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Linux 3.8-rc7
[cris-mirror.git] / fs / btrfs / volumes.c
blob5cbb7f4b16720fc3c3442ffb09752983195836a5
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 if (bdev)
1560 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1561
1562 error_brelse:
1563 brelse(bh);
1564 if (bdev)
1565 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1566 out:
1567 mutex_unlock(&uuid_mutex);
1568 return ret;
1569 error_undo:
1570 if (device->writeable) {
1571 lock_chunks(root);
1572 list_add(&device->dev_alloc_list,
1573 &root->fs_info->fs_devices->alloc_list);
1574 unlock_chunks(root);
1575 root->fs_info->fs_devices->rw_devices++;
1576 }
1577 goto error_brelse;
1578 }
1579
1580 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1581 struct btrfs_device *srcdev)
1582 {
1583 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1584 list_del_rcu(&srcdev->dev_list);
1585 list_del_rcu(&srcdev->dev_alloc_list);
1586 fs_info->fs_devices->num_devices--;
1587 if (srcdev->missing) {
1588 fs_info->fs_devices->missing_devices--;
1589 fs_info->fs_devices->rw_devices++;
1590 }
1591 if (srcdev->can_discard)
1592 fs_info->fs_devices->num_can_discard--;
1593 if (srcdev->bdev)
1594 fs_info->fs_devices->open_devices--;
1595
1596 call_rcu(&srcdev->rcu, free_device);
1597 }
1598
1599 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1600 struct btrfs_device *tgtdev)
1601 {
1602 struct btrfs_device *next_device;
1603
1604 WARN_ON(!tgtdev);
1605 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1606 if (tgtdev->bdev) {
1607 btrfs_scratch_superblock(tgtdev);
1608 fs_info->fs_devices->open_devices--;
1609 }
1610 fs_info->fs_devices->num_devices--;
1611 if (tgtdev->can_discard)
1612 fs_info->fs_devices->num_can_discard++;
1613
1614 next_device = list_entry(fs_info->fs_devices->devices.next,
1615 struct btrfs_device, dev_list);
1616 if (tgtdev->bdev == fs_info->sb->s_bdev)
1617 fs_info->sb->s_bdev = next_device->bdev;
1618 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1619 fs_info->fs_devices->latest_bdev = next_device->bdev;
1620 list_del_rcu(&tgtdev->dev_list);
1621
1622 call_rcu(&tgtdev->rcu, free_device);
1623
1624 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1625 }
1626
1627 int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1628 struct btrfs_device **device)
1629 {
1630 int ret = 0;
1631 struct btrfs_super_block *disk_super;
1632 u64 devid;
1633 u8 *dev_uuid;
1634 struct block_device *bdev;
1635 struct buffer_head *bh;
1636
1637 *device = NULL;
1638 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1639 root->fs_info->bdev_holder, 0, &bdev, &bh);
1640 if (ret)
1641 return ret;
1642 disk_super = (struct btrfs_super_block *)bh->b_data;
1643 devid = btrfs_stack_device_id(&disk_super->dev_item);
1644 dev_uuid = disk_super->dev_item.uuid;
1645 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1646 disk_super->fsid);
1647 brelse(bh);
1648 if (!*device)
1649 ret = -ENOENT;
1650 blkdev_put(bdev, FMODE_READ);
1651 return ret;
1652 }
1653
1654 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1655 char *device_path,
1656 struct btrfs_device **device)
1657 {
1658 *device = NULL;
1659 if (strcmp(device_path, "missing") == 0) {
1660 struct list_head *devices;
1661 struct btrfs_device *tmp;
1662
1663 devices = &root->fs_info->fs_devices->devices;
1664 /*
1665 * It is safe to read the devices since the volume_mutex
1666 * is held by the caller.
1667 */
1668 list_for_each_entry(tmp, devices, dev_list) {
1669 if (tmp->in_fs_metadata && !tmp->bdev) {
1670 *device = tmp;
1671 break;
1672 }
1673 }
1674
1675 if (!*device) {
1676 pr_err("btrfs: no missing device found\n");
1677 return -ENOENT;
1678 }
1679
1680 return 0;
1681 } else {
1682 return btrfs_find_device_by_path(root, device_path, device);
1683 }
1684 }
1685
1686 /*
1687 * does all the dirty work required for changing file system's UUID.
1688 */
1689 static int btrfs_prepare_sprout(struct btrfs_root *root)
1690 {
1691 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1692 struct btrfs_fs_devices *old_devices;
1693 struct btrfs_fs_devices *seed_devices;
1694 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1695 struct btrfs_device *device;
1696 u64 super_flags;
1697
1698 BUG_ON(!mutex_is_locked(&uuid_mutex));
1699 if (!fs_devices->seeding)
1700 return -EINVAL;
1701
1702 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1703 if (!seed_devices)
1704 return -ENOMEM;
1705
1706 old_devices = clone_fs_devices(fs_devices);
1707 if (IS_ERR(old_devices)) {
1708 kfree(seed_devices);
1709 return PTR_ERR(old_devices);
1710 }
1711
1712 list_add(&old_devices->list, &fs_uuids);
1713
1714 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1715 seed_devices->opened = 1;
1716 INIT_LIST_HEAD(&seed_devices->devices);
1717 INIT_LIST_HEAD(&seed_devices->alloc_list);
1718 mutex_init(&seed_devices->device_list_mutex);
1719
1720 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1721 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1722 synchronize_rcu);
1723 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1724
1725 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1726 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1727 device->fs_devices = seed_devices;
1728 }
1729
1730 fs_devices->seeding = 0;
1731 fs_devices->num_devices = 0;
1732 fs_devices->open_devices = 0;
1733 fs_devices->total_devices = 0;
1734 fs_devices->seed = seed_devices;
1735
1736 generate_random_uuid(fs_devices->fsid);
1737 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1738 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1739 super_flags = btrfs_super_flags(disk_super) &
1740 ~BTRFS_SUPER_FLAG_SEEDING;
1741 btrfs_set_super_flags(disk_super, super_flags);
1742
1743 return 0;
1744 }
1745
1746 /*
1747 * strore the expected generation for seed devices in device items.
1748 */
1749 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1750 struct btrfs_root *root)
1751 {
1752 struct btrfs_path *path;
1753 struct extent_buffer *leaf;
1754 struct btrfs_dev_item *dev_item;
1755 struct btrfs_device *device;
1756 struct btrfs_key key;
1757 u8 fs_uuid[BTRFS_UUID_SIZE];
1758 u8 dev_uuid[BTRFS_UUID_SIZE];
1759 u64 devid;
1760 int ret;
1761
1762 path = btrfs_alloc_path();
1763 if (!path)
1764 return -ENOMEM;
1765
1766 root = root->fs_info->chunk_root;
1767 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1768 key.offset = 0;
1769 key.type = BTRFS_DEV_ITEM_KEY;
1770
1771 while (1) {
1772 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1773 if (ret < 0)
1774 goto error;
1775
1776 leaf = path->nodes[0];
1777 next_slot:
1778 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1779 ret = btrfs_next_leaf(root, path);
1780 if (ret > 0)
1781 break;
1782 if (ret < 0)
1783 goto error;
1784 leaf = path->nodes[0];
1785 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1786 btrfs_release_path(path);
1787 continue;
1788 }
1789
1790 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1791 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1792 key.type != BTRFS_DEV_ITEM_KEY)
1793 break;
1794
1795 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1796 struct btrfs_dev_item);
1797 devid = btrfs_device_id(leaf, dev_item);
1798 read_extent_buffer(leaf, dev_uuid,
1799 (unsigned long)btrfs_device_uuid(dev_item),
1800 BTRFS_UUID_SIZE);
1801 read_extent_buffer(leaf, fs_uuid,
1802 (unsigned long)btrfs_device_fsid(dev_item),
1803 BTRFS_UUID_SIZE);
1804 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1805 fs_uuid);
1806 BUG_ON(!device); /* Logic error */
1807
1808 if (device->fs_devices->seeding) {
1809 btrfs_set_device_generation(leaf, dev_item,
1810 device->generation);
1811 btrfs_mark_buffer_dirty(leaf);
1812 }
1813
1814 path->slots[0]++;
1815 goto next_slot;
1816 }
1817 ret = 0;
1818 error:
1819 btrfs_free_path(path);
1820 return ret;
1821 }
1822
1823 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1824 {
1825 struct request_queue *q;
1826 struct btrfs_trans_handle *trans;
1827 struct btrfs_device *device;
1828 struct block_device *bdev;
1829 struct list_head *devices;
1830 struct super_block *sb = root->fs_info->sb;
1831 struct rcu_string *name;
1832 u64 total_bytes;
1833 int seeding_dev = 0;
1834 int ret = 0;
1835
1836 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1837 return -EROFS;
1838
1839 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1840 root->fs_info->bdev_holder);
1841 if (IS_ERR(bdev))
1842 return PTR_ERR(bdev);
1843
1844 if (root->fs_info->fs_devices->seeding) {
1845 seeding_dev = 1;
1846 down_write(&sb->s_umount);
1847 mutex_lock(&uuid_mutex);
1848 }
1849
1850 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1851
1852 devices = &root->fs_info->fs_devices->devices;
1853
1854 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1855 list_for_each_entry(device, devices, dev_list) {
1856 if (device->bdev == bdev) {
1857 ret = -EEXIST;
1858 mutex_unlock(
1859 &root->fs_info->fs_devices->device_list_mutex);
1860 goto error;
1861 }
1862 }
1863 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1864
1865 device = kzalloc(sizeof(*device), GFP_NOFS);
1866 if (!device) {
1867 /* we can safely leave the fs_devices entry around */
1868 ret = -ENOMEM;
1869 goto error;
1870 }
1871
1872 name = rcu_string_strdup(device_path, GFP_NOFS);
1873 if (!name) {
1874 kfree(device);
1875 ret = -ENOMEM;
1876 goto error;
1877 }
1878 rcu_assign_pointer(device->name, name);
1879
1880 ret = find_next_devid(root, &device->devid);
1881 if (ret) {
1882 rcu_string_free(device->name);
1883 kfree(device);
1884 goto error;
1885 }
1886
1887 trans = btrfs_start_transaction(root, 0);
1888 if (IS_ERR(trans)) {
1889 rcu_string_free(device->name);
1890 kfree(device);
1891 ret = PTR_ERR(trans);
1892 goto error;
1893 }
1894
1895 lock_chunks(root);
1896
1897 q = bdev_get_queue(bdev);
1898 if (blk_queue_discard(q))
1899 device->can_discard = 1;
1900 device->writeable = 1;
1901 device->work.func = pending_bios_fn;
1902 generate_random_uuid(device->uuid);
1903 spin_lock_init(&device->io_lock);
1904 device->generation = trans->transid;
1905 device->io_width = root->sectorsize;
1906 device->io_align = root->sectorsize;
1907 device->sector_size = root->sectorsize;
1908 device->total_bytes = i_size_read(bdev->bd_inode);
1909 device->disk_total_bytes = device->total_bytes;
1910 device->dev_root = root->fs_info->dev_root;
1911 device->bdev = bdev;
1912 device->in_fs_metadata = 1;
1913 device->is_tgtdev_for_dev_replace = 0;
1914 device->mode = FMODE_EXCL;
1915 set_blocksize(device->bdev, 4096);
1916
1917 if (seeding_dev) {
1918 sb->s_flags &= ~MS_RDONLY;
1919 ret = btrfs_prepare_sprout(root);
1920 BUG_ON(ret); /* -ENOMEM */
1921 }
1922
1923 device->fs_devices = root->fs_info->fs_devices;
1924
1925 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1926 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1927 list_add(&device->dev_alloc_list,
1928 &root->fs_info->fs_devices->alloc_list);
1929 root->fs_info->fs_devices->num_devices++;
1930 root->fs_info->fs_devices->open_devices++;
1931 root->fs_info->fs_devices->rw_devices++;
1932 root->fs_info->fs_devices->total_devices++;
1933 if (device->can_discard)
1934 root->fs_info->fs_devices->num_can_discard++;
1935 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1936
1937 spin_lock(&root->fs_info->free_chunk_lock);
1938 root->fs_info->free_chunk_space += device->total_bytes;
1939 spin_unlock(&root->fs_info->free_chunk_lock);
1940
1941 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1942 root->fs_info->fs_devices->rotating = 1;
1943
1944 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
1945 btrfs_set_super_total_bytes(root->fs_info->super_copy,
1946 total_bytes + device->total_bytes);
1947
1948 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
1949 btrfs_set_super_num_devices(root->fs_info->super_copy,
1950 total_bytes + 1);
1951 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1952
1953 if (seeding_dev) {
1954 ret = init_first_rw_device(trans, root, device);
1955 if (ret) {
1956 btrfs_abort_transaction(trans, root, ret);
1957 goto error_trans;
1958 }
1959 ret = btrfs_finish_sprout(trans, root);
1960 if (ret) {
1961 btrfs_abort_transaction(trans, root, ret);
1962 goto error_trans;
1963 }
1964 } else {
1965 ret = btrfs_add_device(trans, root, device);
1966 if (ret) {
1967 btrfs_abort_transaction(trans, root, ret);
1968 goto error_trans;
1969 }
1970 }
1971
1972 /*
1973 * we've got more storage, clear any full flags on the space
1974 * infos
1975 */
1976 btrfs_clear_space_info_full(root->fs_info);
1977
1978 unlock_chunks(root);
1979 root->fs_info->num_tolerated_disk_barrier_failures =
1980 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1981 ret = btrfs_commit_transaction(trans, root);
1982
1983 if (seeding_dev) {
1984 mutex_unlock(&uuid_mutex);
1985 up_write(&sb->s_umount);
1986
1987 if (ret) /* transaction commit */
1988 return ret;
1989
1990 ret = btrfs_relocate_sys_chunks(root);
1991 if (ret < 0)
1992 btrfs_error(root->fs_info, ret,
1993 "Failed to relocate sys chunks after "
1994 "device initialization. This can be fixed "
1995 "using the \"btrfs balance\" command.");
1996 trans = btrfs_attach_transaction(root);
1997 if (IS_ERR(trans)) {
1998 if (PTR_ERR(trans) == -ENOENT)
1999 return 0;
2000 return PTR_ERR(trans);
2001 }
2002 ret = btrfs_commit_transaction(trans, root);
2003 }
2004
2005 return ret;
2006
2007 error_trans:
2008 unlock_chunks(root);
2009 btrfs_end_transaction(trans, root);
2010 rcu_string_free(device->name);
2011 kfree(device);
2012 error:
2013 blkdev_put(bdev, FMODE_EXCL);
2014 if (seeding_dev) {
2015 mutex_unlock(&uuid_mutex);
2016 up_write(&sb->s_umount);
2017 }
2018 return ret;
2019 }
2020
2021 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2022 struct btrfs_device **device_out)
2023 {
2024 struct request_queue *q;
2025 struct btrfs_device *device;
2026 struct block_device *bdev;
2027 struct btrfs_fs_info *fs_info = root->fs_info;
2028 struct list_head *devices;
2029 struct rcu_string *name;
2030 int ret = 0;
2031
2032 *device_out = NULL;
2033 if (fs_info->fs_devices->seeding)
2034 return -EINVAL;
2035
2036 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2037 fs_info->bdev_holder);
2038 if (IS_ERR(bdev))
2039 return PTR_ERR(bdev);
2040
2041 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2042
2043 devices = &fs_info->fs_devices->devices;
2044 list_for_each_entry(device, devices, dev_list) {
2045 if (device->bdev == bdev) {
2046 ret = -EEXIST;
2047 goto error;
2048 }
2049 }
2050
2051 device = kzalloc(sizeof(*device), GFP_NOFS);
2052 if (!device) {
2053 ret = -ENOMEM;
2054 goto error;
2055 }
2056
