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clocksource: nomadik-mtu: support of probe
[linux-2.6/btrfs-unstable.git] / fs / btrfs / volumes.c
blob0e925ced971ba87bc0e356c6a2c7e3dbf1b5e91e
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <linux/ratelimit.h>
27 #include <linux/kthread.h>
28 #include <linux/raid/pq.h>
29 #include <asm/div64.h>
30 #include "compat.h"
31 #include "ctree.h"
32 #include "extent_map.h"
33 #include "disk-io.h"
34 #include "transaction.h"
35 #include "print-tree.h"
36 #include "volumes.h"
37 #include "raid56.h"
38 #include "async-thread.h"
39 #include "check-integrity.h"
40 #include "rcu-string.h"
41 #include "math.h"
42 #include "dev-replace.h"
43
44 static int init_first_rw_device(struct btrfs_trans_handle *trans,
45 struct btrfs_root *root,
46 struct btrfs_device *device);
47 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
48 static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
49 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
50 static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
51
52 static DEFINE_MUTEX(uuid_mutex);
53 static LIST_HEAD(fs_uuids);
54
55 static void lock_chunks(struct btrfs_root *root)
56 {
57 mutex_lock(&root->fs_info->chunk_mutex);
58 }
59
60 static void unlock_chunks(struct btrfs_root *root)
61 {
62 mutex_unlock(&root->fs_info->chunk_mutex);
63 }
64
65 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
66 {
67 struct btrfs_device *device;
68 WARN_ON(fs_devices->opened);
69 while (!list_empty(&fs_devices->devices)) {
70 device = list_entry(fs_devices->devices.next,
71 struct btrfs_device, dev_list);
72 list_del(&device->dev_list);
73 rcu_string_free(device->name);
74 kfree(device);
75 }
76 kfree(fs_devices);
77 }
78
79 static void btrfs_kobject_uevent(struct block_device *bdev,
80 enum kobject_action action)
81 {
82 int ret;
83
84 ret = kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, action);
85 if (ret)
86 pr_warn("Sending event '%d' to kobject: '%s' (%p): failed\n",
87 action,
88 kobject_name(&disk_to_dev(bdev->bd_disk)->kobj),
89 &disk_to_dev(bdev->bd_disk)->kobj);
90 }
91
92 void btrfs_cleanup_fs_uuids(void)
93 {
94 struct btrfs_fs_devices *fs_devices;
95
96 while (!list_empty(&fs_uuids)) {
97 fs_devices = list_entry(fs_uuids.next,
98 struct btrfs_fs_devices, list);
99 list_del(&fs_devices->list);
100 free_fs_devices(fs_devices);
101 }
102 }
103
104 static noinline struct btrfs_device *__find_device(struct list_head *head,
105 u64 devid, u8 *uuid)
106 {
107 struct btrfs_device *dev;
108
109 list_for_each_entry(dev, head, dev_list) {
110 if (dev->devid == devid &&
111 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
112 return dev;
113 }
114 }
115 return NULL;
116 }
117
118 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
119 {
120 struct btrfs_fs_devices *fs_devices;
121
122 list_for_each_entry(fs_devices, &fs_uuids, list) {
123 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
124 return fs_devices;
125 }
126 return NULL;
127 }
128
129 static int
130 btrfs_get_bdev_and_sb(const char *device_path, fmode_t flags, void *holder,
131 int flush, struct block_device **bdev,
132 struct buffer_head **bh)
133 {
134 int ret;
135
136 *bdev = blkdev_get_by_path(device_path, flags, holder);
137
138 if (IS_ERR(*bdev)) {
139 ret = PTR_ERR(*bdev);
140 printk(KERN_INFO "btrfs: open %s failed\n", device_path);
141 goto error;
142 }
143
144 if (flush)
145 filemap_write_and_wait((*bdev)->bd_inode->i_mapping);
146 ret = set_blocksize(*bdev, 4096);
147 if (ret) {
148 blkdev_put(*bdev, flags);
149 goto error;
150 }
151 invalidate_bdev(*bdev);
152 *bh = btrfs_read_dev_super(*bdev);
153 if (!*bh) {
154 ret = -EINVAL;
155 blkdev_put(*bdev, flags);
156 goto error;
157 }
158
159 return 0;
160
161 error:
162 *bdev = NULL;
163 *bh = NULL;
164 return ret;
165 }
166
167 static void requeue_list(struct btrfs_pending_bios *pending_bios,
168 struct bio *head, struct bio *tail)
169 {
170
171 struct bio *old_head;
172
173 old_head = pending_bios->head;
174 pending_bios->head = head;
175 if (pending_bios->tail)
176 tail->bi_next = old_head;
177 else
178 pending_bios->tail = tail;
179 }
180
181 /*
182 * we try to collect pending bios for a device so we don't get a large
183 * number of procs sending bios down to the same device. This greatly
184 * improves the schedulers ability to collect and merge the bios.
185 *
186 * But, it also turns into a long list of bios to process and that is sure
187 * to eventually make the worker thread block. The solution here is to
188 * make some progress and then put this work struct back at the end of
189 * the list if the block device is congested. This way, multiple devices
190 * can make progress from a single worker thread.
