init(&device->io_lock);
5351 INIT_LIST_HEAD(&device->dev_alloc_list);
5352 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
5353 return device;
5354 }
5355
5356 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5357 struct extent_buffer *leaf,
5358 struct btrfs_chunk *chunk)
5359 {
5360 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5361 struct map_lookup *map;
5362 struct extent_map *em;
5363 u64 logical;
5364 u64 length;
5365 u64 devid;
5366 u8 uuid[BTRFS_UUID_SIZE];
5367 int num_stripes;
5368 int ret;
5369 int i;
5370
5371 logical = key->offset;
5372 length = btrfs_chunk_length(leaf, chunk);
5373
5374 read_lock(&map_tree->map_tree.lock);
5375 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5376 read_unlock(&map_tree->map_tree.lock);
5377
5378 /* already mapped? */
5379 if (em && em->start <= logical && em->start + em->len > logical) {
5380 free_extent_map(em);
5381 return 0;
5382 } else if (em) {
5383 free_extent_map(em);
5384 }
5385
5386 em = alloc_extent_map();
5387 if (!em)
5388 return -ENOMEM;
5389 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5390 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5391 if (!map) {
5392 free_extent_map(em);
5393 return -ENOMEM;
5394 }
5395
5396 em->bdev = (struct block_device *)map;
5397 em->start = logical;
5398 em->len = length;
5399 em->orig_start = 0;
5400 em->block_start = 0;
5401 em->block_len = em->len;
5402
5403 map->num_stripes = num_stripes;
5404 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5405 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5406 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5407 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5408 map->type = btrfs_chunk_type(leaf, chunk);
5409 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5410 for (i = 0; i < num_stripes; i++) {
5411 map->stripes[i].physical =
5412 btrfs_stripe_offset_nr(leaf, chunk, i);
5413 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5414 read_extent_buffer(leaf, uuid, (unsigned long)
5415 btrfs_stripe_dev_uuid_nr(chunk, i),
5416 BTRFS_UUID_SIZE);
5417 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5418 uuid, NULL);
5419 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5420 kfree(map);
5421 free_extent_map(em);
5422 return -EIO;
5423 }
5424 if (!map->stripes[i].dev) {
5425 map->stripes[i].dev =
5426 add_missing_dev(root, devid, uuid);
5427 if (!map->stripes[i].dev) {
5428 kfree(map);
5429 free_extent_map(em);
5430 return -EIO;
5431 }
5432 }
5433 map->stripes[i].dev->in_fs_metadata = 1;
5434 }
5435
5436 write_lock(&map_tree->map_tree.lock);
5437 ret = add_extent_mapping(&map_tree->map_tree, em);
5438 write_unlock(&map_tree->map_tree.lock);
5439 BUG_ON(ret); /* Tree corruption */
5440 free_extent_map(em);
5441
5442 return 0;
5443 }
5444
5445 static void fill_device_from_item(struct extent_buffer *leaf,
5446 struct btrfs_dev_item *dev_item,
5447 struct btrfs_device *device)
5448 {
5449 unsigned long ptr;
5450
5451 device->devid = btrfs_device_id(leaf, dev_item);
5452 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5453 device->total_bytes = device->disk_total_bytes;
5454 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5455 device->type = btrfs_device_type(leaf, dev_item);
5456 device->io_align = btrfs_device_io_align(leaf, dev_item);
5457 device->io_width = btrfs_device_io_width(leaf, dev_item);
5458 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5459 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5460 device->is_tgtdev_for_dev_replace = 0;
5461
5462 ptr = (unsigned long)btrfs_device_uuid(dev_item);
5463 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5464 }
5465
5466 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5467 {
5468 struct btrfs_fs_devices *fs_devices;
5469 int ret;
5470