2057 name = rcu_string_strdup(device_path, GFP_NOFS);
2058 if (!name) {
2059 kfree(device);
2060 ret = -ENOMEM;
2061 goto error;
2062 }
2063 rcu_assign_pointer(device->name, name);
2064
2065 q = bdev_get_queue(bdev);
2066 if (blk_queue_discard(q))
2067 device->can_discard = 1;
2068 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2069 device->writeable = 1;
2070 device->work.func = pending_bios_fn;
2071 generate_random_uuid(device->uuid);
2072 device->devid = BTRFS_DEV_REPLACE_DEVID;
2073 spin_lock_init(&device->io_lock);
2074 device->generation = 0;
2075 device->io_width = root->sectorsize;
2076 device->io_align = root->sectorsize;
2077 device->sector_size = root->sectorsize;
2078 device->total_bytes = i_size_read(bdev->bd_inode);
2079 device->disk_total_bytes = device->total_bytes;
2080 device->dev_root = fs_info->dev_root;
2081 device->bdev = bdev;
2082 device->in_fs_metadata = 1;
2083 device->is_tgtdev_for_dev_replace = 1;
2084 device->mode = FMODE_EXCL;
2085 set_blocksize(device->bdev, 4096);
2086 device->fs_devices = fs_info->fs_devices;
2087 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2088 fs_info->fs_devices->num_devices++;
2089 fs_info->fs_devices->open_devices++;
2090 if (device->can_discard)
2091 fs_info->fs_devices->num_can_discard++;
2092 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2093
2094 *device_out = device;
2095 return ret;
2096
2097 error:
2098 blkdev_put(bdev, FMODE_EXCL);
2099 return ret;
2100 }
2101
2102 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2103 struct btrfs_device *tgtdev)
2104 {
2105 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2106 tgtdev->io_width = fs_info->dev_root->sectorsize;
2107 tgtdev->io_align = fs_info->dev_root->sectorsize;
2108 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2109 tgtdev->dev_root = fs_info->dev_root;
2110 tgtdev->in_fs_metadata = 1;
2111 }
2112
2113 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2114 struct btrfs_device *device)
2115 {
2116 int ret;
2117 struct btrfs_path *path;
2118 struct btrfs_root *root;
2119 struct btrfs_dev_item *dev_item;
2120 struct extent_buffer *leaf;
2121 struct btrfs_key key;
2122
2123 root = device->dev_root->fs_info->chunk_root;
2124
2125 path = btrfs_alloc_path();
2126 if (!path)
2127 return -ENOMEM;
2128
2129 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2130 key.type = BTRFS_DEV_ITEM_KEY;
2131 key.offset = device->devid;
2132
2133 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2134 if (ret < 0)
2135 goto out;
2136
2137 if (ret > 0) {
2138 ret = -ENOENT;
2139 goto out;
2140 }
2141
2142 leaf = path->nodes[0];
2143 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2144
2145 btrfs_set_device_id(leaf, dev_item, device->devid);
2146 btrfs_set_device_type(leaf, dev_item, device->type);
2147 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2148 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2149 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2150 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2151 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2152 btrfs_mark_buffer_dirty(leaf);
2153
2154 out:
2155 btrfs_free_path(path);
2156 return ret;
2157 }
2158
2159 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2160 struct btrfs_device *device, u64 new_size)
2161 {
2162 struct btrfs_super_block *super_copy =
2163 device->dev_root->fs_info->super_copy;
2164 u64 old_total = btrfs_super_total_bytes(super_copy);
2165 u64 diff = new_size - device->total_bytes;
2166
2167 if (!device->writeable)
2168 return -EACCES;
2169 if (new_size <= device->total_bytes ||
2170 device->is_tgtdev_for_dev_replace)
2171 return -EINVAL;
2172
2173 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2174 device->fs_devices->total_rw_bytes += diff;
2175
2176 device->total_bytes = new_size;
2177 device->disk_total_bytes = new_size;
2178 btrfs_clear_space_info_full(device->dev_root->fs_info);
2179
2180 return btrfs_update_device(trans, device);
2181 }
2182
2183 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2184 struct btrfs_device *device, u64 new_size)
2185 {
2186 int ret;
2187 lock_chunks(device->dev_root);
2188 ret = __btrfs_grow_device(trans, device, new_size);
2189 unlock_chunks(device->dev_root);
2190 return ret;
2191 }
2192
2193 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2194 struct btrfs_root *root,
2195 u64 chunk_tree, u64 chunk_objectid,
2196 u64 chunk_offset)
2197 {
2198 int ret;
2199 struct btrfs_path *path;
2200 struct btrfs_key key;
2201
2202 root = root->fs_info->chunk_root;
2203 path = btrfs_alloc_path();
2204 if (!path)
2205 return -ENOMEM;
2206
2207 key.objectid = chunk_objectid;
2208 key.offset = chunk_offset;
2209 key.type = BTRFS_CHUNK_ITEM_KEY;
2210
2211 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2212 if (ret < 0)
2213 goto out;
2214 else if (ret > 0) { /* Logic error or corruption */
2215 btrfs_error(root->fs_info, -ENOENT,
2216 "Failed lookup while freeing chunk.");
2217 ret = -ENOENT;
2218 goto out;
2219 }
2220
2221 ret = btrfs_del_item(trans, root, path);
2222 if (ret < 0)
2223 btrfs_error(root->fs_info, ret,
2224 "Failed to delete chunk item.");
2225 out:
2226 btrfs_free_path(path);
2227 return ret;
2228 }
2229
2230 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2231 chunk_offset)
2232 {
2233 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2234 struct btrfs_disk_key *disk_key;
2235 struct btrfs_chunk *chunk;
2236 u8 *ptr;
2237 int ret = 0;
2238 u32 num_stripes;
2239 u32 array_size;
2240 u32 len = 0;
2241 u32 cur;
2242 struct btrfs_key key;
2243
2244 array_size = btrfs_super_sys_array_size(super_copy);
2245
2246 ptr = super_copy->sys_chunk_array;
2247 cur = 0;
2248
2249 while (cur < array_size) {
2250 disk_key = (struct btrfs_disk_key *)ptr;
2251 btrfs_disk_key_to_cpu(&key, disk_key);
2252
2253 len = sizeof(*disk_key);
2254
2255 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2256 chunk = (struct btrfs_chunk *)(ptr + len);
2257 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2258 len += btrfs_chunk_item_size(num_stripes);
2259 } else {
2260 ret = -EIO;
2261 break;
2262 }
2263 if (key.objectid == chunk_objectid &&
2264 key.offset == chunk_offset) {
2265 memmove(ptr, ptr + len, array_size - (cur + len));
2266 array_size -= len;
2267 btrfs_set_super_sys_array_size(super_copy, array_size);
2268 } else {
2269 ptr += len;
2270 cur += len;
2271 }
2272 }
2273 return ret;
2274 }
2275
2276 static int btrfs_relocate_chunk(struct btrfs_root *root,
2277 u64 chunk_tree, u64 chunk_objectid,
2278 u64 chunk_offset)
2279 {
2280 struct extent_map_tree *em_tree;
2281 struct btrfs_root *extent_root;
2282 struct btrfs_trans_handle *trans;
2283 struct extent_map *em;
2284 struct map_lookup *map;
2285 int ret;
2286 int i;
2287
2288 root = root->fs_info->chunk_root;
2289 extent_root = root->fs_info->extent_root;
2290 em_tree = &root->fs_info->mapping_tree.map_tree;
2291
2292 ret = btrfs_can_relocate(extent_root, chunk_offset);
2293 if (ret)
2294 return -ENOSPC;
2295
2296 /* step one, relocate all the extents inside this chunk */
2297 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2298 if (ret)
2299 return ret;
2300
2301 trans = btrfs_start_transaction(root, 0);
2302 BUG_ON(IS_ERR(trans));
2303
2304 lock_chunks(root);
2305
2306 /*
2307 * step two, delete the device extents and the
2308 * chunk tree entries
2309 */
2310 read_lock(&em_tree->lock);
2311 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2312 read_unlock(&em_tree->lock);
2313
2314 BUG_ON(!em || em->start > chunk_offset ||
2315 em->start + em->len < chunk_offset);
2316 map = (struct map_lookup *)em->bdev;
2317
2318 for (i = 0; i < map->num_stripes; i++) {
2319 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2320 map->stripes[i].physical);
2321 BUG_ON(ret);
2322
2323 if (map->stripes[i].dev) {
2324 ret = btrfs_update_device(trans, map->stripes[i].dev);
2325 BUG_ON(ret);
2326 }
2327 }
2328 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2329 chunk_offset);
2330
2331 BUG_ON(ret);
2332
2333 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2334
2335 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2336 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2337 BUG_ON(ret);
2338 }
2339
2340 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2341 BUG_ON(ret);
2342
2343 write_lock(&em_tree->lock);
2344 remove_extent_mapping(em_tree, em);
2345 write_unlock(&em_tree->lock);
2346
2347 kfree(map);
2348 em->bdev = NULL;
2349
2350 /* once for the tree */
2351 free_extent_map(em);
2352 /* once for us */
2353 free_extent_map(em);
2354
2355 unlock_chunks(root);
2356 btrfs_end_transaction(trans, root);
2357 return 0;
2358 }
2359
2360 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2361 {
2362 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2363 struct btrfs_path *path;
2364 struct extent_buffer *leaf;
2365 struct btrfs_chunk *chunk;
2366 struct btrfs_key key;
2367 struct btrfs_key found_key;
2368 u64 chunk_tree = chunk_root->root_key.objectid;
2369 u64 chunk_type;
2370 bool retried = false;
2371 int failed = 0;
2372 int ret;
2373
2374 path = btrfs_alloc_path();
2375 if (!path)
2376 return -ENOMEM;
2377
2378 again:
2379 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2380 key.offset = (u64)-1;
2381 key.type = BTRFS_CHUNK_ITEM_KEY;
2382
2383 while (1) {
2384 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2385 if (ret < 0)
2386 goto error;
2387 BUG_ON(ret == 0); /* Corruption */
2388
2389 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2390 key.type);
2391 if (ret < 0)
2392 goto error;
2393 if (ret > 0)
2394 break;
2395
2396 leaf = path->nodes[0];
2397 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2398
2399 chunk = btrfs_item_ptr(leaf, path->slots[0],
2400 struct btrfs_chunk);
2401 chunk_type = btrfs_chunk_type(leaf, chunk);
2402 btrfs_release_path(path);
2403
2404 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2405 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2406 found_key.objectid,
2407 found_key.offset);
2408 if (ret == -ENOSPC)
2409 failed++;
2410 else if (ret)
2411 BUG();
2412 }
2413
2414 if (found_key.offset == 0)
2415 break;
2416 key.offset = found_key.offset - 1;
2417 }
2418 ret = 0;
2419 if (failed && !retried) {
2420 failed = 0;
2421 retried = true;
2422 goto again;
2423 } else if (failed && retried) {
2424 WARN_ON(1);
2425 ret = -ENOSPC;
2426 }
2427 error:
2428 btrfs_free_path(path);
2429 return ret;
2430 }
2431
2432 static int insert_balance_item(struct btrfs_root *root,
2433 struct btrfs_balance_control *bctl)
2434 {
2435 struct btrfs_trans_handle *trans;
2436 struct btrfs_balance_item *item;
2437 struct btrfs_disk_balance_args disk_bargs;
2438 struct btrfs_path *path;
2439 struct extent_buffer *leaf;
2440 struct btrfs_key key;
2441 int ret, err;
2442
2443 path = btrfs_alloc_path();
2444 if (!path)
2445 return -ENOMEM;
2446
2447 trans = btrfs_start_transaction(root, 0);
2448 if (IS_ERR(trans)) {
2449 btrfs_free_path(path);
2450 return PTR_ERR(trans);
2451 }
2452
2453 key.objectid = BTRFS_BALANCE_OBJECTID;
2454 key.type = BTRFS_BALANCE_ITEM_KEY;
2455 key.offset = 0;
2456
2457 ret = btrfs_insert_empty_item(trans, root, path, &key,
2458 sizeof(*item));
2459 if (ret)
2460 goto out;
2461
2462 leaf = path->nodes[0];
2463 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2464
2465 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2466
2467 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2468 btrfs_set_balance_data(leaf, item, &disk_bargs);
2469 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2470 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2471 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2472 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2473
2474 btrfs_set_balance_flags(leaf, item, bctl->flags);
2475
2476 btrfs_mark_buffer_dirty(leaf);
2477 out:
2478 btrfs_free_path(path);
2479 err = btrfs_commit_transaction(trans, root);
2480 if (err && !ret)
2481 ret = err;
2482 return ret;
2483 }
2484
2485 static int del_balance_item(struct btrfs_root *root)
2486 {
2487 struct btrfs_trans_handle *trans;
2488 struct btrfs_path *path;
2489 struct btrfs_key key;
2490 int ret, err;
2491
2492 path = btrfs_alloc_path();
2493 if (!path)
2494 return -ENOMEM;
2495
2496 trans = btrfs_start_transaction(root, 0);
2497 if (IS_ERR(trans)) {
2498 btrfs_free_path(path);
2499 return PTR_ERR(trans);
2500 }
2501
2502 key.objectid = BTRFS_BALANCE_OBJECTID;
2503 key.type = BTRFS_BALANCE_ITEM_KEY;
2504 key.offset = 0;
2505
2506 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2507 if (ret < 0)
2508 goto out;
2509 if (ret > 0) {
2510 ret = -ENOENT;
2511 goto out;
2512 }
2513
2514 ret = btrfs_del_item(trans, root, path);
2515 out:
2516 btrfs_free_path(path);
2517 err = btrfs_commit_transaction(trans, root);
2518 if (err && !ret)
2519 ret = err;
2520 return ret;
2521 }
2522
2523 /*
2524 * This is a heuristic used to reduce the number of chunks balanced on
2525 * resume after balance was interrupted.
2526 */
2527 static void update_balance_args(struct btrfs_balance_control *bctl)
2528 {
2529 /*
2530 * Turn on soft mode for chunk types that were being converted.
2531 */
2532 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2533 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2534 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2535 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2536 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2537 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2538
2539 /*
2540 * Turn on usage filter if is not already used. The idea is
2541 * that chunks that we have already balanced should be
2542 * reasonably full. Don't do it for chunks that are being
2543 * converted - that will keep us from relocating unconverted
2544 * (albeit full) chunks.
2545 */
2546 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2547 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2548 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2549 bctl->data.usage = 90;
2550 }
2551 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2552 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2553 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2554 bctl->sys.usage = 90;
2555 }
2556 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2557 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2558 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2559 bctl->meta.usage = 90;
2560 }
2561 }
2562
2563 /*
2564 * Should be called with both balance and volume mutexes held to
2565 * serialize other volume operations (add_dev/rm_dev/resize) with
2566 * restriper. Same goes for unset_balance_control.