191 */
192 static noinline void run_scheduled_bios(struct btrfs_device *device)
193 {
194 struct bio *pending;
195 struct backing_dev_info *bdi;
196 struct btrfs_fs_info *fs_info;
197 struct btrfs_pending_bios *pending_bios;
198 struct bio *tail;
199 struct bio *cur;
200 int again = 0;
201 unsigned long num_run;
202 unsigned long batch_run = 0;
203 unsigned long limit;
204 unsigned long last_waited = 0;
205 int force_reg = 0;
206 int sync_pending = 0;
207 struct blk_plug plug;
208
209 /*
210 * this function runs all the bios we've collected for
211 * a particular device. We don't want to wander off to
212 * another device without first sending all of these down.
213 * So, setup a plug here and finish it off before we return
214 */
215 blk_start_plug(&plug);
216
217 bdi = blk_get_backing_dev_info(device->bdev);
218 fs_info = device->dev_root->fs_info;
219 limit = btrfs_async_submit_limit(fs_info);
220 limit = limit * 2 / 3;
221
222 loop:
223 spin_lock(&device->io_lock);
224
225 loop_lock:
226 num_run = 0;
227
228 /* take all the bios off the list at once and process them
229 * later on (without the lock held). But, remember the
230 * tail and other pointers so the bios can be properly reinserted
231 * into the list if we hit congestion
232 */
233 if (!force_reg && device->pending_sync_bios.head) {
234 pending_bios = &device->pending_sync_bios;
235 force_reg = 1;
236 } else {
237 pending_bios = &device->pending_bios;
238 force_reg = 0;
239 }
240
241 pending = pending_bios->head;
242 tail = pending_bios->tail;
243 WARN_ON(pending && !tail);
244
245 /*
246 * if pending was null this time around, no bios need processing
247 * at all and we can stop. Otherwise it'll loop back up again
248 * and do an additional check so no bios are missed.
249 *
250 * device->running_pending is used to synchronize with the
251 * schedule_bio code.
252 */
253 if (device->pending_sync_bios.head == NULL &&
254 device->pending_bios.head == NULL) {
255 again = 0;
256 device->running_pending = 0;
257 } else {
258 again = 1;
259 device->running_pending = 1;
260 }
261
262 pending_bios->head = NULL;
263 pending_bios->tail = NULL;
264
265 spin_unlock(&device->io_lock);
266
267 while (pending) {
268
269 rmb();
270 /* we want to work on both lists, but do more bios on the
271 * sync list than the regular list
272 */
273 if ((num_run > 32 &&
274 pending_bios != &device->pending_sync_bios &&
275 device->pending_sync_bios.head) ||
276 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
277 device->pending_bios.head)) {
278 spin_lock(&device->io_lock);
279 requeue_list(pending_bios, pending, tail);
280 goto loop_lock;
281 }
282
283 cur = pending;
284 pending = pending->bi_next;
285 cur->bi_next = NULL;
286
287 if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
288 waitqueue_active(&fs_info->async_submit_wait))
289 wake_up(&fs_info->async_submit_wait);
290
291 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
292
293 /*
294 * if we're doing the sync list, record that our
295 * plug has some sync requests on it
296 *
297 * If we're doing the regular list and there are
298 * sync requests sitting around, unplug before
299 * we add more
300 */
301 if (pending_bios == &device->pending_sync_bios) {
302 sync_pending = 1;
303 } else if (sync_pending) {
304 blk_finish_plug(&plug);
305 blk_start_plug(&plug);
306 sync_pending = 0;
307 }
308
309 btrfsic_submit_bio(cur->bi_rw, cur);
310 num_run++;
311 batch_run++;
312 if (need_resched())
313 cond_resched();
314
315 /*
316 * we made progress, there is more work to do and the bdi
317 * is now congested. Back off and let other work structs
318 * run instead
319 */
320 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
321 fs_info->fs_devices->open_devices > 1) {
322 struct io_context *ioc;
323
324 ioc = current->io_context;
325
326 /*
327 * the main goal here is that we don't want to
328 * block if we're going to be able to submit
329 * more requests without blocking.
330 *
331 * This code does two great things, it pokes into
332 * the elevator code from a filesystem _and_
333 * it makes assumptions about how batching works.
