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Merge branch 'timer/cleanup' into late/mvebu2
[GitHub/mt8127/android_kernel_alcatel_ttab.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 "compat.h"
29 #include "ctree.h"
30 #include "extent_map.h"
31 #include "disk-io.h"
32 #include "transaction.h"
33 #include "print-tree.h"
34 #include "volumes.h"
35 #include "async-thread.h"
36 #include "check-integrity.h"
37 #include "rcu-string.h"
38 #include "math.h"
39 #include "dev-replace.h"
40
41 static int init_first_rw_device(struct btrfs_trans_handle *trans,
42 struct btrfs_root *root,
43 struct btrfs_device *device);
44 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
45 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
46 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
47
48 static DEFINE_MUTEX(uuid_mutex);
49 static LIST_HEAD(fs_uuids);
50
51 static void lock_chunks(struct btrfs_root *root)
52 {
53 mutex_lock(&root->fs_info->chunk_mutex);
54 }
55
56 static void unlock_chunks(struct btrfs_root *root)
57 {
58 mutex_unlock(&root->fs_info->chunk_mutex);
59 }
60
61 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
62 {
63 struct btrfs_device *device;
64 WARN_ON(fs_devices->opened);
65 while (!list_empty(&fs_devices->devices)) {
66 device = list_entry(fs_devices->devices.next,
67 struct btrfs_device, dev_list);
68 list_del(&device->dev_list);
69 rcu_string_free(device->name);
70 kfree(device);
71 }
72 kfree(fs_devices);
73 }
74
75 static void btrfs_kobject_uevent(struct block_device *bdev,
76 enum kobject_action action)
77 {
78 int ret;
79
80 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
81 if (ret)
82 pr_warn("Sending event '%d' to kobject: '%s' (%p): failed\n",
83 action,
84 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
85 &disk_to_dev(bdev->bd_disk)->kobj);
86 }
87
88 void btrfs_cleanup_fs_uuids(void)
89 {
90 struct btrfs_fs_devices *fs_devices;
91
92 while (!list_empty(&fs_uuids)) {
93 fs_devices = list_entry(fs_uuids.next,
94 struct btrfs_fs_devices, list);
95 list_del(&fs_devices->list);
96 free_fs_devices(fs_devices);
97 }
98 }
99
100 static noinline struct btrfs_device *__find_device(struct list_head *head,
101 u64 devid, u8 *uuid)
102 {
103 struct btrfs_device *dev;
104
105 list_for_each_entry(dev, head, dev_list) {
106 if (dev->devid == devid &&
107 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
108 return dev;
109 }
110 }
111 return NULL;
112 }
113
114 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
115 {
116 struct btrfs_fs_devices *fs_devices;
117
118 list_for_each_entry(fs_devices, &fs_uuids, list) {
119 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
120 return fs_devices;
121 }
122 return NULL;
123 }
124
125 static int
126 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
127 int flush, struct block_device **bdev,
128 struct buffer_head **bh)
129 {
130 int ret;
131
132 *bdev = blkdev_get_by_path(device_path, flags, holder);
133
134 if (IS_ERR(*bdev)) {
135 ret = PTR_ERR(*bdev);
136 printk(KERN_INFO "btrfs: open %s failed\n", device_path);
137 goto error;
138 }
139
140 if (flush)
141 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
142 ret = set_blocksize(*bdev, 4096);
143 if (ret) {
144 blkdev_put(*bdev, flags);
145 goto error;
146 }
147 invalidate_bdev(*bdev);
148 *bh = btrfs_read_dev_super(*bdev);
149 if (!*bh) {
150 ret = -EINVAL;
151 blkdev_put(*bdev, flags);
152 goto error;
153 }
154
155 return 0;
156
157 error:
158 *bdev = NULL;
159 *bh = NULL;
160 return ret;
161 }
162
163 static void requeue_list(struct btrfs_pending_bios *pending_bios,
164 struct bio *head, struct bio *tail)
165 {
166
167 struct bio *old_head;
168
169 old_head = pending_bios->head;
170 pending_bios->head = head;
171 if (pending_bios->tail)
172 tail->bi_next = old_head;
173 else
174 pending_bios->tail = tail;
175 }
176
177 /*
178 * we try to collect pending bios for a device so we don't get a large
179 * number of procs sending bios down to the same device. This greatly
180 * improves the schedulers ability to collect and merge the bios.
181 *
182 * But, it also turns into a long list of bios to process and that is sure
183 * to eventually make the worker thread block. The solution here is to
184 * make some progress and then put this work struct back at the end of
185 * the list if the block device is congested. This way, multiple devices
186 * can make progress from a single worker thread.
187 */
188 static noinline void run_scheduled_bios(struct btrfs_device *device)
189 {
190 struct bio *pending;
191 struct backing_dev_info *bdi;
192 struct btrfs_fs_info *fs_info;
193 struct btrfs_pending_bios *pending_bios;
194 struct bio *tail;
195 struct bio *cur;
196 int again = 0;
197 unsigned long num_run;
198 unsigned long batch_run = 0;
199 unsigned long limit;
200 unsigned long last_waited = 0;
201 int force_reg = 0;
202 int sync_pending = 0;
203 struct blk_plug plug;
204
205 /*
206 * this function runs all the bios we've collected for
207 * a particular device. We don't want to wander off to
208 * another device without first sending all of these down.
209 * So, setup a plug here and finish it off before we return
210 */
211 blk_start_plug(&plug);
212
213 bdi = blk_get_backing_dev_info(device->bdev);
214 fs_info = device->dev_root->fs_info;
215 limit = btrfs_async_submit_limit(fs_info);
216 limit = limit * 2 / 3;
217
218 loop:
219 spin_lock(&device->io_lock);
220
221 loop_lock:
222 num_run = 0;
223
224 /* take all the bios off the list at once and process them
225 * later on (without the lock held). But, remember the
226 * tail and other pointers so the bios can be properly reinserted
227 * into the list if we hit congestion
228 */
229 if (!force_reg && device->pending_sync_bios.head) {
230 pending_bios = &device->pending_sync_bios;
231 force_reg = 1;
232 } else {
233 pending_bios = &device->pending_bios;
234 force_reg = 0;
235 }
236
237 pending = pending_bios->head;
238 tail = pending_bios->tail;
239 WARN_ON(pending && !tail);
240
241 /*
242 * if pending was null this time around, no bios need processing
243 * at all and we can stop. Otherwise it'll loop back up again
244 * and do an additional check so no bios are missed.
245 *
246 * device->running_pending is used to synchronize with the
247 * schedule_bio code.
248 */
249 if (device->pending_sync_bios.head == NULL &&
250 device->pending_bios.head == NULL) {
251 again = 0;
252 device->running_pending = 0;
253 } else {
254 again = 1;
255 device->running_pending = 1;
256 }
257
258 pending_bios->head = NULL;
259 pending_bios->tail = NULL;
260
261 spin_unlock(&device->io_lock);
262
263 while (pending) {
264
265 rmb();
266 /* we want to work on both lists, but do more bios on the
267 * sync list than the regular list
268 */
269 if ((num_run > 32 &&
270 pending_bios != &device->pending_sync_bios &&
271 device->pending_sync_bios.head) ||
272 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
273 device->pending_bios.head)) {
274 spin_lock(&device->io_lock);
275 requeue_list(pending_bios, pending, tail);
276 goto loop_lock;
277 }
278
279 cur = pending;
280 pending = pending->bi_next;
281 cur->bi_next = NULL;
282
283 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
284 waitqueue_active(&fs_info->async_submit_wait))
285 wake_up(&fs_info->async_submit_wait);
286
287 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
288
289 /*
290 * if we're doing the sync list, record that our
291 * plug has some sync requests on it
292 *
293 * If we're doing the regular list and there are
294 * sync requests sitting around, unplug before
295 * we add more
296 */
297 if (pending_bios == &device->pending_sync_bios) {
298 sync_pending = 1;
299 } else if (sync_pending) {
300 blk_finish_plug(&plug);
301 blk_start_plug(&plug);
302 sync_pending = 0;
303 }
304
305 btrfsic_submit_bio(cur->bi_rw, cur);
306 num_run++;
307 batch_run++;
308 if (need_resched())
309 cond_resched();
310
311 /*
312 * we made progress, there is more work to do and the bdi
313 * is now congested. Back off and let other work structs
314 * run instead
315 */
316 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
317 fs_info->fs_devices->open_devices > 1) {
318 struct io_context *ioc;
319
320 ioc = current->io_context;
321
322 /*
323 * the main goal here is that we don't want to
324 * block if we're going to be able to submit
325 * more requests without blocking.
326 *
327 * This code does two great things, it pokes into
328 * the elevator code from a filesystem _and_
329 * it makes assumptions about how batching works.
330 */
331 if (ioc && ioc->nr_batch_requests > 0 &&
332 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
333 (last_waited == 0 ||
334 ioc->last_waited == last_waited)) {
335 /*
336 * we want to go through our batch of
337 * requests and stop. So, we copy out
338 * the ioc->last_waited time and test
339 * against it before looping
340 */
341 last_waited = ioc->last_waited;
342 if (need_resched())
343 cond_resched();
344 continue;
345 }
346 spin_lock(&device->io_lock);
347 requeue_list(pending_bios, pending, tail);
348 device->running_pending = 1;
349
350 spin_unlock(&device->io_lock);
351 btrfs_requeue_work(&device->work);
352 goto done;
353 }
354 /* unplug every 64 requests just for good measure */
355 if (batch_run % 64 == 0) {
356 blk_finish_plug(&plug);
357 blk_start_plug(&plug);
358 sync_pending = 0;
359 }
360 }
361
362 cond_resched();
363 if (again)
364 goto loop;
365
366 spin_lock(&device->io_lock);
367 if (device->pending_bios.head || device->pending_sync_bios.head)
368 goto loop_lock;
369 spin_unlock(&device->io_lock);
370
371 done:
372 blk_finish_plug(&plug);
373 }
374
375 static void pending_bios_fn(struct btrfs_work *work)
376 {
377 struct btrfs_device *device;
378
379 device = container_of(work, struct btrfs_device, work);
380 run_scheduled_bios(device);
381 }
382
383 static noinline int device_list_add(const char *path,
384 struct btrfs_super_block *disk_super,
385 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
386 {
387 struct btrfs_device *device;
388 struct btrfs_fs_devices *fs_devices;
389 struct rcu_string *name;
390 u64 found_transid = btrfs_super_generation(disk_super);
391
392 fs_devices = find_fsid(disk_super->fsid);
393 if (!fs_devices) {
394 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
395 if (!fs_devices)
396 return -ENOMEM;
397 INIT_LIST_HEAD(&fs_devices->devices);
398 INIT_LIST_HEAD(&fs_devices->alloc_list);
399 list_add(&fs_devices->list, &fs_uuids);
400 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
401 fs_devices->latest_devid = devid;
402 fs_devices->latest_trans = found_transid;
403 mutex_init(&fs_devices->device_list_mutex);
404 device = NULL;
405 } else {
406 device = __find_device(&fs_devices->devices, devid,
407 disk_super->dev_item.uuid);
408 }
409 if (!device) {
410 if (fs_devices->opened)
411 return -EBUSY;
412
413 device = kzalloc(sizeof(*device), GFP_NOFS);
414 if (!device) {
415 /* we can safely leave the fs_devices entry around */
416 return -ENOMEM;
417 }
418 device->devid = devid;
419 device->dev_stats_valid = 0;
420 device->work.func = pending_bios_fn;
421 memcpy(device->uuid, disk_super->dev_item.uuid,
422 BTRFS_UUID_SIZE);
423 spin_lock_init(&device->io_lock);
424
425 name = rcu_string_strdup(path, GFP_NOFS);
426 if (!name) {
427 kfree(device);
428 return -ENOMEM;
429 }
430 rcu_assign_pointer(device->name, name);
431 INIT_LIST_HEAD(&device->dev_alloc_list);
432
433 /* init readahead state */
434 spin_lock_init(&device->reada_lock);
435 device->reada_curr_zone = NULL;
436 atomic_set(&device->reada_in_flight, 0);
437 device->reada_next = 0;
438 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
439 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
440
441 mutex_lock(&fs_devices->device_list_mutex);
442 list_add_rcu(&device->dev_list, &fs_devices->devices);
443 mutex_unlock(&fs_devices->device_list_mutex);
444
445 device->fs_devices = fs_devices;
446 fs_devices->num_devices++;
447 } else if (!device->name || strcmp(device->name->str, path)) {
448 name = rcu_string_strdup(path, GFP_NOFS);
449 if (!name)
450 return -ENOMEM;
451 rcu_string_free(device->name);
452 rcu_assign_pointer(device->name, name);
453 if (device->missing) {
454 fs_devices->missing_devices--;
455 device->missing = 0;
456 }
457 }
458
459 if (found_transid > fs_devices->latest_trans) {
460 fs_devices->latest_devid = devid;
461 fs_devices->latest_trans = found_transid;
462 }
463 *fs_devices_ret = fs_devices;
464 return 0;
465 }
466
467 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
468 {
469 struct btrfs_fs_devices *fs_devices;
470 struct btrfs_device *device;
471 struct btrfs_device *orig_dev;
472
473 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
474 if (!fs_devices)
475 return ERR_PTR(-ENOMEM);
476
477 INIT_LIST_HEAD(&fs_devices->devices);
478 INIT_LIST_HEAD(&fs_devices->alloc_list);
479 INIT_LIST_HEAD(&fs_devices->list);
480 mutex_init(&fs_devices->device_list_mutex);
481 fs_devices->latest_devid = orig->latest_devid;
482 fs_devices->latest_trans = orig->latest_trans;
483 fs_devices->total_devices = orig->total_devices;
484 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
485
486 /* We have held the volume lock, it is safe to get the devices. */
487 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
488 struct rcu_string *name;
489
490 device = kzalloc(sizeof(*device), GFP_NOFS);
491 if (!device)
492 goto error;
493
494 /*
495 * This is ok to do without rcu read locked because we hold the
496 * uuid mutex so nothing we touch in here is going to disappear.
497 */
498 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
499 if (!name) {
500 kfree(device);
501 goto error;
502 }
503 rcu_assign_pointer(device->name, name);
504
505 device->devid = orig_dev->devid;
506 device->work.func = pending_bios_fn;
507 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
508 spin_lock_init(&device->io_lock);
509 INIT_LIST_HEAD(&device->dev_list);
510 INIT_LIST_HEAD(&device->dev_alloc_list);
511
512 list_add(&device->dev_list, &fs_devices->devices);
513 device->fs_devices = fs_devices;
514 fs_devices->num_devices++;
515 }
516 return fs_devices;
517 error:
518 free_fs_devices(fs_devices);
519 return ERR_PTR(-ENOMEM);
520 }
521
522 void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
523 struct btrfs_fs_devices *fs_devices, int step)
524 {
525 struct btrfs_device *device, *next;
526
527 struct block_device *latest_bdev = NULL;
528 u64 latest_devid = 0;
529 u64 latest_transid = 0;
530
531 mutex_lock(&uuid_mutex);
532 again:
533 /* This is the initialized path, it is safe to release the devices. */
534 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
535 if (device->in_fs_metadata) {
536 if (!device->is_tgtdev_for_dev_replace &&
537 (!latest_transid ||
538 device->generation > latest_transid)) {
539 latest_devid = device->devid;
540 latest_transid = device->generation;
541 latest_bdev = device->bdev;
542 }
543 continue;
544 }
545
546 if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
547 /*
548 * In the first step, keep the device which has
549 * the correct fsid and the devid that is used
550 * for the dev_replace procedure.
551 * In the second step, the dev_replace state is
552 * read from the device tree and it is known
553 * whether the procedure is really active or
554 * not, which means whether this device is
555 * used or whether it should be removed.