2567 */
2568 static void set_balance_control(struct btrfs_balance_control *bctl)
2569 {
2570 struct btrfs_fs_info *fs_info = bctl->fs_info;
2571
2572 BUG_ON(fs_info->balance_ctl);
2573
2574 spin_lock(&fs_info->balance_lock);
2575 fs_info->balance_ctl = bctl;
2576 spin_unlock(&fs_info->balance_lock);
2577 }
2578
2579 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2580 {
2581 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2582
2583 BUG_ON(!fs_info->balance_ctl);
2584
2585 spin_lock(&fs_info->balance_lock);
2586 fs_info->balance_ctl = NULL;
2587 spin_unlock(&fs_info->balance_lock);
2588
2589 kfree(bctl);
2590 }
2591
2592 /*
2593 * Balance filters. Return 1 if chunk should be filtered out
2594 * (should not be balanced).
2595 */
2596 static int chunk_profiles_filter(u64 chunk_type,
2597 struct btrfs_balance_args *bargs)
2598 {
2599 chunk_type = chunk_to_extended(chunk_type) &
2600 BTRFS_EXTENDED_PROFILE_MASK;
2601
2602 if (bargs->profiles & chunk_type)
2603 return 0;
2604
2605 return 1;
2606 }
2607
2608 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2609 struct btrfs_balance_args *bargs)
2610 {
2611 struct btrfs_block_group_cache *cache;
2612 u64 chunk_used, user_thresh;
2613 int ret = 1;
2614
2615 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2616 chunk_used = btrfs_block_group_used(&cache->item);
2617
2618 if (bargs->usage == 0)
2619 user_thresh = 0;
2620 else if (bargs->usage > 100)
2621 user_thresh = cache->key.offset;
2622 else
2623 user_thresh = div_factor_fine(cache->key.offset,
2624 bargs->usage);
2625
2626 if (chunk_used < user_thresh)
2627 ret = 0;
2628
2629 btrfs_put_block_group(cache);
2630 return ret;
2631 }
2632
2633 static int chunk_devid_filter(struct extent_buffer *leaf,
2634 struct btrfs_chunk *chunk,
2635 struct btrfs_balance_args *bargs)
2636 {
2637 struct btrfs_stripe *stripe;
2638 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2639 int i;
2640
2641 for (i = 0; i < num_stripes; i++) {
2642 stripe = btrfs_stripe_nr(chunk, i);
2643 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2644 return 0;
2645 }
2646
2647 return 1;
2648 }
2649
2650 /* [pstart, pend) */
2651 static int chunk_drange_filter(struct extent_buffer *leaf,
2652 struct btrfs_chunk *chunk,
2653 u64 chunk_offset,
2654 struct btrfs_balance_args *bargs)
2655 {
2656 struct btrfs_stripe *stripe;
2657 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2658 u64 stripe_offset;
2659 u64 stripe_length;
2660 int factor;
2661 int i;
2662
2663 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2664 return 0;
2665
2666 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2667 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))
2668 factor = 2;
2669 else
2670 factor = 1;
2671 factor = num_stripes / factor;
2672
2673 for (i = 0; i < num_stripes; i++) {
2674 stripe = btrfs_stripe_nr(chunk, i);
2675 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2676 continue;
2677
2678 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2679 stripe_length = btrfs_chunk_length(leaf, chunk);
2680 do_div(stripe_length, factor);
2681
2682 if (stripe_offset < bargs->pend &&
2683 stripe_offset + stripe_length > bargs->pstart)
2684 return 0;
2685 }
2686
2687 return 1;
2688 }
2689
2690 /* [vstart, vend) */
2691 static int chunk_vrange_filter(struct extent_buffer *leaf,
2692 struct btrfs_chunk *chunk,
2693 u64 chunk_offset,
2694 struct btrfs_balance_args *bargs)
2695 {
2696 if (chunk_offset < bargs->vend &&
2697 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2698 /* at least part of the chunk is inside this vrange */
2699 return 0;
2700
2701 return 1;
2702 }
2703
2704 static int chunk_soft_convert_filter(u64 chunk_type,
2705 struct btrfs_balance_args *bargs)
2706 {
2707 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2708 return 0;
2709
2710 chunk_type = chunk_to_extended(chunk_type) &
2711 BTRFS_EXTENDED_PROFILE_MASK;
2712
2713 if (bargs->target == chunk_type)
2714 return 1;
2715
2716 return 0;
2717 }
2718
2719 static int should_balance_chunk(struct btrfs_root *root,
2720 struct extent_buffer *leaf,
2721 struct btrfs_chunk *chunk, u64 chunk_offset)
2722 {
2723 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2724 struct btrfs_balance_args *bargs = NULL;
2725 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2726
2727 /* type filter */
2728 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2729 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2730 return 0;
2731 }
2732
2733 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2734 bargs = &bctl->data;
2735 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2736 bargs = &bctl->sys;
2737 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2738 bargs = &bctl->meta;
2739
2740 /* profiles filter */
2741 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2742 chunk_profiles_filter(chunk_type, bargs)) {
2743 return 0;
2744 }
2745
2746 /* usage filter */
2747 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2748 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2749 return 0;
2750 }
2751
2752 /* devid filter */
2753 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2754 chunk_devid_filter(leaf, chunk, bargs)) {
2755 return 0;
2756 }
2757
2758 /* drange filter, makes sense only with devid filter */
2759 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2760 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2761 return 0;
2762 }
2763
2764 /* vrange filter */
2765 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2766 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2767 return 0;
2768 }
2769
2770 /* soft profile changing mode */
2771 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2772 chunk_soft_convert_filter(chunk_type, bargs)) {
2773 return 0;
2774 }
2775
2776 return 1;
2777 }
2778
2779 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2780 {
2781 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2782 struct btrfs_root *chunk_root = fs_info->chunk_root;
2783 struct btrfs_root *dev_root = fs_info->dev_root;
2784 struct list_head *devices;
2785 struct btrfs_device *device;
2786 u64 old_size;
2787 u64 size_to_free;
2788 struct btrfs_chunk *chunk;
2789 struct btrfs_path *path;
2790 struct btrfs_key key;
2791 struct btrfs_key found_key;
2792 struct btrfs_trans_handle *trans;
2793 struct extent_buffer *leaf;
2794 int slot;
2795 int ret;
2796 int enospc_errors = 0;
2797 bool counting = true;
2798
2799 /* step one make some room on all the devices */
2800 devices = &fs_info->fs_devices->devices;
2801 list_for_each_entry(device, devices, dev_list) {
2802 old_size = device->total_bytes;
2803 size_to_free = div_factor(old_size, 1);
2804 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2805 if (!device->writeable ||
2806 device->total_bytes - device->bytes_used > size_to_free ||
2807 device->is_tgtdev_for_dev_replace)
2808 continue;
2809
2810 ret = btrfs_shrink_device(device, old_size - size_to_free);
2811 if (ret == -ENOSPC)
2812 break;
2813 BUG_ON(ret);
2814
2815 trans = btrfs_start_transaction(dev_root, 0);
2816 BUG_ON(IS_ERR(trans));
2817
2818 ret = btrfs_grow_device(trans, device, old_size);
2819 BUG_ON(ret);
2820
2821 btrfs_end_transaction(trans, dev_root);
2822 }
2823
2824 /* step two, relocate all the chunks */
2825 path = btrfs_alloc_path();
2826 if (!path) {
2827 ret = -ENOMEM;
2828 goto error;
2829 }
2830
2831 /* zero out stat counters */
2832 spin_lock(&fs_info->balance_lock);
2833 memset(&bctl->stat, 0, sizeof(bctl->stat));
2834 spin_unlock(&fs_info->balance_lock);
2835 again:
2836 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2837 key.offset = (u64)-1;
2838 key.type = BTRFS_CHUNK_ITEM_KEY;
2839
2840 while (1) {
2841 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2842 atomic_read(&fs_info->balance_cancel_req)) {
2843 ret = -ECANCELED;
2844 goto error;
2845 }
2846
2847 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2848 if (ret < 0)
2849 goto error;
2850
2851 /*
2852 * this shouldn't happen, it means the last relocate
2853 * failed
2854 */
2855 if (ret == 0)
2856 BUG(); /* FIXME break ? */
2857
2858 ret = btrfs_previous_item(chunk_root, path, 0,
2859 BTRFS_CHUNK_ITEM_KEY);
2860 if (ret) {
2861 ret = 0;
2862 break;
2863 }
2864
2865 leaf = path->nodes[0];
2866 slot = path->slots[0];
2867 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2868
2869 if (found_key.objectid != key.objectid)
2870 break;
2871
2872 /* chunk zero is special */
2873 if (found_key.offset == 0)
2874 break;
2875
2876 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2877
2878 if (!counting) {
2879 spin_lock(&fs_info->balance_lock);
2880 bctl->stat.considered++;
2881 spin_unlock(&fs_info->balance_lock);
2882 }
2883
2884 ret = should_balance_chunk(chunk_root, leaf, chunk,
2885 found_key.offset);
2886 btrfs_release_path(path);
2887 if (!ret)
2888 goto loop;
2889
2890 if (counting) {
2891 spin_lock(&fs_info->balance_lock);
2892 bctl->stat.expected++;
2893 spin_unlock(&fs_info->balance_lock);
2894 goto loop;
2895 }
2896
2897 ret = btrfs_relocate_chunk(chunk_root,
2898 chunk_root->root_key.objectid,
2899 found_key.objectid,
2900 found_key.offset);
2901 if (ret && ret != -ENOSPC)
2902 goto error;
2903 if (ret == -ENOSPC) {
2904 enospc_errors++;
2905 } else {
2906 spin_lock(&fs_info->balance_lock);
2907 bctl->stat.completed++;
2908 spin_unlock(&fs_info->balance_lock);
2909 }
2910 loop:
2911 key.offset = found_key.offset - 1;
2912 }
2913
2914 if (counting) {
2915 btrfs_release_path(path);
2916 counting = false;
2917 goto again;
2918 }
2919 error:
2920 btrfs_free_path(path);
2921 if (enospc_errors) {
2922 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
2923 enospc_errors);
2924 if (!ret)
2925 ret = -ENOSPC;
2926 }
2927
2928 return ret;
2929 }
2930
2931 /**
2932 * alloc_profile_is_valid - see if a given profile is valid and reduced
2933 * @flags: profile to validate
2934 * @extended: if true @flags is treated as an extended profile
2935 */
2936 static int alloc_profile_is_valid(u64 flags, int extended)
2937 {
2938 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
2939 BTRFS_BLOCK_GROUP_PROFILE_MASK);
2940
2941 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
2942
2943 /* 1) check that all other bits are zeroed */
2944 if (flags & ~mask)
2945 return 0;
2946
2947 /* 2) see if profile is reduced */
2948 if (flags == 0)
2949 return !extended; /* "0" is valid for usual profiles */
2950
2951 /* true if exactly one bit set */
2952 return (flags & (flags - 1)) == 0;
2953 }
2954
2955 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
2956 {
2957 /* cancel requested || normal exit path */
2958 return atomic_read(&fs_info->balance_cancel_req) ||
2959 (atomic_read(&fs_info->balance_pause_req) == 0 &&
2960 atomic_read(&fs_info->balance_cancel_req) == 0);
2961 }
2962
2963 static void __cancel_balance(struct btrfs_fs_info *fs_info)
2964 {
2965 int ret;
2966
2967 unset_balance_control(fs_info);
2968 ret = del_balance_item(fs_info->tree_root);
2969 BUG_ON(ret);
2970
2971 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
2972 }
2973
2974 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
2975 struct btrfs_ioctl_balance_args *bargs);
2976
2977 /*
2978 * Should be called with both balance and volume mutexes held
2979 */
2980 int btrfs_balance(struct btrfs_balance_control *bctl,
2981 struct btrfs_ioctl_balance_args *bargs)
2982 {
2983 struct btrfs_fs_info *fs_info = bctl->fs_info;
2984 u64 allowed;
2985 int mixed = 0;
2986 int ret;
2987 u64 num_devices;
2988
2989 if (btrfs_fs_closing(fs_info) ||
2990 atomic_read(&fs_info->balance_pause_req) ||
2991 atomic_read(&fs_info->balance_cancel_req)) {
2992 ret = -EINVAL;
2993 goto out;
2994 }
2995
2996 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
2997 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
2998 mixed = 1;
2999
3000 /*
3001 * In case of mixed groups both data and meta should be picked,
3002 * and identical options should be given for both of them.