334 */
335 if (ioc && ioc->nr_batch_requests > 0 &&
336 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
337 (last_waited == 0 ||
338 ioc->last_waited == last_waited)) {
339 /*
340 * we want to go through our batch of
341 * requests and stop. So, we copy out
342 * the ioc->last_waited time and test
343 * against it before looping
344 */
345 last_waited = ioc->last_waited;
346 if (need_resched())
347 cond_resched();
348 continue;
349 }
350 spin_lock(&device->io_lock);
351 requeue_list(pending_bios, pending, tail);
352 device->running_pending = 1;
353
354 spin_unlock(&device->io_lock);
355 btrfs_requeue_work(&device->work);
356 goto done;
357 }
358 /* unplug every 64 requests just for good measure */
359 if (batch_run % 64 == 0) {
360 blk_finish_plug(&plug);
361 blk_start_plug(&plug);
362 sync_pending = 0;
363 }
364 }
365
366 cond_resched();
367 if (again)
368 goto loop;
369
370 spin_lock(&device->io_lock);
371 if (device->pending_bios.head || device->pending_sync_bios.head)
372 goto loop_lock;
373 spin_unlock(&device->io_lock);
374
375 done:
376 blk_finish_plug(&plug);
377 }
378
379 static void pending_bios_fn(struct btrfs_work *work)
380 {
381 struct btrfs_device *device;
382
383 device = container_of(work, struct btrfs_device, work);
384 run_scheduled_bios(device);
385 }
386
387 static noinline int device_list_add(const char *path,
388 struct btrfs_super_block *disk_super,
389 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
390 {
391 struct btrfs_device *device;
392 struct btrfs_fs_devices *fs_devices;
393 struct rcu_string *name;
394 u64 found_transid = btrfs_super_generation(disk_super);
395
396 fs_devices = find_fsid(disk_super->fsid);
397 if (!fs_devices) {
398 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
399 if (!fs_devices)
400 return -ENOMEM;
401 INIT_LIST_HEAD(&fs_devices->devices);
402 INIT_LIST_HEAD(&fs_devices->alloc_list);
403 list_add(&fs_devices->list, &fs_uuids);
404 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
405 fs_devices->latest_devid = devid;
406 fs_devices->latest_trans = found_transid;
407 mutex_init(&fs_devices->device_list_mutex);
408 device = NULL;
409 } else {
410 device = __find_device(&fs_devices->devices, devid,
411 disk_super->dev_item.uuid);
412 }
413 if (!device) {
414 if (fs_devices->opened)
415 return -EBUSY;
416
417 device = kzalloc(sizeof(*device), GFP_NOFS);
418 if (!device) {
419 /* we can safely leave the fs_devices entry around */
420 return -ENOMEM;
421 }
422 device->devid = devid;
423 device->dev_stats_valid = 0;
424 device->work.func = pending_bios_fn;
425 memcpy(device->uuid, disk_super->dev_item.uuid,
426 BTRFS_UUID_SIZE);
427 spin_lock_init(&device->io_lock);
428
429 name = rcu_string_strdup(path, GFP_NOFS);
430 if (!name) {
431 kfree(device);
432 return -ENOMEM;
433 }
434 rcu_assign_pointer(device->name, name);
435 INIT_LIST_HEAD(&device->dev_alloc_list);
436
437 /* init readahead state */
438 spin_lock_init(&device->reada_lock);
439 device->reada_curr_zone = NULL;
440 atomic_set(&device->reada_in_flight, 0);
441 device->reada_next = 0;
442 INIT_RADIX_TREE(&device->reada_zones, GFP_NOFS & ~__GFP_WAIT);
443 INIT_RADIX_TREE(&device->reada_extents, GFP_NOFS & ~__GFP_WAIT);
444
445 mutex_lock(&fs_devices->device_list_mutex);
446 list_add_rcu(&device->dev_list, &fs_devices->devices);
447 mutex_unlock(&fs_devices->device_list_mutex);
448
449 device->fs_devices = fs_devices;
450 fs_devices->num_devices++;
451 } else if (!device->name || strcmp(device->name->str, path)) {
452 name = rcu_string_strdup(path, GFP_NOFS);
453 if (!name)
454 return -ENOMEM;
455 rcu_string_free(device->name);
456 rcu_assign_pointer(device->name, name);
457 if (device->missing) {
458 fs_devices->missing_devices--;
459 device->missing = 0;
460 }
461 }
462
463 if (found_transid > fs_devices->latest_trans) {
464 fs_devices->latest_devid = devid;
465 fs_devices->latest_trans = found_transid;
466 }
467 *fs_devices_ret = fs_devices;
468 return 0;
469 }
470
471 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
472 {
473 struct btrfs_fs_devices *fs_devices;
474 struct btrfs_device *device;
475 struct btrfs_device *orig_dev;
476
477 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
478 if (!fs_devices)
479 return ERR_PTR(-ENOMEM);
480
481 INIT_LIST_HEAD(&fs_devices->devices);
482 INIT_LIST_HEAD(&fs_devices->alloc_list);
483 INIT_LIST_HEAD(&fs_devices->list);
484 mutex_init(&fs_devices->device_list_mutex);
485 fs_devices->latest_devid = orig->latest_devid;
486 fs_devices->latest_trans = orig->latest_trans;
487 fs_devices->total_devices = orig->total_devices;
488 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
489
490 /* We have held the volume lock, it is safe to get the devices. */
491 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
492 struct rcu_string *name;
493
494 device = kzalloc(sizeof(*device), GFP_NOFS);
495 if (!device)
496 goto error;
497
498 /*
499 * This is ok to do without rcu read locked because we hold the
500 * uuid mutex so nothing we touch in here is going to disappear.