5471 BUG_ON(!mutex_is_locked(&uuid_mutex));
5472
5473 fs_devices = root->fs_info->fs_devices->seed;
5474 while (fs_devices) {
5475 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5476 ret = 0;
5477 goto out;
5478 }
5479 fs_devices = fs_devices->seed;
5480 }
5481
5482 fs_devices = find_fsid(fsid);
5483 if (!fs_devices) {
5484 ret = -ENOENT;
5485 goto out;
5486 }
5487
5488 fs_devices = clone_fs_devices(fs_devices);
5489 if (IS_ERR(fs_devices)) {
5490 ret = PTR_ERR(fs_devices);
5491 goto out;
5492 }
5493
5494 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5495 root->fs_info->bdev_holder);
5496 if (ret) {
5497 free_fs_devices(fs_devices);
5498 goto out;
5499 }
5500
5501 if (!fs_devices->seeding) {
5502 __btrfs_close_devices(fs_devices);
5503 free_fs_devices(fs_devices);
5504 ret = -EINVAL;
5505 goto out;
5506 }
5507
5508 fs_devices->seed = root->fs_info->fs_devices->seed;
5509 root->fs_info->fs_devices->seed = fs_devices;
5510 out:
5511 return ret;
5512 }
5513
5514 static int read_one_dev(struct btrfs_root *root,
5515 struct extent_buffer *leaf,
5516 struct btrfs_dev_item *dev_item)
5517 {
5518 struct btrfs_device *device;
5519 u64 devid;
5520 int ret;
5521 u8 fs_uuid[BTRFS_UUID_SIZE];
5522 u8 dev_uuid[BTRFS_UUID_SIZE];
5523
5524 devid = btrfs_device_id(leaf, dev_item);
5525 read_extent_buffer(leaf, dev_uuid,
5526 (unsigned long)btrfs_device_uuid(dev_item),
5527 BTRFS_UUID_SIZE);
5528 read_extent_buffer(leaf, fs_uuid,
5529 (unsigned long)btrfs_device_fsid(dev_item),
5530 BTRFS_UUID_SIZE);
5531
5532 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5533 ret = open_seed_devices(root, fs_uuid);
5534 if (ret && !btrfs_test_opt(root, DEGRADED))
5535 return ret;
5536 }
5537
5538 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5539 if (!device || !device->bdev) {
5540 if (!btrfs_test_opt(root, DEGRADED))
5541 return -EIO;
5542
5543 if (!device) {
5544 printk(KERN_WARNING "warning devid %llu missing\n",
5545 (unsigned long long)devid);
5546 device = add_missing_dev(root, devid, dev_uuid);
5547 if (!device)
5548 return -ENOMEM;
5549 } else if (!device->missing) {
5550 /*
5551 * this happens when a device that was properly setup
5552 * in the device info lists suddenly goes bad.
5553 * device->bdev is NULL, and so we have to set
5554 * device->missing to one here
5555 */
5556 root->fs_info->fs_devices->missing_devices++;
5557 device->missing = 1;
5558 }
5559 }
5560
5561 if (device->fs_devices != root->fs_info->fs_devices) {
5562 BUG_ON(device->writeable);
5563 if (device->generation !=
5564 btrfs_device_generation(leaf, dev_item))
5565 return -EINVAL;
5566 }
5567
5568 fill_device_from_item(leaf, dev_item, device);
5569 device->dev_root = root->fs_info->dev_root;
5570 device->in_fs_metadata = 1;
5571 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5572 device->fs_devices->total_rw_bytes += device->total_bytes;
5573 spin_lock(&root->fs_info->free_chunk_lock);
5574 root->fs_info->free_chunk_space += device->total_bytes -
5575 device->bytes_used;
5576 spin_unlock(&root->fs_info->free_chunk_lock);
5577 }
5578 ret = 0;
5579 return ret;
5580 }
5581
5582 int btrfs_read_sys_array(struct btrfs_root *root)
5583 {
5584 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5585 struct extent_buffer *sb;
5586 struct btrfs_disk_key *disk_key;
5587 struct btrfs_chunk *chunk;
5588 u8 *ptr;
5589 unsigned long sb_ptr;
5590 int ret = 0;
5591 u32 num_stripes;
5592 u32 array_size;
5593 u32 len = 0;
5594 u32 cur;
5595 struct btrfs_key key;
5596
5597 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5598 BTRFS_SUPER_INFO_SIZE);
5599 if (!sb)
5600 return -ENOMEM;
5601 btrfs_set_buffer_uptodate(sb);
5602 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5603 /*
5604 * The sb extent buffer is artifical and just used to read the system array.