3003 */
3004 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3005 if (mixed && (bctl->flags & allowed)) {
3006 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3007 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3008 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3009 printk(KERN_ERR "btrfs: with mixed groups data and "
3010 "metadata balance options must be the same\n");
3011 ret = -EINVAL;
3012 goto out;
3013 }
3014 }
3015
3016 num_devices = fs_info->fs_devices->num_devices;
3017 btrfs_dev_replace_lock(&fs_info->dev_replace);
3018 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3019 BUG_ON(num_devices < 1);
3020 num_devices--;
3021 }
3022 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3023 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3024 if (num_devices == 1)
3025 allowed |= BTRFS_BLOCK_GROUP_DUP;
3026 else if (num_devices < 4)
3027 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3028 else
3029 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
3030 BTRFS_BLOCK_GROUP_RAID10);
3031
3032 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3033 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3034 (bctl->data.target & ~allowed))) {
3035 printk(KERN_ERR "btrfs: unable to start balance with target "
3036 "data profile %llu\n",
3037 (unsigned long long)bctl->data.target);
3038 ret = -EINVAL;
3039 goto out;
3040 }
3041 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3042 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3043 (bctl->meta.target & ~allowed))) {
3044 printk(KERN_ERR "btrfs: unable to start balance with target "
3045 "metadata profile %llu\n",
3046 (unsigned long long)bctl->meta.target);
3047 ret = -EINVAL;
3048 goto out;
3049 }
3050 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3051 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3052 (bctl->sys.target & ~allowed))) {
3053 printk(KERN_ERR "btrfs: unable to start balance with target "
3054 "system profile %llu\n",
3055 (unsigned long long)bctl->sys.target);
3056 ret = -EINVAL;
3057 goto out;
3058 }
3059
3060 /* allow dup'ed data chunks only in mixed mode */
3061 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3062 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3063 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3064 ret = -EINVAL;
3065 goto out;
3066 }
3067
3068 /* allow to reduce meta or sys integrity only if force set */
3069 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3070 BTRFS_BLOCK_GROUP_RAID10;
3071 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3072 (fs_info->avail_system_alloc_bits & allowed) &&
3073 !(bctl->sys.target & allowed)) ||
3074 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3075 (fs_info->avail_metadata_alloc_bits & allowed) &&
3076 !(bctl->meta.target & allowed))) {
3077 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3078 printk(KERN_INFO "btrfs: force reducing metadata "
3079 "integrity\n");
3080 } else {
3081 printk(KERN_ERR "btrfs: balance will reduce metadata "
3082 "integrity, use force if you want this\n");
3083 ret = -EINVAL;
3084 goto out;
3085 }
3086 }
3087
3088 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3089 int num_tolerated_disk_barrier_failures;
3090 u64 target = bctl->sys.target;
3091
3092 num_tolerated_disk_barrier_failures =
3093 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3094 if (num_tolerated_disk_barrier_failures > 0 &&
3095 (target &
3096 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3097 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3098 num_tolerated_disk_barrier_failures = 0;
3099 else if (num_tolerated_disk_barrier_failures > 1 &&
3100 (target &
3101 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3102 num_tolerated_disk_barrier_failures = 1;
3103
3104 fs_info->num_tolerated_disk_barrier_failures =
3105 num_tolerated_disk_barrier_failures;
3106 }
3107
3108 ret = insert_balance_item(fs_info->tree_root, bctl);
3109 if (ret && ret != -EEXIST)
3110 goto out;
3111
3112 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3113 BUG_ON(ret == -EEXIST);
3114 set_balance_control(bctl);
3115 } else {
3116 BUG_ON(ret != -EEXIST);
3117 spin_lock(&fs_info->balance_lock);
3118 update_balance_args(bctl);
3119 spin_unlock(&fs_info->balance_lock);
3120 }
3121
3122 atomic_inc(&fs_info->balance_running);
3123 mutex_unlock(&fs_info->balance_mutex);
3124
3125 ret = __btrfs_balance(fs_info);
3126
3127 mutex_lock(&fs_info->balance_mutex);
3128 atomic_dec(&fs_info->balance_running);
3129
3130 if (bargs) {
3131 memset(bargs, 0, sizeof(*bargs));
3132 update_ioctl_balance_args(fs_info, 0, bargs);
3133 }
3134
3135 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3136 balance_need_close(fs_info)) {
3137 __cancel_balance(fs_info);
3138 }
3139
3140 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3141 fs_info->num_tolerated_disk_barrier_failures =
3142 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3143 }
3144
3145 wake_up(&fs_info->balance_wait_q);
3146
3147 return ret;
3148 out:
3149 if (bctl->flags & BTRFS_BALANCE_RESUME)
3150 __cancel_balance(fs_info);
3151 else {
3152 kfree(bctl);
3153 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3154 }
3155 return ret;
3156 }
3157
3158 static int balance_kthread(void *data)
3159 {
3160 struct btrfs_fs_info *fs_info = data;
3161 int ret = 0;
3162
3163 mutex_lock(&fs_info->volume_mutex);
3164 mutex_lock(&fs_info->balance_mutex);
3165
3166 if (fs_info->balance_ctl) {
3167 printk(KERN_INFO "btrfs: continuing balance\n");
3168 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3169 }
3170
3171 mutex_unlock(&fs_info->balance_mutex);
3172 mutex_unlock(&fs_info->volume_mutex);
3173
3174 return ret;
3175 }
3176
3177 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3178 {
3179 struct task_struct *tsk;
3180
3181 spin_lock(&fs_info->balance_lock);
3182 if (!fs_info->balance_ctl) {
3183 spin_unlock(&fs_info->balance_lock);
3184 return 0;
3185 }
3186 spin_unlock(&fs_info->balance_lock);
3187
3188 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3189 printk(KERN_INFO "btrfs: force skipping balance\n");
3190 return 0;
3191 }
3192
3193 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3194 if (IS_ERR(tsk))
3195 return PTR_ERR(tsk);
3196
3197 return 0;
3198 }
3199
3200 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3201 {
3202 struct btrfs_balance_control *bctl;
3203 struct btrfs_balance_item *item;
3204 struct btrfs_disk_balance_args disk_bargs;
3205 struct btrfs_path *path;
3206 struct extent_buffer *leaf;
3207 struct btrfs_key key;
3208 int ret;
3209
3210 path = btrfs_alloc_path();
3211 if (!path)
3212 return -ENOMEM;
3213
3214 key.objectid = BTRFS_BALANCE_OBJECTID;
3215 key.type = BTRFS_BALANCE_ITEM_KEY;
3216 key.offset = 0;
3217
3218 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3219 if (ret < 0)
3220 goto out;
3221 if (ret > 0) { /* ret = -ENOENT; */
3222 ret = 0;
3223 goto out;
3224 }
3225
3226 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3227 if (!bctl) {
3228 ret = -ENOMEM;
3229 goto out;
3230 }
3231
3232 leaf = path->nodes[0];
3233 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3234
3235 bctl->fs_info = fs_info;
3236 bctl->flags = btrfs_balance_flags(leaf, item);
3237 bctl->flags |= BTRFS_BALANCE_RESUME;
3238
3239 btrfs_balance_data(leaf, item, &disk_bargs);
3240 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3241 btrfs_balance_meta(leaf, item, &disk_bargs);
3242 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3243 btrfs_balance_sys(leaf, item, &disk_bargs);
3244 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3245
3246 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3247
3248 mutex_lock(&fs_info->volume_mutex);
3249 mutex_lock(&fs_info->balance_mutex);
3250
3251 set_balance_control(bctl);
3252
3253 mutex_unlock(&fs_info->balance_mutex);
3254 mutex_unlock(&fs_info->volume_mutex);
3255 out:
3256 btrfs_free_path(path);
3257 return ret;
3258 }
3259
3260 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3261 {
3262 int ret = 0;
3263
3264 mutex_lock(&fs_info->balance_mutex);
3265 if (!fs_info->balance_ctl) {
3266 mutex_unlock(&fs_info->balance_mutex);
3267 return -ENOTCONN;
3268 }
3269
3270 if (atomic_read(&fs_info->balance_running)) {
3271 atomic_inc(&fs_info->balance_pause_req);
3272 mutex_unlock(&fs_info->balance_mutex);
3273
3274 wait_event(fs_info->balance_wait_q,
3275 atomic_read(&fs_info->balance_running) == 0);
3276
3277 mutex_lock(&fs_info->balance_mutex);
3278 /* we are good with balance_ctl ripped off from under us */
3279 BUG_ON(atomic_read(&fs_info->balance_running));
3280 atomic_dec(&fs_info->balance_pause_req);
3281 } else {
3282 ret = -ENOTCONN;
3283 }
3284
3285 mutex_unlock(&fs_info->balance_mutex);
3286 return ret;
3287 }
3288
3289 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3290 {
3291 mutex_lock(&fs_info->balance_mutex);
3292 if (!fs_info->balance_ctl) {
3293 mutex_unlock(&fs_info->balance_mutex);
3294 return -ENOTCONN;
3295 }
3296
3297 atomic_inc(&fs_info->balance_cancel_req);
3298 /*
3299 * if we are running just wait and return, balance item is
3300 * deleted in btrfs_balance in this case
3301 */
3302 if (atomic_read(&fs_info->balance_running)) {
3303 mutex_unlock(&fs_info->balance_mutex);
3304 wait_event(fs_info->balance_wait_q,
3305 atomic_read(&fs_info->balance_running) == 0);
3306 mutex_lock(&fs_info->balance_mutex);
3307 } else {
3308 /* __cancel_balance needs volume_mutex */
3309 mutex_unlock(&fs_info->balance_mutex);
3310 mutex_lock(&fs_info->volume_mutex);
3311 mutex_lock(&fs_info->balance_mutex);
3312
3313 if (fs_info->balance_ctl)
3314 __cancel_balance(fs_info);
3315
3316 mutex_unlock(&fs_info->volume_mutex);
3317 }
3318
3319 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3320 atomic_dec(&fs_info->balance_cancel_req);
3321 mutex_unlock(&fs_info->balance_mutex);
3322 return 0;
3323 }
3324
3325 /*
3326 * shrinking a device means finding all of the device extents past
3327 * the new size, and then following the back refs to the chunks.
3328 * The chunk relocation code actually frees the device extent
3329 */
3330 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3331 {
3332 struct btrfs_trans_handle *trans;
3333 struct btrfs_root *root = device->dev_root;
3334 struct btrfs_dev_extent *dev_extent = NULL;
3335 struct btrfs_path *path;
3336 u64 length;
3337 u64 chunk_tree;
3338 u64 chunk_objectid;
3339 u64 chunk_offset;
3340 int ret;
3341 int slot;
3342 int failed = 0;
3343 bool retried = false;
3344 struct extent_buffer *l;
3345 struct btrfs_key key;
3346 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3347 u64 old_total = btrfs_super_total_bytes(super_copy);
3348 u64 old_size = device->total_bytes;
3349 u64 diff = device->total_bytes - new_size;
3350
3351 if (device->is_tgtdev_for_dev_replace)
3352 return -EINVAL;
3353
3354 path = btrfs_alloc_path();
3355 if (!path)
3356 return -ENOMEM;
3357
3358 path->reada = 2;
3359
3360 lock_chunks(root);
3361
3362 device->total_bytes = new_size;
3363 if (device->writeable) {
3364 device->fs_devices->total_rw_bytes -= diff;
3365 spin_lock(&root->fs_info->free_chunk_lock);
3366 root->fs_info->free_chunk_space -= diff;
3367 spin_unlock(&root->fs_info->free_chunk_lock);
3368 }
3369 unlock_chunks(root);
3370
3371 again:
3372 key.objectid = device->devid;
3373 key.offset = (u64)-1;
3374 key.type = BTRFS_DEV_EXTENT_KEY;
3375
3376 do {
3377 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3378 if (ret < 0)
3379 goto done;
3380
3381 ret = btrfs_previous_item(root, path, 0, key.type);
3382 if (ret < 0)
3383 goto done;
3384 if (ret) {
3385 ret = 0;
3386 btrfs_release_path(path);
3387 break;
3388 }
3389
3390 l = path->nodes[0];
3391 slot = path->slots[0];
3392 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3393
3394 if (key.objectid != device->devid) {
3395 btrfs_release_path(path);
3396 break;
3397 }
3398
3399 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3400 length = btrfs_dev_extent_length(l, dev_extent);
3401
3402 if (key.offset + length <= new_size) {
3403 btrfs_release_path(path);
3404 break;
3405 }
3406
3407 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3408 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3409 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3410 btrfs_release_path(path);
3411
3412 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3413 chunk_offset);
3414 if (ret && ret != -ENOSPC)
3415 goto done;
3416 if (ret == -ENOSPC)
3417 failed++;
3418 } while (key.offset-- > 0);
3419
3420 if (failed && !retried) {
3421 failed = 0;
3422 retried = true;
3423 goto again;
3424 } else if (failed && retried) {
3425 ret = -ENOSPC;
3426 lock_chunks(root);
3427
3428 device->total_bytes = old_size;
3429 if (device->writeable)
3430 device->fs_devices->total_rw_bytes += diff;
3431 spin_lock(&root->fs_info->free_chunk_lock);
3432 root->fs_info->free_chunk_space += diff;
3433 spin_unlock(&root->fs_info->free_chunk_lock);
3434 unlock_chunks(root);
3435 goto done;
3436 }
3437
3438 /* Shrinking succeeded, else we would be at "done". */
3439 trans = btrfs_start_transaction(root, 0);
3440 if (IS_ERR(trans)) {
3441 ret = PTR_ERR(trans);
3442 goto done;
3443 }
3444
3445 lock_chunks(root);
3446
3447 device->disk_total_bytes = new_size;
3448 /* Now btrfs_update_device() will change the on-disk size. */
3449 ret = btrfs_update_device(trans, device);
3450 if (ret) {
3451 unlock_chunks(root);
3452 btrfs_end_transaction(trans, root);
3453 goto done;
3454 }
3455 WARN_ON(diff > old_total);
3456 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3457 unlock_chunks(root);
3458 btrfs_end_transaction(trans, root);
3459 done:
3460 btrfs_free_path(path);
3461 return ret;
3462 }
3463
3464 static int btrfs_add_system_chunk(struct btrfs_root *root,
3465 struct btrfs_key *key,
3466 struct btrfs_chunk *chunk, int item_size)
3467 {
3468 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3469 struct btrfs_disk_key disk_key;
3470 u32 array_size;
3471 u8 *ptr;
3472
3473 array_size = btrfs_super_sys_array_size(super_copy);
3474 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3475 return -EFBIG;
3476
3477 ptr = super_copy->sys_chunk_array + array_size;
3478 btrfs_cpu_key_to_disk(&disk_key, key);
3479 memcpy(ptr, &disk_key, sizeof(disk_key));
3480 ptr += sizeof(disk_key);
3481 memcpy(ptr, chunk, item_size);
3482 item_size += sizeof(disk_key);
3483 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3484 return 0;
3485 }
3486
3487 /*
3488 * sort the devices in descending order by max_avail, total_avail
3489 */
3490 static int btrfs_cmp_device_info(const void *a, const void *b)
3491 {
3492 const struct btrfs_device_info *di_a = a;
3493 const struct btrfs_device_info *di_b = b;
3494
3495 if (di_a->max_avail > di_b->max_avail)
3496 return -1;
3497 if (di_a->max_avail < di_b->max_avail)
3498 return 1;
3499 if (di_a->total_avail > di_b->total_avail)
3500 return -1;
3501 if (di_a->total_avail < di_b->total_avail)
3502 return 1;
3503 return 0;
3504 }
3505
3506 struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3507 { 2, 1, 0, 4, 2, 2 /* raid10 */ },
3508 { 1, 1, 2, 2, 2, 2 /* raid1 */ },
3509 { 1, 2, 1, 1, 1, 2 /* dup */ },
3510 { 1, 1, 0, 2, 1, 1 /* raid0 */ },
3511 { 1, 1, 1, 1, 1, 1 /* single */ },
3512 };
3513
3514 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3515 struct btrfs_root *extent_root,
3516 struct map_lookup **map_ret,
3517 u64 *num_bytes_out, u64 *stripe_size_out,
3518 u64 start, u64 type)
3519 {
3520 struct btrfs_fs_info *info = extent_root->fs_info;
3521 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3522 struct list_head *cur;
3523 struct map_lookup *map = NULL;
3524 struct extent_map_tree *em_tree;
3525 struct extent_map *em;
3526 struct btrfs_device_info *devices_info = NULL;
3527 u64 total_avail;
3528 int num_stripes; /* total number of stripes to allocate */
3529 int sub_stripes; /* sub_stripes info for map */
3530 int dev_stripes; /* stripes per dev */
3531 int devs_max; /* max devs to use */
3532 int devs_min; /* min devs needed */
3533 int devs_increment; /* ndevs has to be a multiple of this */
3534 int ncopies; /* how many copies to data has */
3535 int ret;
3536 u64 max_stripe_size;
3537 u64 max_chunk_size;
3538 u64 stripe_size;
3539 u64 num_bytes;
3540 int ndevs;
3541 int i;
3542 int j;
3543 int index;
3544
3545 BUG_ON(!alloc_profile_is_valid(type, 0));
3546
3547 if (list_empty(&fs_devices->alloc_list))
3548 return -ENOSPC;
3549
3550 index = __get_raid_index(type);
3551
3552 sub_stripes = btrfs_raid_array[index].sub_stripes;
3553 dev_stripes = btrfs_raid_array[index].dev_stripes;
3554 devs_max = btrfs_raid_array[index].devs_max;
3555 devs_min = btrfs_raid_array[index].devs_min;
3556 devs_increment = btrfs_raid_array[index].devs_increment;
3557 ncopies = btrfs_raid_array[index].ncopies;
3558
3559 if (type & BTRFS_BLOCK_GROUP_DATA) {
3560 max_stripe_size = 1024 * 1024 * 1024;
3561 max_chunk_size = 10 * max_stripe_size;
3562 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3563 /* for larger filesystems, use larger metadata chunks */
3564 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3565 max_stripe_size = 1024 * 1024 * 1024;
3566 else
3567 max_stripe_size = 256 * 1024 * 1024;
3568 max_chunk_size = max_stripe_size;
3569 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3570 max_stripe_size = 32 * 1024 * 1024;
3571 max_chunk_size = 2 * max_stripe_size;
3572 } else {
3573 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3574 type);
3575 BUG_ON(1);
3576 }
3577
3578 /* we don't want a chunk larger than 10% of writeable space */
3579 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3580 max_chunk_size);
3581
3582 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3583 GFP_NOFS);
3584 if (!devices_info)
3585 return -ENOMEM;
3586
3587 cur = fs_devices->alloc_list.next;
3588
3589 /*
3590 * in the first pass through the devices list, we gather information
3591 * about the available holes on each device.