501 */
502 name = rcu_string_strdup(orig_dev->name->str, GFP_NOFS);
503 if (!name) {
504 kfree(device);
505 goto error;
506 }
507 rcu_assign_pointer(device->name, name);
508
509 device->devid = orig_dev->devid;
510 device->work.func = pending_bios_fn;
511 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
512 spin_lock_init(&device->io_lock);
513 INIT_LIST_HEAD(&device->dev_list);
514 INIT_LIST_HEAD(&device->dev_alloc_list);
515
516 list_add(&device->dev_list, &fs_devices->devices);
517 device->fs_devices = fs_devices;
518 fs_devices->num_devices++;
519 }
520 return fs_devices;
521 error:
522 free_fs_devices(fs_devices);
523 return ERR_PTR(-ENOMEM);
524 }
525
526 void btrfs_close_extra_devices(struct btrfs_fs_info *fs_info,
527 struct btrfs_fs_devices *fs_devices, int step)
528 {
529 struct btrfs_device *device, *next;
530
531 struct block_device *latest_bdev = NULL;
532 u64 latest_devid = 0;
533 u64 latest_transid = 0;
534
535 mutex_lock(&uuid_mutex);
536 again:
537 /* This is the initialized path, it is safe to release the devices. */
538 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
539 if (device->in_fs_metadata) {
540 if (!device->is_tgtdev_for_dev_replace &&
541 (!latest_transid ||
542 device->generation > latest_transid)) {
543 latest_devid = device->devid;
544 latest_transid = device->generation;
545 latest_bdev = device->bdev;
546 }
547 continue;
548 }
549
550 if (device->devid == BTRFS_DEV_REPLACE_DEVID) {
551 /*
552 * In the first step, keep the device which has
553 * the correct fsid and the devid that is used
554 * for the dev_replace procedure.
555 * In the second step, the dev_replace state is
556 * read from the device tree and it is known
557 * whether the procedure is really active or
558 * not, which means whether this device is
559 * used or whether it should be removed.
560 */
561 if (step == 0 || device->is_tgtdev_for_dev_replace) {
562 continue;
563 }
564 }
565 if (device->bdev) {
566 blkdev_put(device->bdev, device->mode);
567 device->bdev = NULL;
568 fs_devices->open_devices--;
569 }
570 if (device->writeable) {
571 list_del_init(&device->dev_alloc_list);
572 device->writeable = 0;
573 if (!device->is_tgtdev_for_dev_replace)
574 fs_devices->rw_devices--;
575 }
576 list_del_init(&device->dev_list);
577 fs_devices->num_devices--;
578 rcu_string_free(device->name);
579 kfree(device);
580 }
581
582 if (fs_devices->seed) {
583 fs_devices = fs_devices->seed;
584 goto again;
585 }
586
587 fs_devices->latest_bdev = latest_bdev;
588 fs_devices->latest_devid = latest_devid;
589 fs_devices->latest_trans = latest_transid;
590
591 mutex_unlock(&uuid_mutex);
592 }
593
594 static void __free_device(struct work_struct *work)
595 {
596 struct btrfs_device *device;
597
598 device = container_of(work, struct btrfs_device, rcu_work);
599
600 if (device->bdev)
601 blkdev_put(device->bdev, device->mode);
602
603 rcu_string_free(device->name);
604 kfree(device);
605 }
606
607 static void free_device(struct rcu_head *head)
608 {
609 struct btrfs_device *device;
610
611 device = container_of(head, struct btrfs_device, rcu);
612
613 INIT_WORK(&device->rcu_work, __free_device);
614 schedule_work(&device->rcu_work);
615 }
616
617 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
618 {
619 struct btrfs_device *device;
620
621 if (--fs_devices->opened > 0)
622 return 0;
623
624 mutex_lock(&fs_devices->device_list_mutex);
625 list_for_each_entry(device, &fs_devices->devices, dev_list) {
626 struct btrfs_device *new_device;
627 struct rcu_string *name;
628
629 if (device->bdev)
630 fs_devices->open_devices--;
631
632 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
633 list_del_init(&device->dev_alloc_list);
634 fs_devices->rw_devices--;
635 }
636
637 if (device->can_discard)
638 fs_devices->num_can_discard--;
639
640 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
641 BUG_ON(!new_device); /* -ENOMEM */
642 memcpy(new_device, device, sizeof(*new_device));
643
644 /* Safe because we are under uuid_mutex */
645 if (device->name) {
646 name = rcu_string_strdup(device->name->str, GFP_NOFS);
647 BUG_ON(device->name && !name); /* -ENOMEM */
648 rcu_assign_pointer(new_device->name, name);
649 }
650 new_device->bdev = NULL;
651 new_device->writeable = 0;
652 new_device->in_fs_metadata = 0;
653 new_device->can_discard = 0;
654 spin_lock_init(&new_device->io_lock);
655 list_replace_rcu(&device->dev_list, &new_device->dev_list);
656
657 call_rcu(&device->rcu, free_device);
658 }
659 mutex_unlock(&fs_devices->device_list_mutex);
660
661 WARN_ON(fs_devices->open_devices);
662 WARN_ON(fs_devices->rw_devices);
663 fs_devices->opened = 0;
664 fs_devices->seeding = 0;
665
666 return 0;
667 }
668
669 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
670 {
671 struct btrfs_fs_devices *seed_devices = NULL;
672 int ret;
673
674 mutex_lock(&uuid_mutex);
675 ret = __btrfs_close_devices(fs_devices);
676 if (!fs_devices->opened) {
677 seed_devices = fs_devices->seed;
678 fs_devices->seed = NULL;
679 }
680 mutex_unlock(&uuid_mutex);
681
682 while (seed_devices) {
683 fs_devices = seed_devices;
684 seed_devices = fs_devices->seed;
685 __btrfs_close_devices(fs_devices);
686 free_fs_devices(fs_devices);
687 }
688 /*
689 * Wait for rcu kworkers under __btrfs_close_devices
690 * to finish all blkdev_puts so device is really
691 * free when umount is done.