556 */
557 if (step == 0 || device->is_tgtdev_for_dev_replace) {
558 continue;
559 }
560 }
561 if (device->bdev) {
562 blkdev_put(device->bdev, device->mode);
563 device->bdev = NULL;
564 fs_devices->open_devices--;
565 }
566 if (device->writeable) {
567 list_del_init(&device->dev_alloc_list);
568 device->writeable = 0;
569 if (!device->is_tgtdev_for_dev_replace)
570 fs_devices->rw_devices--;
571 }
572 list_del_init(&device->dev_list);
573 fs_devices->num_devices--;
574 rcu_string_free(device->name);
575 kfree(device);
576 }
577
578 if (fs_devices->seed) {
579 fs_devices = fs_devices->seed;
580 goto again;
581 }
582
583 fs_devices->latest_bdev = latest_bdev;
584 fs_devices->latest_devid = latest_devid;
585 fs_devices->latest_trans = latest_transid;
586
587 mutex_unlock(&uuid_mutex);
588 }
589
590 static void __free_device(struct work_struct *work)
591 {
592 struct btrfs_device *device;
593
594 device = container_of(work, struct btrfs_device, rcu_work);
595
596 if (device->bdev)
597 blkdev_put(device->bdev, device->mode);
598
599 rcu_string_free(device->name);
600 kfree(device);
601 }
602
603 static void free_device(struct rcu_head *head)
604 {
605 struct btrfs_device *device;
606
607 device = container_of(head, struct btrfs_device, rcu);
608
609 INIT_WORK(&device->rcu_work, __free_device);
610 schedule_work(&device->rcu_work);
611 }
612
613 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
614 {
615 struct btrfs_device *device;
616
617 if (--fs_devices->opened > 0)
618 return 0;
619
620 mutex_lock(&fs_devices->device_list_mutex);
621 list_for_each_entry(device, &fs_devices->devices, dev_list) {
622 struct btrfs_device *new_device;
623 struct rcu_string *name;
624
625 if (device->bdev)
626 fs_devices->open_devices--;
627
628 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
629 list_del_init(&device->dev_alloc_list);
630 fs_devices->rw_devices--;
631 }
632
633 if (device->can_discard)
634 fs_devices->num_can_discard--;
635
636 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
637 BUG_ON(!new_device); /* -ENOMEM */
638 memcpy(new_device, device, sizeof(*new_device));
639
640 /* Safe because we are under uuid_mutex */
641 if (device->name) {
642 name = rcu_string_strdup(device->name->str, GFP_NOFS);
643 BUG_ON(device->name && !name); /* -ENOMEM */
644 rcu_assign_pointer(new_device->name, name);
645 }
646 new_device->bdev = NULL;
647 new_device->writeable = 0;
648 new_device->in_fs_metadata = 0;
649 new_device->can_discard = 0;
650 list_replace_rcu(&device->dev_list, &new_device->dev_list);
651
652 call_rcu(&device->rcu, free_device);
653 }
654 mutex_unlock(&fs_devices->device_list_mutex);
655
656 WARN_ON(fs_devices->open_devices);
657 WARN_ON(fs_devices->rw_devices);
658 fs_devices->opened = 0;
659 fs_devices->seeding = 0;
660
661 return 0;
662 }
663
664 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
665 {
666 struct btrfs_fs_devices *seed_devices = NULL;
667 int ret;
668
669 mutex_lock(&uuid_mutex);
670 ret = __btrfs_close_devices(fs_devices);
671 if (!fs_devices->opened) {
672 seed_devices = fs_devices->seed;
673 fs_devices->seed = NULL;
674 }
675 mutex_unlock(&uuid_mutex);
676
677 while (seed_devices) {
678 fs_devices = seed_devices;
679 seed_devices = fs_devices->seed;
680 __btrfs_close_devices(fs_devices);
681 free_fs_devices(fs_devices);
682 }
683 return ret;
684 }
685
686 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
687 fmode_t flags, void *holder)
688 {
689 struct request_queue *q;
690 struct block_device *bdev;
691 struct list_head *head = &fs_devices->devices;
692 struct btrfs_device *device;
693 struct block_device *latest_bdev = NULL;
694 struct buffer_head *bh;
695 struct btrfs_super_block *disk_super;
696 u64 latest_devid = 0;
697 u64 latest_transid = 0;
698 u64 devid;
699 int seeding = 1;
700 int ret = 0;
701
702 flags |= FMODE_EXCL;
703
704 list_for_each_entry(device, head, dev_list) {
705 if (device->bdev)
706 continue;
707 if (!device->name)
708 continue;
709
710 ret = btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
711 &bdev, &bh);
712 if (ret)
713 continue;
714
715 disk_super = (struct btrfs_super_block *)bh->b_data;
716 devid = btrfs_stack_device_id(&disk_super->dev_item);
717 if (devid != device->devid)
718 goto error_brelse;
719
720 if (memcmp(device->uuid, disk_super->dev_item.uuid,
721 BTRFS_UUID_SIZE))
722 goto error_brelse;
723
724 device->generation = btrfs_super_generation(disk_super);
725 if (!latest_transid || device->generation > latest_transid) {
726 latest_devid = devid;
727 latest_transid = device->generation;
728 latest_bdev = bdev;
729 }
730
731 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
732 device->writeable = 0;
733 } else {
734 device->writeable = !bdev_read_only(bdev);
735 seeding = 0;
736 }
737
738 q = bdev_get_queue(bdev);
739 if (blk_queue_discard(q)) {
740 device->can_discard = 1;
741 fs_devices->num_can_discard++;
742 }
743
744 device->bdev = bdev;
745 device->in_fs_metadata = 0;
746 device->mode = flags;
747
748 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
749 fs_devices->rotating = 1;
750
751 fs_devices->open_devices++;
752 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
753 fs_devices->rw_devices++;
754 list_add(&device->dev_alloc_list,
755 &fs_devices->alloc_list);
756 }
757 brelse(bh);
758 continue;
759
760 error_brelse:
761 brelse(bh);
762 blkdev_put(bdev, flags);
763 continue;
764 }
765 if (fs_devices->open_devices == 0) {
766 ret = -EINVAL;
767 goto out;
768 }
769 fs_devices->seeding = seeding;
770 fs_devices->opened = 1;
771 fs_devices->latest_bdev = latest_bdev;
772 fs_devices->latest_devid = latest_devid;
773 fs_devices->latest_trans = latest_transid;
774 fs_devices->total_rw_bytes = 0;
775 out:
776 return ret;
777 }
778
779 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
780 fmode_t flags, void *holder)
781 {
782 int ret;
783
784 mutex_lock(&uuid_mutex);
785 if (fs_devices->opened) {
786 fs_devices->opened++;
787 ret = 0;
788 } else {
789 ret = __btrfs_open_devices(fs_devices, flags, holder);
790 }
791 mutex_unlock(&uuid_mutex);
792 return ret;
793 }
794
795 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
796 struct btrfs_fs_devices **fs_devices_ret)
797 {
798 struct btrfs_super_block *disk_super;
799 struct block_device *bdev;
800 struct buffer_head *bh;
801 int ret;
802 u64 devid;
803 u64 transid;
804 u64 total_devices;
805
806 flags |= FMODE_EXCL;
807 mutex_lock(&uuid_mutex);
808 ret = btrfs_get_bdev_and_sb(path, flags, holder, 0, &bdev, &bh);
809 if (ret)
810 goto error;
811 disk_super = (struct btrfs_super_block *)bh->b_data;
812 devid = btrfs_stack_device_id(&disk_super->dev_item);
813 transid = btrfs_super_generation(disk_super);
814 total_devices = btrfs_super_num_devices(disk_super);
815 if (disk_super->label[0]) {
816 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
817 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
818 printk(KERN_INFO "device label %s ", disk_super->label);
819 } else {
820 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
821 }
822 printk(KERN_CONT "devid %llu transid %llu %s\n",
823 (unsigned long long)devid, (unsigned long long)transid, path);
824 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
825 if (!ret && fs_devices_ret)
826 (*fs_devices_ret)->total_devices = total_devices;
827 brelse(bh);
828 blkdev_put(bdev, flags);
829 error:
830 mutex_unlock(&uuid_mutex);
831 return ret;
832 }
833
834 /* helper to account the used device space in the range */
835 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
836 u64 end, u64 *length)
837 {
838 struct btrfs_key key;
839 struct btrfs_root *root = device->dev_root;
840 struct btrfs_dev_extent *dev_extent;
841 struct btrfs_path *path;
842 u64 extent_end;
843 int ret;
844 int slot;
845 struct extent_buffer *l;
846
847 *length = 0;
848
849 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
850 return 0;
851
852 path = btrfs_alloc_path();
853 if (!path)
854 return -ENOMEM;
855 path->reada = 2;
856
857 key.objectid = device->devid;
858 key.offset = start;
859 key.type = BTRFS_DEV_EXTENT_KEY;
860
861 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
862 if (ret < 0)
863 goto out;
864 if (ret > 0) {
865 ret = btrfs_previous_item(root, path, key.objectid, key.type);
866 if (ret < 0)
867 goto out;
868 }
869
870 while (1) {
871 l = path->nodes[0];
872 slot = path->slots[0];
873 if (slot >= btrfs_header_nritems(l)) {
874 ret = btrfs_next_leaf(root, path);
875 if (ret == 0)
876 continue;
877 if (ret < 0)
878 goto out;
879
880 break;
881 }
882 btrfs_item_key_to_cpu(l, &key, slot);
883
884 if (key.objectid < device->devid)
885 goto next;
886
887 if (key.objectid > device->devid)
888 break;
889
890 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
891 goto next;
892
893 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
894 extent_end = key.offset + btrfs_dev_extent_length(l,
895 dev_extent);
896 if (key.offset <= start && extent_end > end) {
897 *length = end - start + 1;
898 break;
899 } else if (key.offset <= start && extent_end > start)
900 *length += extent_end - start;
901 else if (key.offset > start && extent_end <= end)
902 *length += extent_end - key.offset;
903 else if (key.offset > start && key.offset <= end) {
904 *length += end - key.offset + 1;
905 break;
906 } else if (key.offset > end)
907 break;
908
909 next:
910 path->slots[0]++;
911 }
912 ret = 0;
913 out:
914 btrfs_free_path(path);
915 return ret;
916 }
917
918 /*
919 * find_free_dev_extent - find free space in the specified device
920 * @device: the device which we search the free space in
921 * @num_bytes: the size of the free space that we need
922 * @start: store the start of the free space.
923 * @len: the size of the free space. that we find, or the size of the max
924 * free space if we don't find suitable free space
925 *
926 * this uses a pretty simple search, the expectation is that it is
927 * called very infrequently and that a given device has a small number
928 * of extents
929 *
930 * @start is used to store the start of the free space if we find. But if we
931 * don't find suitable free space, it will be used to store the start position
932 * of the max free space.
933 *
934 * @len is used to store the size of the free space that we find.
935 * But if we don't find suitable free space, it is used to store the size of
936 * the max free space.
937 */
938 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
939 u64 *start, u64 *len)
940 {
941 struct btrfs_key key;
942 struct btrfs_root *root = device->dev_root;
943 struct btrfs_dev_extent *dev_extent;
944 struct btrfs_path *path;
945 u64 hole_size;
946 u64 max_hole_start;
947 u64 max_hole_size;
948 u64 extent_end;
949 u64 search_start;
950 u64 search_end = device->total_bytes;
951 int ret;
952 int slot;
953 struct extent_buffer *l;
954
955 /* FIXME use last free of some kind */
956
957 /* we don't want to overwrite the superblock on the drive,
958 * so we make sure to start at an offset of at least 1MB
959 */
960 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
961
962 max_hole_start = search_start;
963 max_hole_size = 0;
964 hole_size = 0;
965
966 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
967 ret = -ENOSPC;
968 goto error;
969 }
970
971 path = btrfs_alloc_path();
972 if (!path) {
973 ret = -ENOMEM;
974 goto error;
975 }
976 path->reada = 2;
977
978 key.objectid = device->devid;
979 key.offset = search_start;
980 key.type = BTRFS_DEV_EXTENT_KEY;
981
982 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
983 if (ret < 0)
984 goto out;
985 if (ret > 0) {
986 ret = btrfs_previous_item(root, path, key.objectid, key.type);
987 if (ret < 0)
988 goto out;
989 }
990
991 while (1) {
992 l = path->nodes[0];
993 slot = path->slots[0];
994 if (slot >= btrfs_header_nritems(l)) {
995 ret = btrfs_next_leaf(root, path);
996 if (ret == 0)
997 continue;
998 if (ret < 0)
999 goto out;
1000
1001 break;
1002 }
1003 btrfs_item_key_to_cpu(l, &key, slot);
1004
1005 if (key.objectid < device->devid)
1006 goto next;
1007
1008 if (key.objectid > device->devid)
1009 break;
1010
1011 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1012 goto next;
1013
1014 if (key.offset > search_start) {
1015 hole_size = key.offset - search_start;
1016
1017 if (hole_size > max_hole_size) {
1018 max_hole_start = search_start;
1019 max_hole_size = hole_size;
1020 }
1021
1022 /*
1023 * If this free space is greater than which we need,
1024 * it must be the max free space that we have found
1025 * until now, so max_hole_start must point to the start
1026 * of this free space and the length of this free space
1027 * is stored in max_hole_size. Thus, we return
1028 * max_hole_start and max_hole_size and go back to the
1029 * caller.
1030 */
1031 if (hole_size >= num_bytes) {
1032 ret = 0;
1033 goto out;
1034 }
1035 }
1036
1037 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1038 extent_end = key.offset + btrfs_dev_extent_length(l,
1039 dev_extent);
1040 if (extent_end > search_start)
1041 search_start = extent_end;
1042 next:
1043 path->slots[0]++;
1044 cond_resched();
1045 }
1046
1047 /*
1048 * At this point, search_start should be the end of
1049 * allocated dev extents, and when shrinking the device,
1050 * search_end may be smaller than search_start.
1051 */
1052 if (search_end > search_start)
1053 hole_size = search_end - search_start;
1054
1055 if (hole_size > max_hole_size) {
1056 max_hole_start = search_start;
1057 max_hole_size = hole_size;
1058 }
1059
1060 /* See above. */
1061 if (hole_size < num_bytes)
1062 ret = -ENOSPC;
1063 else
1064 ret = 0;
1065
1066 out:
1067 btrfs_free_path(path);
1068 error:
1069 *start = max_hole_start;
1070 if (len)
1071 *len = max_hole_size;
1072 return ret;
1073 }
1074
1075 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1076 struct btrfs_device *device,
1077 u64 start)
1078 {
1079 int ret;
1080 struct btrfs_path *path;
1081 struct btrfs_root *root = device->dev_root;
1082 struct btrfs_key key;
1083 struct btrfs_key found_key;
1084 struct extent_buffer *leaf = NULL;
1085 struct btrfs_dev_extent *extent = NULL;
1086
1087 path = btrfs_alloc_path();
1088 if (!path)
1089 return -ENOMEM;
1090
1091 key.objectid = device->devid;
1092 key.offset = start;
1093 key.type = BTRFS_DEV_EXTENT_KEY;
1094 again:
1095 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1096 if (ret > 0) {
1097 ret = btrfs_previous_item(root, path, key.objectid,
1098 BTRFS_DEV_EXTENT_KEY);
1099 if (ret)
1100 goto out;
1101 leaf = path->nodes[0];
1102 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1103 extent = btrfs_item_ptr(leaf, path->slots[0],
1104 struct btrfs_dev_extent);
1105 BUG_ON(found_key.offset > start || found_key.offset +
1106 btrfs_dev_extent_length(leaf, extent) < start);
1107 key = found_key;
1108 btrfs_release_path(path);
1109 goto again;
1110 } else if (ret == 0) {
1111 leaf = path->nodes[0];
1112 extent = btrfs_item_ptr(leaf, path->slots[0],
1113 struct btrfs_dev_extent);
1114 } else {
1115 btrfs_error(root->fs_info, ret, "Slot search failed");
1116 goto out;
1117 }
1118
1119 if (device->bytes_used > 0) {
1120 u64 len = btrfs_dev_extent_length(leaf, extent);
1121 device->bytes_used -= len;
1122 spin_lock(&root->fs_info->free_chunk_lock);
1123 root->fs_info->free_chunk_space += len;
1124 spin_unlock(&root->fs_info->free_chunk_lock);
1125 }
1126 ret = btrfs_del_item(trans, root, path);
1127 if (ret) {
1128 btrfs_error(root->fs_info, ret,
1129 "Failed to remove dev extent item");
1130 }
1131 out:
1132 btrfs_free_path(path);
1133 return ret;
1134 }
1135
1136 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1137 struct btrfs_device *device,
1138 u64 chunk_tree, u64 chunk_objectid,
1139 u64 chunk_offset, u64 start, u64 num_bytes)
1140 {
1141 int ret;
1142 struct btrfs_path *path;
1143 struct btrfs_root *root = device->dev_root;
1144 struct btrfs_dev_extent *extent;
1145 struct extent_buffer *leaf;
1146 struct btrfs_key key;
1147
1148 WARN_ON(!device->in_fs_metadata);
1149 WARN_ON(device->is_tgtdev_for_dev_replace);
1150 path = btrfs_alloc_path();
1151 if (!path)
1152 return -ENOMEM;
1153
1154 key.objectid = device->devid;
1155 key.offset = start;
1156 key.type = BTRFS_DEV_EXTENT_KEY;
1157 ret = btrfs_insert_empty_item(trans, root, path, &key,
1158 sizeof(*extent));
1159 if (ret)
1160 goto out;
1161
1162 leaf = path->nodes[0];
1163 extent = btrfs_item_ptr(leaf, path->slots[0],
1164 struct btrfs_dev_extent);
1165 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1166 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1167 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1168
1169 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1170 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1171 BTRFS_UUID_SIZE);
1172
1173 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1174 btrfs_mark_buffer_dirty(leaf);
1175 out:
1176 btrfs_free_path(path);
1177 return ret;
1178 }
1179
1180 static noinline int find_next_chunk(struct btrfs_root *root,
1181 u64 objectid, u64 *offset)
1182 {
1183 struct btrfs_path *path;
1184 int ret;
1185 struct btrfs_key key;
1186 struct btrfs_chunk *chunk;
1187 struct btrfs_key found_key;
1188
1189 path = btrfs_alloc_path();
1190 if (!path)
1191 return -ENOMEM;
1192
1193 key.objectid = objectid;
1194 key.offset = (u64)-1;
1195 key.type = BTRFS_CHUNK_ITEM_KEY;
1196
1197 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1198 if (ret < 0)
1199 goto error;
1200
1201 BUG_ON(ret == 0); /* Corruption */
1202
1203 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1204 if (ret) {
1205 *offset = 0;
1206 } else {
1207 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1208 path->slots[0]);
1209 if (found_key.objectid != objectid)
1210 *offset = 0;
1211 else {
1212 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1213 struct btrfs_chunk);
1214 *offset = found_key.offset +
1215 btrfs_chunk_length(path->nodes[0], chunk);
1216 }
1217 }
1218 ret = 0;
1219 error:
1220 btrfs_free_path(path);
1221 return ret;
1222 }
1223
1224 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1225 {
1226 int ret;
1227 struct btrfs_key key;
1228 struct btrfs_key found_key;
1229 struct btrfs_path *path;
1230
1231 root = root->fs_info->chunk_root;
1232
1233 path = btrfs_alloc_path();
1234 if (!path)
1235 return -ENOMEM;
1236
1237 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1238 key.type = BTRFS_DEV_ITEM_KEY;
1239 key.offset = (u64)-1;
1240
1241 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1242 if (ret < 0)
1243 goto error;
1244
1245 BUG_ON(ret == 0); /* Corruption */
1246
1247 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1248 BTRFS_DEV_ITEM_KEY);
1249 if (ret) {
1250 *objectid = 1;
1251 } else {
1252 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1253 path->slots[0]);
1254 *objectid = found_key.offset + 1;
1255 }
1256 ret = 0;
1257 error:
1258 btrfs_free_path(path);
1259 return ret;
1260 }
1261
1262 /*
1263 * the device information is stored in the chunk root
1264 * the btrfs_device struct should be fully filled in
1265 */
1266 int btrfs_add_device(struct btrfs_trans_handle *trans,
1267 struct btrfs_root *root,
1268 struct btrfs_device *device)
1269 {
1270 int ret;
1271 struct btrfs_path *path;
1272 struct btrfs_dev_item *dev_item;
1273 struct extent_buffer *leaf;
1274 struct btrfs_key key;
1275 unsigned long ptr;
1276
1277 root = root->fs_info->chunk_root;
1278
1279 path = btrfs_alloc_path();
1280 if (!path)
1281 return -ENOMEM;
1282
1283 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1284 key.type = BTRFS_DEV_ITEM_KEY;
1285 key.offset = device->devid;
1286
1287 ret = btrfs_insert_empty_item(trans, root, path, &key,
1288 sizeof(*dev_item));
1289 if (ret)
1290 goto out;
1291
1292 leaf = path->nodes[0];
1293 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1294
1295 btrfs_set_device_id(leaf, dev_item, device->devid);
1296 btrfs_set_device_generation(leaf, dev_item, 0);
1297 btrfs_set_device_type(leaf, dev_item, device->type);
1298 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1299 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1300 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1301 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1302 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1303 btrfs_set_device_group(leaf, dev_item, 0);
1304 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1305 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1306 btrfs_set_device_start_offset(leaf, dev_item, 0);
1307
1308 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1309 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1310 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1311 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1312 btrfs_mark_buffer_dirty(leaf);
1313
1314 ret = 0;
1315 out:
1316 btrfs_free_path(path);
1317 return ret;
1318 }
1319
1320 static int btrfs_rm_dev_item(struct btrfs_root *root,
1321 struct btrfs_device *device)
1322 {
1323 int ret;
1324 struct btrfs_path *path;
1325 struct btrfs_key key;
1326 struct btrfs_trans_handle *trans;
1327
1328 root = root->fs_info->chunk_root;
1329
1330 path = btrfs_alloc_path();
1331 if (!path)
1332 return -ENOMEM;
1333
1334 trans = btrfs_start_transaction(root, 0);
1335 if (IS_ERR(trans)) {
1336 btrfs_free_path(path);
1337 return PTR_ERR(trans);
1338 }
1339 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1340 key.type = BTRFS_DEV_ITEM_KEY;
1341 key.offset = device->devid;
1342 lock_chunks(root);
1343
1344 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1345 if (ret < 0)
1346 goto out;
1347
1348 if (ret > 0) {
1349 ret = -ENOENT;
1350 goto out;
1351 }
1352
1353 ret = btrfs_del_item(trans, root, path);
1354 if (ret)
1355 goto out;
1356 out:
1357 btrfs_free_path(path);
1358 unlock_chunks(root);
1359 btrfs_commit_transaction(trans, root);
1360 return ret;
1361 }
1362
1363 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1364 {
1365 struct btrfs_device *device;
1366 struct btrfs_device *next_device;
1367 struct block_device *bdev;
1368 struct buffer_head *bh = NULL;
1369 struct btrfs_super_block *disk_super;
1370 struct btrfs_fs_devices *cur_devices;
1371 u64 all_avail;
1372 u64 devid;
1373 u64 num_devices;
1374 u8 *dev_uuid;
1375 int ret = 0;
1376 bool clear_super = false;
1377
1378 mutex_lock(&uuid_mutex);
1379
1380 all_avail = root->fs_info->avail_data_alloc_bits |
1381 root->fs_info->avail_system_alloc_bits |
1382 root->fs_info->avail_metadata_alloc_bits;
1383
1384 num_devices = root->fs_info->fs_devices->num_devices;
1385 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1386 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1387 WARN_ON(num_devices < 1);
1388 num_devices--;
1389 }
1390 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1391
1392 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1393 printk(KERN_ERR "btrfs: unable to go below four devices "
1394 "on raid10\n");
1395 ret = -EINVAL;
1396 goto out;
1397 }
1398
1399 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1400 printk(KERN_ERR "btrfs: unable to go below two "
1401 "devices on raid1\n");
1402 ret = -EINVAL;
1403 goto out;
1404 }
1405
1406 if (strcmp(device_path, "missing") == 0) {
1407 struct list_head *devices;
1408 struct btrfs_device *tmp;
1409
1410 device = NULL;
1411 devices = &root->fs_info->fs_devices->devices;
1412 /*
1413 * It is safe to read the devices since the volume_mutex
1414 * is held.
1415 */
1416 list_for_each_entry(tmp, devices, dev_list) {
1417 if (tmp->in_fs_metadata &&
1418 !tmp->is_tgtdev_for_dev_replace &&
1419 !tmp->bdev) {
1420 device = tmp;
1421 break;
1422 }
1423 }
1424 bdev = NULL;
1425 bh = NULL;
1426 disk_super = NULL;
1427 if (!device) {
1428 printk(KERN_ERR "btrfs: no missing devices found to "
1429 "remove\n");
1430 goto out;
1431 }
1432 } else {
1433 ret = btrfs_get_bdev_and_sb(device_path,
1434 FMODE_WRITE | FMODE_EXCL,
1435 root->fs_info->bdev_holder, 0,
1436 &bdev, &bh);
1437 if (ret)
1438 goto out;
1439 disk_super = (struct btrfs_super_block *)bh->b_data;
1440 devid = btrfs_stack_device_id(&disk_super->dev_item);
1441 dev_uuid = disk_super->dev_item.uuid;
1442 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1443 disk_super->fsid);
1444 if (!device) {
1445 ret = -ENOENT;
1446 goto error_brelse;
1447 }
1448 }
1449
1450 if (device->is_tgtdev_for_dev_replace) {
1451 pr_err("btrfs: unable to remove the dev_replace target dev\n");
1452 ret = -EINVAL;
1453 goto error_brelse;
1454 }
1455
1456 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1457 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1458 "device\n");
1459 ret = -EINVAL;
1460 goto error_brelse;
1461 }
1462
1463 if (device->writeable) {
1464 lock_chunks(root);
1465 list_del_init(&device->dev_alloc_list);
1466 unlock_chunks(root);
1467 root->fs_info->fs_devices->rw_devices--;
1468 clear_super = true;
1469 }
1470
1471 ret = btrfs_shrink_device(device, 0);
1472 if (ret)
1473 goto error_undo;
1474
1475 /*
1476 * TODO: the superblock still includes this device in its num_devices
1477 * counter although write_all_supers() is not locked out. This
1478 * could give a filesystem state which requires a degraded mount.