3592 */
3593 ndevs = 0;
3594 while (cur != &fs_devices->alloc_list) {
3595 struct btrfs_device *device;
3596 u64 max_avail;
3597 u64 dev_offset;
3598
3599 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3600
3601 cur = cur->next;
3602
3603 if (!device->writeable) {
3604 WARN(1, KERN_ERR
3605 "btrfs: read-only device in alloc_list\n");
3606 continue;
3607 }
3608
3609 if (!device->in_fs_metadata ||
3610 device->is_tgtdev_for_dev_replace)
3611 continue;
3612
3613 if (device->total_bytes > device->bytes_used)
3614 total_avail = device->total_bytes - device->bytes_used;
3615 else
3616 total_avail = 0;
3617
3618 /* If there is no space on this device, skip it. */
3619 if (total_avail == 0)
3620 continue;
3621
3622 ret = find_free_dev_extent(device,
3623 max_stripe_size * dev_stripes,
3624 &dev_offset, &max_avail);
3625 if (ret && ret != -ENOSPC)
3626 goto error;
3627
3628 if (ret == 0)
3629 max_avail = max_stripe_size * dev_stripes;
3630
3631 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3632 continue;
3633
3634 devices_info[ndevs].dev_offset = dev_offset;
3635 devices_info[ndevs].max_avail = max_avail;
3636 devices_info[ndevs].total_avail = total_avail;
3637 devices_info[ndevs].dev = device;
3638 ++ndevs;
3639 WARN_ON(ndevs > fs_devices->rw_devices);
3640 }
3641
3642 /*
3643 * now sort the devices by hole size / available space
3644 */
3645 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3646 btrfs_cmp_device_info, NULL);
3647
3648 /* round down to number of usable stripes */
3649 ndevs -= ndevs % devs_increment;
3650
3651 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3652 ret = -ENOSPC;
3653 goto error;
3654 }
3655
3656 if (devs_max && ndevs > devs_max)
3657 ndevs = devs_max;
3658 /*
3659 * the primary goal is to maximize the number of stripes, so use as many
3660 * devices as possible, even if the stripes are not maximum sized.
3661 */
3662 stripe_size = devices_info[ndevs-1].max_avail;
3663 num_stripes = ndevs * dev_stripes;
3664
3665 if (stripe_size * ndevs > max_chunk_size * ncopies) {
3666 stripe_size = max_chunk_size * ncopies;
3667 do_div(stripe_size, ndevs);
3668 }
3669
3670 do_div(stripe_size, dev_stripes);
3671
3672 /* align to BTRFS_STRIPE_LEN */
3673 do_div(stripe_size, BTRFS_STRIPE_LEN);
3674 stripe_size *= BTRFS_STRIPE_LEN;
3675
3676 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3677 if (!map) {
3678 ret = -ENOMEM;
3679 goto error;
3680 }
3681 map->num_stripes = num_stripes;
3682
3683 for (i = 0; i < ndevs; ++i) {
3684 for (j = 0; j < dev_stripes; ++j) {
3685 int s = i * dev_stripes + j;
3686 map->stripes[s].dev = devices_info[i].dev;
3687 map->stripes[s].physical = devices_info[i].dev_offset +
3688 j * stripe_size;
3689 }
3690 }
3691 map->sector_size = extent_root->sectorsize;
3692 map->stripe_len = BTRFS_STRIPE_LEN;
3693 map->io_align = BTRFS_STRIPE_LEN;
3694 map->io_width = BTRFS_STRIPE_LEN;
3695 map->type = type;
3696 map->sub_stripes = sub_stripes;
3697
3698 *map_ret = map;
3699 num_bytes = stripe_size * (num_stripes / ncopies);
3700
3701 *stripe_size_out = stripe_size;
3702 *num_bytes_out = num_bytes;
3703
3704 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3705
3706 em = alloc_extent_map();
3707 if (!em) {
3708 ret = -ENOMEM;
3709 goto error;
3710 }
3711 em->bdev = (struct block_device *)map;
3712 em->start = start;
3713 em->len = num_bytes;
3714 em->block_start = 0;
3715 em->block_len = em->len;
3716
3717 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3718 write_lock(&em_tree->lock);
3719 ret = add_extent_mapping(em_tree, em);
3720 write_unlock(&em_tree->lock);
3721 free_extent_map(em);
3722 if (ret)
3723 goto error;
3724
3725 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3726 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3727 start, num_bytes);
3728 if (ret)
3729 goto error;
3730
3731 for (i = 0; i < map->num_stripes; ++i) {
3732 struct btrfs_device *device;
3733 u64 dev_offset;
3734
3735 device = map->stripes[i].dev;
3736 dev_offset = map->stripes[i].physical;
3737
3738 ret = btrfs_alloc_dev_extent(trans, device,
3739 info->chunk_root->root_key.objectid,
3740 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3741 start, dev_offset, stripe_size);
3742 if (ret) {
3743 btrfs_abort_transaction(trans, extent_root, ret);
3744 goto error;
3745 }
3746 }
3747
3748 kfree(devices_info);
3749 return 0;
3750
3751 error:
3752 kfree(map);
3753 kfree(devices_info);
3754 return ret;
3755 }
3756
3757 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3758 struct btrfs_root *extent_root,
3759 struct map_lookup *map, u64 chunk_offset,
3760 u64 chunk_size, u64 stripe_size)
3761 {
3762 u64 dev_offset;
3763 struct btrfs_key key;
3764 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3765 struct btrfs_device *device;
3766 struct btrfs_chunk *chunk;
3767 struct btrfs_stripe *stripe;
3768 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
3769 int index = 0;
3770 int ret;
3771
3772 chunk = kzalloc(item_size, GFP_NOFS);
3773 if (!chunk)
3774 return -ENOMEM;
3775
3776 index = 0;
3777 while (index < map->num_stripes) {
3778 device = map->stripes[index].dev;
3779 device->bytes_used += stripe_size;
3780 ret = btrfs_update_device(trans, device);
3781 if (ret)
3782 goto out_free;
3783 index++;
3784 }
3785
3786 spin_lock(&extent_root->fs_info->free_chunk_lock);
3787 extent_root->fs_info->free_chunk_space -= (stripe_size *
3788 map->num_stripes);
3789 spin_unlock(&extent_root->fs_info->free_chunk_lock);
3790
3791 index = 0;
3792 stripe = &chunk->stripe;
3793 while (index < map->num_stripes) {
3794 device = map->stripes[index].dev;
3795 dev_offset = map->stripes[index].physical;
3796
3797 btrfs_set_stack_stripe_devid(stripe, device->devid);
3798 btrfs_set_stack_stripe_offset(stripe, dev_offset);
3799 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
3800 stripe++;
3801 index++;
3802 }
3803
3804 btrfs_set_stack_chunk_length(chunk, chunk_size);
3805 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
3806 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
3807 btrfs_set_stack_chunk_type(chunk, map->type);
3808 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
3809 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
3810 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
3811 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
3812 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
3813
3814 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
3815 key.type = BTRFS_CHUNK_ITEM_KEY;
3816 key.offset = chunk_offset;
3817
3818 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
3819
3820 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
3821 /*
3822 * TODO: Cleanup of inserted chunk root in case of
3823 * failure.
3824 */
3825 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
3826 item_size);
3827 }
3828
3829 out_free:
3830 kfree(chunk);
3831 return ret;
3832 }
3833
3834 /*
3835 * Chunk allocation falls into two parts. The first part does works
3836 * that make the new allocated chunk useable, but not do any operation
3837 * that modifies the chunk tree. The second part does the works that
3838 * require modifying the chunk tree. This division is important for the
3839 * bootstrap process of adding storage to a seed btrfs.
3840 */
3841 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3842 struct btrfs_root *extent_root, u64 type)
3843 {
3844 u64 chunk_offset;
3845 u64 chunk_size;
3846 u64 stripe_size;
3847 struct map_lookup *map;
3848 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3849 int ret;
3850
3851 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3852 &chunk_offset);
3853 if (ret)
3854 return ret;
3855
3856 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3857 &stripe_size, chunk_offset, type);
3858 if (ret)
3859 return ret;
3860
3861 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3862 chunk_size, stripe_size);
3863 if (ret)
3864 return ret;
3865 return 0;
3866 }
3867
3868 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
3869 struct btrfs_root *root,
3870 struct btrfs_device *device)
3871 {
3872 u64 chunk_offset;
3873 u64 sys_chunk_offset;
3874 u64 chunk_size;
3875 u64 sys_chunk_size;
3876 u64 stripe_size;
3877 u64 sys_stripe_size;
3878 u64 alloc_profile;
3879 struct map_lookup *map;
3880 struct map_lookup *sys_map;
3881 struct btrfs_fs_info *fs_info = root->fs_info;
3882 struct btrfs_root *extent_root = fs_info->extent_root;
3883 int ret;
3884
3885 ret = find_next_chunk(fs_info->chunk_root,
3886 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
3887 if (ret)
3888 return ret;
3889
3890 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
3891 fs_info->avail_metadata_alloc_bits;
3892 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3893
3894 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
3895 &stripe_size, chunk_offset, alloc_profile);
3896 if (ret)
3897 return ret;
3898
3899 sys_chunk_offset = chunk_offset + chunk_size;
3900
3901 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
3902 fs_info->avail_system_alloc_bits;
3903 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
3904
3905 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
3906 &sys_chunk_size, &sys_stripe_size,
3907 sys_chunk_offset, alloc_profile);
3908 if (ret) {
3909 btrfs_abort_transaction(trans, root, ret);
3910 goto out;
3911 }
3912
3913 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
3914 if (ret) {
3915 btrfs_abort_transaction(trans, root, ret);
3916 goto out;
3917 }
3918
3919 /*
3920 * Modifying chunk tree needs allocating new blocks from both
3921 * system block group and metadata block group. So we only can
3922 * do operations require modifying the chunk tree after both
3923 * block groups were created.
3924 */
3925 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
3926 chunk_size, stripe_size);
3927 if (ret) {
3928 btrfs_abort_transaction(trans, root, ret);
3929 goto out;
3930 }
3931
3932 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
3933 sys_chunk_offset, sys_chunk_size,
3934 sys_stripe_size);
3935 if (ret)
3936 btrfs_abort_transaction(trans, root, ret);
3937
3938 out:
3939
3940 return ret;
3941 }
3942
3943 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
3944 {
3945 struct extent_map *em;
3946 struct map_lookup *map;
3947 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3948 int readonly = 0;
3949 int i;
3950
3951 read_lock(&map_tree->map_tree.lock);
3952 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
3953 read_unlock(&map_tree->map_tree.lock);
3954 if (!em)
3955 return 1;
3956
3957 if (btrfs_test_opt(root, DEGRADED)) {
3958 free_extent_map(em);
3959 return 0;
3960 }
3961
3962 map = (struct map_lookup *)em->bdev;
3963 for (i = 0; i < map->num_stripes; i++) {
3964 if (!map->stripes[i].dev->writeable) {
3965 readonly = 1;
3966 break;
3967 }
3968 }
3969 free_extent_map(em);
3970 return readonly;
3971 }
3972
3973 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
3974 {
3975 extent_map_tree_init(&tree->map_tree);
3976 }
3977
3978 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
3979 {
3980 struct extent_map *em;
3981
3982 while (1) {
3983 write_lock(&tree->map_tree.lock);
3984 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
3985 if (em)
3986 remove_extent_mapping(&tree->map_tree, em);
3987 write_unlock(&tree->map_tree.lock);
3988 if (!em)
3989 break;
3990 kfree(em->bdev);
3991 /* once for us */
3992 free_extent_map(em);
3993 /* once for the tree */
3994 free_extent_map(em);
3995 }
3996 }
3997
3998 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
3999 {
4000 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4001 struct extent_map *em;
4002 struct map_lookup *map;
4003 struct extent_map_tree *em_tree = &map_tree->map_tree;
4004 int ret;
4005
4006 read_lock(&em_tree->lock);
4007 em = lookup_extent_mapping(em_tree, logical, len);
4008 read_unlock(&em_tree->lock);
4009 BUG_ON(!em);
4010
4011 BUG_ON(em->start > logical || em->start + em->len < logical);
4012 map = (struct map_lookup *)em->bdev;
4013 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4014 ret = map->num_stripes;
4015 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4016 ret = map->sub_stripes;
4017 else
4018 ret = 1;
4019 free_extent_map(em);
4020
4021 btrfs_dev_replace_lock(&fs_info->dev_replace);
4022 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4023 ret++;
4024 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4025
4026 return ret;
4027 }
4028
4029 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4030 struct map_lookup *map, int first, int num,
4031 int optimal, int dev_replace_is_ongoing)
4032 {
4033 int i;
4034 int tolerance;
4035 struct btrfs_device *srcdev;
4036
4037 if (dev_replace_is_ongoing &&
4038 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4039 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4040 srcdev = fs_info->dev_replace.srcdev;
4041 else
4042 srcdev = NULL;
4043
4044 /*
4045 * try to avoid the drive that is the source drive for a
4046 * dev-replace procedure, only choose it if no other non-missing
4047 * mirror is available
4048 */
4049 for (tolerance = 0; tolerance < 2; tolerance++) {
4050 if (map->stripes[optimal].dev->bdev &&
4051 (tolerance || map->stripes[optimal].dev != srcdev))
4052 return optimal;
4053 for (i = first; i < first + num; i++) {
4054 if (map->stripes[i].dev->bdev &&
4055 (tolerance || map->stripes[i].dev != srcdev))
4056 return i;
4057 }
4058 }
4059
4060 /* we couldn't find one that doesn't fail. Just return something
4061 * and the io error handling code will clean up eventually
4062 */
4063 return optimal;
4064 }
4065
4066 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4067 u64 logical, u64 *length,
4068 struct btrfs_bio **bbio_ret,
4069 int mirror_num)
4070 {
4071 struct extent_map *em;
4072 struct map_lookup *map;
4073 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4074 struct extent_map_tree *em_tree = &map_tree->map_tree;
4075 u64 offset;
4076 u64 stripe_offset;
4077 u64 stripe_end_offset;
4078 u64 stripe_nr;
4079 u64 stripe_nr_orig;
4080 u64 stripe_nr_end;
4081 int stripe_index;
4082 int i;
4083 int ret = 0;
4084 int num_stripes;
4085 int max_errors = 0;
4086 struct btrfs_bio *bbio = NULL;
4087 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4088 int dev_replace_is_ongoing = 0;
4089 int num_alloc_stripes;
4090 int patch_the_first_stripe_for_dev_replace = 0;
4091 u64 physical_to_patch_in_first_stripe = 0;
4092
4093 read_lock(&em_tree->lock);
4094 em = lookup_extent_mapping(em_tree, logical, *length);
4095 read_unlock(&em_tree->lock);
4096
4097 if (!em) {
4098 printk(KERN_CRIT "btrfs: unable to find logical %llu len %llu\n",
4099 (unsigned long long)logical,
4100 (unsigned long long)*length);
4101 BUG();
4102 }
4103
4104 BUG_ON(em->start > logical || em->start + em->len < logical);
4105 map = (struct map_lookup *)em->bdev;
4106 offset = logical - em->start;
4107
4108 stripe_nr = offset;
4109 /*
4110 * stripe_nr counts the total number of stripes we have to stride
4111 * to get to this block
4112 */
4113 do_div(stripe_nr, map->stripe_len);
4114
4115 stripe_offset = stripe_nr * map->stripe_len;
4116 BUG_ON(offset < stripe_offset);
4117
4118 /* stripe_offset is the offset of this block in its stripe*/
4119 stripe_offset = offset - stripe_offset;
4120
4121 if (rw & REQ_DISCARD)
4122 *length = min_t(u64, em->len - offset, *length);
4123 else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4124 /* we limit the length of each bio to what fits in a stripe */
4125 *length = min_t(u64, em->len - offset,
4126 map->stripe_len - stripe_offset);
4127 } else {
4128 *length = em->len - offset;
4129 }
4130
4131 if (!bbio_ret)
4132 goto out;
4133
4134 btrfs_dev_replace_lock(dev_replace);
4135 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4136 if (!dev_replace_is_ongoing)
4137 btrfs_dev_replace_unlock(dev_replace);
4138
4139 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4140 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4141 dev_replace->tgtdev != NULL) {
4142 /*
4143 * in dev-replace case, for repair case (that's the only
4144 * case where the mirror is selected explicitly when
4145 * calling btrfs_map_block), blocks left of the left cursor
4146 * can also be read from the target drive.