692 */
693 rcu_barrier();
694 return ret;
695 }
696
697 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
698 fmode_t flags, void *holder)
699 {
700 struct request_queue *q;
701 struct block_device *bdev;
702 struct list_head *head = &fs_devices->devices;
703 struct btrfs_device *device;
704 struct block_device *latest_bdev = NULL;
705 struct buffer_head *bh;
706 struct btrfs_super_block *disk_super;
707 u64 latest_devid = 0;
708 u64 latest_transid = 0;
709 u64 devid;
710 int seeding = 1;
711 int ret = 0;
712
713 flags |= FMODE_EXCL;
714
715 list_for_each_entry(device, head, dev_list) {
716 if (device->bdev)
717 continue;
718 if (!device->name)
719 continue;
720
721 /* Just open everything we can; ignore failures here */
722 if (btrfs_get_bdev_and_sb(device->name->str, flags, holder, 1,
723 &bdev, &bh))
724 continue;
725
726 disk_super = (struct btrfs_super_block *)bh->b_data;
727 devid = btrfs_stack_device_id(&disk_super->dev_item);
728 if (devid != device->devid)
729 goto error_brelse;
730
731 if (memcmp(device->uuid, disk_super->dev_item.uuid,
732 BTRFS_UUID_SIZE))
733 goto error_brelse;
734
735 device->generation = btrfs_super_generation(disk_super);
736 if (!latest_transid || device->generation > latest_transid) {
737 latest_devid = devid;
738 latest_transid = device->generation;
739 latest_bdev = bdev;
740 }
741
742 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
743 device->writeable = 0;
744 } else {
745 device->writeable = !bdev_read_only(bdev);
746 seeding = 0;
747 }
748
749 q = bdev_get_queue(bdev);
750 if (blk_queue_discard(q)) {
751 device->can_discard = 1;
752 fs_devices->num_can_discard++;
753 }
754
755 device->bdev = bdev;
756 device->in_fs_metadata = 0;
757 device->mode = flags;
758
759 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
760 fs_devices->rotating = 1;
761
762 fs_devices->open_devices++;
763 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
764 fs_devices->rw_devices++;
765 list_add(&device->dev_alloc_list,
766 &fs_devices->alloc_list);
767 }
768 brelse(bh);
769 continue;
770
771 error_brelse:
772 brelse(bh);
773 blkdev_put(bdev, flags);
774 continue;
775 }
776 if (fs_devices->open_devices == 0) {
777 ret = -EINVAL;
778 goto out;
779 }
780 fs_devices->seeding = seeding;
781 fs_devices->opened = 1;
782 fs_devices->latest_bdev = latest_bdev;
783 fs_devices->latest_devid = latest_devid;
784 fs_devices->latest_trans = latest_transid;
785 fs_devices->total_rw_bytes = 0;
786 out:
787 return ret;
788 }
789
790 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
791 fmode_t flags, void *holder)
792 {
793 int ret;
794
795 mutex_lock(&uuid_mutex);
796 if (fs_devices->opened) {
797 fs_devices->opened++;
798 ret = 0;
799 } else {
800 ret = __btrfs_open_devices(fs_devices, flags, holder);
801 }
802 mutex_unlock(&uuid_mutex);
803 return ret;
804 }
805
806 /*
807 * Look for a btrfs signature on a device. This may be called out of the mount path
808 * and we are not allowed to call set_blocksize during the scan. The superblock
809 * is read via pagecache
810 */
811 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
812 struct btrfs_fs_devices **fs_devices_ret)
813 {
814 struct btrfs_super_block *disk_super;
815 struct block_device *bdev;
816 struct page *page;
817 void *p;
818 int ret = -EINVAL;
819 u64 devid;
820 u64 transid;
821 u64 total_devices;
822 u64 bytenr;
823 pgoff_t index;
824
825 /*
826 * we would like to check all the supers, but that would make
827 * a btrfs mount succeed after a mkfs from a different FS.