1479 */
1480 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1481 if (ret)
1482 goto error_undo;
1483
1484 spin_lock(&root->fs_info->free_chunk_lock);
1485 root->fs_info->free_chunk_space = device->total_bytes -
1486 device->bytes_used;
1487 spin_unlock(&root->fs_info->free_chunk_lock);
1488
1489 device->in_fs_metadata = 0;
1490 btrfs_scrub_cancel_dev(root->fs_info, device);
1491
1492 /*
1493 * the device list mutex makes sure that we don't change
1494 * the device list while someone else is writing out all
1495 * the device supers.
1496 */
1497
1498 cur_devices = device->fs_devices;
1499 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1500 list_del_rcu(&device->dev_list);
1501
1502 device->fs_devices->num_devices--;
1503 device->fs_devices->total_devices--;
1504
1505 if (device->missing)
1506 root->fs_info->fs_devices->missing_devices--;
1507
1508 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1509 struct btrfs_device, dev_list);
1510 if (device->bdev == root->fs_info->sb->s_bdev)
1511 root->fs_info->sb->s_bdev = next_device->bdev;
1512 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1513 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1514
1515 if (device->bdev)
1516 device->fs_devices->open_devices--;
1517
1518 call_rcu(&device->rcu, free_device);
1519 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1520
1521 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1522 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1523
1524 if (cur_devices->open_devices == 0) {
1525 struct btrfs_fs_devices *fs_devices;
1526 fs_devices = root->fs_info->fs_devices;
1527 while (fs_devices) {
1528 if (fs_devices->seed == cur_devices)
1529 break;
1530 fs_devices = fs_devices->seed;
1531 }
1532 fs_devices->seed = cur_devices->seed;
1533 cur_devices->seed = NULL;
1534 lock_chunks(root);
1535 __btrfs_close_devices(cur_devices);
1536 unlock_chunks(root);
1537 free_fs_devices(cur_devices);
1538 }
1539
1540 root->fs_info->num_tolerated_disk_barrier_failures =
1541 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1542
1543 /*
1544 * at this point, the device is zero sized. We want to
1545 * remove it from the devices list and zero out the old super
1546 */
1547 if (clear_super && disk_super) {
1548 /* make sure this device isn't detected as part of
1549 * the FS anymore
1550 */
1551 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1552 set_buffer_dirty(bh);
1553 sync_dirty_buffer(bh);
1554 }
1555
1556 ret = 0;
1557
1558 /* Notify udev that device has changed */
1559 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1560
1561 error_brelse:
1562 brelse(bh);
1563 if (bdev)
1564 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1565 out:
1566 mutex_unlock(&uuid_mutex);
1567 return ret;
1568 error_undo:
1569 if (device->writeable) {
1570 lock_chunks(root);
1571 list_add(&device->dev_alloc_list,
1572 &root->fs_info->fs_devices->alloc_list);
1573 unlock_chunks(root);
1574 root->fs_info->fs_devices->rw_devices++;
1575 }
1576 goto error_brelse;
1577 }
1578
1579 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1580 struct btrfs_device *srcdev)
1581 {
1582 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1583 list_del_rcu(&srcdev->dev_list);
1584 list_del_rcu(&srcdev->dev_alloc_list);
1585 fs_info->fs_devices->num_devices--;
1586 if (srcdev->missing) {
1587 fs_info->fs_devices->missing_devices--;
1588 fs_info->fs_devices->rw_devices++;
1589 }
1590 if (srcdev->can_discard)
1591 fs_info->fs_devices->num_can_discard--;
1592 if (srcdev->bdev)
1593 fs_info->fs_devices->open_devices--;
1594
1595 call_rcu(&srcdev->rcu, free_device);
1596 }
1597
1598 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1599 struct btrfs_device *tgtdev)
1600 {
1601 struct btrfs_device *next_device;
1602
1603 WARN_ON(!tgtdev);
1604 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1605 if (tgtdev->bdev) {
1606 btrfs_scratch_superblock(tgtdev);
1607 fs_info->fs_devices->open_devices--;
1608 }
1609 fs_info->fs_devices->num_devices--;
1610 if (tgtdev->can_discard)
1611 fs_info->fs_devices->num_can_discard++;
1612
1613 next_device = list_entry(fs_info->fs_devices->devices.next,
1614 struct btrfs_device, dev_list);
1615 if (tgtdev->bdev == fs_info->sb->s_bdev)
1616 fs_info->sb->s_bdev = next_device->bdev;
1617 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1618 fs_info->fs_devices->latest_bdev = next_device->bdev;
1619 list_del_rcu(&tgtdev->dev_list);
1620
1621 call_rcu(&tgtdev->rcu, free_device);
1622
1623 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1624 }
1625
1626 int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1627 struct btrfs_device **device)
1628 {
1629 int ret = 0;
1630 struct btrfs_super_block *disk_super;
1631 u64 devid;
1632 u8 *dev_uuid;
1633 struct block_device *bdev;
1634 struct buffer_head *bh;
1635
1636 *device = NULL;
1637 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1638 root->fs_info->bdev_holder, 0, &bdev, &bh);
1639 if (ret)
1640 return ret;
1641 disk_super = (struct btrfs_super_block *)bh->b_data;
1642 devid = btrfs_stack_device_id(&disk_super->dev_item);
1643 dev_uuid = disk_super->dev_item.uuid;
1644 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1645 disk_super->fsid);
1646 brelse(bh);
1647 if (!*device)
1648 ret = -ENOENT;
1649 blkdev_put(bdev, FMODE_READ);
1650 return ret;
1651 }
1652
1653 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1654 char *device_path,
1655 struct btrfs_device **device)
1656 {
1657 *device = NULL;
1658 if (strcmp(device_path, "missing") == 0) {
1659 struct list_head *devices;
1660 struct btrfs_device *tmp;
1661
1662 devices = &root->fs_info->fs_devices->devices;
1663 /*
1664 * It is safe to read the devices since the volume_mutex
1665 * is held by the caller.
1666 */
1667 list_for_each_entry(tmp, devices, dev_list) {
1668 if (tmp->in_fs_metadata && !tmp->bdev) {
1669 *device = tmp;
1670 break;
1671 }
1672 }
1673
1674 if (!*device) {
1675 pr_err("btrfs: no missing device found\n");
1676 return -ENOENT;
1677 }
1678
1679 return 0;
1680 } else {
1681 return btrfs_find_device_by_path(root, device_path, device);
1682 }
1683 }
1684
1685 /*
1686 * does all the dirty work required for changing file system's UUID.
1687 */
1688 static int btrfs_prepare_sprout(struct btrfs_root *root)
1689 {
1690 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1691 struct btrfs_fs_devices *old_devices;
1692 struct btrfs_fs_devices *seed_devices;
1693 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1694 struct btrfs_device *device;
1695 u64 super_flags;
1696
1697 BUG_ON(!mutex_is_locked(&uuid_mutex));
1698 if (!fs_devices->seeding)
1699 return -EINVAL;
1700
1701 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1702 if (!seed_devices)
1703 return -ENOMEM;
1704
1705 old_devices = clone_fs_devices(fs_devices);
1706 if (IS_ERR(old_devices)) {
1707 kfree(seed_devices);
1708 return PTR_ERR(old_devices);
1709 }
1710
1711 list_add(&old_devices->list, &fs_uuids);
1712
1713 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1714 seed_devices->opened = 1;
1715 INIT_LIST_HEAD(&seed_devices->devices);
1716 INIT_LIST_HEAD(&seed_devices->alloc_list);
1717 mutex_init(&seed_devices->device_list_mutex);
1718
1719 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1720 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1721 synchronize_rcu);
1722 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1723
1724 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1725 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1726 device->fs_devices = seed_devices;
1727 }
1728
1729 fs_devices->seeding = 0;
1730 fs_devices->num_devices = 0;
1731 fs_devices->open_devices = 0;
1732 fs_devices->total_devices = 0;
1733 fs_devices->seed = seed_devices;
1734
1735 generate_random_uuid(fs_devices->fsid);
1736 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1737 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1738 super_flags = btrfs_super_flags(disk_super) &
1739 ~BTRFS_SUPER_FLAG_SEEDING;
1740 btrfs_set_super_flags(disk_super, super_flags);
1741
1742 return 0;
1743 }
1744
1745 /*
1746 * strore the expected generation for seed devices in device items.
1747 */
1748 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1749 struct btrfs_root *root)
1750 {
1751 struct btrfs_path *path;
1752 struct extent_buffer *leaf;
1753 struct btrfs_dev_item *dev_item;
1754 struct btrfs_device *device;
1755 struct btrfs_key key;
1756 u8 fs_uuid[BTRFS_UUID_SIZE];
1757 u8 dev_uuid[BTRFS_UUID_SIZE];
1758 u64 devid;
1759 int ret;
1760
1761 path = btrfs_alloc_path();
1762 if (!path)
1763 return -ENOMEM;
1764
1765 root = root->fs_info->chunk_root;
1766 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1767 key.offset = 0;
1768 key.type = BTRFS_DEV_ITEM_KEY;
1769
1770 while (1) {
1771 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1772 if (ret < 0)
1773 goto error;
1774
1775 leaf = path->nodes[0];
1776 next_slot:
1777 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1778 ret = btrfs_next_leaf(root, path);
1779 if (ret > 0)
1780 break;
1781 if (ret < 0)
1782 goto error;
1783 leaf = path->nodes[0];
1784 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1785 btrfs_release_path(path);
1786 continue;
1787 }
1788
1789 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1790 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1791 key.type != BTRFS_DEV_ITEM_KEY)
1792 break;
1793
1794 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1795 struct btrfs_dev_item);
1796 devid = btrfs_device_id(leaf, dev_item);
1797 read_extent_buffer(leaf, dev_uuid,
1798 (unsigned long)btrfs_device_uuid(dev_item),
1799 BTRFS_UUID_SIZE);
1800 read_extent_buffer(leaf, fs_uuid,
1801 (unsigned long)btrfs_device_fsid(dev_item),
1802 BTRFS_UUID_SIZE);
1803 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1804 fs_uuid);
1805 BUG_ON(!device); /* Logic error */
1806
1807 if (device->fs_devices->seeding) {
1808 btrfs_set_device_generation(leaf, dev_item,
1809 device->generation);
1810 btrfs_mark_buffer_dirty(leaf);
1811 }
1812
1813 path->slots[0]++;
1814 goto next_slot;
1815 }
1816 ret = 0;
1817 error:
1818 btrfs_free_path(path);
1819 return ret;
1820 }
1821
1822 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1823 {
1824 struct request_queue *q;
1825 struct btrfs_trans_handle *trans;
1826 struct btrfs_device *device;
1827 struct block_device *bdev;
1828 struct list_head *devices;
1829 struct super_block *sb = root->fs_info->sb;
1830 struct rcu_string *name;
1831 u64 total_bytes;
1832 int seeding_dev = 0;
1833 int ret = 0;
1834
1835 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1836 return -EROFS;
1837
1838 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1839 root->fs_info->bdev_holder);
1840 if (IS_ERR(bdev))
1841 return PTR_ERR(bdev);
1842
1843 if (root->fs_info->fs_devices->seeding) {
1844 seeding_dev = 1;
1845 down_write(&sb->s_umount);
1846 mutex_lock(&uuid_mutex);
1847 }
1848
1849 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1850
1851 devices = &root->fs_info->fs_devices->devices;
1852
1853 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1854 list_for_each_entry(device, devices, dev_list) {
1855 if (device->bdev == bdev) {
1856 ret = -EEXIST;
1857 mutex_unlock(
1858 &root->fs_info->fs_devices->device_list_mutex);
1859 goto error;
1860 }
1861 }
1862 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1863
1864 device = kzalloc(sizeof(*device), GFP_NOFS);
1865 if (!device) {
1866 /* we can safely leave the fs_devices entry around */
1867 ret = -ENOMEM;
1868 goto error;
1869 }
1870
1871 name = rcu_string_strdup(device_path, GFP_NOFS);
1872 if (!name) {
1873 kfree(device);
1874 ret = -ENOMEM;
1875 goto error;
1876 }
1877 rcu_assign_pointer(device->name, name);
1878
1879 ret = find_next_devid(root, &device->devid);
1880 if (ret) {
1881 rcu_string_free(device->name);
1882 kfree(device);
1883 goto error;
1884 }
1885
1886 trans = btrfs_start_transaction(root, 0);
1887 if (IS_ERR(trans)) {
1888 rcu_string_free(device->name);
1889 kfree(device);
1890 ret = PTR_ERR(trans);
1891 goto error;
1892 }
1893
1894 lock_chunks(root);
1895
1896 q = bdev_get_queue(bdev);
1897 if (blk_queue_discard(q))
1898 device->can_discard = 1;
1899 device->writeable = 1;
1900 device->work.func = pending_bios_fn;
1901 generate_random_uuid(device->uuid);
1902 spin_lock_init(&device->io_lock);
1903 device->generation = trans->transid;
1904 device->io_width = root->sectorsize;
1905 device->io_align = root->sectorsize;
1906 device->sector_size = root->sectorsize;
1907 device->total_bytes = i_size_read(bdev->bd_inode);
1908 device->disk_total_bytes = device->total_bytes;
1909 device->dev_root = root->fs_info->dev_root;
1910 device->bdev = bdev;
1911 device->in_fs_metadata = 1;
1912 device->is_tgtdev_for_dev_replace = 0;
1913 device->mode = FMODE_EXCL;
1914 set_blocksize(device->bdev, 4096);
1915
1916 if (seeding_dev) {
1917 sb->s_flags &= ~MS_RDONLY;
1918 ret = btrfs_prepare_sprout(root);
1919 BUG_ON(ret); /* -ENOMEM */
1920 }
1921
1922 device->fs_devices = root->fs_info->fs_devices;
1923
1924 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1925 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1926 list_add(&device->dev_alloc_list,
1927 &root->fs_info->fs_devices->alloc_list);
1928 root->fs_info->fs_devices->num_devices++;
1929 root->fs_info->fs_devices->open_devices++;
1930 root->fs_info->fs_devices->rw_devices++;
1931 root->fs_info->fs_devices->total_devices++;
1932 if (device->can_discard)
1933 root->fs_info->fs_devices->num_can_discard++;
1934 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1935
1936 spin_lock(&root->fs_info->free_chunk_lock);
1937 root->fs_info->free_chunk_space += device->total_bytes;
1938 spin_unlock(&root->fs_info->free_chunk_lock);
1939
1940 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1941 root->fs_info->fs_devices->rotating = 1;
1942
1943 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1944 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1945 total_bytes + device->total_bytes);
1946
1947 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1948 btrfs_set_super_num_devices(root->fs_info->super_copy,
1949 total_bytes + 1);
1950 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1951
1952 if (seeding_dev) {
1953 ret = init_first_rw_device(trans, root, device);
1954 if (ret) {
1955 btrfs_abort_transaction(trans, root, ret);
1956 goto error_trans;
1957 }
1958 ret = btrfs_finish_sprout(trans, root);
1959 if (ret) {
1960 btrfs_abort_transaction(trans, root, ret);
1961 goto error_trans;
1962 }
1963 } else {
1964 ret = btrfs_add_device(trans, root, device);
1965 if (ret) {
1966 btrfs_abort_transaction(trans, root, ret);
1967 goto error_trans;
1968 }
1969 }
1970
1971 /*
1972 * we've got more storage, clear any full flags on the space
1973 * infos
1974 */
1975 btrfs_clear_space_info_full(root->fs_info);
1976
1977 unlock_chunks(root);
1978 root->fs_info->num_tolerated_disk_barrier_failures =
1979 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1980 ret = btrfs_commit_transaction(trans, root);
1981
1982 if (seeding_dev) {
1983 mutex_unlock(&uuid_mutex);
1984 up_write(&sb->s_umount);
1985
1986 if (ret) /* transaction commit */
1987 return ret;
1988
1989 ret = btrfs_relocate_sys_chunks(root);
1990 if (ret < 0)
1991 btrfs_error(root->fs_info, ret,
1992 "Failed to relocate sys chunks after "
1993 "device initialization. This can be fixed "
1994 "using the \"btrfs balance\" command.");
1995 trans = btrfs_attach_transaction(root);
1996 if (IS_ERR(trans)) {
1997 if (PTR_ERR(trans) == -ENOENT)
1998 return 0;
1999 return PTR_ERR(trans);
2000 }
2001 ret = btrfs_commit_transaction(trans, root);
2002 }
2003
2004 return ret;
2005
2006 error_trans:
2007 unlock_chunks(root);
2008 btrfs_end_transaction(trans, root);
2009 rcu_string_free(device->name);
2010 kfree(device);
2011 error:
2012 blkdev_put(bdev, FMODE_EXCL);
2013 if (seeding_dev) {
2014 mutex_unlock(&uuid_mutex);
2015 up_write(&sb->s_umount);
2016 }
2017 return ret;
2018 }
2019
2020 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2021 struct btrfs_device **device_out)
2022 {
2023 struct request_queue *q;
2024 struct btrfs_device *device;
2025 struct block_device *bdev;
2026 struct btrfs_fs_info *fs_info = root->fs_info;
2027 struct list_head *devices;
2028 struct rcu_string *name;
2029 int ret = 0;
2030
2031 *device_out = NULL;
2032 if (fs_info->fs_devices->seeding)
2033 return -EINVAL;
2034
2035 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2036 fs_info->bdev_holder);
2037 if (IS_ERR(bdev))
2038 return PTR_ERR(bdev);
2039
2040 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2041
2042 devices = &fs_info->fs_devices->devices;
2043 list_for_each_entry(device, devices, dev_list) {
2044 if (device->bdev == bdev) {
2045 ret = -EEXIST;
2046 goto error;
2047 }
2048 }
2049
2050 device = kzalloc(sizeof(*device), GFP_NOFS);
2051 if (!device) {
2052 ret = -ENOMEM;
2053 goto error;
2054 }
2055
2056 name = rcu_string_strdup(device_path, GFP_NOFS);
2057 if (!name) {
2058 kfree(device);
2059 ret = -ENOMEM;
2060 goto error;
2061 }
2062 rcu_assign_pointer(device->name, name);
2063
2064 q = bdev_get_queue(bdev);
2065 if (blk_queue_discard(q))
2066 device->can_discard = 1;
2067 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2068 device->writeable = 1;
2069 device->work.func = pending_bios_fn;
2070 generate_random_uuid(device->uuid);
2071 device->devid = BTRFS_DEV_REPLACE_DEVID;
2072 spin_lock_init(&device->io_lock);
2073 device->generation = 0;
2074 device->io_width = root->sectorsize;
2075 device->io_align = root->sectorsize;
2076 device->sector_size = root->sectorsize;
2077 device->total_bytes = i_size_read(bdev->bd_inode);
2078 device->disk_total_bytes = device->total_bytes;
2079 device->dev_root = fs_info->dev_root;
2080 device->bdev = bdev;
2081 device->in_fs_metadata = 1;
2082 device->is_tgtdev_for_dev_replace = 1;
2083 device->mode = FMODE_EXCL;
2084 set_blocksize(device->bdev, 4096);
2085 device->fs_devices = fs_info->fs_devices;
2086 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2087 fs_info->fs_devices->num_devices++;
2088 fs_info->fs_devices->open_devices++;
2089 if (device->can_discard)
2090 fs_info->fs_devices->num_can_discard++;
2091 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2092
2093 *device_out = device;
2094 return ret;
2095
2096 error:
2097 blkdev_put(bdev, FMODE_EXCL);
2098 return ret;
2099 }
2100
2101 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2102 struct btrfs_device *tgtdev)
2103 {
2104 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2105 tgtdev->io_width = fs_info->dev_root->sectorsize;
2106 tgtdev->io_align = fs_info->dev_root->sectorsize;
2107 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2108 tgtdev->dev_root = fs_info->dev_root;
2109 tgtdev->in_fs_metadata = 1;
2110 }
2111
2112 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2113 struct btrfs_device *device)
2114 {
2115 int ret;
2116 struct btrfs_path *path;
2117 struct btrfs_root *root;
2118 struct btrfs_dev_item *dev_item;
2119 struct extent_buffer *leaf;
2120 struct btrfs_key key;
2121
2122 root = device->dev_root->fs_info->chunk_root;
2123
2124 path = btrfs_alloc_path();
2125 if (!path)
2126 return -ENOMEM;
2127
2128 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2129 key.type = BTRFS_DEV_ITEM_KEY;
2130 key.offset = device->devid;
2131
2132 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2133 if (ret < 0)
2134 goto out;
2135
2136 if (ret > 0) {
2137 ret = -ENOENT;
2138 goto out;
2139 }
2140
2141 leaf = path->nodes[0];
2142 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2143
2144 btrfs_set_device_id(leaf, dev_item, device->devid);
2145 btrfs_set_device_type(leaf, dev_item, device->type);
2146 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2147 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2148 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2149 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2150 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2151 btrfs_mark_buffer_dirty(leaf);
2152
2153 out:
2154 btrfs_free_path(path);
2155 return ret;
2156 }
2157
2158 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2159 struct btrfs_device *device, u64 new_size)
2160 {
2161 struct btrfs_super_block *super_copy =
2162 device->dev_root->fs_info->super_copy;
2163 u64 old_total = btrfs_super_total_bytes(super_copy);
2164 u64 diff = new_size - device->total_bytes;
2165
2166 if (!device->writeable)
2167 return -EACCES;
2168 if (new_size <= device->total_bytes ||
2169 device->is_tgtdev_for_dev_replace)
2170 return -EINVAL;
2171
2172 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2173 device->fs_devices->total_rw_bytes += diff;
2174
2175 device->total_bytes = new_size;
2176 device->disk_total_bytes = new_size;
2177 btrfs_clear_space_info_full(device->dev_root->fs_info);
2178
2179 return btrfs_update_device(trans, device);
2180 }
2181
2182 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2183 struct btrfs_device *device, u64 new_size)
2184 {
2185 int ret;
2186 lock_chunks(device->dev_root);
2187 ret = __btrfs_grow_device(trans, device, new_size);
2188 unlock_chunks(device->dev_root);
2189 return ret;
2190 }
2191
2192 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2193 struct btrfs_root *root,
2194 u64 chunk_tree, u64 chunk_objectid,
2195 u64 chunk_offset)
2196 {
2197 int ret;
2198 struct btrfs_path *path;
2199 struct btrfs_key key;
2200
2201 root = root->fs_info->chunk_root;
2202 path = btrfs_alloc_path();
2203 if (!path)
2204 return -ENOMEM;
2205
2206 key.objectid = chunk_objectid;
2207 key.offset = chunk_offset;
2208 key.type = BTRFS_CHUNK_ITEM_KEY;
2209
2210 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2211 if (ret < 0)
2212 goto out;