4147 * For REQ_GET_READ_MIRRORS, the target drive is added as
4148 * the last one to the array of stripes. For READ, it also
4149 * needs to be supported using the same mirror number.
4150 * If the requested block is not left of the left cursor,
4151 * EIO is returned. This can happen because btrfs_num_copies()
4152 * returns one more in the dev-replace case.
4153 */
4154 u64 tmp_length = *length;
4155 struct btrfs_bio *tmp_bbio = NULL;
4156 int tmp_num_stripes;
4157 u64 srcdev_devid = dev_replace->srcdev->devid;
4158 int index_srcdev = 0;
4159 int found = 0;
4160 u64 physical_of_found = 0;
4161
4162 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4163 logical, &tmp_length, &tmp_bbio, 0);
4164 if (ret) {
4165 WARN_ON(tmp_bbio != NULL);
4166 goto out;
4167 }
4168
4169 tmp_num_stripes = tmp_bbio->num_stripes;
4170 if (mirror_num > tmp_num_stripes) {
4171 /*
4172 * REQ_GET_READ_MIRRORS does not contain this
4173 * mirror, that means that the requested area
4174 * is not left of the left cursor
4175 */
4176 ret = -EIO;
4177 kfree(tmp_bbio);
4178 goto out;
4179 }
4180
4181 /*
4182 * process the rest of the function using the mirror_num
4183 * of the source drive. Therefore look it up first.
4184 * At the end, patch the device pointer to the one of the
4185 * target drive.
4186 */
4187 for (i = 0; i < tmp_num_stripes; i++) {
4188 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4189 /*
4190 * In case of DUP, in order to keep it
4191 * simple, only add the mirror with the
4192 * lowest physical address
4193 */
4194 if (found &&
4195 physical_of_found <=
4196 tmp_bbio->stripes[i].physical)
4197 continue;
4198 index_srcdev = i;
4199 found = 1;
4200 physical_of_found =
4201 tmp_bbio->stripes[i].physical;
4202 }
4203 }
4204
4205 if (found) {
4206 mirror_num = index_srcdev + 1;
4207 patch_the_first_stripe_for_dev_replace = 1;
4208 physical_to_patch_in_first_stripe = physical_of_found;
4209 } else {
4210 WARN_ON(1);
4211 ret = -EIO;
4212 kfree(tmp_bbio);
4213 goto out;
4214 }
4215
4216 kfree(tmp_bbio);
4217 } else if (mirror_num > map->num_stripes) {
4218 mirror_num = 0;
4219 }
4220
4221 num_stripes = 1;
4222 stripe_index = 0;
4223 stripe_nr_orig = stripe_nr;
4224 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
4225 (~(map->stripe_len - 1));
4226 do_div(stripe_nr_end, map->stripe_len);
4227 stripe_end_offset = stripe_nr_end * map->stripe_len -
4228 (offset + *length);
4229 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4230 if (rw & REQ_DISCARD)
4231 num_stripes = min_t(u64, map->num_stripes,
4232 stripe_nr_end - stripe_nr_orig);
4233 stripe_index = do_div(stripe_nr, map->num_stripes);
4234 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4235 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4236 num_stripes = map->num_stripes;
4237 else if (mirror_num)
4238 stripe_index = mirror_num - 1;
4239 else {
4240 stripe_index = find_live_mirror(fs_info, map, 0,
4241 map->num_stripes,
4242 current->pid % map->num_stripes,
4243 dev_replace_is_ongoing);
4244 mirror_num = stripe_index + 1;
4245 }
4246
4247 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4248 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4249 num_stripes = map->num_stripes;
4250 } else if (mirror_num) {
4251 stripe_index = mirror_num - 1;
4252 } else {
4253 mirror_num = 1;
4254 }
4255
4256 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4257 int factor = map->num_stripes / map->sub_stripes;
4258
4259 stripe_index = do_div(stripe_nr, factor);
4260 stripe_index *= map->sub_stripes;
4261
4262 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4263 num_stripes = map->sub_stripes;
4264 else if (rw & REQ_DISCARD)
4265 num_stripes = min_t(u64, map->sub_stripes *
4266 (stripe_nr_end - stripe_nr_orig),
4267 map->num_stripes);
4268 else if (mirror_num)
4269 stripe_index += mirror_num - 1;
4270 else {
4271 int old_stripe_index = stripe_index;
4272 stripe_index = find_live_mirror(fs_info, map,
4273 stripe_index,
4274 map->sub_stripes, stripe_index +
4275 current->pid % map->sub_stripes,
4276 dev_replace_is_ongoing);
4277 mirror_num = stripe_index - old_stripe_index + 1;
4278 }
4279 } else {
4280 /*
4281 * after this do_div call, stripe_nr is the number of stripes
4282 * on this device we have to walk to find the data, and
4283 * stripe_index is the number of our device in the stripe array
4284 */
4285 stripe_index = do_div(stripe_nr, map->num_stripes);
4286 mirror_num = stripe_index + 1;
4287 }
4288 BUG_ON(stripe_index >= map->num_stripes);
4289
4290 num_alloc_stripes = num_stripes;
4291 if (dev_replace_is_ongoing) {
4292 if (rw & (REQ_WRITE | REQ_DISCARD))
4293 num_alloc_stripes <<= 1;
4294 if (rw & REQ_GET_READ_MIRRORS)
4295 num_alloc_stripes++;
4296 }
4297 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4298 if (!bbio) {
4299 ret = -ENOMEM;
4300 goto out;
4301 }
4302 atomic_set(&bbio->error, 0);
4303
4304 if (rw & REQ_DISCARD) {
4305 int factor = 0;
4306 int sub_stripes = 0;
4307 u64 stripes_per_dev = 0;
4308 u32 remaining_stripes = 0;
4309 u32 last_stripe = 0;
4310
4311 if (map->type &
4312 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4313 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4314 sub_stripes = 1;
4315 else
4316 sub_stripes = map->sub_stripes;
4317
4318 factor = map->num_stripes / sub_stripes;
4319 stripes_per_dev = div_u64_rem(stripe_nr_end -
4320 stripe_nr_orig,
4321 factor,
4322 &remaining_stripes);
4323 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4324 last_stripe *= sub_stripes;
4325 }
4326
4327 for (i = 0; i < num_stripes; i++) {
4328 bbio->stripes[i].physical =
4329 map->stripes[stripe_index].physical +
4330 stripe_offset + stripe_nr * map->stripe_len;
4331 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4332
4333 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4334 BTRFS_BLOCK_GROUP_RAID10)) {
4335 bbio->stripes[i].length = stripes_per_dev *
4336 map->stripe_len;
4337
4338 if (i / sub_stripes < remaining_stripes)
4339 bbio->stripes[i].length +=
4340 map->stripe_len;
4341
4342 /*
4343 * Special for the first stripe and
4344 * the last stripe:
4345 *
4346 * |-------|...|-------|
4347 * |----------|
4348 * off end_off
4349 */
4350 if (i < sub_stripes)
4351 bbio->stripes[i].length -=
4352 stripe_offset;
4353
4354 if (stripe_index >= last_stripe &&
4355 stripe_index <= (last_stripe +
4356 sub_stripes - 1))
4357 bbio->stripes[i].length -=
4358 stripe_end_offset;
4359
4360 if (i == sub_stripes - 1)
4361 stripe_offset = 0;
4362 } else
4363 bbio->stripes[i].length = *length;
4364
4365 stripe_index++;
4366 if (stripe_index == map->num_stripes) {
4367 /* This could only happen for RAID0/10 */
4368 stripe_index = 0;
4369 stripe_nr++;
4370 }
4371 }
4372 } else {
4373 for (i = 0; i < num_stripes; i++) {
4374 bbio->stripes[i].physical =
4375 map->stripes[stripe_index].physical +
4376 stripe_offset +
4377 stripe_nr * map->stripe_len;
4378 bbio->stripes[i].dev =
4379 map->stripes[stripe_index].dev;
4380 stripe_index++;
4381 }
4382 }
4383
4384 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
4385 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4386 BTRFS_BLOCK_GROUP_RAID10 |
4387 BTRFS_BLOCK_GROUP_DUP)) {
4388 max_errors = 1;
4389 }
4390 }
4391
4392 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
4393 dev_replace->tgtdev != NULL) {
4394 int index_where_to_add;
4395 u64 srcdev_devid = dev_replace->srcdev->devid;
4396
4397 /*
4398 * duplicate the write operations while the dev replace
4399 * procedure is running. Since the copying of the old disk
4400 * to the new disk takes place at run time while the
4401 * filesystem is mounted writable, the regular write
4402 * operations to the old disk have to be duplicated to go
4403 * to the new disk as well.
4404 * Note that device->missing is handled by the caller, and
4405 * that the write to the old disk is already set up in the
4406 * stripes array.
4407 */
4408 index_where_to_add = num_stripes;
4409 for (i = 0; i < num_stripes; i++) {
4410 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4411 /* write to new disk, too */
4412 struct btrfs_bio_stripe *new =
4413 bbio->stripes + index_where_to_add;
4414 struct btrfs_bio_stripe *old =
4415 bbio->stripes + i;
4416
4417 new->physical = old->physical;
4418 new->length = old->length;
4419 new->dev = dev_replace->tgtdev;
4420 index_where_to_add++;
4421 max_errors++;
4422 }
4423 }
4424 num_stripes = index_where_to_add;
4425 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
4426 dev_replace->tgtdev != NULL) {
4427 u64 srcdev_devid = dev_replace->srcdev->devid;
4428 int index_srcdev = 0;
4429 int found = 0;
4430 u64 physical_of_found = 0;
4431
4432 /*
4433 * During the dev-replace procedure, the target drive can
4434 * also be used to read data in case it is needed to repair
4435 * a corrupt block elsewhere. This is possible if the
4436 * requested area is left of the left cursor. In this area,
4437 * the target drive is a full copy of the source drive.
4438 */
4439 for (i = 0; i < num_stripes; i++) {
4440 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4441 /*
4442 * In case of DUP, in order to keep it
4443 * simple, only add the mirror with the
4444 * lowest physical address
4445 */
4446 if (found &&
4447 physical_of_found <=
4448 bbio->stripes[i].physical)
4449 continue;
4450 index_srcdev = i;
4451 found = 1;
4452 physical_of_found = bbio->stripes[i].physical;
4453 }
4454 }
4455 if (found) {
4456 u64 length = map->stripe_len;
4457
4458 if (physical_of_found + length <=
4459 dev_replace->cursor_left) {
4460 struct btrfs_bio_stripe *tgtdev_stripe =
4461 bbio->stripes + num_stripes;
4462
4463 tgtdev_stripe->physical = physical_of_found;
4464 tgtdev_stripe->length =
4465 bbio->stripes[index_srcdev].length;
4466 tgtdev_stripe->dev = dev_replace->tgtdev;
4467
4468 num_stripes++;
4469 }
4470 }
4471 }
4472
4473 *bbio_ret = bbio;
4474 bbio->num_stripes = num_stripes;
4475 bbio->max_errors = max_errors;
4476 bbio->mirror_num = mirror_num;
4477
4478 /*
4479 * this is the case that REQ_READ && dev_replace_is_ongoing &&
4480 * mirror_num == num_stripes + 1 && dev_replace target drive is
4481 * available as a mirror
4482 */
4483 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
4484 WARN_ON(num_stripes > 1);
4485 bbio->stripes[0].dev = dev_replace->tgtdev;
4486 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
4487 bbio->mirror_num = map->num_stripes + 1;
4488 }
4489 out:
4490 if (dev_replace_is_ongoing)
4491 btrfs_dev_replace_unlock(dev_replace);
4492 free_extent_map(em);
4493 return ret;
4494 }
4495
4496 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4497 u64 logical, u64 *length,
4498 struct btrfs_bio **bbio_ret, int mirror_num)
4499 {
4500 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
4501 mirror_num);
4502 }
4503
4504 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4505 u64 chunk_start, u64 physical, u64 devid,
4506 u64 **logical, int *naddrs, int *stripe_len)
4507 {
4508 struct extent_map_tree *em_tree = &map_tree->map_tree;
4509 struct extent_map *em;
4510 struct map_lookup *map;
4511 u64 *buf;
4512 u64 bytenr;
4513 u64 length;
4514 u64 stripe_nr;
4515 int i, j, nr = 0;
4516
4517 read_lock(&em_tree->lock);
4518 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4519 read_unlock(&em_tree->lock);
4520
4521 BUG_ON(!em || em->start != chunk_start);
4522 map = (struct map_lookup *)em->bdev;
4523
4524 length = em->len;
4525 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4526 do_div(length, map->num_stripes / map->sub_stripes);
4527 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4528 do_div(length, map->num_stripes);
4529
4530 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4531 BUG_ON(!buf); /* -ENOMEM */
4532
4533 for (i = 0; i < map->num_stripes; i++) {
4534 if (devid && map->stripes[i].dev->devid != devid)
4535 continue;
4536 if (map->stripes[i].physical > physical ||
4537 map->stripes[i].physical + length <= physical)
4538 continue;
4539
4540 stripe_nr = physical - map->stripes[i].physical;
4541 do_div(stripe_nr, map->stripe_len);
4542
4543 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4544 stripe_nr = stripe_nr * map->num_stripes + i;
4545 do_div(stripe_nr, map->sub_stripes);
4546 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4547 stripe_nr = stripe_nr * map->num_stripes + i;
4548 }
4549 bytenr = chunk_start + stripe_nr * map->stripe_len;
4550 WARN_ON(nr >= map->num_stripes);
4551 for (j = 0; j < nr; j++) {
4552 if (buf[j] == bytenr)
4553 break;
4554 }
4555 if (j == nr) {
4556 WARN_ON(nr >= map->num_stripes);
4557 buf[nr++] = bytenr;
4558 }
4559 }
4560
4561 *logical = buf;
4562 *naddrs = nr;
4563 *stripe_len = map->stripe_len;
4564
4565 free_extent_map(em);
4566 return 0;
4567 }
4568
4569 static void *merge_stripe_index_into_bio_private(void *bi_private,
4570 unsigned int stripe_index)
4571 {
4572 /*
4573 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
4574 * at most 1.