828 * So, we need to add a special mount option to scan for
829 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
830 */
831 bytenr = btrfs_sb_offset(0);
832 flags |= FMODE_EXCL;
833 mutex_lock(&uuid_mutex);
834
835 bdev = blkdev_get_by_path(path, flags, holder);
836
837 if (IS_ERR(bdev)) {
838 ret = PTR_ERR(bdev);
839 goto error;
840 }
841
842 /* make sure our super fits in the device */
843 if (bytenr + PAGE_CACHE_SIZE >= i_size_read(bdev->bd_inode))
844 goto error_bdev_put;
845
846 /* make sure our super fits in the page */
847 if (sizeof(*disk_super) > PAGE_CACHE_SIZE)
848 goto error_bdev_put;
849
850 /* make sure our super doesn't straddle pages on disk */
851 index = bytenr >> PAGE_CACHE_SHIFT;
852 if ((bytenr + sizeof(*disk_super) - 1) >> PAGE_CACHE_SHIFT != index)
853 goto error_bdev_put;
854
855 /* pull in the page with our super */
856 page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
857 index, GFP_NOFS);
858
859 if (IS_ERR_OR_NULL(page))
860 goto error_bdev_put;
861
862 p = kmap(page);
863
864 /* align our pointer to the offset of the super block */
865 disk_super = p + (bytenr & ~PAGE_CACHE_MASK);
866
867 if (btrfs_super_bytenr(disk_super) != bytenr ||
868 disk_super->magic != cpu_to_le64(BTRFS_MAGIC))
869 goto error_unmap;
870
871 devid = btrfs_stack_device_id(&disk_super->dev_item);
872 transid = btrfs_super_generation(disk_super);
873 total_devices = btrfs_super_num_devices(disk_super);
874
875 if (disk_super->label[0]) {
876 if (disk_super->label[BTRFS_LABEL_SIZE - 1])
877 disk_super->label[BTRFS_LABEL_SIZE - 1] = '\0';
878 printk(KERN_INFO "device label %s ", disk_super->label);
879 } else {
880 printk(KERN_INFO "device fsid %pU ", disk_super->fsid);
881 }
882
883 printk(KERN_CONT "devid %llu transid %llu %s\n",
884 (unsigned long long)devid, (unsigned long long)transid, path);
885
886 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
887 if (!ret && fs_devices_ret)
888 (*fs_devices_ret)->total_devices = total_devices;
889
890 error_unmap:
891 kunmap(page);
892 page_cache_release(page);
893
894 error_bdev_put:
895 blkdev_put(bdev, flags);
896 error:
897 mutex_unlock(&uuid_mutex);
898 return ret;
899 }
900
901 /* helper to account the used device space in the range */
902 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
903 u64 end, u64 *length)
904 {
905 struct btrfs_key key;
906 struct btrfs_root *root = device->dev_root;
907 struct btrfs_dev_extent *dev_extent;
908 struct btrfs_path *path;
909 u64 extent_end;
910 int ret;
911 int slot;
912 struct extent_buffer *l;
913
914 *length = 0;
915
916 if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
917 return 0;
918
919 path = btrfs_alloc_path();
920 if (!path)
921 return -ENOMEM;
922 path->reada = 2;
923
924 key.objectid = device->devid;
925 key.offset = start;
926 key.type = BTRFS_DEV_EXTENT_KEY;
927
928 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
929 if (ret < 0)
930 goto out;
931 if (ret > 0) {
932 ret = btrfs_previous_item(root, path, key.objectid, key.type);
933 if (ret < 0)
934 goto out;
935 }
936
937 while (1) {
938 l = path->nodes[0];
939 slot = path->slots[0];
940 if (slot >= btrfs_header_nritems(l)) {
941 ret = btrfs_next_leaf(root, path);
942 if (ret == 0)
943 continue;
944 if (ret < 0)
945 goto out;
946
947 break;
948 }
949 btrfs_item_key_to_cpu(l, &key, slot);
950
951 if (key.objectid < device->devid)
952 goto next;
953
954 if (key.objectid > device->devid)
955 break;
956
957 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
958 goto next;
959
960 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
961 extent_end = key.offset + btrfs_dev_extent_length(l,
962 dev_extent);
963 if (key.offset <= start && extent_end > end) {
964 *length = end - start + 1;
965 break;
966 } else if (key.offset <= start && extent_end > start)
967 *length += extent_end - start;
968 else if (key.offset > start && extent_end <= end)
969 *length += extent_end - key.offset;
970 else if (key.offset > start && key.offset <= end) {
971 *length += end - key.offset + 1;
972 break;
973 } else if (key.offset > end)
974 break;
975
976 next:
977 path->slots[0]++;
978 }
979 ret = 0;
980 out:
981 btrfs_free_path(path);
982 return ret;
983 }
984
985 /*
986 * find_free_dev_extent - find free space in the specified device
987 * @device: the device which we search the free space in
988 * @num_bytes: the size of the free space that we need
989 * @start: store the start of the free space.
990 * @len: the size of the free space. that we find, or the size of the max
991 * free space if we don't find suitable free space
992 *
993 * this uses a pretty simple search, the expectation is that it is
994 * called very infrequently and that a given device has a small number
995 * of extents
996 *
997 * @start is used to store the start of the free space if we find. But if we
998 * don't find suitable free space, it will be used to store the start position
999 * of the max free space.
1000 *
1001 * @len is used to store the size of the free space that we find.
1002 * But if we don't find suitable free space, it is used to store the size of
1003 * the max free space.