2213 else if (ret > 0) { /* Logic error or corruption */
2214 btrfs_error(root->fs_info, -ENOENT,
2215 "Failed lookup while freeing chunk.");
2216 ret = -ENOENT;
2217 goto out;
2218 }
2219
2220 ret = btrfs_del_item(trans, root, path);
2221 if (ret < 0)
2222 btrfs_error(root->fs_info, ret,
2223 "Failed to delete chunk item.");
2224 out:
2225 btrfs_free_path(path);
2226 return ret;
2227 }
2228
2229 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2230 chunk_offset)
2231 {
2232 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2233 struct btrfs_disk_key *disk_key;
2234 struct btrfs_chunk *chunk;
2235 u8 *ptr;
2236 int ret = 0;
2237 u32 num_stripes;
2238 u32 array_size;
2239 u32 len = 0;
2240 u32 cur;
2241 struct btrfs_key key;
2242
2243 array_size = btrfs_super_sys_array_size(super_copy);
2244
2245 ptr = super_copy->sys_chunk_array;
2246 cur = 0;
2247
2248 while (cur < array_size) {
2249 disk_key = (struct btrfs_disk_key *)ptr;
2250 btrfs_disk_key_to_cpu(&key, disk_key);
2251
2252 len = sizeof(*disk_key);
2253
2254 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2255 chunk = (struct btrfs_chunk *)(ptr + len);
2256 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2257 len += btrfs_chunk_item_size(num_stripes);
2258 } else {
2259 ret = -EIO;
2260 break;
2261 }
2262 if (key.objectid == chunk_objectid &&
2263 key.offset == chunk_offset) {
2264 memmove(ptr, ptr + len, array_size - (cur + len));
2265 array_size -= len;
2266 btrfs_set_super_sys_array_size(super_copy, array_size);
2267 } else {
2268 ptr += len;
2269 cur += len;
2270 }
2271 }
2272 return ret;
2273 }
2274
2275 static int btrfs_relocate_chunk(struct btrfs_root *root,
2276 u64 chunk_tree, u64 chunk_objectid,
2277 u64 chunk_offset)
2278 {
2279 struct extent_map_tree *em_tree;
2280 struct btrfs_root *extent_root;
2281 struct btrfs_trans_handle *trans;
2282 struct extent_map *em;
2283 struct map_lookup *map;
2284 int ret;
2285 int i;
2286
2287 root = root->fs_info->chunk_root;
2288 extent_root = root->fs_info->extent_root;
2289 em_tree = &root->fs_info->mapping_tree.map_tree;
2290
2291 ret = btrfs_can_relocate(extent_root, chunk_offset);
2292 if (ret)
2293 return -ENOSPC;
2294
2295 /* step one, relocate all the extents inside this chunk */
2296 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2297 if (ret)
2298 return ret;
2299
2300 trans = btrfs_start_transaction(root, 0);
2301 BUG_ON(IS_ERR(trans));
2302
2303 lock_chunks(root);
2304
2305 /*
2306 * step two, delete the device extents and the
2307 * chunk tree entries
2308 */
2309 read_lock(&em_tree->lock);
2310 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2311 read_unlock(&em_tree->lock);
2312
2313 BUG_ON(!em || em->start > chunk_offset ||
2314 em->start + em->len < chunk_offset);
2315 map = (struct map_lookup *)em->bdev;
2316
2317 for (i = 0; i < map->num_stripes; i++) {
2318 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2319 map->stripes[i].physical);
2320 BUG_ON(ret);
2321
2322 if (map->stripes[i].dev) {
2323 ret = btrfs_update_device(trans, map->stripes[i].dev);
2324 BUG_ON(ret);
2325 }
2326 }
2327 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2328 chunk_offset);
2329
2330 BUG_ON(ret);
2331
2332 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2333
2334 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2335 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2336 BUG_ON(ret);
2337 }
2338
2339 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2340 BUG_ON(ret);
2341
2342 write_lock(&em_tree->lock);
2343 remove_extent_mapping(em_tree, em);
2344 write_unlock(&em_tree->lock);
2345
2346 kfree(map);
2347 em->bdev = NULL;
2348
2349 /* once for the tree */
2350 free_extent_map(em);
2351 /* once for us */
2352 free_extent_map(em);
2353
2354 unlock_chunks(root);
2355 btrfs_end_transaction(trans, root);
2356 return 0;
2357 }
2358
2359 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2360 {
2361 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2362 struct btrfs_path *path;
2363 struct extent_buffer *leaf;
2364 struct btrfs_chunk *chunk;
2365 struct btrfs_key key;
2366 struct btrfs_key found_key;
2367 u64 chunk_tree = chunk_root->root_key.objectid;
2368 u64 chunk_type;
2369 bool retried = false;
2370 int failed = 0;
2371 int ret;
2372
2373 path = btrfs_alloc_path();
2374 if (!path)
2375 return -ENOMEM;
2376
2377 again:
2378 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2379 key.offset = (u64)-1;
2380 key.type = BTRFS_CHUNK_ITEM_KEY;
2381
2382 while (1) {
2383 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2384 if (ret < 0)
2385 goto error;
2386 BUG_ON(ret == 0); /* Corruption */
2387
2388 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2389 key.type);
2390 if (ret < 0)
2391 goto error;
2392 if (ret > 0)
2393 break;
2394
2395 leaf = path->nodes[0];
2396 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2397
2398 chunk = btrfs_item_ptr(leaf, path->slots[0],
2399 struct btrfs_chunk);
2400 chunk_type = btrfs_chunk_type(leaf, chunk);
2401 btrfs_release_path(path);
2402
2403 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2404 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2405 found_key.objectid,
2406 found_key.offset);
2407 if (ret == -ENOSPC)
2408 failed++;
2409 else if (ret)
2410 BUG();
2411 }
2412
2413 if (found_key.offset == 0)
2414 break;
2415 key.offset = found_key.offset - 1;
2416 }
2417 ret = 0;
2418 if (failed && !retried) {
2419 failed = 0;
2420 retried = true;
2421 goto again;
2422 } else if (failed && retried) {
2423 WARN_ON(1);
2424 ret = -ENOSPC;
2425 }
2426 error:
2427 btrfs_free_path(path);
2428 return ret;
2429 }
2430
2431 static int insert_balance_item(struct btrfs_root *root,
2432 struct btrfs_balance_control *bctl)
2433 {
2434 struct btrfs_trans_handle *trans;
2435 struct btrfs_balance_item *item;
2436 struct btrfs_disk_balance_args disk_bargs;
2437 struct btrfs_path *path;
2438 struct extent_buffer *leaf;
2439 struct btrfs_key key;
2440 int ret, err;
2441
2442 path = btrfs_alloc_path();
2443 if (!path)
2444 return -ENOMEM;
2445
2446 trans = btrfs_start_transaction(root, 0);
2447 if (IS_ERR(trans)) {
2448 btrfs_free_path(path);
2449 return PTR_ERR(trans);
2450 }
2451
2452 key.objectid = BTRFS_BALANCE_OBJECTID;
2453 key.type = BTRFS_BALANCE_ITEM_KEY;
2454 key.offset = 0;
2455
2456 ret = btrfs_insert_empty_item(trans, root, path, &key,
2457 sizeof(*item));
2458 if (ret)
2459 goto out;
2460
2461 leaf = path->nodes[0];
2462 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2463
2464 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2465
2466 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2467 btrfs_set_balance_data(leaf, item, &disk_bargs);
2468 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2469 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2470 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2471 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2472
2473 btrfs_set_balance_flags(leaf, item, bctl->flags);
2474
2475 btrfs_mark_buffer_dirty(leaf);
2476 out:
2477 btrfs_free_path(path);
2478 err = btrfs_commit_transaction(trans, root);
2479 if (err && !ret)
2480 ret = err;
2481 return ret;
2482 }
2483
2484 static int del_balance_item(struct btrfs_root *root)
2485 {
2486 struct btrfs_trans_handle *trans;
2487 struct btrfs_path *path;
2488 struct btrfs_key key;
2489 int ret, err;
2490
2491 path = btrfs_alloc_path();
2492 if (!path)
2493 return -ENOMEM;
2494
2495 trans = btrfs_start_transaction(root, 0);
2496 if (IS_ERR(trans)) {
2497 btrfs_free_path(path);
2498 return PTR_ERR(trans);
2499 }
2500
2501 key.objectid = BTRFS_BALANCE_OBJECTID;
2502 key.type = BTRFS_BALANCE_ITEM_KEY;
2503 key.offset = 0;
2504
2505 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2506 if (ret < 0)
2507 goto out;
2508 if (ret > 0) {
2509 ret = -ENOENT;
2510 goto out;
2511 }
2512
2513 ret = btrfs_del_item(trans, root, path);
2514 out:
2515 btrfs_free_path(path);
2516 err = btrfs_commit_transaction(trans, root);
2517 if (err && !ret)
2518 ret = err;
2519 return ret;
2520 }
2521
2522 /*
2523 * This is a heuristic used to reduce the number of chunks balanced on
2524 * resume after balance was interrupted.
2525 */
2526 static void update_balance_args(struct btrfs_balance_control *bctl)
2527 {
2528 /*
2529 * Turn on soft mode for chunk types that were being converted.
2530 */
2531 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2532 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2533 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2534 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2535 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2536 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2537
2538 /*
2539 * Turn on usage filter if is not already used. The idea is
2540 * that chunks that we have already balanced should be
2541 * reasonably full. Don't do it for chunks that are being
2542 * converted - that will keep us from relocating unconverted
2543 * (albeit full) chunks.
2544 */
2545 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2546 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2547 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2548 bctl->data.usage = 90;
2549 }
2550 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2551 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2552 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2553 bctl->sys.usage = 90;
2554 }
2555 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2556 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2557 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2558 bctl->meta.usage = 90;
2559 }
2560 }
2561
2562 /*
2563 * Should be called with both balance and volume mutexes held to
2564 * serialize other volume operations (add_dev/rm_dev/resize) with
2565 * restriper. Same goes for unset_balance_control.
2566 */
2567 static void set_balance_control(struct btrfs_balance_control *bctl)
2568 {
2569 struct btrfs_fs_info *fs_info = bctl->fs_info;
2570
2571 BUG_ON(fs_info->balance_ctl);
2572
2573 spin_lock(&fs_info->balance_lock);
2574 fs_info->balance_ctl = bctl;
2575 spin_unlock(&fs_info->balance_lock);
2576 }
2577
2578 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2579 {
2580 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2581
2582 BUG_ON(!fs_info->balance_ctl);
2583
2584 spin_lock(&fs_info->balance_lock);
2585 fs_info->balance_ctl = NULL;
2586 spin_unlock(&fs_info->balance_lock);
2587
2588 kfree(bctl);
2589 }
2590
2591 /*
2592 * Balance filters. Return 1 if chunk should be filtered out
2593 * (should not be balanced).
2594 */
2595 static int chunk_profiles_filter(u64 chunk_type,
2596 struct btrfs_balance_args *bargs)
2597 {
2598 chunk_type = chunk_to_extended(chunk_type) &
2599 BTRFS_EXTENDED_PROFILE_MASK;
2600
2601 if (bargs->profiles & chunk_type)
2602 return 0;
2603
2604 return 1;
2605 }
2606
2607 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2608 struct btrfs_balance_args *bargs)
2609 {
2610 struct btrfs_block_group_cache *cache;
2611 u64 chunk_used, user_thresh;
2612 int ret = 1;
2613
2614 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2615 chunk_used = btrfs_block_group_used(&cache->item);
2616
2617 if (bargs->usage == 0)
2618 user_thresh = 0;
2619 else if (bargs->usage > 100)
2620 user_thresh = cache->key.offset;
2621 else
2622 user_thresh = div_factor_fine(cache->key.offset,
2623 bargs->usage);
2624
2625 if (chunk_used < user_thresh)
2626 ret = 0;
2627
2628 btrfs_put_block_group(cache);
2629 return ret;
2630 }
2631
2632 static int chunk_devid_filter(struct extent_buffer *leaf,
2633 struct btrfs_chunk *chunk,
2634 struct btrfs_balance_args *bargs)
2635 {
2636 struct btrfs_stripe *stripe;
2637 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2638 int i;
2639
2640 for (i = 0; i < num_stripes; i++) {
2641 stripe = btrfs_stripe_nr(chunk, i);
2642 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2643 return 0;
2644 }
2645
2646 return 1;
2647 }
2648
2649 /* [pstart, pend) */
2650 static int chunk_drange_filter(struct extent_buffer *leaf,
2651 struct btrfs_chunk *chunk,
2652 u64 chunk_offset,
2653 struct btrfs_balance_args *bargs)
2654 {
2655 struct btrfs_stripe *stripe;
2656 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2657 u64 stripe_offset;
2658 u64 stripe_length;
2659 int factor;
2660 int i;
2661
2662 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2663 return 0;
2664
2665 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2666 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2667 factor = 2;
2668 else
2669 factor = 1;
2670 factor = num_stripes / factor;
2671
2672 for (i = 0; i < num_stripes; i++) {
2673 stripe = btrfs_stripe_nr(chunk, i);
2674 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2675 continue;
2676
2677 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2678 stripe_length = btrfs_chunk_length(leaf, chunk);
2679 do_div(stripe_length, factor);
2680
2681 if (stripe_offset < bargs->pend &&
2682 stripe_offset + stripe_length > bargs->pstart)
2683 return 0;
2684 }
2685
2686 return 1;
2687 }
2688
2689 /* [vstart, vend) */
2690 static int chunk_vrange_filter(struct extent_buffer *leaf,
2691 struct btrfs_chunk *chunk,
2692 u64 chunk_offset,
2693 struct btrfs_balance_args *bargs)
2694 {
2695 if (chunk_offset < bargs->vend &&
2696 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2697 /* at least part of the chunk is inside this vrange */
2698 return 0;
2699
2700 return 1;
2701 }
2702
2703 static int chunk_soft_convert_filter(u64 chunk_type,
2704 struct btrfs_balance_args *bargs)
2705 {
2706 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2707 return 0;
2708
2709 chunk_type = chunk_to_extended(chunk_type) &
2710 BTRFS_EXTENDED_PROFILE_MASK;
2711
2712 if (bargs->target == chunk_type)
2713 return 1;
2714
2715 return 0;
2716 }
2717
2718 static int should_balance_chunk(struct btrfs_root *root,
2719 struct extent_buffer *leaf,
2720 struct btrfs_chunk *chunk, u64 chunk_offset)
2721 {
2722 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2723 struct btrfs_balance_args *bargs = NULL;
2724 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2725
2726 /* type filter */
2727 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2728 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2729 return 0;
2730 }
2731
2732 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2733 bargs = &bctl->data;
2734 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2735 bargs = &bctl->sys;
2736 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2737 bargs = &bctl->meta;
2738
2739 /* profiles filter */
2740 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2741 chunk_profiles_filter(chunk_type, bargs)) {
2742 return 0;
2743 }
2744
2745 /* usage filter */
2746 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2747 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2748 return 0;
2749 }
2750
2751 /* devid filter */
2752 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2753 chunk_devid_filter(leaf, chunk, bargs)) {
2754 return 0;
2755 }
2756
2757 /* drange filter, makes sense only with devid filter */
2758 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2759 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2760 return 0;
2761 }
2762
2763 /* vrange filter */
2764 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2765 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2766 return 0;
2767 }
2768
2769 /* soft profile changing mode */
2770 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2771 chunk_soft_convert_filter(chunk_type, bargs)) {
2772 return 0;
2773 }
2774
2775 return 1;
2776 }
2777
2778 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2779 {
2780 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2781 struct btrfs_root *chunk_root = fs_info->chunk_root;
2782 struct btrfs_root *dev_root = fs_info->dev_root;
2783 struct list_head *devices;
2784 struct btrfs_device *device;
2785 u64 old_size;
2786 u64 size_to_free;
2787 struct btrfs_chunk *chunk;
2788 struct btrfs_path *path;
2789 struct btrfs_key key;
2790 struct btrfs_key found_key;
2791 struct btrfs_trans_handle *trans;
2792 struct extent_buffer *leaf;
2793 int slot;
2794 int ret;
2795 int enospc_errors = 0;
2796 bool counting = true;
2797
2798 /* step one make some room on all the devices */
2799 devices = &fs_info->fs_devices->devices;
2800 list_for_each_entry(device, devices, dev_list) {
2801 old_size = device->total_bytes;
2802 size_to_free = div_factor(old_size, 1);
2803 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2804 if (!device->writeable ||
2805 device->total_bytes - device->bytes_used > size_to_free ||
2806 device->is_tgtdev_for_dev_replace)
2807 continue;
2808
2809 ret = btrfs_shrink_device(device, old_size - size_to_free);
2810 if (ret == -ENOSPC)
2811 break;
2812 BUG_ON(ret);
2813
2814 trans = btrfs_start_transaction(dev_root, 0);
2815 BUG_ON(IS_ERR(trans));
2816
2817 ret = btrfs_grow_device(trans, device, old_size);
2818 BUG_ON(ret);
2819
2820 btrfs_end_transaction(trans, dev_root);
2821 }
2822
2823 /* step two, relocate all the chunks */
2824 path = btrfs_alloc_path();
2825 if (!path) {
2826 ret = -ENOMEM;
2827 goto error;
2828 }
2829
2830 /* zero out stat counters */
2831 spin_lock(&fs_info->balance_lock);
2832 memset(&bctl->stat, 0, sizeof(bctl->stat));
2833 spin_unlock(&fs_info->balance_lock);
2834 again:
2835 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2836 key.offset = (u64)-1;
2837 key.type = BTRFS_CHUNK_ITEM_KEY;
2838
2839 while (1) {
2840 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2841 atomic_read(&fs_info->balance_cancel_req)) {
2842 ret = -ECANCELED;
2843 goto error;
2844 }
2845
2846 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2847 if (ret < 0)
2848 goto error;
2849
2850 /*
2851 * this shouldn't happen, it means the last relocate
2852 * failed
2853 */
2854 if (ret == 0)
2855 BUG(); /* FIXME break ? */
2856
2857 ret = btrfs_previous_item(chunk_root, path, 0,
2858 BTRFS_CHUNK_ITEM_KEY);
2859 if (ret) {
2860 ret = 0;
2861 break;
2862 }
2863
2864 leaf = path->nodes[0];
2865 slot = path->slots[0];
2866 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2867
2868 if (found_key.objectid != key.objectid)
2869 break;
2870
2871 /* chunk zero is special */
2872 if (found_key.offset == 0)
2873 break;
2874
2875 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2876
2877 if (!counting) {
2878 spin_lock(&fs_info->balance_lock);
2879 bctl->stat.considered++;
2880 spin_unlock(&fs_info->balance_lock);
2881 }
2882
2883 ret = should_balance_chunk(chunk_root, leaf, chunk,
2884 found_key.offset);
2885 btrfs_release_path(path);
2886 if (!ret)
2887 goto loop;
2888
2889 if (counting) {
2890 spin_lock(&fs_info->balance_lock);
2891 bctl->stat.expected++;
2892 spin_unlock(&fs_info->balance_lock);
2893 goto loop;
2894 }
2895
2896 ret = btrfs_relocate_chunk(chunk_root,
2897 chunk_root->root_key.objectid,
2898 found_key.objectid,
2899 found_key.offset);
2900 if (ret && ret != -ENOSPC)
2901 goto error;
2902 if (ret == -ENOSPC) {
2903 enospc_errors++;
2904 } else {
2905 spin_lock(&fs_info->balance_lock);
2906 bctl->stat.completed++;
2907 spin_unlock(&fs_info->balance_lock);
2908 }
2909 loop:
2910 key.offset = found_key.offset - 1;
2911 }
2912
2913 if (counting) {
2914 btrfs_release_path(path);
2915 counting = false;
2916 goto again;
2917 }
2918 error:
2919 btrfs_free_path(path);
2920 if (enospc_errors) {
2921 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2922 enospc_errors);
2923 if (!ret)
2924 ret = -ENOSPC;
2925 }
2926
2927 return ret;
2928 }
2929
2930 /**
2931 * alloc_profile_is_valid - see if a given profile is valid and reduced
2932 * @flags: profile to validate
2933 * @extended: if true @flags is treated as an extended profile
2934 */
2935 static int alloc_profile_is_valid(u64 flags, int extended)
2936 {
2937 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
2938 BTRFS_BLOCK_GROUP_PROFILE_MASK);
2939
2940 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
2941
2942 /* 1) check that all other bits are zeroed */
2943 if (flags & ~mask)
2944 return 0;
2945
2946 /* 2) see if profile is reduced */
2947 if (flags == 0)
2948 return !extended; /* "0" is valid for usual profiles */
2949
2950 /* true if exactly one bit set */
2951 return (flags & (flags - 1)) == 0;
2952 }
2953
2954 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2955 {
2956 /* cancel requested || normal exit path */
2957 return atomic_read(&fs_info->balance_cancel_req) ||
2958 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2959 atomic_read(&fs_info->balance_cancel_req) == 0);
2960 }
2961
2962 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2963 {
2964 int ret;
2965
2966 unset_balance_control(fs_info);
2967 ret = del_balance_item(fs_info->tree_root);
2968 BUG_ON(ret);
2969
2970 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2971 }
2972
2973 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2974 struct btrfs_ioctl_balance_args *bargs);
2975
2976 /*
2977 * Should be called with both balance and volume mutexes held
2978 */
2979 int btrfs_balance(struct btrfs_balance_control *bctl,
2980 struct btrfs_ioctl_balance_args *bargs)
2981 {
2982 struct btrfs_fs_info *fs_info = bctl->fs_info;
2983 u64 allowed;
2984 int mixed = 0;
2985 int ret;
2986 u64 num_devices;
2987
2988 if (btrfs_fs_closing(fs_info) ||
2989 atomic_read(&fs_info->balance_pause_req) ||
2990 atomic_read(&fs_info->balance_cancel_req)) {
2991 ret = -EINVAL;
2992 goto out;
2993 }
2994
2995 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2996 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
2997 mixed = 1;
2998
2999 /*
3000 * In case of mixed groups both data and meta should be picked,
3001 * and identical options should be given for both of them.