4575 * The alternative solution (instead of stealing bits from the
4576 * pointer) would be to allocate an intermediate structure
4577 * that contains the old private pointer plus the stripe_index.
4578 */
4579 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
4580 BUG_ON(stripe_index > 3);
4581 return (void *)(((uintptr_t)bi_private) | stripe_index);
4582 }
4583
4584 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
4585 {
4586 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
4587 }
4588
4589 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
4590 {
4591 return (unsigned int)((uintptr_t)bi_private) & 3;
4592 }
4593
4594 static void btrfs_end_bio(struct bio *bio, int err)
4595 {
4596 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
4597 int is_orig_bio = 0;
4598
4599 if (err) {
4600 atomic_inc(&bbio->error);
4601 if (err == -EIO || err == -EREMOTEIO) {
4602 unsigned int stripe_index =
4603 extract_stripe_index_from_bio_private(
4604 bio->bi_private);
4605 struct btrfs_device *dev;
4606
4607 BUG_ON(stripe_index >= bbio->num_stripes);
4608 dev = bbio->stripes[stripe_index].dev;
4609 if (dev->bdev) {
4610 if (bio->bi_rw & WRITE)
4611 btrfs_dev_stat_inc(dev,
4612 BTRFS_DEV_STAT_WRITE_ERRS);
4613 else
4614 btrfs_dev_stat_inc(dev,
4615 BTRFS_DEV_STAT_READ_ERRS);
4616 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
4617 btrfs_dev_stat_inc(dev,
4618 BTRFS_DEV_STAT_FLUSH_ERRS);
4619 btrfs_dev_stat_print_on_error(dev);
4620 }
4621 }
4622 }
4623
4624 if (bio == bbio->orig_bio)
4625 is_orig_bio = 1;
4626
4627 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4628 if (!is_orig_bio) {
4629 bio_put(bio);
4630 bio = bbio->orig_bio;
4631 }
4632 bio->bi_private = bbio->private;
4633 bio->bi_end_io = bbio->end_io;
4634 bio->bi_bdev = (struct block_device *)
4635 (unsigned long)bbio->mirror_num;
4636 /* only send an error to the higher layers if it is
4637 * beyond the tolerance of the multi-bio
4638 */
4639 if (atomic_read(&bbio->error) > bbio->max_errors) {
4640 err = -EIO;
4641 } else {
4642 /*
4643 * this bio is actually up to date, we didn't
4644 * go over the max number of errors
4645 */
4646 set_bit(BIO_UPTODATE, &bio->bi_flags);
4647 err = 0;
4648 }
4649 kfree(bbio);
4650
4651 bio_endio(bio, err);
4652 } else if (!is_orig_bio) {
4653 bio_put(bio);
4654 }
4655 }
4656
4657 struct async_sched {
4658 struct bio *bio;
4659 int rw;
4660 struct btrfs_fs_info *info;
4661 struct btrfs_work work;
4662 };
4663
4664 /*
4665 * see run_scheduled_bios for a description of why bios are collected for
4666 * async submit.
4667 *
4668 * This will add one bio to the pending list for a device and make sure
4669 * the work struct is scheduled.
4670 */
4671 static noinline void schedule_bio(struct btrfs_root *root,
4672 struct btrfs_device *device,
4673 int rw, struct bio *bio)
4674 {
4675 int should_queue = 1;
4676 struct btrfs_pending_bios *pending_bios;
4677
4678 /* don't bother with additional async steps for reads, right now */
4679 if (!(rw & REQ_WRITE)) {
4680 bio_get(bio);
4681 btrfsic_submit_bio(rw, bio);
4682 bio_put(bio);
4683 return;
4684 }
4685
4686 /*
4687 * nr_async_bios allows us to reliably return congestion to the
4688 * higher layers. Otherwise, the async bio makes it appear we have
4689 * made progress against dirty pages when we've really just put it
4690 * on a queue for later
4691 */
4692 atomic_inc(&root->fs_info->nr_async_bios);
4693 WARN_ON(bio->bi_next);
4694 bio->bi_next = NULL;
4695 bio->bi_rw |= rw;
4696
4697 spin_lock(&device->io_lock);
4698 if (bio->bi_rw & REQ_SYNC)
4699 pending_bios = &device->pending_sync_bios;
4700 else
4701 pending_bios = &device->pending_bios;
4702
4703 if (pending_bios->tail)
4704 pending_bios->tail->bi_next = bio;
4705
4706 pending_bios->tail = bio;
4707 if (!pending_bios->head)
4708 pending_bios->head = bio;
4709 if (device->running_pending)
4710 should_queue = 0;
4711
4712 spin_unlock(&device->io_lock);
4713
4714 if (should_queue)
4715 btrfs_queue_worker(&root->fs_info->submit_workers,
4716 &device->work);
4717 }
4718
4719 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
4720 sector_t sector)
4721 {
4722 struct bio_vec *prev;
4723 struct request_queue *q = bdev_get_queue(bdev);
4724 unsigned short max_sectors = queue_max_sectors(q);
4725 struct bvec_merge_data bvm = {
4726 .bi_bdev = bdev,
4727 .bi_sector = sector,
4728 .bi_rw = bio->bi_rw,
4729 };
4730
4731 if (bio->bi_vcnt == 0) {
4732 WARN_ON(1);
4733 return 1;
4734 }
4735
4736 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
4737 if ((bio->bi_size >> 9) > max_sectors)
4738 return 0;
4739
4740 if (!q->merge_bvec_fn)
4741 return 1;
4742
4743 bvm.bi_size = bio->bi_size - prev->bv_len;
4744 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
4745 return 0;
4746 return 1;
4747 }
4748
4749 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
4750 struct bio *bio, u64 physical, int dev_nr,
4751 int rw, int async)
4752 {
4753 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
4754
4755 bio->bi_private = bbio;
4756 bio->bi_private = merge_stripe_index_into_bio_private(
4757 bio->bi_private, (unsigned int)dev_nr);
4758 bio->bi_end_io = btrfs_end_bio;
4759 bio->bi_sector = physical >> 9;
4760 #ifdef DEBUG
4761 {
4762 struct rcu_string *name;
4763
4764 rcu_read_lock();
4765 name = rcu_dereference(dev->name);
4766 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
4767 "(%s id %llu), size=%u\n", rw,
4768 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
4769 name->str, dev->devid, bio->bi_size);
4770 rcu_read_unlock();
4771 }
4772 #endif
4773 bio->bi_bdev = dev->bdev;
4774 if (async)
4775 schedule_bio(root, dev, rw, bio);
4776 else
4777 btrfsic_submit_bio(rw, bio);
4778 }
4779
4780 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
4781 struct bio *first_bio, struct btrfs_device *dev,
4782 int dev_nr, int rw, int async)
4783 {
4784 struct bio_vec *bvec = first_bio->bi_io_vec;
4785 struct bio *bio;
4786 int nr_vecs = bio_get_nr_vecs(dev->bdev);
4787 u64 physical = bbio->stripes[dev_nr].physical;
4788
4789 again:
4790 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
4791 if (!bio)
4792 return -ENOMEM;
4793
4794 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
4795 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
4796 bvec->bv_offset) < bvec->bv_len) {
4797 u64 len = bio->bi_size;
4798
4799 atomic_inc(&bbio->stripes_pending);
4800 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
4801 rw, async);
4802 physical += len;
4803 goto again;
4804 }
4805 bvec++;
4806 }
4807
4808 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
4809 return 0;
4810 }
4811
4812 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
4813 {
4814 atomic_inc(&bbio->error);
4815 if (atomic_dec_and_test(&bbio->stripes_pending)) {
4816 bio->bi_private = bbio->private;
4817 bio->bi_end_io = bbio->end_io;
4818 bio->bi_bdev = (struct block_device *)
4819 (unsigned long)bbio->mirror_num;
4820 bio->bi_sector = logical >> 9;
4821 kfree(bbio);
4822 bio_endio(bio, -EIO);
4823 }
4824 }
4825
4826 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
4827 int mirror_num, int async_submit)
4828 {
4829 struct btrfs_device *dev;
4830 struct bio *first_bio = bio;
4831 u64 logical = (u64)bio->bi_sector << 9;
4832 u64 length = 0;
4833 u64 map_length;
4834 int ret;
4835 int dev_nr = 0;
4836 int total_devs = 1;
4837 struct btrfs_bio *bbio = NULL;
4838
4839 length = bio->bi_size;
4840 map_length = length;
4841
4842 ret = btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
4843 mirror_num);
4844 if (ret)
4845 return ret;
4846
4847 total_devs = bbio->num_stripes;
4848 if (map_length < length) {
4849 printk(KERN_CRIT "btrfs: mapping failed logical %llu bio len %llu "
4850 "len %llu\n", (unsigned long long)logical,
4851 (unsigned long long)length,
4852 (unsigned long long)map_length);
4853 BUG();
4854 }
4855
4856 bbio->orig_bio = first_bio;
4857 bbio->private = first_bio->bi_private;
4858 bbio->end_io = first_bio->bi_end_io;
4859 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
4860
4861 while (dev_nr < total_devs) {
4862 dev = bbio->stripes[dev_nr].dev;
4863 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
4864 bbio_error(bbio, first_bio, logical);
4865 dev_nr++;
4866 continue;
4867 }
4868
4869 /*
4870 * Check and see if we're ok with this bio based on it's size
4871 * and offset with the given device.
4872 */
4873 if (!bio_size_ok(dev->bdev, first_bio,
4874 bbio->stripes[dev_nr].physical >> 9)) {
4875 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
4876 dev_nr, rw, async_submit);
4877 BUG_ON(ret);
4878 dev_nr++;
4879 continue;
4880 }
4881
4882 if (dev_nr < total_devs - 1) {
4883 bio = bio_clone(first_bio, GFP_NOFS);
4884 BUG_ON(!bio); /* -ENOMEM */
4885 } else {
4886 bio = first_bio;
4887 }
4888
4889 submit_stripe_bio(root, bbio, bio,
4890 bbio->stripes[dev_nr].physical, dev_nr, rw,
4891 async_submit);
4892 dev_nr++;
4893 }
4894 return 0;
4895 }
4896
4897 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
4898 u8 *uuid, u8 *fsid)
4899 {
4900 struct btrfs_device *device;
4901 struct btrfs_fs_devices *cur_devices;
4902
4903 cur_devices = fs_info->fs_devices;
4904 while (cur_devices) {
4905 if (!fsid ||
4906 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
4907 device = __find_device(&cur_devices->devices,
4908 devid, uuid);
4909 if (device)
4910 return device;
4911 }
4912 cur_devices = cur_devices->seed;
4913 }
4914 return NULL;
4915 }
4916
4917 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
4918 u64 devid, u8 *dev_uuid)
4919 {
4920 struct btrfs_device *device;
4921 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
4922
4923 device = kzalloc(sizeof(*device), GFP_NOFS);
4924 if (!device)
4925 return NULL;
4926 list_add(&device->dev_list,
4927 &fs_devices->devices);
4928 device->dev_root = root->fs_info->dev_root;
4929 device->devid = devid;
4930 device->work.func = pending_bios_fn;
4931 device->fs_devices = fs_devices;
4932 device->missing = 1;
4933 fs_devices->num_devices++;
4934 fs_devices->missing_devices++;
4935 spin_lock_init(&device->io_lock);
4936 INIT_LIST_HEAD(&device->dev_alloc_list);
4937 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
4938 return device;
4939 }
4940
4941 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
4942 struct extent_buffer *leaf,
4943 struct btrfs_chunk *chunk)
4944 {
4945 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4946 struct map_lookup *map;
4947 struct extent_map *em;
4948 u64 logical;
4949 u64 length;
4950 u64 devid;
4951 u8 uuid[BTRFS_UUID_SIZE];
4952 int num_stripes;
4953 int ret;
4954 int i;
4955
4956 logical = key->offset;
4957 length = btrfs_chunk_length(leaf, chunk);
4958
4959 read_lock(&map_tree->map_tree.lock);
4960 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
4961 read_unlock(&map_tree->map_tree.lock);
4962
4963 /* already mapped? */
4964 if (em && em->start <= logical && em->start + em->len > logical) {
4965 free_extent_map(em);
4966 return 0;
4967 } else if (em) {
4968 free_extent_map(em);
4969 }
4970
4971 em = alloc_extent_map();
4972 if (!em)
4973 return -ENOMEM;
4974 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
4975 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
4976 if (!map) {
4977 free_extent_map(em);
4978 return -ENOMEM;
4979 }
4980
4981 em->bdev = (struct block_device *)map;
4982 em->start = logical;
4983 em->len = length;
4984 em->orig_start = 0;
4985 em->block_start = 0;
4986 em->block_len = em->len;
4987
4988 map->num_stripes = num_stripes;
4989 map->io_width = btrfs_chunk_io_width(leaf, chunk);
4990 map->io_align = btrfs_chunk_io_align(leaf, chunk);
4991 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
4992 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
4993 map->type = btrfs_chunk_type(leaf, chunk);
4994 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
4995 for (i = 0; i < num_stripes; i++) {
4996 map->stripes[i].physical =
4997 btrfs_stripe_offset_nr(leaf, chunk, i);
4998 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
4999 read_extent_buffer(leaf, uuid, (unsigned long)
5000 btrfs_stripe_dev_uuid_nr(chunk, i),
5001 BTRFS_UUID_SIZE);
5002 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5003 uuid, NULL);
5004 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5005 kfree(map);
5006 free_extent_map(em);
5007 return -EIO;
5008 }
5009 if (!map->stripes[i].dev) {
5010 map->stripes[i].dev =
5011 add_missing_dev(root, devid, uuid);
5012 if (!map->stripes[i].dev) {
5013 kfree(map);
5014 free_extent_map(em);
5015 return -EIO;
5016 }
5017 }
5018 map->stripes[i].dev->in_fs_metadata = 1;
5019 }
5020
5021 write_lock(&map_tree->map_tree.lock);
5022 ret = add_extent_mapping(&map_tree->map_tree, em);
5023 write_unlock(&map_tree->map_tree.lock);
5024 BUG_ON(ret); /* Tree corruption */
5025 free_extent_map(em);
5026
5027 return 0;
5028 }
5029
5030 static void fill_device_from_item(struct extent_buffer *leaf,
5031 struct btrfs_dev_item *dev_item,
5032 struct btrfs_device *device)
5033 {
5034 unsigned long ptr;
5035
5036 device->devid = btrfs_device_id(leaf, dev_item);
5037 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5038 device->total_bytes = device->disk_total_bytes;
5039 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5040 device->type = btrfs_device_type(leaf, dev_item);
5041 device->io_align = btrfs_device_io_align(leaf, dev_item);
5042 device->io_width = btrfs_device_io_width(leaf, dev_item);
5043 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5044 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5045 device->is_tgtdev_for_dev_replace = 0;
5046
5047 ptr = (unsigned long)btrfs_device_uuid(dev_item);
5048 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5049 }
5050
5051 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5052 {
5053 struct btrfs_fs_devices *fs_devices;
5054 int ret;
5055
5056 BUG_ON(!mutex_is_locked(&uuid_mutex));
5057
5058 fs_devices = root->fs_info->fs_devices->seed;
5059 while (fs_devices) {
5060 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5061 ret = 0;
5062 goto out;
5063 }
5064 fs_devices = fs_devices->seed;
5065 }
5066
5067 fs_devices = find_fsid(fsid);
5068 if (!fs_devices) {
5069 ret = -ENOENT;
5070 goto out;
5071 }
5072
5073 fs_devices = clone_fs_devices(fs_devices);
5074 if (IS_ERR(fs_devices)) {
5075 ret = PTR_ERR(fs_devices);
5076 goto out;
5077 }
5078
5079 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5080 root->fs_info->bdev_holder);
5081 if (ret) {
5082 free_fs_devices(fs_devices);
5083 goto out;
5084 }
5085
5086 if (!fs_devices->seeding) {
5087 __btrfs_close_devices(fs_devices);
5088 free_fs_devices(fs_devices);
5089 ret = -EINVAL;
5090 goto out;
5091 }
5092
5093 fs_devices->seed = root->fs_info->fs_devices->seed;
5094 root->fs_info->fs_devices->seed = fs_devices;
5095 out:
5096 return ret;
5097 }
5098
5099 static int read_one_dev(struct btrfs_root *root,
5100 struct extent_buffer *leaf,
5101 struct btrfs_dev_item *dev_item)
5102 {
5103 struct btrfs_device *device;
5104 u64 devid;
5105 int ret;
5106 u8 fs_uuid[BTRFS_UUID_SIZE];
5107 u8 dev_uuid[BTRFS_UUID_SIZE];
5108
5109 devid = btrfs_device_id(leaf, dev_item);
5110 read_extent_buffer(leaf, dev_uuid,
5111 (unsigned long)btrfs_device_uuid(dev_item),
5112 BTRFS_UUID_SIZE);
5113 read_extent_buffer(leaf, fs_uuid,
5114 (unsigned long)btrfs_device_fsid(dev_item),
5115 BTRFS_UUID_SIZE);
5116
5117 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5118 ret = open_seed_devices(root, fs_uuid);
5119 if (ret && !btrfs_test_opt(root, DEGRADED))
5120 return ret;
5121 }
5122
5123 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5124 if (!device || !device->bdev) {
5125 if (!btrfs_test_opt(root, DEGRADED))
5126 return -EIO;
5127
5128 if (!device) {
5129 printk(KERN_WARNING "warning devid %llu missing\n",
5130 (unsigned long long)devid);
5131 device = add_missing_dev(root, devid, dev_uuid);
5132 if (!device)
5133 return -ENOMEM;
5134 } else if (!device->missing) {
5135 /*
5136 * this happens when a device that was properly setup
5137 * in the device info lists suddenly goes bad.