5605 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5606 * pages up-to-date when the page is larger: extent does not cover the
5607 * whole page and consequently check_page_uptodate does not find all
5608 * the page's extents up-to-date (the hole beyond sb),
5609 * write_extent_buffer then triggers a WARN_ON.
5610 *
5611 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5612 * but sb spans only this function. Add an explicit SetPageUptodate call
5613 * to silence the warning eg. on PowerPC 64.
5614 */
5615 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5616 SetPageUptodate(sb->pages[0]);
5617
5618 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5619 array_size = btrfs_super_sys_array_size(super_copy);
5620
5621 ptr = super_copy->sys_chunk_array;
5622 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5623 cur = 0;
5624
5625 while (cur < array_size) {
5626 disk_key = (struct btrfs_disk_key *)ptr;
5627 btrfs_disk_key_to_cpu(&key, disk_key);
5628
5629 len = sizeof(*disk_key); ptr += len;
5630 sb_ptr += len;
5631 cur += len;
5632
5633 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5634 chunk = (struct btrfs_chunk *)sb_ptr;
5635 ret = read_one_chunk(root, &key, sb, chunk);
5636 if (ret)
5637 break;
5638 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5639 len = btrfs_chunk_item_size(num_stripes);
5640 } else {
5641 ret = -EIO;
5642 break;
5643 }
5644 ptr += len;
5645 sb_ptr += len;
5646 cur += len;
5647 }
5648 free_extent_buffer(sb);
5649 return ret;
5650 }
5651
5652 int btrfs_read_chunk_tree(struct btrfs_root *root)
5653 {
5654 struct btrfs_path *path;
5655 struct extent_buffer *leaf;
5656 struct btrfs_key key;
5657 struct btrfs_key found_key;
5658 int ret;
5659 int slot;
5660
5661 root = root->fs_info->chunk_root;
5662
5663 path = btrfs_alloc_path();
5664 if (!path)
5665 return -ENOMEM;
5666
5667 mutex_lock(&uuid_mutex);
5668 lock_chunks(root);
5669
5670 /* first we search for all of the device items, and then we
5671 * read in all of the chunk items. This way we can create chunk
5672 * mappings that reference all of the devices that are afound
5673 */
5674 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5675 key.offset = 0;
5676 key.type = 0;
5677 again:
5678 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5679 if (ret < 0)
5680 goto error;
5681 while (1) {
5682 leaf = path->nodes[0];
5683 slot = path->slots[0];
5684 if (slot >= btrfs_header_nritems(leaf)) {
5685 ret = btrfs_next_leaf(root, path);
5686 if (ret == 0)
5687 continue;
5688 if (ret < 0)
5689 goto error;
5690 break;
5691 }
5692 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5693 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5694 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
5695 break;
5696 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
5697 struct btrfs_dev_item *dev_item;
5698 dev_item = btrfs_item_ptr(leaf, slot,
5699 struct btrfs_dev_item);
5700 ret = read_one_dev(root, leaf, dev_item);
5701 if (ret)
5702 goto error;
5703 }
5704 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
5705 struct btrfs_chunk *chunk;
5706 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
5707 ret = read_one_chunk(root, &found_key, leaf, chunk);
5708 if (ret)
5709 goto error;
5710 }
5711 path->slots[0]++;
5712 }
5713 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5714 key.objectid = 0;
5715 btrfs_release_path(path);
5716 goto again;
5717 }
5718 ret = 0;
5719 error:
5720 unlock_chunks(root);
5721 mutex_unlock(&uuid_mutex);
5722
5723 btrfs_free_path(path);
5724 return ret;
5725 }
5726