3002 */
3003 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3004 if (mixed && (bctl->flags & allowed)) {
3005 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3006 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3007 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3008 printk(KERN_ERR "btrfs: with mixed groups data and "
3009 "metadata balance options must be the same\n");
3010 ret = -EINVAL;
3011 goto out;
3012 }
3013 }
3014
3015 num_devices = fs_info->fs_devices->num_devices;
3016 btrfs_dev_replace_lock(&fs_info->dev_replace);
3017 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3018 BUG_ON(num_devices < 1);
3019 num_devices--;
3020 }
3021 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3022 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3023 if (num_devices == 1)
3024 allowed |= BTRFS_BLOCK_GROUP_DUP;
3025 else if (num_devices < 4)
3026 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3027 else
3028 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
3029 BTRFS_BLOCK_GROUP_RAID10);
3030
3031 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3032 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3033 (bctl->data.target & ~allowed))) {
3034 printk(KERN_ERR "btrfs: unable to start balance with target "
3035 "data profile %llu\n",
3036 (unsigned long long)bctl->data.target);
3037 ret = -EINVAL;
3038 goto out;
3039 }
3040 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3041 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3042 (bctl->meta.target & ~allowed))) {
3043 printk(KERN_ERR "btrfs: unable to start balance with target "
3044 "metadata profile %llu\n",
3045 (unsigned long long)bctl->meta.target);
3046 ret = -EINVAL;
3047 goto out;
3048 }
3049 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3050 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3051 (bctl->sys.target & ~allowed))) {
3052 printk(KERN_ERR "btrfs: unable to start balance with target "
3053 "system profile %llu\n",
3054 (unsigned long long)bctl->sys.target);
3055 ret = -EINVAL;
3056 goto out;
3057 }
3058
3059 /* allow dup'ed data chunks only in mixed mode */
3060 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3061 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3062 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3063 ret = -EINVAL;
3064 goto out;
3065 }
3066
3067 /* allow to reduce meta or sys integrity only if force set */
3068 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3069 BTRFS_BLOCK_GROUP_RAID10;
3070 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3071 (fs_info->avail_system_alloc_bits & allowed) &&
3072 !(bctl->sys.target & allowed)) ||
3073 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3074 (fs_info->avail_metadata_alloc_bits & allowed) &&
3075 !(bctl->meta.target & allowed))) {
3076 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3077 printk(KERN_INFO "btrfs: force reducing metadata "
3078 "integrity\n");
3079 } else {
3080 printk(KERN_ERR "btrfs: balance will reduce metadata "
3081 "integrity, use force if you want this\n");
3082 ret = -EINVAL;
3083 goto out;
3084 }
3085 }
3086
3087 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3088 int num_tolerated_disk_barrier_failures;
3089 u64 target = bctl->sys.target;
3090
3091 num_tolerated_disk_barrier_failures =
3092 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3093 if (num_tolerated_disk_barrier_failures > 0 &&
3094 (target &
3095 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3096 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3097 num_tolerated_disk_barrier_failures = 0;
3098 else if (num_tolerated_disk_barrier_failures > 1 &&
3099 (target &
3100 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3101 num_tolerated_disk_barrier_failures = 1;
3102
3103 fs_info->num_tolerated_disk_barrier_failures =
3104 num_tolerated_disk_barrier_failures;
3105 }
3106
3107 ret = insert_balance_item(fs_info->tree_root, bctl);
3108 if (ret && ret != -EEXIST)
3109 goto out;
3110
3111 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3112 BUG_ON(ret == -EEXIST);
3113 set_balance_control(bctl);
3114 } else {
3115 BUG_ON(ret != -EEXIST);
3116 spin_lock(&fs_info->balance_lock);
3117 update_balance_args(bctl);
3118 spin_unlock(&fs_info->balance_lock);
3119 }
3120
3121 atomic_inc(&fs_info->balance_running);
3122 mutex_unlock(&fs_info->balance_mutex);
3123
3124 ret = __btrfs_balance(fs_info);
3125
3126 mutex_lock(&fs_info->balance_mutex);
3127 atomic_dec(&fs_info->balance_running);
3128
3129 if (bargs) {
3130 memset(bargs, 0, sizeof(*bargs));
3131 update_ioctl_balance_args(fs_info, 0, bargs);
3132 }
3133
3134 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3135 balance_need_close(fs_info)) {
3136 __cancel_balance(fs_info);
3137 }
3138
3139 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3140 fs_info->num_tolerated_disk_barrier_failures =
3141 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3142 }
3143
3144 wake_up(&fs_info->balance_wait_q);
3145
3146 return ret;
3147 out:
3148 if (bctl->flags & BTRFS_BALANCE_RESUME)
3149 __cancel_balance(fs_info);
3150 else {
3151 kfree(bctl);
3152 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3153 }
3154 return ret;
3155 }
3156
3157 static int balance_kthread(void *data)
3158 {
3159 struct btrfs_fs_info *fs_info = data;
3160 int ret = 0;
3161
3162 mutex_lock(&fs_info->volume_mutex);
3163 mutex_lock(&fs_info->balance_mutex);
3164
3165 if (fs_info->balance_ctl) {
3166 printk(KERN_INFO "btrfs: continuing balance\n");
3167 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3168 }
3169
3170 mutex_unlock(&fs_info->balance_mutex);
3171 mutex_unlock(&fs_info->volume_mutex);
3172
3173 return ret;
3174 }
3175
3176 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3177 {
3178 struct task_struct *tsk;
3179
3180 spin_lock(&fs_info->balance_lock);
3181 if (!fs_info->balance_ctl) {
3182 spin_unlock(&fs_info->balance_lock);
3183 return 0;
3184 }
3185 spin_unlock(&fs_info->balance_lock);
3186
3187 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3188 printk(KERN_INFO "btrfs: force skipping balance\n");
3189 return 0;
3190 }
3191
3192 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3193 if (IS_ERR(tsk))
3194 return PTR_ERR(tsk);
3195
3196 return 0;
3197 }
3198
3199 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3200 {
3201 struct btrfs_balance_control *bctl;
3202 struct btrfs_balance_item *item;
3203 struct btrfs_disk_balance_args disk_bargs;
3204 struct btrfs_path *path;
3205 struct extent_buffer *leaf;
3206 struct btrfs_key key;
3207 int ret;
3208
3209 path = btrfs_alloc_path();
3210 if (!path)
3211 return -ENOMEM;
3212
3213 key.objectid = BTRFS_BALANCE_OBJECTID;
3214 key.type = BTRFS_BALANCE_ITEM_KEY;
3215 key.offset = 0;
3216
3217 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3218 if (ret < 0)
3219 goto out;
3220 if (ret > 0) { /* ret = -ENOENT; */
3221 ret = 0;
3222 goto out;
3223 }
3224
3225 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3226 if (!bctl) {
3227 ret = -ENOMEM;
3228 goto out;
3229 }
3230
3231 leaf = path->nodes[0];
3232 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3233
3234 bctl->fs_info = fs_info;
3235 bctl->flags = btrfs_balance_flags(leaf, item);
3236 bctl->flags |= BTRFS_BALANCE_RESUME;
3237
3238 btrfs_balance_data(leaf, item, &disk_bargs);
3239 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3240 btrfs_balance_meta(leaf, item, &disk_bargs);
3241 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3242 btrfs_balance_sys(leaf, item, &disk_bargs);
3243 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3244
3245 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3246
3247 mutex_lock(&fs_info->volume_mutex);
3248 mutex_lock(&fs_info->balance_mutex);
3249
3250 set_balance_control(bctl);
3251
3252 mutex_unlock(&fs_info->balance_mutex);
3253 mutex_unlock(&fs_info->volume_mutex);
3254 out:
3255 btrfs_free_path(path);
3256 return ret;
3257 }
3258
3259 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3260 {
3261 int ret = 0;
3262
3263 mutex_lock(&fs_info->balance_mutex);
3264 if (!fs_info->balance_ctl) {
3265 mutex_unlock(&fs_info->balance_mutex);
3266 return -ENOTCONN;
3267 }
3268
3269 if (atomic_read(&fs_info->balance_running)) {
3270 atomic_inc(&fs_info->balance_pause_req);
3271 mutex_unlock(&fs_info->balance_mutex);
3272
3273 wait_event(fs_info->balance_wait_q,
3274 atomic_read(&fs_info->balance_running) == 0);
3275
3276 mutex_lock(&fs_info->balance_mutex);
3277 /* we are good with balance_ctl ripped off from under us */
3278 BUG_ON(atomic_read(&fs_info->balance_running));
3279 atomic_dec(&fs_info->balance_pause_req);
3280 } else {
3281 ret = -ENOTCONN;
3282 }
3283
3284 mutex_unlock(&fs_info->balance_mutex);
3285 return ret;
3286 }
3287
3288 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3289 {
3290 mutex_lock(&fs_info->balance_mutex);
3291 if (!fs_info->balance_ctl) {
3292 mutex_unlock(&fs_info->balance_mutex);
3293 return -ENOTCONN;
3294 }
3295
3296 atomic_inc(&fs_info->balance_cancel_req);
3297 /*
3298 * if we are running just wait and return, balance item is
3299 * deleted in btrfs_balance in this case
3300 */
3301 if (atomic_read(&fs_info->balance_running)) {
3302 mutex_unlock(&fs_info->balance_mutex);
3303 wait_event(fs_info->balance_wait_q,
3304 atomic_read(&fs_info->balance_running) == 0);
3305 mutex_lock(&fs_info->balance_mutex);
3306 } else {
3307 /* __cancel_balance needs volume_mutex */
3308 mutex_unlock(&fs_info->balance_mutex);
3309 mutex_lock(&fs_info->volume_mutex);
3310 mutex_lock(&fs_info->balance_mutex);
3311
3312 if (fs_info->balance_ctl)
3313 __cancel_balance(fs_info);
3314
3315 mutex_unlock(&fs_info->volume_mutex);
3316 }
3317
3318 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3319 atomic_dec(&fs_info->balance_cancel_req);
3320 mutex_unlock(&fs_info->balance_mutex);
3321 return 0;
3322 }
3323
3324 /*
3325 * shrinking a device means finding all of the device extents past
3326 * the new size, and then following the back refs to the chunks.
3327 * The chunk relocation code actually frees the device extent
3328 */
3329 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3330 {
3331 struct btrfs_trans_handle *trans;
3332 struct btrfs_root *root = device->dev_root;
3333 struct btrfs_dev_extent *dev_extent = NULL;
3334 struct btrfs_path *path;
3335 u64 length;
3336 u64 chunk_tree;
3337 u64 chunk_objectid;
3338 u64 chunk_offset;
3339 int ret;
3340 int slot;
3341 int failed = 0;
3342 bool retried = false;
3343 struct extent_buffer *l;
3344 struct btrfs_key key;
3345 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3346 u64 old_total = btrfs_super_total_bytes(super_copy);
3347 u64 old_size = device->total_bytes;
3348 u64 diff = device->total_bytes - new_size;
3349
3350 if (device->is_tgtdev_for_dev_replace)
3351 return -EINVAL;
3352
3353 path = btrfs_alloc_path();
3354 if (!path)
3355 return -ENOMEM;
3356
3357 path->reada = 2;
3358
3359 lock_chunks(root);
3360
3361 device->total_bytes = new_size;
3362 if (device->writeable) {
3363 device->fs_devices->total_rw_bytes -= diff;
3364 spin_lock(&root->fs_info->free_chunk_lock);
3365 root->fs_info->free_chunk_space -= diff;
3366 spin_unlock(&root->fs_info->free_chunk_lock);
3367 }
3368 unlock_chunks(root);
3369
3370 again:
3371 key.objectid = device->devid;
3372 key.offset = (u64)-1;
3373 key.type = BTRFS_DEV_EXTENT_KEY;
3374
3375 do {
3376 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3377 if (ret < 0)
3378 goto done;
3379
3380 ret = btrfs_previous_item(root, path, 0, key.type);
3381 if (ret < 0)
3382 goto done;
3383 if (ret) {
3384 ret = 0;
3385 btrfs_release_path(path);
3386 break;
3387 }
3388
3389 l = path->nodes[0];
3390 slot = path->slots[0];
3391 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3392
3393 if (key.objectid != device->devid) {
3394 btrfs_release_path(path);
3395 break;
3396 }
3397
3398 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3399 length = btrfs_dev_extent_length(l, dev_extent);
3400
3401 if (key.offset + length <= new_size) {
3402 btrfs_release_path(path);
3403 break;
3404 }
3405
3406 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3407 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3408 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3409 btrfs_release_path(path);
3410
3411 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3412 chunk_offset);
3413 if (ret && ret != -ENOSPC)
3414 goto done;
3415 if (ret == -ENOSPC)
3416 failed++;
3417 } while (key.offset-- > 0);
3418
3419 if (failed && !retried) {
3420 failed = 0;
3421 retried = true;
3422 goto again;
3423 } else if (failed && retried) {
3424 ret = -ENOSPC;
3425 lock_chunks(root);
3426
3427 device->total_bytes = old_size;
3428 if (device->writeable)
3429 device->fs_devices->total_rw_bytes += diff;
3430 spin_lock(&root->fs_info->free_chunk_lock);
3431 root->fs_info->free_chunk_space += diff;
3432 spin_unlock(&root->fs_info->free_chunk_lock);
3433 unlock_chunks(root);
3434 goto done;
3435 }
3436
3437 /* Shrinking succeeded, else we would be at "done". */
3438 trans = btrfs_start_transaction(root, 0);
3439 if (IS_ERR(trans)) {
3440 ret = PTR_ERR(trans);
3441 goto done;
3442 }
3443
3444 lock_chunks(root);
3445
3446 device->disk_total_bytes = new_size;
3447 /* Now btrfs_update_device() will change the on-disk size. */
3448 ret = btrfs_update_device(trans, device);
3449 if (ret) {
3450 unlock_chunks(root);
3451 btrfs_end_transaction(trans, root);
3452 goto done;
3453 }
3454 WARN_ON(diff > old_total);
3455 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3456 unlock_chunks(root);
3457 btrfs_end_transaction(trans, root);
3458 done:
3459 btrfs_free_path(path);
3460 return ret;
3461 }
3462
3463 static int btrfs_add_system_chunk(struct btrfs_root *root,
3464 struct btrfs_key *key,
3465 struct btrfs_chunk *chunk, int item_size)
3466 {
3467 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3468 struct btrfs_disk_key disk_key;
3469 u32 array_size;
3470 u8 *ptr;
3471
3472 array_size = btrfs_super_sys_array_size(super_copy);
3473 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3474 return -EFBIG;
3475
3476 ptr = super_copy->sys_chunk_array + array_size;
3477 btrfs_cpu_key_to_disk(&disk_key, key);
3478 memcpy(ptr, &disk_key, sizeof(disk_key));
3479 ptr += sizeof(disk_key);
3480 memcpy(ptr, chunk, item_size);
3481 item_size += sizeof(disk_key);
3482 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3483 return 0;
3484 }
3485
3486 /*
3487 * sort the devices in descending order by max_avail, total_avail
3488 */
3489 static int btrfs_cmp_device_info(const void *a, const void *b)
3490 {
3491 const struct btrfs_device_info *di_a = a;
3492 const struct btrfs_device_info *di_b = b;
3493
3494 if (di_a->max_avail > di_b->max_avail)
3495 return -1;
3496 if (di_a->max_avail < di_b->max_avail)
3497 return 1;
3498 if (di_a->total_avail > di_b->total_avail)
3499 return -1;
3500 if (di_a->total_avail < di_b->total_avail)
3501 return 1;
3502 return 0;
3503 }
3504
3505 struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3506 { 2, 1, 0, 4, 2, 2 /* raid10 */ },
3507 { 1, 1, 2, 2, 2, 2 /* raid1 */ },
3508 { 1, 2, 1, 1, 1, 2 /* dup */ },
3509 { 1, 1, 0, 2, 1, 1 /* raid0 */ },
3510 { 1, 1, 1, 1, 1, 1 /* single */ },
3511 };
3512
3513 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3514 struct btrfs_root *extent_root,
3515 struct map_lookup **map_ret,
3516 u64 *num_bytes_out, u64 *stripe_size_out,
3517 u64 start, u64 type)
3518 {
3519 struct btrfs_fs_info *info = extent_root->fs_info;
3520 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3521 struct list_head *cur;
3522 struct map_lookup *map = NULL;
3523 struct extent_map_tree *em_tree;
3524 struct extent_map *em;
3525 struct btrfs_device_info *devices_info = NULL;
3526 u64 total_avail;
3527 int num_stripes; /* total number of stripes to allocate */
3528 int sub_stripes; /* sub_stripes info for map */
3529 int dev_stripes; /* stripes per dev */
3530 int devs_max; /* max devs to use */
3531 int devs_min; /* min devs needed */
3532 int devs_increment; /* ndevs has to be a multiple of this */
3533 int ncopies; /* how many copies to data has */
3534 int ret;
3535 u64 max_stripe_size;
3536 u64 max_chunk_size;
3537 u64 stripe_size;
3538 u64 num_bytes;
3539 int ndevs;
3540 int i;
3541 int j;
3542 int index;
3543
3544 BUG_ON(!alloc_profile_is_valid(type, 0));
3545
3546 if (list_empty(&fs_devices->alloc_list))
3547 return -ENOSPC;
3548
3549 index = __get_raid_index(type);
3550
3551 sub_stripes = btrfs_raid_array[index].sub_stripes;
3552 dev_stripes = btrfs_raid_array[index].dev_stripes;
3553 devs_max = btrfs_raid_array[index].devs_max;
3554 devs_min = btrfs_raid_array[index].devs_min;
3555 devs_increment = btrfs_raid_array[index].devs_increment;
3556 ncopies = btrfs_raid_array[index].ncopies;
3557
3558 if (type & BTRFS_BLOCK_GROUP_DATA) {
3559 max_stripe_size = 1024 * 1024 * 1024;
3560 max_chunk_size = 10 * max_stripe_size;
3561 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3562 /* for larger filesystems, use larger metadata chunks */
3563 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3564 max_stripe_size = 1024 * 1024 * 1024;
3565 else
3566 max_stripe_size = 256 * 1024 * 1024;
3567 max_chunk_size = max_stripe_size;
3568 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3569 max_stripe_size = 32 * 1024 * 1024;
3570 max_chunk_size = 2 * max_stripe_size;
3571 } else {
3572 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3573 type);
3574 BUG_ON(1);
3575 }
3576
3577 /* we don't want a chunk larger than 10% of writeable space */
3578 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3579 max_chunk_size);
3580
3581 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3582 GFP_NOFS);
3583 if (!devices_info)
3584 return -ENOMEM;
3585
3586 cur = fs_devices->alloc_list.next;
3587
3588 /*
3589 * in the first pass through the devices list, we gather information
3590 * about the available holes on each device.