5138 * device->bdev is NULL, and so we have to set
5139 * device->missing to one here
5140 */
5141 root->fs_info->fs_devices->missing_devices++;
5142 device->missing = 1;
5143 }
5144 }
5145
5146 if (device->fs_devices != root->fs_info->fs_devices) {
5147 BUG_ON(device->writeable);
5148 if (device->generation !=
5149 btrfs_device_generation(leaf, dev_item))
5150 return -EINVAL;
5151 }
5152
5153 fill_device_from_item(leaf, dev_item, device);
5154 device->dev_root = root->fs_info->dev_root;
5155 device->in_fs_metadata = 1;
5156 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5157 device->fs_devices->total_rw_bytes += device->total_bytes;
5158 spin_lock(&root->fs_info->free_chunk_lock);
5159 root->fs_info->free_chunk_space += device->total_bytes -
5160 device->bytes_used;
5161 spin_unlock(&root->fs_info->free_chunk_lock);
5162 }
5163 ret = 0;
5164 return ret;
5165 }
5166
5167 int btrfs_read_sys_array(struct btrfs_root *root)
5168 {
5169 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5170 struct extent_buffer *sb;
5171 struct btrfs_disk_key *disk_key;
5172 struct btrfs_chunk *chunk;
5173 u8 *ptr;
5174 unsigned long sb_ptr;
5175 int ret = 0;
5176 u32 num_stripes;
5177 u32 array_size;
5178 u32 len = 0;
5179 u32 cur;
5180 struct btrfs_key key;
5181
5182 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5183 BTRFS_SUPER_INFO_SIZE);
5184 if (!sb)
5185 return -ENOMEM;
5186 btrfs_set_buffer_uptodate(sb);
5187 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5188 /*
5189 * The sb extent buffer is artifical and just used to read the system array.
5190 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5191 * pages up-to-date when the page is larger: extent does not cover the
5192 * whole page and consequently check_page_uptodate does not find all
5193 * the page's extents up-to-date (the hole beyond sb),
5194 * write_extent_buffer then triggers a WARN_ON.
5195 *
5196 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5197 * but sb spans only this function. Add an explicit SetPageUptodate call
5198 * to silence the warning eg. on PowerPC 64.
5199 */
5200 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5201 SetPageUptodate(sb->pages[0]);
5202
5203 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5204 array_size = btrfs_super_sys_array_size(super_copy);
5205
5206 ptr = super_copy->sys_chunk_array;
5207 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5208 cur = 0;
5209
5210 while (cur < array_size) {
5211 disk_key = (struct btrfs_disk_key *)ptr;
5212 btrfs_disk_key_to_cpu(&key, disk_key);
5213
5214 len = sizeof(*disk_key); ptr += len;
5215 sb_ptr += len;
5216 cur += len;
5217
5218 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5219 chunk = (struct btrfs_chunk *)sb_ptr;
5220 ret = read_one_chunk(root, &key, sb, chunk);
5221 if (ret)
5222 break;
5223 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5224 len = btrfs_chunk_item_size(num_stripes);
5225 } else {
5226 ret = -EIO;
5227 break;
5228 }
5229 ptr += len;
5230 sb_ptr += len;
5231 cur += len;
5232 }
5233 free_extent_buffer(sb);
5234 return ret;
5235 }
5236
5237 int btrfs_read_chunk_tree(struct btrfs_root *root)
5238 {
5239 struct btrfs_path *path;
5240 struct extent_buffer *leaf;
5241 struct btrfs_key key;
5242 struct btrfs_key found_key;
5243 int ret;
5244 int slot;
5245
5246 root = root->fs_info->chunk_root;
5247
5248 path = btrfs_alloc_path();
5249 if (!path)
5250 return -ENOMEM;
5251
5252 mutex_lock(&uuid_mutex);
5253 lock_chunks(root);
5254
5255 /* first we search for all of the device items, and then we
5256 * read in all of the chunk items. This way we can create chunk
5257 * mappings that reference all of the devices that are afound
5258 */
5259 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5260 key.offset = 0;
5261 key.type = 0;
5262 again:
5263 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5264 if (ret < 0)
5265 goto error;
5266 while (1) {
5267 leaf = path->nodes[0];
5268 slot = path->slots[0];
5269 if (slot >= btrfs_header_nritems(leaf)) {
5270 ret = btrfs_next_leaf(root, path);
5271 if (ret == 0)
5272 continue;
5273 if (ret < 0)
5274 goto error;
5275 break;
5276 }
5277 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5278 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5279 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
5280 break;
5281 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
5282 struct btrfs_dev_item *dev_item;
5283 dev_item = btrfs_item_ptr(leaf, slot,
5284 struct btrfs_dev_item);
5285 ret = read_one_dev(root, leaf, dev_item);
5286 if (ret)
5287 goto error;
5288 }
5289 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
5290 struct btrfs_chunk *chunk;
5291 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
5292 ret = read_one_chunk(root, &found_key, leaf, chunk);
5293 if (ret)
5294 goto error;
5295 }
5296 path->slots[0]++;
5297 }
5298 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5299 key.objectid = 0;
5300 btrfs_release_path(path);
5301 goto again;
5302 }
5303 ret = 0;
5304 error:
5305 unlock_chunks(root);
5306 mutex_unlock(&uuid_mutex);
5307
5308 btrfs_free_path(path);
5309 return ret;
5310 }
5311
5312 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
5313 {
5314 int i;
5315
5316 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5317 btrfs_dev_stat_reset(dev, i);
5318 }
5319
5320 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
5321 {
5322 struct btrfs_key key;
5323 struct btrfs_key found_key;
5324 struct btrfs_root *dev_root = fs_info->dev_root;
5325 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5326 struct extent_buffer *eb;
5327 int slot;
5328 int ret = 0;
5329 struct btrfs_device *device;
5330 struct btrfs_path *path = NULL;
5331 int i;
5332
5333 path = btrfs_alloc_path();
5334 if (!path) {
5335 ret = -ENOMEM;
5336 goto out;
5337 }
5338
5339 mutex_lock(&fs_devices->device_list_mutex);
5340 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5341 int item_size;
5342 struct btrfs_dev_stats_item *ptr;
5343
5344 key.objectid = 0;
5345 key.type = BTRFS_DEV_STATS_KEY;
5346 key.offset = device->devid;
5347 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
5348 if (ret) {
5349 __btrfs_reset_dev_stats(device);
5350 device->dev_stats_valid = 1;
5351 btrfs_release_path(path);
5352 continue;
5353 }
5354 slot = path->slots[0];
5355 eb = path->nodes[0];
5356 btrfs_item_key_to_cpu(eb, &found_key, slot);
5357 item_size = btrfs_item_size_nr(eb, slot);
5358
5359 ptr = btrfs_item_ptr(eb, slot,
5360 struct btrfs_dev_stats_item);
5361
5362 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5363 if (item_size >= (1 + i) * sizeof(__le64))
5364 btrfs_dev_stat_set(device, i,
5365 btrfs_dev_stats_value(eb, ptr, i));
5366 else
5367 btrfs_dev_stat_reset(device, i);
5368 }
5369
5370 device->dev_stats_valid = 1;
5371 btrfs_dev_stat_print_on_load(device);
5372 btrfs_release_path(path);
5373 }
5374 mutex_unlock(&fs_devices->device_list_mutex);
5375
5376 out:
5377 btrfs_free_path(path);
5378 return ret < 0 ? ret : 0;
5379 }
5380
5381 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
5382 struct btrfs_root *dev_root,
5383 struct btrfs_device *device)
5384 {
5385 struct btrfs_path *path;
5386 struct btrfs_key key;
5387 struct extent_buffer *eb;
5388 struct btrfs_dev_stats_item *ptr;
5389 int ret;
5390 int i;
5391
5392 key.objectid = 0;
5393 key.type = BTRFS_DEV_STATS_KEY;
5394 key.offset = device->devid;
5395
5396 path = btrfs_alloc_path();
5397 BUG_ON(!path);
5398 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
5399 if (ret < 0) {
5400 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
5401 ret, rcu_str_deref(device->name));
5402 goto out;
5403 }
5404
5405 if (ret == 0 &&
5406 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
5407 /* need to delete old one and insert a new one */
5408 ret = btrfs_del_item(trans, dev_root, path);
5409 if (ret != 0) {
5410 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
5411 rcu_str_deref(device->name), ret);
5412 goto out;
5413 }
5414 ret = 1;
5415 }
5416
5417 if (ret == 1) {
5418 /* need to insert a new item */
5419 btrfs_release_path(path);
5420 ret = btrfs_insert_empty_item(trans, dev_root, path,
5421 &key, sizeof(*ptr));
5422 if (ret < 0) {
5423 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
5424 rcu_str_deref(device->name), ret);
5425 goto out;
5426 }
5427 }
5428
5429 eb = path->nodes[0];
5430 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
5431 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5432 btrfs_set_dev_stats_value(eb, ptr, i,
5433 btrfs_dev_stat_read(device, i));
5434 btrfs_mark_buffer_dirty(eb);
5435
5436 out:
5437 btrfs_free_path(path);
5438 return ret;
5439 }
5440
5441 /*
5442 * called from commit_transaction. Writes all changed device stats to disk.
5443 */
5444 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
5445 struct btrfs_fs_info *fs_info)
5446 {
5447 struct btrfs_root *dev_root = fs_info->dev_root;
5448 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5449 struct btrfs_device *device;
5450 int ret = 0;
5451
5452 mutex_lock(&fs_devices->device_list_mutex);
5453 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5454 if (!device->dev_stats_valid || !device->dev_stats_dirty)
5455 continue;
5456
5457 ret = update_dev_stat_item(trans, dev_root, device);
5458 if (!ret)
5459 device->dev_stats_dirty = 0;
5460 }
5461 mutex_unlock(&fs_devices->device_list_mutex);
5462
5463 return ret;
5464 }
5465
5466 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
5467 {
5468 btrfs_dev_stat_inc(dev, index);
5469 btrfs_dev_stat_print_on_error(dev);
5470 }
5471
5472 void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
5473 {
5474 if (!dev->dev_stats_valid)
5475 return;
5476 printk_ratelimited_in_rcu(KERN_ERR
5477 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5478 rcu_str_deref(dev->name),
5479 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5480 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5481 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5482 btrfs_dev_stat_read(dev,
5483 BTRFS_DEV_STAT_CORRUPTION_ERRS),
5484 btrfs_dev_stat_read(dev,
5485 BTRFS_DEV_STAT_GENERATION_ERRS));
5486 }
5487
5488 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
5489 {
5490 int i;
5491
5492 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5493 if (btrfs_dev_stat_read(dev, i) != 0)
5494 break;
5495 if (i == BTRFS_DEV_STAT_VALUES_MAX)
5496 return; /* all values == 0, suppress message */
5497
5498 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5499 rcu_str_deref(dev->name),
5500 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5501 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5502 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5503 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
5504 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
5505 }
5506
5507 int btrfs_get_dev_stats(struct btrfs_root *root,
5508 struct btrfs_ioctl_get_dev_stats *stats)
5509 {
5510 struct btrfs_device *dev;
5511 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5512 int i;
5513
5514 mutex_lock(&fs_devices->device_list_mutex);
5515 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
5516 mutex_unlock(&fs_devices->device_list_mutex);
5517
5518 if (!dev) {
5519 printk(KERN_WARNING
5520 "btrfs: get dev_stats failed, device not found\n");
5521 return -ENODEV;
5522 } else if (!dev->dev_stats_valid) {
5523 printk(KERN_WARNING
5524 "btrfs: get dev_stats failed, not yet valid\n");
5525 return -ENODEV;
5526 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
5527 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5528 if (stats->nr_items > i)
5529 stats->values[i] =
5530 btrfs_dev_stat_read_and_reset(dev, i);
5531 else
5532 btrfs_dev_stat_reset(dev, i);
5533 }
5534 } else {
5535 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5536 if (stats->nr_items > i)
5537 stats->values[i] = btrfs_dev_stat_read(dev, i);
5538 }
5539 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
5540 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
5541 return 0;
5542 }
5543
5544 int btrfs_scratch_superblock(struct btrfs_device *device)
5545 {
5546 struct buffer_head *bh;
5547 struct btrfs_super_block *disk_super;
5548
5549 bh = btrfs_read_dev_super(device->bdev);
5550 if (!bh)
5551 return -EINVAL;
5552 disk_super = (struct btrfs_super_block *)bh->b_data;
5553
5554 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
5555 set_buffer_dirty(bh);
5556 sync_dirty_buffer(bh);
5557 brelse(bh);
5558
5559 return 0;
5560 }
CRIS linux kernel tree