1004 */
1005 int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
1006 u64 *start, u64 *len)
1007 {
1008 struct btrfs_key key;
1009 struct btrfs_root *root = device->dev_root;
1010 struct btrfs_dev_extent *dev_extent;
1011 struct btrfs_path *path;
1012 u64 hole_size;
1013 u64 max_hole_start;
1014 u64 max_hole_size;
1015 u64 extent_end;
1016 u64 search_start;
1017 u64 search_end = device->total_bytes;
1018 int ret;
1019 int slot;
1020 struct extent_buffer *l;
1021
1022 /* FIXME use last free of some kind */
1023
1024 /* we don't want to overwrite the superblock on the drive,
1025 * so we make sure to start at an offset of at least 1MB
1026 */
1027 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
1028
1029 max_hole_start = search_start;
1030 max_hole_size = 0;
1031 hole_size = 0;
1032
1033 if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
1034 ret = -ENOSPC;
1035 goto error;
1036 }
1037
1038 path = btrfs_alloc_path();
1039 if (!path) {
1040 ret = -ENOMEM;
1041 goto error;
1042 }
1043 path->reada = 2;
1044
1045 key.objectid = device->devid;
1046 key.offset = search_start;
1047 key.type = BTRFS_DEV_EXTENT_KEY;
1048
1049 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1050 if (ret < 0)
1051 goto out;
1052 if (ret > 0) {
1053 ret = btrfs_previous_item(root, path, key.objectid, key.type);
1054 if (ret < 0)
1055 goto out;
1056 }
1057
1058 while (1) {
1059 l = path->nodes[0];
1060 slot = path->slots[0];
1061 if (slot >= btrfs_header_nritems(l)) {
1062 ret = btrfs_next_leaf(root, path);
1063 if (ret == 0)
1064 continue;
1065 if (ret < 0)
1066 goto out;
1067
1068 break;
1069 }
1070 btrfs_item_key_to_cpu(l, &key, slot);
1071
1072 if (key.objectid < device->devid)
1073 goto next;
1074
1075 if (key.objectid > device->devid)
1076 break;
1077
1078 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
1079 goto next;
1080
1081 if (key.offset > search_start) {
1082 hole_size = key.offset - search_start;
1083
1084 if (hole_size > max_hole_size) {
1085 max_hole_start = search_start;
1086 max_hole_size = hole_size;
1087 }
1088
1089 /*
1090 * If this free space is greater than which we need,
1091 * it must be the max free space that we have found
1092 * until now, so max_hole_start must point to the start
1093 * of this free space and the length of this free space
1094 * is stored in max_hole_size. Thus, we return
1095 * max_hole_start and max_hole_size and go back to the
1096 * caller.
1097 */
1098 if (hole_size >= num_bytes) {
1099 ret = 0;
1100 goto out;
1101 }
1102 }
1103
1104 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1105 extent_end = key.offset + btrfs_dev_extent_length(l,
1106 dev_extent);
1107 if (extent_end > search_start)
1108 search_start = extent_end;
1109 next:
1110 path->slots[0]++;
1111 cond_resched();
1112 }
1113
1114 /*
1115 * At this point, search_start should be the end of
1116 * allocated dev extents, and when shrinking the device,
1117 * search_end may be smaller than search_start.
1118 */
1119 if (search_end > search_start)
1120 hole_size = search_end - search_start;
1121
1122 if (hole_size > max_hole_size) {
1123 max_hole_start = search_start;
1124 max_hole_size = hole_size;
1125 }
1126
1127 /* See above. */
1128 if (hole_size < num_bytes)
1129 ret = -ENOSPC;
1130 else
1131 ret = 0;
1132
1133 out:
1134 btrfs_free_path(path);
1135 error:
1136 *start = max_hole_start;
1137 if (len)
1138 *len = max_hole_size;
1139 return ret;
1140 }
1141
1142 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
1143 struct btrfs_device *device,
1144 u64 start)
1145 {
1146 int ret;
1147 struct btrfs_path *path;
1148 struct btrfs_root *root = device->dev_root;
1149 struct btrfs_key key;
1150 struct btrfs_key found_key;
1151 struct extent_buffer *leaf = NULL;
1152 struct btrfs_dev_extent *extent = NULL;
1153
1154 path = btrfs_alloc_path();
1155 if (!path)
1156 return -ENOMEM;
1157
1158 key.objectid = device->devid;
1159 key.offset = start;
1160 key.type = BTRFS_DEV_EXTENT_KEY;
1161 again:
1162 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1163 if (ret > 0) {
1164 ret = btrfs_previous_item(root, path, key.objectid,
1165 BTRFS_DEV_EXTENT_KEY);
1166 if (ret)
1167 goto out;
1168 leaf = path->nodes[0];
1169 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1170 extent = btrfs_item_ptr(leaf, path->slots[0],
1171 struct btrfs_dev_extent);
1172 BUG_ON(found_key.offset > start || found_key.offset +
1173 btrfs_dev_extent_length(leaf, extent) < start);
1174 key = found_key;
1175 btrfs_release_path(path);
1176 goto again;
1177 } else if (ret == 0) {
1178 leaf = path->nodes[0];