3591 */
3592 ndevs = 0;
3593 while (cur != &fs_devices->alloc_list) {
3594 struct btrfs_device *device;
3595 u64 max_avail;
3596 u64 dev_offset;
3597
3598 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3599
3600 cur = cur->next;
3601
3602 if (!device->writeable) {
3603 WARN(1, KERN_ERR
3604 "btrfs: read-only device in alloc_list\n");
3605 continue;
3606 }
3607
3608 if (!device->in_fs_metadata ||
3609 device->is_tgtdev_for_dev_replace)
3610 continue;
3611
3612 if (device->total_bytes > device->bytes_used)
3613 total_avail = device->total_bytes - device->bytes_used;
3614 else
3615 total_avail = 0;
3616
3617 /* If there is no space on this device, skip it. */
3618 if (total_avail == 0)
3619 continue;
3620
3621 ret = find_free_dev_extent(device,
3622 max_stripe_size * dev_stripes,
3623 &dev_offset, &max_avail);
3624 if (ret && ret != -ENOSPC)
3625 goto error;
3626
3627 if (ret == 0)
3628 max_avail = max_stripe_size * dev_stripes;
3629
3630 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3631 continue;
3632
3633 devices_info[ndevs].dev_offset = dev_offset;
3634 devices_info[ndevs].max_avail = max_avail;
3635 devices_info[ndevs].total_avail = total_avail;
3636 devices_info[ndevs].dev = device;
3637 ++ndevs;
3638 WARN_ON(ndevs > fs_devices->rw_devices);
3639 }
3640
3641 /*
3642 * now sort the devices by hole size / available space
3643 */
3644 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3645 btrfs_cmp_device_info, NULL);
3646
3647 /* round down to number of usable stripes */
3648 ndevs -= ndevs % devs_increment;
3649
3650 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3651 ret = -ENOSPC;
3652 goto error;
3653 }
3654
3655 if (devs_max && ndevs > devs_max)
3656 ndevs = devs_max;
3657 /*
3658 * the primary goal is to maximize the number of stripes, so use as many
3659 * devices as possible, even if the stripes are not maximum sized.
3660 */
3661 stripe_size = devices_info[ndevs-1].max_avail;
3662 num_stripes = ndevs * dev_stripes;
3663
3664 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3665 stripe_size = max_chunk_size * ncopies;
3666 do_div(stripe_size, ndevs);
3667 }
3668
3669 do_div(stripe_size, dev_stripes);
3670
3671 /* align to BTRFS_STRIPE_LEN */
3672 do_div(stripe_size, BTRFS_STRIPE_LEN);
3673 stripe_size *= BTRFS_STRIPE_LEN;
3674
3675 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3676 if (!map) {
3677 ret = -ENOMEM;
3678 goto error;
3679 }
3680 map->num_stripes = num_stripes;
3681
3682 for (i = 0; i < ndevs; ++i) {
3683 for (j = 0; j < dev_stripes; ++j) {
3684 int s = i * dev_stripes + j;
3685 map->stripes[s].dev = devices_info[i].dev;
3686 map->stripes[s].physical = devices_info[i].dev_offset +
3687 j * stripe_size;
3688 }
3689 }
3690 map->sector_size = extent_root->sectorsize;
3691 map->stripe_len = BTRFS_STRIPE_LEN;
3692 map->io_align = BTRFS_STRIPE_LEN;
3693 map->io_width = BTRFS_STRIPE_LEN;
3694 map->type = type;
3695 map->sub_stripes = sub_stripes;
3696
3697 *map_ret = map;
3698 num_bytes = stripe_size * (num_stripes / ncopies);
3699
3700 *stripe_size_out = stripe_size;
3701 *num_bytes_out = num_bytes;
3702
3703 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3704
3705 em = alloc_extent_map();
3706 if (!em) {
3707 ret = -ENOMEM;
3708 goto error;
3709 }
3710 em->bdev = (struct block_device *)map;
3711 em->start = start;
3712 em->len = num_bytes;
3713 em->block_start = 0;
3714 em->block_len = em->len;
3715
3716 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3717 write_lock(&em_tree->lock);
3718 ret = add_extent_mapping(em_tree, em);
3719 write_unlock(&em_tree->lock);
3720 free_extent_map(em);
3721 if (ret)
3722 goto error;
3723
3724 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3725 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3726 start, num_bytes);
3727 if (ret)
3728 goto error;
3729
3730 for (i = 0; i < map->num_stripes; ++i) {
3731 struct btrfs_device *device;
3732 u64 dev_offset;
3733
3734 device = map->stripes[i].dev;
3735 dev_offset = map->stripes[i].physical;
3736
3737 ret = btrfs_alloc_dev_extent(trans, device,
3738 info->chunk_root->root_key.objectid,
3739 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3740 start, dev_offset, stripe_size);
3741 if (ret) {
3742 btrfs_abort_transaction(trans, extent_root, ret);
3743 goto error;
3744 }
3745 }
3746
3747 kfree(devices_info);
3748 return 0;
3749
3750 error:
3751 kfree(map);
3752 kfree(devices_info);
3753 return ret;
3754 }
3755
3756 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3757 struct btrfs_root *extent_root,
3758 struct map_lookup *map, u64 chunk_offset,
3759 u64 chunk_size, u64 stripe_size)
3760 {
3761 u64 dev_offset;
3762 struct btrfs_key key;
3763 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3764 struct btrfs_device *device;
3765 struct btrfs_chunk *chunk;
3766 struct btrfs_stripe *stripe;
3767 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3768 int index = 0;
3769 int ret;
3770
3771 chunk = kzalloc(item_size, GFP_NOFS);
3772 if (!chunk)
3773 return -ENOMEM;
3774
3775 index = 0;
3776 while (index < map->num_stripes) {
3777 device = map->stripes[index].dev;
3778 device->bytes_used += stripe_size;
3779 ret = btrfs_update_device(trans, device);
3780 if (ret)
3781 goto out_free;
3782 index++;
3783 }
3784
3785 spin_lock(&extent_root->fs_info->free_chunk_lock);
3786 extent_root->fs_info->free_chunk_space -= (stripe_size *
3787 map->num_stripes);
3788 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3789
3790 index = 0;
3791 stripe = &chunk->stripe;
3792 while (index < map->num_stripes) {
3793 device = map->stripes[index].dev;
3794 dev_offset = map->stripes[index].physical;
3795
3796 btrfs_set_stack_stripe_devid(stripe, device->devid);
3797 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3798 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3799 stripe++;
3800 index++;
3801 }
3802
3803 btrfs_set_stack_chunk_length(chunk, chunk_size);
3804 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3805 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3806 btrfs_set_stack_chunk_type(chunk, map->type);
3807 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3808 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3809 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3810 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3811 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3812
3813 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3814 key.type = BTRFS_CHUNK_ITEM_KEY;
3815 key.offset = chunk_offset;
3816
3817 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3818
3819 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3820 /*
3821 * TODO: Cleanup of inserted chunk root in case of
3822 * failure.
3823 */
3824 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3825 item_size);
3826 }
3827
3828 out_free:
3829 kfree(chunk);
3830 return ret;
3831 }
3832
3833 /*
3834 * Chunk allocation falls into two parts. The first part does works
3835 * that make the new allocated chunk useable, but not do any operation
3836 * that modifies the chunk tree. The second part does the works that
3837 * require modifying the chunk tree. This division is important for the
3838 * bootstrap process of adding storage to a seed btrfs.
3839 */
3840 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3841 struct btrfs_root *extent_root, u64 type)
3842 {
3843 u64 chunk_offset;
3844 u64 chunk_size;
3845 u64 stripe_size;
3846 struct map_lookup *map;
3847 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3848 int ret;
3849
3850 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3851 &chunk_offset);
3852 if (ret)
3853 return ret;
3854
3855 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3856 &stripe_size, chunk_offset, type);
3857 if (ret)
3858 return ret;
3859
3860 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3861 chunk_size, stripe_size);
3862 if (ret)
3863 return ret;
3864 return 0;
3865 }
3866
3867 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3868 struct btrfs_root *root,
3869 struct btrfs_device *device)
3870 {
3871 u64 chunk_offset;
3872 u64 sys_chunk_offset;
3873 u64 chunk_size;
3874 u64 sys_chunk_size;
3875 u64 stripe_size;
3876 u64 sys_stripe_size;
3877 u64 alloc_profile;
3878 struct map_lookup *map;
3879 struct map_lookup *sys_map;
3880 struct btrfs_fs_info *fs_info = root->fs_info;
3881 struct btrfs_root *extent_root = fs_info->extent_root;
3882 int ret;
3883
3884 ret = find_next_chunk(fs_info->chunk_root,
3885 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3886 if (ret)
3887 return ret;
3888
3889 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3890 fs_info->avail_metadata_alloc_bits;
3891 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3892
3893 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3894 &stripe_size, chunk_offset, alloc_profile);
3895 if (ret)
3896 return ret;
3897
3898 sys_chunk_offset = chunk_offset + chunk_size;
3899
3900 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3901 fs_info->avail_system_alloc_bits;
3902 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3903
3904 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3905 &sys_chunk_size, &sys_stripe_size,
3906 sys_chunk_offset, alloc_profile);
3907 if (ret) {
3908 btrfs_abort_transaction(trans, root, ret);
3909 goto out;
3910 }
3911
3912 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3913 if (ret) {
3914 btrfs_abort_transaction(trans, root, ret);
3915 goto out;
3916 }
3917
3918 /*
3919 * Modifying chunk tree needs allocating new blocks from both
3920 * system block group and metadata block group. So we only can
3921 * do operations require modifying the chunk tree after both
3922 * block groups were created.
3923 */
3924 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3925 chunk_size, stripe_size);
3926 if (ret) {
3927 btrfs_abort_transaction(trans, root, ret);
3928 goto out;
3929 }
3930
3931 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3932 sys_chunk_offset, sys_chunk_size,
3933 sys_stripe_size);
3934 if (ret)
3935 btrfs_abort_transaction(trans, root, ret);
3936
3937 out:
3938
3939 return ret;
3940 }
3941
3942 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3943 {
3944 struct extent_map *em;
3945 struct map_lookup *map;
3946 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3947 int readonly = 0;
3948 int i;
3949
3950 read_lock(&map_tree->map_tree.lock);
3951 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3952 read_unlock(&map_tree->map_tree.lock);
3953 if (!em)
3954 return 1;
3955
3956 if (btrfs_test_opt(root, DEGRADED)) {
3957 free_extent_map(em);
3958 return 0;
3959 }
3960
3961 map = (struct map_lookup *)em->bdev;
3962 for (i = 0; i < map->num_stripes; i++) {
3963 if (!map->stripes[i].dev->writeable) {
3964 readonly = 1;
3965 break;
3966 }
3967 }
3968 free_extent_map(em);
3969 return readonly;
3970 }
3971
3972 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3973 {
3974 extent_map_tree_init(&tree->map_tree);
3975 }
3976
3977 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3978 {
3979 struct extent_map *em;
3980
3981 while (1) {
3982 write_lock(&tree->map_tree.lock);
3983 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3984 if (em)
3985 remove_extent_mapping(&tree->map_tree, em);
3986 write_unlock(&tree->map_tree.lock);
3987 if (!em)
3988 break;
3989 kfree(em->bdev);
3990 /* once for us */
3991 free_extent_map(em);
3992 /* once for the tree */
3993 free_extent_map(em);
3994 }
3995 }
3996
3997 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
3998 {
3999 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4000 struct extent_map *em;
4001 struct map_lookup *map;
4002 struct extent_map_tree *em_tree = &map_tree->map_tree;
4003 int ret;
4004
4005 read_lock(&em_tree->lock);
4006 em = lookup_extent_mapping(em_tree, logical, len);
4007 read_unlock(&em_tree->lock);
4008 BUG_ON(!em);
4009
4010 BUG_ON(em->start > logical || em->start + em->len < logical);
4011 map = (struct map_lookup *)em->bdev;
4012 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4013 ret = map->num_stripes;
4014 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4015 ret = map->sub_stripes;
4016 else
4017 ret = 1;
4018 free_extent_map(em);
4019
4020 btrfs_dev_replace_lock(&fs_info->dev_replace);
4021 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4022 ret++;
4023 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4024
4025 return ret;
4026 }
4027
4028 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4029 struct map_lookup *map, int first, int num,
4030 int optimal, int dev_replace_is_ongoing)
4031 {
4032 int i;
4033 int tolerance;
4034 struct btrfs_device *srcdev;
4035
4036 if (dev_replace_is_ongoing &&
4037 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4038 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4039 srcdev = fs_info->dev_replace.srcdev;
4040 else
4041 srcdev = NULL;
4042
4043 /*
4044 * try to avoid the drive that is the source drive for a
4045 * dev-replace procedure, only choose it if no other non-missing
4046 * mirror is available
4047 */
4048 for (tolerance = 0; tolerance < 2; tolerance++) {
4049 if (map->stripes[optimal].dev->bdev &&
4050 (tolerance || map->stripes[optimal].dev != srcdev))
4051 return optimal;
4052 for (i = first; i < first + num; i++) {
4053 if (map->stripes[i].dev->bdev &&
4054 (tolerance || map->stripes[i].dev != srcdev))
4055 return i;
4056 }
4057 }
4058
4059 /* we couldn't find one that doesn't fail. Just return something
4060 * and the io error handling code will clean up eventually
4061 */
4062 return optimal;
4063 }
4064
4065 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4066 u64 logical, u64 *length,
4067 struct btrfs_bio **bbio_ret,
4068 int mirror_num)
4069 {
4070 struct extent_map *em;
4071 struct map_lookup *map;
4072 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4073 struct extent_map_tree *em_tree = &map_tree->map_tree;
4074 u64 offset;
4075 u64 stripe_offset;
4076 u64 stripe_end_offset;
4077 u64 stripe_nr;
4078 u64 stripe_nr_orig;
4079 u64 stripe_nr_end;
4080 int stripe_index;
4081 int i;
4082 int ret = 0;
4083 int num_stripes;
4084 int max_errors = 0;
4085 struct btrfs_bio *bbio = NULL;
4086 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4087 int dev_replace_is_ongoing = 0;
4088 int num_alloc_stripes;
4089 int patch_the_first_stripe_for_dev_replace = 0;
4090 u64 physical_to_patch_in_first_stripe = 0;
4091
4092 read_lock(&em_tree->lock);
4093 em = lookup_extent_mapping(em_tree, logical, *length);
4094 read_unlock(&em_tree->lock);
4095
4096 if (!em) {
4097 printk(KERN_CRIT "btrfs: unable to find logical %llu len %llu\n",
4098 (unsigned long long)logical,
4099 (unsigned long long)*length);
4100 BUG();
4101 }
4102
4103 BUG_ON(em->start > logical || em->start + em->len < logical);
4104 map = (struct map_lookup *)em->bdev;
4105 offset = logical - em->start;
4106
4107 stripe_nr = offset;
4108 /*
4109 * stripe_nr counts the total number of stripes we have to stride
4110 * to get to this block
4111 */
4112 do_div(stripe_nr, map->stripe_len);
4113
4114 stripe_offset = stripe_nr * map->stripe_len;
4115 BUG_ON(offset < stripe_offset);
4116
4117 /* stripe_offset is the offset of this block in its stripe*/
4118 stripe_offset = offset - stripe_offset;
4119
4120 if (rw & REQ_DISCARD)
4121 *length = min_t(u64, em->len - offset, *length);
4122 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4123 /* we limit the length of each bio to what fits in a stripe */
4124 *length = min_t(u64, em->len - offset,
4125 map->stripe_len - stripe_offset);
4126 } else {
4127 *length = em->len - offset;
4128 }
4129
4130 if (!bbio_ret)
4131 goto out;
4132
4133 btrfs_dev_replace_lock(dev_replace);
4134 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4135 if (!dev_replace_is_ongoing)
4136 btrfs_dev_replace_unlock(dev_replace);
4137
4138 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4139 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4140 dev_replace->tgtdev != NULL) {
4141 /*
4142 * in dev-replace case, for repair case (that's the only
4143 * case where the mirror is selected explicitly when
4144 * calling btrfs_map_block), blocks left of the left cursor
4145 * can also be read from the target drive.
4146 * For REQ_GET_READ_MIRRORS, the target drive is added as
4147 * the last one to the array of stripes. For READ, it also
4148 * needs to be supported using the same mirror number.
4149 * If the requested block is not left of the left cursor,
4150 * EIO is returned. This can happen because btrfs_num_copies()
4151 * returns one more in the dev-replace case.
4152 */
4153 u64 tmp_length = *length;
4154 struct btrfs_bio *tmp_bbio = NULL;
4155 int tmp_num_stripes;
4156 u64 srcdev_devid = dev_replace->srcdev->devid;
4157 int index_srcdev = 0;
4158 int found = 0;
4159 u64 physical_of_found = 0;
4160
4161 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4162 logical, &tmp_length, &tmp_bbio, 0);
4163 if (ret) {
4164 WARN_ON(tmp_bbio != NULL);
4165 goto out;
4166 }
4167
4168 tmp_num_stripes = tmp_bbio->num_stripes;
4169 if (mirror_num > tmp_num_stripes) {
4170 /*
4171 * REQ_GET_READ_MIRRORS does not contain this
4172 * mirror, that means that the requested area
4173 * is not left of the left cursor
4174 */
4175 ret = -EIO;
4176 kfree(tmp_bbio);
4177 goto out;
4178 }
4179
4180 /*
4181 * process the rest of the function using the mirror_num
4182 * of the source drive. Therefore look it up first.
4183 * At the end, patch the device pointer to the one of the
4184 * target drive.