5727 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
5728 {
5729 int i;
5730
5731 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5732 btrfs_dev_stat_reset(dev, i);
5733 }
5734
5735 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
5736 {
5737 struct btrfs_key key;
5738 struct btrfs_key found_key;
5739 struct btrfs_root *dev_root = fs_info->dev_root;
5740 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5741 struct extent_buffer *eb;
5742 int slot;
5743 int ret = 0;
5744 struct btrfs_device *device;
5745 struct btrfs_path *path = NULL;
5746 int i;
5747
5748 path = btrfs_alloc_path();
5749 if (!path) {
5750 ret = -ENOMEM;
5751 goto out;
5752 }
5753
5754 mutex_lock(&fs_devices->device_list_mutex);
5755 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5756 int item_size;
5757 struct btrfs_dev_stats_item *ptr;
5758
5759 key.objectid = 0;
5760 key.type = BTRFS_DEV_STATS_KEY;
5761 key.offset = device->devid;
5762 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
5763 if (ret) {
5764 __btrfs_reset_dev_stats(device);
5765 device->dev_stats_valid = 1;
5766 btrfs_release_path(path);
5767 continue;
5768 }
5769 slot = path->slots[0];
5770 eb = path->nodes[0];
5771 btrfs_item_key_to_cpu(eb, &found_key, slot);
5772 item_size = btrfs_item_size_nr(eb, slot);
5773
5774 ptr = btrfs_item_ptr(eb, slot,
5775 struct btrfs_dev_stats_item);
5776
5777 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5778 if (item_size >= (1 + i) * sizeof(__le64))
5779 btrfs_dev_stat_set(device, i,
5780 btrfs_dev_stats_value(eb, ptr, i));
5781 else
5782 btrfs_dev_stat_reset(device, i);
5783 }
5784
5785 device->dev_stats_valid = 1;
5786 btrfs_dev_stat_print_on_load(device);
5787 btrfs_release_path(path);
5788 }
5789 mutex_unlock(&fs_devices->device_list_mutex);
5790
5791 out:
5792 btrfs_free_path(path);
5793 return ret < 0 ? ret : 0;
5794 }
5795
5796 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
5797 struct btrfs_root *dev_root,
5798 struct btrfs_device *device)
5799 {
5800 struct btrfs_path *path;
5801 struct btrfs_key key;
5802 struct extent_buffer *eb;
5803 struct btrfs_dev_stats_item *ptr;
5804 int ret;
5805 int i;
5806
5807 key.objectid = 0;
5808 key.type = BTRFS_DEV_STATS_KEY;
5809 key.offset = device->devid;
5810
5811 path = btrfs_alloc_path();
5812 BUG_ON(!path);
5813 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
5814 if (ret < 0) {
5815 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
5816 ret, rcu_str_deref(device->name));
5817 goto out;
5818 }
5819
5820 if (ret == 0 &&
5821 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
5822 /* need to delete old one and insert a new one */
5823 ret = btrfs_del_item(trans, dev_root, path);
5824 if (ret != 0) {
5825 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
5826 rcu_str_deref(device->name), ret);
5827 goto out;
5828 }
5829 ret = 1;
5830 }
5831
5832 if (ret == 1) {
5833 /* need to insert a new item */
5834 btrfs_release_path(path);
5835 ret = btrfs_insert_empty_item(trans, dev_root, path,
5836 &key, sizeof(*ptr));
5837 if (ret < 0) {
5838 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
5839 rcu_str_deref(device->name), ret);
5840 goto out;
5841 }
5842 }
5843
5844 eb = path->nodes[0];
5845 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
5846 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5847 btrfs_set_dev_stats_value(eb, ptr, i,
5848 btrfs_dev_stat_read(device, i));
5849 btrfs_mark_buffer_dirty(eb);
5850
5851 out:
5852 btrfs_free_path(path);
5853 return ret;
5854 }
5855
5856 /*
5857 * called from commit_transaction. Writes all changed device stats to disk.