4185 */
4186 for (i = 0; i < tmp_num_stripes; i++) {
4187 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4188 /*
4189 * In case of DUP, in order to keep it
4190 * simple, only add the mirror with the
4191 * lowest physical address
4192 */
4193 if (found &&
4194 physical_of_found <=
4195 tmp_bbio->stripes[i].physical)
4196 continue;
4197 index_srcdev = i;
4198 found = 1;
4199 physical_of_found =
4200 tmp_bbio->stripes[i].physical;
4201 }
4202 }
4203
4204 if (found) {
4205 mirror_num = index_srcdev + 1;
4206 patch_the_first_stripe_for_dev_replace = 1;
4207 physical_to_patch_in_first_stripe = physical_of_found;
4208 } else {
4209 WARN_ON(1);
4210 ret = -EIO;
4211 kfree(tmp_bbio);
4212 goto out;
4213 }
4214
4215 kfree(tmp_bbio);
4216 } else if (mirror_num > map->num_stripes) {
4217 mirror_num = 0;
4218 }
4219
4220 num_stripes = 1;
4221 stripe_index = 0;
4222 stripe_nr_orig = stripe_nr;
4223 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
4224 (~(map->stripe_len - 1));
4225 do_div(stripe_nr_end, map->stripe_len);
4226 stripe_end_offset = stripe_nr_end * map->stripe_len -
4227 (offset + *length);
4228 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4229 if (rw & REQ_DISCARD)
4230 num_stripes = min_t(u64, map->num_stripes,
4231 stripe_nr_end - stripe_nr_orig);
4232 stripe_index = do_div(stripe_nr, map->num_stripes);
4233 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4234 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4235 num_stripes = map->num_stripes;
4236 else if (mirror_num)
4237 stripe_index = mirror_num - 1;
4238 else {
4239 stripe_index = find_live_mirror(fs_info, map, 0,
4240 map->num_stripes,
4241 current->pid % map->num_stripes,
4242 dev_replace_is_ongoing);
4243 mirror_num = stripe_index + 1;
4244 }
4245
4246 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4247 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4248 num_stripes = map->num_stripes;
4249 } else if (mirror_num) {
4250 stripe_index = mirror_num - 1;
4251 } else {
4252 mirror_num = 1;
4253 }
4254
4255 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4256 int factor = map->num_stripes / map->sub_stripes;
4257
4258 stripe_index = do_div(stripe_nr, factor);
4259 stripe_index *= map->sub_stripes;
4260
4261 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4262 num_stripes = map->sub_stripes;
4263 else if (rw & REQ_DISCARD)
4264 num_stripes = min_t(u64, map->sub_stripes *
4265 (stripe_nr_end - stripe_nr_orig),
4266 map->num_stripes);
4267 else if (mirror_num)
4268 stripe_index += mirror_num - 1;
4269 else {
4270 int old_stripe_index = stripe_index;
4271 stripe_index = find_live_mirror(fs_info, map,
4272 stripe_index,
4273 map->sub_stripes, stripe_index +
4274 current->pid % map->sub_stripes,
4275 dev_replace_is_ongoing);
4276 mirror_num = stripe_index - old_stripe_index + 1;
4277 }
4278 } else {
4279 /*
4280 * after this do_div call, stripe_nr is the number of stripes
4281 * on this device we have to walk to find the data, and
4282 * stripe_index is the number of our device in the stripe array
4283 */
4284 stripe_index = do_div(stripe_nr, map->num_stripes);
4285 mirror_num = stripe_index + 1;
4286 }
4287 BUG_ON(stripe_index >= map->num_stripes);
4288
4289 num_alloc_stripes = num_stripes;
4290 if (dev_replace_is_ongoing) {
4291 if (rw & (REQ_WRITE | REQ_DISCARD))
4292 num_alloc_stripes <<= 1;
4293 if (rw & REQ_GET_READ_MIRRORS)
4294 num_alloc_stripes++;
4295 }
4296 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4297 if (!bbio) {
4298 ret = -ENOMEM;
4299 goto out;
4300 }
4301 atomic_set(&bbio->error, 0);
4302
4303 if (rw & REQ_DISCARD) {
4304 int factor = 0;
4305 int sub_stripes = 0;
4306 u64 stripes_per_dev = 0;
4307 u32 remaining_stripes = 0;
4308 u32 last_stripe = 0;
4309
4310 if (map->type &
4311 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4312 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4313 sub_stripes = 1;
4314 else
4315 sub_stripes = map->sub_stripes;
4316
4317 factor = map->num_stripes / sub_stripes;
4318 stripes_per_dev = div_u64_rem(stripe_nr_end -
4319 stripe_nr_orig,
4320 factor,
4321 &remaining_stripes);
4322 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4323 last_stripe *= sub_stripes;
4324 }
4325
4326 for (i = 0; i < num_stripes; i++) {
4327 bbio->stripes[i].physical =
4328 map->stripes[stripe_index].physical +
4329 stripe_offset + stripe_nr * map->stripe_len;
4330 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4331
4332 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4333 BTRFS_BLOCK_GROUP_RAID10)) {
4334 bbio->stripes[i].length = stripes_per_dev *
4335 map->stripe_len;
4336
4337 if (i / sub_stripes < remaining_stripes)
4338 bbio->stripes[i].length +=
4339 map->stripe_len;
4340
4341 /*
4342 * Special for the first stripe and
4343 * the last stripe:
4344 *
4345 * |-------|...|-------|
4346 * |----------|
4347 * off end_off
4348 */
4349 if (i < sub_stripes)
4350 bbio->stripes[i].length -=
4351 stripe_offset;
4352
4353 if (stripe_index >= last_stripe &&
4354 stripe_index <= (last_stripe +
4355 sub_stripes - 1))
4356 bbio->stripes[i].length -=
4357 stripe_end_offset;
4358
4359 if (i == sub_stripes - 1)
4360 stripe_offset = 0;
4361 } else
4362 bbio->stripes[i].length = *length;
4363
4364 stripe_index++;
4365 if (stripe_index == map->num_stripes) {
4366 /* This could only happen for RAID0/10 */
4367 stripe_index = 0;
4368 stripe_nr++;
4369 }
4370 }
4371 } else {
4372 for (i = 0; i < num_stripes; i++) {
4373 bbio->stripes[i].physical =
4374 map->stripes[stripe_index].physical +
4375 stripe_offset +
4376 stripe_nr * map->stripe_len;
4377 bbio->stripes[i].dev =
4378 map->stripes[stripe_index].dev;
4379 stripe_index++;
4380 }
4381 }
4382
4383 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
4384 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4385 BTRFS_BLOCK_GROUP_RAID10 |
4386 BTRFS_BLOCK_GROUP_DUP)) {
4387 max_errors = 1;
4388 }
4389 }
4390
4391 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
4392 dev_replace->tgtdev != NULL) {
4393 int index_where_to_add;
4394 u64 srcdev_devid = dev_replace->srcdev->devid;
4395
4396 /*
4397 * duplicate the write operations while the dev replace
4398 * procedure is running. Since the copying of the old disk
4399 * to the new disk takes place at run time while the
4400 * filesystem is mounted writable, the regular write
4401 * operations to the old disk have to be duplicated to go
4402 * to the new disk as well.
4403 * Note that device->missing is handled by the caller, and
4404 * that the write to the old disk is already set up in the
4405 * stripes array.
4406 */
4407 index_where_to_add = num_stripes;
4408 for (i = 0; i < num_stripes; i++) {
4409 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4410 /* write to new disk, too */
4411 struct btrfs_bio_stripe *new =
4412 bbio->stripes + index_where_to_add;
4413 struct btrfs_bio_stripe *old =
4414 bbio->stripes + i;
4415
4416 new->physical = old->physical;
4417 new->length = old->length;
4418 new->dev = dev_replace->tgtdev;
4419 index_where_to_add++;
4420 max_errors++;
4421 }
4422 }
4423 num_stripes = index_where_to_add;
4424 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
4425 dev_replace->tgtdev != NULL) {
4426 u64 srcdev_devid = dev_replace->srcdev->devid;
4427 int index_srcdev = 0;
4428 int found = 0;
4429 u64 physical_of_found = 0;
4430
4431 /*
4432 * During the dev-replace procedure, the target drive can
4433 * also be used to read data in case it is needed to repair
4434 * a corrupt block elsewhere. This is possible if the
4435 * requested area is left of the left cursor. In this area,
4436 * the target drive is a full copy of the source drive.
4437 */
4438 for (i = 0; i < num_stripes; i++) {
4439 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4440 /*
4441 * In case of DUP, in order to keep it
4442 * simple, only add the mirror with the
4443 * lowest physical address
4444 */
4445 if (found &&
4446 physical_of_found <=
4447 bbio->stripes[i].physical)
4448 continue;
4449 index_srcdev = i;
4450 found = 1;
4451 physical_of_found = bbio->stripes[i].physical;
4452 }
4453 }
4454 if (found) {
4455 u64 length = map->stripe_len;
4456
4457 if (physical_of_found + length <=
4458 dev_replace->cursor_left) {
4459 struct btrfs_bio_stripe *tgtdev_stripe =
4460 bbio->stripes + num_stripes;
4461
4462 tgtdev_stripe->physical = physical_of_found;
4463 tgtdev_stripe->length =
4464 bbio->stripes[index_srcdev].length;
4465 tgtdev_stripe->dev = dev_replace->tgtdev;
4466
4467 num_stripes++;
4468 }
4469 }
4470 }
4471
4472 *bbio_ret = bbio;
4473 bbio->num_stripes = num_stripes;
4474 bbio->max_errors = max_errors;
4475 bbio->mirror_num = mirror_num;
4476
4477 /*
4478 * this is the case that REQ_READ && dev_replace_is_ongoing &&
4479 * mirror_num == num_stripes + 1 && dev_replace target drive is
4480 * available as a mirror
4481 */
4482 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
4483 WARN_ON(num_stripes > 1);
4484 bbio->stripes[0].dev = dev_replace->tgtdev;
4485 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
4486 bbio->mirror_num = map->num_stripes + 1;
4487 }
4488 out:
4489 if (dev_replace_is_ongoing)
4490 btrfs_dev_replace_unlock(dev_replace);
4491 free_extent_map(em);
4492 return ret;
4493 }
4494
4495 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4496 u64 logical, u64 *length,
4497 struct btrfs_bio **bbio_ret, int mirror_num)
4498 {
4499 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
4500 mirror_num);
4501 }
4502
4503 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4504 u64 chunk_start, u64 physical, u64 devid,
4505 u64 **logical, int *naddrs, int *stripe_len)
4506 {
4507 struct extent_map_tree *em_tree = &map_tree->map_tree;
4508 struct extent_map *em;
4509 struct map_lookup *map;
4510 u64 *buf;
4511 u64 bytenr;
4512 u64 length;
4513 u64 stripe_nr;
4514 int i, j, nr = 0;
4515
4516 read_lock(&em_tree->lock);
4517 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4518 read_unlock(&em_tree->lock);
4519
4520 BUG_ON(!em || em->start != chunk_start);
4521 map = (struct map_lookup *)em->bdev;
4522
4523 length = em->len;
4524 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4525 do_div(length, map->num_stripes / map->sub_stripes);
4526 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4527 do_div(length, map->num_stripes);
4528
4529 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4530 BUG_ON(!buf); /* -ENOMEM */
4531
4532 for (i = 0; i < map->num_stripes; i++) {
4533 if (devid && map->stripes[i].dev->devid != devid)
4534 continue;
4535 if (map->stripes[i].physical > physical ||
4536 map->stripes[i].physical + length <= physical)
4537 continue;
4538
4539 stripe_nr = physical - map->stripes[i].physical;
4540 do_div(stripe_nr, map->stripe_len);
4541
4542 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4543 stripe_nr = stripe_nr * map->num_stripes + i;
4544 do_div(stripe_nr, map->sub_stripes);
4545 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4546 stripe_nr = stripe_nr * map->num_stripes + i;
4547 }
4548 bytenr = chunk_start + stripe_nr * map->stripe_len;
4549 WARN_ON(nr >= map->num_stripes);
4550 for (j = 0; j < nr; j++) {
4551 if (buf[j] == bytenr)
4552 break;
4553 }
4554 if (j == nr) {
4555 WARN_ON(nr >= map->num_stripes);
4556 buf[nr++] = bytenr;
4557 }
4558 }
4559
4560 *logical = buf;
4561 *naddrs = nr;
4562 *stripe_len = map->stripe_len;
4563
4564 free_extent_map(em);
4565 return 0;
4566 }
4567
4568 static void *merge_stripe_index_into_bio_private(void *bi_private,
4569 unsigned int stripe_index)
4570 {
4571 /*
4572 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4573 * at most 1.
4574 * The alternative solution (instead of stealing bits from the
4575 * pointer) would be to allocate an intermediate structure
4576 * that contains the old private pointer plus the stripe_index.
4577 */
4578 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4579 BUG_ON(stripe_index > 3);
4580 return (void *)(((uintptr_t)bi_private) | stripe_index);
4581 }
4582
4583 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4584 {
4585 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4586 }
4587
4588 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4589 {
4590 return (unsigned int)((uintptr_t)bi_private) & 3;
4591 }
4592
4593 static void btrfs_end_bio(struct bio *bio, int err)
4594 {
4595 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4596 int is_orig_bio = 0;
4597
4598 if (err) {
4599 atomic_inc(&bbio->error);
4600 if (err == -EIO || err == -EREMOTEIO) {
4601 unsigned int stripe_index =
4602 extract_stripe_index_from_bio_private(
4603 bio->bi_private);
4604 struct btrfs_device *dev;
4605
4606 BUG_ON(stripe_index >= bbio->num_stripes);
4607 dev = bbio->stripes[stripe_index].dev;
4608 if (dev->bdev) {
4609 if (bio->bi_rw & WRITE)
4610 btrfs_dev_stat_inc(dev,
4611 BTRFS_DEV_STAT_WRITE_ERRS);
4612 else
4613 btrfs_dev_stat_inc(dev,
4614 BTRFS_DEV_STAT_READ_ERRS);
4615 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4616 btrfs_dev_stat_inc(dev,
4617 BTRFS_DEV_STAT_FLUSH_ERRS);
4618 btrfs_dev_stat_print_on_error(dev);
4619 }
4620 }
4621 }
4622
4623 if (bio == bbio->orig_bio)
4624 is_orig_bio = 1;
4625
4626 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4627 if (!is_orig_bio) {
4628 bio_put(bio);
4629 bio = bbio->orig_bio;
4630 }
4631 bio->bi_private = bbio->private;
4632 bio->bi_end_io = bbio->end_io;
4633 bio->bi_bdev = (struct block_device *)
4634 (unsigned long)bbio->mirror_num;
4635 /* only send an error to the higher layers if it is
4636 * beyond the tolerance of the multi-bio
4637 */
4638 if (atomic_read(&bbio->error) > bbio->max_errors) {
4639 err = -EIO;
4640 } else {
4641 /*
4642 * this bio is actually up to date, we didn't
4643 * go over the max number of errors
4644 */
4645 set_bit(BIO_UPTODATE, &bio->bi_flags);
4646 err = 0;
4647 }
4648 kfree(bbio);
4649
4650 bio_endio(bio, err);
4651 } else if (!is_orig_bio) {
4652 bio_put(bio);
4653 }
4654 }
4655
4656 struct async_sched {
4657 struct bio *bio;
4658 int rw;
4659 struct btrfs_fs_info *info;
4660 struct btrfs_work work;
4661 };
4662
4663 /*
4664 * see run_scheduled_bios for a description of why bios are collected for
4665 * async submit.
4666 *
4667 * This will add one bio to the pending list for a device and make sure
4668 * the work struct is scheduled.
4669 */
4670 static noinline void schedule_bio(struct btrfs_root *root,
4671 struct btrfs_device *device,
4672 int rw, struct bio *bio)
4673 {
4674 int should_queue = 1;
4675 struct btrfs_pending_bios *pending_bios;
4676
4677 /* don't bother with additional async steps for reads, right now */
4678 if (!(rw & REQ_WRITE)) {
4679 bio_get(bio);
4680 btrfsic_submit_bio(rw, bio);
4681 bio_put(bio);
4682 return;
4683 }
4684
4685 /*
4686 * nr_async_bios allows us to reliably return congestion to the
4687 * higher layers. Otherwise, the async bio makes it appear we have
4688 * made progress against dirty pages when we've really just put it
4689 * on a queue for later
4690 */
4691 atomic_inc(&root->fs_info->nr_async_bios);
4692 WARN_ON(bio->bi_next);
4693 bio->bi_next = NULL;
4694 bio->bi_rw |= rw;
4695
4696 spin_lock(&device->io_lock);
4697 if (bio->bi_rw & REQ_SYNC)
4698 pending_bios = &device->pending_sync_bios;
4699 else
4700 pending_bios = &device->pending_bios;
4701
4702 if (pending_bios->tail)
4703 pending_bios->tail->bi_next = bio;
4704
4705 pending_bios->tail = bio;
4706 if (!pending_bios->head)
4707 pending_bios->head = bio;
4708 if (device->running_pending)
4709 should_queue = 0;
4710
4711 spin_unlock(&device->io_lock);
4712
4713 if (should_queue)
4714 btrfs_queue_worker(&root->fs_info->submit_workers,
4715 &device->work);
4716 }
4717
4718 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
4719 sector_t sector)
4720 {
4721 struct bio_vec *prev;
4722 struct request_queue *q = bdev_get_queue(bdev);
4723 unsigned short max_sectors = queue_max_sectors(q);
4724 struct bvec_merge_data bvm = {
4725 .bi_bdev = bdev,
4726 .bi_sector = sector,
4727 .bi_rw = bio->bi_rw,
4728 };
4729
4730 if (bio->bi_vcnt == 0) {
4731 WARN_ON(1);
4732 return 1;
4733 }
4734
4735 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
4736 if ((bio->bi_size >> 9) > max_sectors)
4737 return 0;
4738
4739 if (!q->merge_bvec_fn)
4740 return 1;
4741
4742 bvm.bi_size = bio->bi_size - prev->bv_len;
4743 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
4744 return 0;
4745 return 1;
4746 }
4747
4748 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
4749 struct bio *bio, u64 physical, int dev_nr,
4750 int rw, int async)
4751 {
4752 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
4753
4754 bio->bi_private = bbio;
4755 bio->bi_private = merge_stripe_index_into_bio_private(
4756 bio->bi_private, (unsigned int)dev_nr);
4757 bio->bi_end_io = btrfs_end_bio;
4758 bio->bi_sector = physical >> 9;
4759 #ifdef DEBUG
4760 {
4761 struct rcu_string *name;
4762
4763 rcu_read_lock();
4764 name = rcu_dereference(dev->name);
4765 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
4766 "(%s id %llu), size=%u\n", rw,
4767 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4768 name->str, dev->devid, bio->bi_size);
4769 rcu_read_unlock();
4770 }
4771 #endif
4772 bio->bi_bdev = dev->bdev;
4773 if (async)
4774 schedule_bio(root, dev, rw, bio);
4775 else
4776 btrfsic_submit_bio(rw, bio);
4777 }
4778
4779 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
4780 struct bio *first_bio, struct btrfs_device *dev,
4781 int dev_nr, int rw, int async)
4782 {
4783 struct bio_vec *bvec = first_bio->bi_io_vec;
4784 struct bio *bio;
4785 int nr_vecs = bio_get_nr_vecs(dev->bdev);
4786 u64 physical = bbio->stripes[dev_nr].physical;
4787
4788 again:
4789 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
4790 if (!bio)
4791 return -ENOMEM;
4792
4793 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
4794 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
4795 bvec->bv_offset) < bvec->bv_len) {
4796 u64 len = bio->bi_size;
4797
4798 atomic_inc(&bbio->stripes_pending);
4799 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
4800 rw, async);
4801 physical += len;
4802 goto again;
4803 }
4804 bvec++;
4805 }
4806
4807 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
4808 return 0;
4809 }
4810
4811 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
4812 {
4813 atomic_inc(&bbio->error);
4814 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4815 bio->bi_private = bbio->private;
4816 bio->bi_end_io = bbio->end_io;
4817 bio->bi_bdev = (struct block_device *)
4818 (unsigned long)bbio->mirror_num;
4819 bio->bi_sector = logical >> 9;
4820 kfree(bbio);
4821 bio_endio(bio, -EIO);
4822 }
4823 }
4824
4825 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4826 int mirror_num, int async_submit)
4827 {
4828 struct btrfs_device *dev;
4829 struct bio *first_bio = bio;
4830 u64 logical = (u64)bio->bi_sector << 9;
4831 u64 length = 0;
4832 u64 map_length;
4833 int ret;
4834 int dev_nr = 0;
4835 int total_devs = 1;
4836 struct btrfs_bio *bbio = NULL;
4837
4838 length = bio->bi_size;
4839 map_length = length;
4840
4841 ret = btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
4842 mirror_num);
4843 if (ret)
4844 return ret;
4845
4846 total_devs = bbio->num_stripes;
4847 if (map_length < length) {
4848 printk(KERN_CRIT "btrfs: mapping failed logical %llu bio len %llu "
4849 "len %llu\n", (unsigned long long)logical,
4850 (unsigned long long)length,
4851 (unsigned long long)map_length);
4852 BUG();
4853 }
4854
4855 bbio->orig_bio = first_bio;
4856 bbio->private = first_bio->bi_private;
4857 bbio->end_io = first_bio->bi_end_io;
4858 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4859
4860 while (dev_nr < total_devs) {
4861 dev = bbio->stripes[dev_nr].dev;
4862 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
4863 bbio_error(bbio, first_bio, logical);
4864 dev_nr++;
4865 continue;
4866 }
4867
4868 /*
4869 * Check and see if we're ok with this bio based on it's size
4870 * and offset with the given device.
4871 */
4872 if (!bio_size_ok(dev->bdev, first_bio,
4873 bbio->stripes[dev_nr].physical >> 9)) {
4874 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
4875 dev_nr, rw, async_submit);
4876 BUG_ON(ret);
4877 dev_nr++;
4878 continue;
4879 }
4880
4881 if (dev_nr < total_devs - 1) {
4882 bio = bio_clone(first_bio, GFP_NOFS);
4883 BUG_ON(!bio); /* -ENOMEM */
4884 } else {
4885 bio = first_bio;
4886 }
4887
4888 submit_stripe_bio(root, bbio, bio,
4889 bbio->stripes[dev_nr].physical, dev_nr, rw,
4890 async_submit);
4891 dev_nr++;
4892 }
4893 return 0;
4894 }
4895
4896 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
4897 u8 *uuid, u8 *fsid)
4898 {
4899 struct btrfs_device *device;
4900 struct btrfs_fs_devices *cur_devices;
4901
4902 cur_devices = fs_info->fs_devices;
4903 while (cur_devices) {
4904 if (!fsid ||
4905 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4906 device = __find_device(&cur_devices->devices,
4907 devid, uuid);
4908 if (device)
4909 return device;
4910 }
4911 cur_devices = cur_devices->seed;
4912 }
4913 return NULL;
4914 }
4915
4916 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4917 u64 devid, u8 *dev_uuid)
4918 {
4919 struct btrfs_device *device;
4920 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4921
4922 device = kzalloc(sizeof(*device), GFP_NOFS);
4923 if (!device)
4924 return NULL;
4925 list_add(&device->dev_list,
4926 &fs_devices->devices);
4927 device->dev_root = root->fs_info->dev_root;
4928 device->devid = devid;
4929 device->work.func = pending_bios_fn;
4930 device->fs_devices = fs_devices;
4931 device->missing = 1;
4932 fs_devices->num_devices++;
4933 fs_devices->missing_devices++;
4934 spin_lock_init(&device->io_lock);
4935 INIT_LIST_HEAD(&device->dev_alloc_list);
4936 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4937 return device;
4938 }
4939
4940 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4941 struct extent_buffer *leaf,
4942 struct btrfs_chunk *chunk)
4943 {
4944 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4945 struct map_lookup *map;
4946 struct extent_map *em;
4947 u64 logical;
4948 u64 length;
4949 u64 devid;
4950 u8 uuid[BTRFS_UUID_SIZE];
4951 int num_stripes;
4952 int ret;
4953 int i;
4954
4955 logical = key->offset;
4956 length = btrfs_chunk_length(leaf, chunk);
4957
4958 read_lock(&map_tree->map_tree.lock);
4959 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4960 read_unlock(&map_tree->map_tree.lock);
4961
4962 /* already mapped? */
4963 if (em && em->start <= logical && em->start + em->len > logical) {
4964 free_extent_map(em);
4965 return 0;
4966 } else if (em) {
4967 free_extent_map(em);
4968 }
4969
4970 em = alloc_extent_map();
4971 if (!em)
4972 return -ENOMEM;
4973 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4974 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4975 if (!map) {
4976 free_extent_map(em);
4977 return -ENOMEM;
4978 }
4979
4980 em->bdev = (struct block_device *)map;
4981 em->start = logical;
4982 em->len = length;
4983 em->orig_start = 0;
4984 em->block_start = 0;
4985 em->block_len = em->len;
4986
4987 map->num_stripes = num_stripes;
4988 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4989 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4990 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4991 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4992 map->type = btrfs_chunk_type(leaf, chunk);
4993 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4994 for (i = 0; i < num_stripes; i++) {
4995 map->stripes[i].physical =
4996 btrfs_stripe_offset_nr(leaf, chunk, i);
4997 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4998 read_extent_buffer(leaf, uuid, (unsigned long)
4999 btrfs_stripe_dev_uuid_nr(chunk, i),
5000 BTRFS_UUID_SIZE);
5001 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5002 uuid, NULL);
5003 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5004 kfree(map);
5005 free_extent_map(em);
5006 return -EIO;
5007 }
5008 if (!map->stripes[i].dev) {
5009 map->stripes[i].dev =
5010 add_missing_dev(root, devid, uuid);
5011 if (!map->stripes[i].dev) {
5012 kfree(map);
5013 free_extent_map(em);
5014 return -EIO;
5015 }
5016 }
5017 map->stripes[i].dev->in_fs_metadata = 1;
5018 }
5019
5020 write_lock(&map_tree->map_tree.lock);
5021 ret = add_extent_mapping(&map_tree->map_tree, em);
5022 write_unlock(&map_tree->map_tree.lock);
5023 BUG_ON(ret); /* Tree corruption */
5024 free_extent_map(em);
5025
5026 return 0;
5027 }
5028
5029 static void fill_device_from_item(struct extent_buffer *leaf,
5030 struct btrfs_dev_item *dev_item,
5031 struct btrfs_device *device)
5032 {
5033 unsigned long ptr;
5034
5035 device->devid = btrfs_device_id(leaf, dev_item);
5036 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5037 device->total_bytes = device->disk_total_bytes;
5038 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5039 device->type = btrfs_device_type(leaf, dev_item);
5040 device->io_align = btrfs_device_io_align(leaf, dev_item);
5041 device->io_width = btrfs_device_io_width(leaf, dev_item);
5042 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5043 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5044 device->is_tgtdev_for_dev_replace = 0;
5045
5046 ptr = (unsigned long)btrfs_device_uuid(dev_item);
5047 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5048 }
5049
5050 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5051 {
5052 struct btrfs_fs_devices *fs_devices;
5053 int ret;
5054
5055 BUG_ON(!mutex_is_locked(&uuid_mutex));
5056
5057 fs_devices = root->fs_info->fs_devices->seed;
5058 while (fs_devices) {
5059 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5060 ret = 0;
5061 goto out;
5062 }
5063 fs_devices = fs_devices->seed;
5064 }
5065
5066 fs_devices = find_fsid(fsid);
5067 if (!fs_devices) {
5068 ret = -ENOENT;
5069 goto out;
5070 }
5071
5072 fs_devices = clone_fs_devices(fs_devices);
5073 if (IS_ERR(fs_devices)) {
5074 ret = PTR_ERR(fs_devices);
5075 goto out;
5076 }
5077
5078 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5079 root->fs_info->bdev_holder);
5080 if (ret) {
5081 free_fs_devices(fs_devices);
5082 goto out;
5083 }
5084
5085 if (!fs_devices->seeding) {
5086 __btrfs_close_devices(fs_devices);
5087 free_fs_devices(fs_devices);
5088 ret = -EINVAL;
5089 goto out;
5090 }
5091
5092 fs_devices->seed = root->fs_info->fs_devices->seed;
5093 root->fs_info->fs_devices->seed = fs_devices;
5094 out:
5095 return ret;
5096 }
5097
5098 static int read_one_dev(struct btrfs_root *root,
5099 struct extent_buffer *leaf,
5100 struct btrfs_dev_item *dev_item)
5101 {
5102 struct btrfs_device *device;
5103 u64 devid;
5104 int ret;
5105 u8 fs_uuid[BTRFS_UUID_SIZE];
5106 u8 dev_uuid[BTRFS_UUID_SIZE];
5107
5108 devid = btrfs_device_id(leaf, dev_item);
5109 read_extent_buffer(leaf, dev_uuid,
5110 (unsigned long)btrfs_device_uuid(dev_item),
5111 BTRFS_UUID_SIZE);
5112 read_extent_buffer(leaf, fs_uuid,
5113 (unsigned long)btrfs_device_fsid(dev_item),
5114 BTRFS_UUID_SIZE);
5115
5116 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5117 ret = open_seed_devices(root, fs_uuid);
5118 if (ret && !btrfs_test_opt(root, DEGRADED))
5119 return ret;
5120 }
5121
5122 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5123 if (!device || !device->bdev) {
5124 if (!btrfs_test_opt(root, DEGRADED))
5125 return -EIO;
5126
5127 if (!device) {
5128 printk(KERN_WARNING "warning devid %llu missing\n",
5129 (unsigned long long)devid);
5130 device = add_missing_dev(root, devid, dev_uuid);
5131 if (!device)
5132 return -ENOMEM;
5133 } else if (!device->missing) {
5134 /*
5135 * this happens when a device that was properly setup
5136 * in the device info lists suddenly goes bad.
5137 * device->bdev is NULL, and so we have to set
5138 * device->missing to one here
5139 */
5140 root->fs_info->fs_devices->missing_devices++;
5141 device->missing = 1;
5142 }
5143 }
5144
5145 if (device->fs_devices != root->fs_info->fs_devices) {
5146 BUG_ON(device->writeable);
5147 if (device->generation !=
5148 btrfs_device_generation(leaf, dev_item))
5149 return -EINVAL;
5150 }
5151
5152 fill_device_from_item(leaf, dev_item, device);
5153 device->dev_root = root->fs_info->dev_root;
5154 device->in_fs_metadata = 1;
5155 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5156 device->fs_devices->total_rw_bytes += device->total_bytes;
5157 spin_lock(&root->fs_info->free_chunk_lock);
5158 root->fs_info->free_chunk_space += device->total_bytes -
5159 device->bytes_used;
5160 spin_unlock(&root->fs_info->free_chunk_lock);
5161 }
5162 ret = 0;
5163 return ret;
5164 }
5165
5166 int btrfs_read_sys_array(struct btrfs_root *root)
5167 {
5168 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5169 struct extent_buffer *sb;
5170 struct btrfs_disk_key *disk_key;
5171 struct btrfs_chunk *chunk;
5172 u8 *ptr;
5173 unsigned long sb_ptr;
5174 int ret = 0;
5175 u32 num_stripes;
5176 u32 array_size;
5177 u32 len = 0;
5178 u32 cur;
5179 struct btrfs_key key;
5180
5181 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5182 BTRFS_SUPER_INFO_SIZE);
5183 if (!sb)
5184 return -ENOMEM;
5185 btrfs_set_buffer_uptodate(sb);
5186 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5187 /*
5188 * The sb extent buffer is artifical and just used to read the system array.
5189 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5190 * pages up-to-date when the page is larger: extent does not cover the
5191 * whole page and consequently check_page_uptodate does not find all
5192 * the page's extents up-to-date (the hole beyond sb),
5193 * write_extent_buffer then triggers a WARN_ON.
5194 *
5195 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5196 * but sb spans only this function. Add an explicit SetPageUptodate call
5197 * to silence the warning eg. on PowerPC 64.
5198 */
5199 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5200 SetPageUptodate(sb->pages[0]);
5201
5202 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5203 array_size = btrfs_super_sys_array_size(super_copy);
5204
5205 ptr = super_copy->sys_chunk_array;
5206 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5207 cur = 0;
5208
5209 while (cur < array_size) {
5210 disk_key = (struct btrfs_disk_key *)ptr;
5211 btrfs_disk_key_to_cpu(&key, disk_key);
5212
5213 len = sizeof(*disk_key); ptr += len;
5214 sb_ptr += len;
5215 cur += len;
5216
5217 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5218 chunk = (struct btrfs_chunk *)sb_ptr;
5219 ret = read_one_chunk(root, &key, sb, chunk);
5220 if (ret)
5221 break;
5222 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5223 len = btrfs_chunk_item_size(num_stripes);
5224 } else {
5225 ret = -EIO;
5226 break;
5227 }
5228 ptr += len;
5229 sb_ptr += len;
5230 cur += len;
5231 }
5232 free_extent_buffer(sb);
5233 return ret;
5234 }
5235
5236 int btrfs_read_chunk_tree(struct btrfs_root *root)
5237 {
5238 struct btrfs_path *path;
5239 struct extent_buffer *leaf;
5240 struct btrfs_key key;
5241 struct btrfs_key found_key;
5242 int ret;
5243 int slot;
5244
5245 root = root->fs_info->chunk_root;
5246
5247 path = btrfs_alloc_path();
5248 if (!path)
5249 return -ENOMEM;
5250
5251 mutex_lock(&uuid_mutex);
5252 lock_chunks(root);
5253
5254 /* first we search for all of the device items, and then we
5255 * read in all of the chunk items. This way we can create chunk
5256 * mappings that reference all of the devices that are afound
5257 */
5258 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5259 key.offset = 0;
5260 key.type = 0;
5261 again:
5262 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5263 if (ret < 0)
5264 goto error;
5265 while (1) {
5266 leaf = path->nodes[0];
5267 slot = path->slots[0];
5268 if (slot >= btrfs_header_nritems(leaf)) {
5269 ret = btrfs_next_leaf(root, path);
5270 if (ret == 0)
5271 continue;
5272 if (ret < 0)
5273 goto error;
5274 break;
5275 }
5276 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5277 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5278 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
5279 break;
5280 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
5281 struct btrfs_dev_item *dev_item;
5282 dev_item = btrfs_item_ptr(leaf, slot,
5283 struct btrfs_dev_item);
5284 ret = read_one_dev(root, leaf, dev_item);
5285 if (ret)
5286 goto error;
5287 }
5288 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
5289 struct btrfs_chunk *chunk;
5290 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
5291 ret = read_one_chunk(root, &found_key, leaf, chunk);
5292 if (ret)
5293 goto error;
5294 }
5295 path->slots[0]++;
5296 }
5297 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5298 key.objectid = 0;
5299 btrfs_release_path(path);
5300 goto again;
5301 }
5302 ret = 0;
5303 error:
5304 unlock_chunks(root);
5305 mutex_unlock(&uuid_mutex);
5306
5307 btrfs_free_path(path);
5308 return ret;
5309 }
5310
5311 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
5312 {
5313 int i;
5314
5315 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5316 btrfs_dev_stat_reset(dev, i);
5317 }
5318
5319 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
5320 {
5321 struct btrfs_key key;
5322 struct btrfs_key found_key;
5323 struct btrfs_root *dev_root = fs_info->dev_root;
5324 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5325 struct extent_buffer *eb;
5326 int slot;
5327 int ret = 0;
5328 struct btrfs_device *device;
5329 struct btrfs_path *path = NULL;
5330 int i;
5331
5332 path = btrfs_alloc_path();
5333 if (!path) {
5334 ret = -ENOMEM;
5335 goto out;
5336 }
5337
5338 mutex_lock(&fs_devices->device_list_mutex);
5339 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5340 int item_size;
5341 struct btrfs_dev_stats_item *ptr;
5342
5343 key.objectid = 0;
5344 key.type = BTRFS_DEV_STATS_KEY;
5345 key.offset = device->devid;
5346 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
5347 if (ret) {
5348 __btrfs_reset_dev_stats(device);
5349 device->dev_stats_valid = 1;
5350 btrfs_release_path(path);
5351 continue;
5352 }
5353 slot = path->slots[0];
5354 eb = path->nodes[0];
5355 btrfs_item_key_to_cpu(eb, &found_key, slot);
5356 item_size = btrfs_item_size_nr(eb, slot);
5357
5358 ptr = btrfs_item_ptr(eb, slot,
5359 struct btrfs_dev_stats_item);
5360
5361 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5362 if (item_size >= (1 + i) * sizeof(__le64))
5363 btrfs_dev_stat_set(device, i,
5364 btrfs_dev_stats_value(eb, ptr, i));
5365 else
5366 btrfs_dev_stat_reset(device, i);
5367 }
5368
5369 device->dev_stats_valid = 1;
5370 btrfs_dev_stat_print_on_load(device);
5371 btrfs_release_path(path);
5372 }
5373 mutex_unlock(&fs_devices->device_list_mutex);
5374
5375 out:
5376 btrfs_free_path(path);
5377 return ret < 0 ? ret : 0;
5378 }
5379
5380 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
5381 struct btrfs_root *dev_root,
5382 struct btrfs_device *device)
5383 {
5384 struct btrfs_path *path;
5385 struct btrfs_key key;
5386 struct extent_buffer *eb;
5387 struct btrfs_dev_stats_item *ptr;
5388 int ret;
5389 int i;
5390
5391 key.objectid = 0;
5392 key.type = BTRFS_DEV_STATS_KEY;
5393 key.offset = device->devid;
5394
5395 path = btrfs_alloc_path();
5396 BUG_ON(!path);
5397 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
5398 if (ret < 0) {
5399 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
5400 ret, rcu_str_deref(device->name));
5401 goto out;
5402 }
5403
5404 if (ret == 0 &&
5405 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
5406 /* need to delete old one and insert a new one */
5407 ret = btrfs_del_item(trans, dev_root, path);
5408 if (ret != 0) {
5409 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
5410 rcu_str_deref(device->name), ret);
5411 goto out;
5412 }
5413 ret = 1;
5414 }
5415
5416 if (ret == 1) {
5417 /* need to insert a new item */
5418 btrfs_release_path(path);
5419 ret = btrfs_insert_empty_item(trans, dev_root, path,
5420 &key, sizeof(*ptr));
5421 if (ret < 0) {
5422 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
5423 rcu_str_deref(device->name), ret);
5424 goto out;
5425 }
5426 }
5427
5428 eb = path->nodes[0];
5429 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
5430 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5431 btrfs_set_dev_stats_value(eb, ptr, i,
5432 btrfs_dev_stat_read(device, i));
5433 btrfs_mark_buffer_dirty(eb);
5434
5435 out:
5436 btrfs_free_path(path);
5437 return ret;
5438 }
5439
5440 /*
5441 * called from commit_transaction. Writes all changed device stats to disk.
5442 */
5443 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
5444 struct btrfs_fs_info *fs_info)
5445 {
5446 struct btrfs_root *dev_root = fs_info->dev_root;
5447 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5448 struct btrfs_device *device;
5449 int ret = 0;
5450
5451 mutex_lock(&fs_devices->device_list_mutex);
5452 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5453 if (!device->dev_stats_valid || !device->dev_stats_dirty)
5454 continue;
5455
5456 ret = update_dev_stat_item(trans, dev_root, device);
5457 if (!ret)
5458 device->dev_stats_dirty = 0;
5459 }
5460 mutex_unlock(&fs_devices->device_list_mutex);
5461
5462 return ret;
5463 }
5464
5465 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
5466 {
5467 btrfs_dev_stat_inc(dev, index);
5468 btrfs_dev_stat_print_on_error(dev);
5469 }
5470
5471 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
5472 {
5473 if (!dev->dev_stats_valid)
5474 return;
5475 printk_ratelimited_in_rcu(KERN_ERR
5476 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5477 rcu_str_deref(dev->name),
5478 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5479 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5480 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5481 btrfs_dev_stat_read(dev,
5482 BTRFS_DEV_STAT_CORRUPTION_ERRS),
5483 btrfs_dev_stat_read(dev,
5484 BTRFS_DEV_STAT_GENERATION_ERRS));
5485 }
5486
5487 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
5488 {
5489 int i;
5490
5491 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5492 if (btrfs_dev_stat_read(dev, i) != 0)
5493 break;
5494 if (i == BTRFS_DEV_STAT_VALUES_MAX)
5495 return; /* all values == 0, suppress message */
5496
5497 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5498 rcu_str_deref(dev->name),
5499 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5500 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5501 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5502 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
5503 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
5504 }
5505
5506 int btrfs_get_dev_stats(struct btrfs_root *root,
5507 struct btrfs_ioctl_get_dev_stats *stats)
5508 {
5509 struct btrfs_device *dev;
5510 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5511 int i;
5512
5513 mutex_lock(&fs_devices->device_list_mutex);
5514 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
5515 mutex_unlock(&fs_devices->device_list_mutex);
5516
5517 if (!dev) {
5518 printk(KERN_WARNING
5519 "btrfs: get dev_stats failed, device not found\n");
5520 return -ENODEV;
5521 } else if (!dev->dev_stats_valid) {
5522 printk(KERN_WARNING
5523 "btrfs: get dev_stats failed, not yet valid\n");
5524 return -ENODEV;
5525 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
5526 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5527 if (stats->nr_items > i)
5528 stats->values[i] =
5529 btrfs_dev_stat_read_and_reset(dev, i);
5530 else
5531 btrfs_dev_stat_reset(dev, i);
5532 }
5533 } else {
5534 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5535 if (stats->nr_items > i)
5536 stats->values[i] = btrfs_dev_stat_read(dev, i);
5537 }
5538 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
5539 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
5540 return 0;
5541 }
5542
5543 int btrfs_scratch_superblock(struct btrfs_device *device)
5544 {
5545 struct buffer_head *bh;
5546 struct btrfs_super_block *disk_super;
5547
5548 bh = btrfs_read_dev_super(device->bdev);
5549 if (!bh)
5550 return -EINVAL;
5551 disk_super = (struct btrfs_super_block *)bh->b_data;
5552
5553 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
5554 set_buffer_dirty(bh);
5555 sync_dirty_buffer(bh);
5556 brelse(bh);
5557
5558 return 0;
5559 }
kernel source for telekom puls (alcatel/mediatek)