5858 */
5859 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
5860 struct btrfs_fs_info *fs_info)
5861 {
5862 struct btrfs_root *dev_root = fs_info->dev_root;
5863 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5864 struct btrfs_device *device;
5865 int ret = 0;
5866
5867 mutex_lock(&fs_devices->device_list_mutex);
5868 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5869 if (!device->dev_stats_valid || !device->dev_stats_dirty)
5870 continue;
5871
5872 ret = update_dev_stat_item(trans, dev_root, device);
5873 if (!ret)
5874 device->dev_stats_dirty = 0;
5875 }
5876 mutex_unlock(&fs_devices->device_list_mutex);
5877
5878 return ret;
5879 }
5880
5881 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
5882 {
5883 btrfs_dev_stat_inc(dev, index);
5884 btrfs_dev_stat_print_on_error(dev);
5885 }
5886
5887 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
5888 {
5889 if (!dev->dev_stats_valid)
5890 return;
5891 printk_ratelimited_in_rcu(KERN_ERR
5892 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5893 rcu_str_deref(dev->name),
5894 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5895 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5896 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5897 btrfs_dev_stat_read(dev,
5898 BTRFS_DEV_STAT_CORRUPTION_ERRS),
5899 btrfs_dev_stat_read(dev,
5900 BTRFS_DEV_STAT_GENERATION_ERRS));
5901 }
5902
5903 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
5904 {
5905 int i;
5906
5907 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5908 if (btrfs_dev_stat_read(dev, i) != 0)
5909 break;
5910 if (i == BTRFS_DEV_STAT_VALUES_MAX)
5911 return; /* all values == 0, suppress message */
5912
5913 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5914 rcu_str_deref(dev->name),
5915 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5916 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5917 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5918 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
5919 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
5920 }
5921
5922 int btrfs_get_dev_stats(struct btrfs_root *root,
5923 struct btrfs_ioctl_get_dev_stats *stats)
5924 {
5925 struct btrfs_device *dev;
5926 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5927 int i;
5928
5929 mutex_lock(&fs_devices->device_list_mutex);
5930 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
5931 mutex_unlock(&fs_devices->device_list_mutex);
5932
5933 if (!dev) {
5934 printk(KERN_WARNING
5935 "btrfs: get dev_stats failed, device not found\n");
5936 return -ENODEV;
5937 } else if (!dev->dev_stats_valid) {
5938 printk(KERN_WARNING
5939 "btrfs: get dev_stats failed, not yet valid\n");
5940 return -ENODEV;
5941 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
5942 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5943 if (stats->nr_items > i)
5944 stats->values[i] =
5945 btrfs_dev_stat_read_and_reset(dev, i);
5946 else
5947 btrfs_dev_stat_reset(dev, i);
5948 }
5949 } else {
5950 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5951 if (stats->nr_items > i)
5952 stats->values[i] = btrfs_dev_stat_read(dev, i);
5953 }
5954 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
5955 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
5956 return 0;
5957 }
5958
5959 int btrfs_scratch_superblock(struct btrfs_device *device)
5960 {
5961 struct buffer_head *bh;
5962 struct btrfs_super_block *disk_super;
5963
5964 bh = btrfs_read_dev_super(device->bdev);
5965 if (!bh)
5966 return -EINVAL;
5967 disk_super = (struct btrfs_super_block *)bh->b_data;
5968
5969 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
5970 set_buffer_dirty(bh);
5971 sync_dirty_buffer(bh);
5972 brelse(bh);
5973
5974 return 0;
5975 }
Linux kernel - Deliverables
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