1179 extent = btrfs_item_ptr(leaf, path->slots[0],
1180 struct btrfs_dev_extent);
1181 } else {
1182 btrfs_error(root->fs_info, ret, "Slot search failed");
1183 goto out;
1184 }
1185
1186 if (device->bytes_used > 0) {
1187 u64 len = btrfs_dev_extent_length(leaf, extent);
1188 device->bytes_used -= len;
1189 spin_lock(&root->fs_info->free_chunk_lock);
1190 root->fs_info->free_chunk_space += len;
1191 spin_unlock(&root->fs_info->free_chunk_lock);
1192 }
1193 ret = btrfs_del_item(trans, root, path);
1194 if (ret) {
1195 btrfs_error(root->fs_info, ret,
1196 "Failed to remove dev extent item");
1197 }
1198 out:
1199 btrfs_free_path(path);
1200 return ret;
1201 }
1202
1203 static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
1204 struct btrfs_device *device,
1205 u64 chunk_tree, u64 chunk_objectid,
1206 u64 chunk_offset, u64 start, u64 num_bytes)
1207 {
1208 int ret;
1209 struct btrfs_path *path;
1210 struct btrfs_root *root = device->dev_root;
1211 struct btrfs_dev_extent *extent;
1212 struct extent_buffer *leaf;
1213 struct btrfs_key key;
1214
1215 WARN_ON(!device->in_fs_metadata);
1216 WARN_ON(device->is_tgtdev_for_dev_replace);
1217 path = btrfs_alloc_path();
1218 if (!path)
1219 return -ENOMEM;
1220
1221 key.objectid = device->devid;
1222 key.offset = start;
1223 key.type = BTRFS_DEV_EXTENT_KEY;
1224 ret = btrfs_insert_empty_item(trans, root, path, &key,
1225 sizeof(*extent));
1226 if (ret)
1227 goto out;
1228
1229 leaf = path->nodes[0];
1230 extent = btrfs_item_ptr(leaf, path->slots[0],
1231 struct btrfs_dev_extent);
1232 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1233 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1234 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1235
1236 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1237 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1238 BTRFS_UUID_SIZE);
1239
1240 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1241 btrfs_mark_buffer_dirty(leaf);
1242 out:
1243 btrfs_free_path(path);
1244 return ret;
1245 }
1246
1247 static noinline int find_next_chunk(struct btrfs_root *root,
1248 u64 objectid, u64 *offset)
1249 {
1250 struct btrfs_path *path;
1251 int ret;
1252 struct btrfs_key key;
1253 struct btrfs_chunk *chunk;
1254 struct btrfs_key found_key;
1255
1256 path = btrfs_alloc_path();
1257 if (!path)
1258 return -ENOMEM;
1259
1260 key.objectid = objectid;
1261 key.offset = (u64)-1;
1262 key.type = BTRFS_CHUNK_ITEM_KEY;
1263
1264 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1265 if (ret < 0)
1266 goto error;
1267
1268 BUG_ON(ret == 0); /* Corruption */
1269
1270 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1271 if (ret) {
1272 *offset = 0;
1273 } else {
1274 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1275 path->slots[0]);
1276 if (found_key.objectid != objectid)
1277 *offset = 0;
1278 else {
1279 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1280 struct btrfs_chunk);
1281 *offset = found_key.offset +
1282 btrfs_chunk_length(path->nodes[0], chunk);
1283 }
1284 }
1285 ret = 0;
1286 error:
1287 btrfs_free_path(path);
1288 return ret;
1289 }
1290
1291 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1292 {
1293 int ret;
1294 struct btrfs_key key;
1295 struct btrfs_key found_key;
1296 struct btrfs_path *path;
1297
1298 root = root->fs_info->chunk_root;
1299
1300 path = btrfs_alloc_path();
1301 if (!path)
1302 return -ENOMEM;
1303
1304 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1305 key.type = BTRFS_DEV_ITEM_KEY;
1306 key.offset = (u64)-1;
1307
1308 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1309 if (ret < 0)
1310 goto error;
1311
1312 BUG_ON(ret == 0); /* Corruption */
1313
1314 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1315 BTRFS_DEV_ITEM_KEY);
1316 if (ret) {
1317 *objectid = 1;
1318 } else {
1319 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1320 path->slots[0]);
1321 *objectid = found_key.offset + 1;
1322 }
1323 ret = 0;
1324 error:
1325 btrfs_free_path(path);
1326 return ret;
1327 }
1328
1329 /*
1330 * the device information is stored in the chunk root
1331 * the btrfs_device struct should be fully filled in
1332 */
1333 static int btrfs_add_device(struct btrfs_trans_handle *trans,
1334 struct btrfs_root *root,
1335 struct btrfs_device *device)
1336 {
1337 int ret;
1338 struct btrfs_path *path;
1339 struct btrfs_dev_item *dev_item;
1340 struct extent_buffer *leaf;
1341 struct btrfs_key key;
1342 unsigned long ptr;
1343
1344 root = root->fs_info->chunk_root;
1345
1346 path = btrfs_alloc_path();
1347 if (!path)
1348 return -ENOMEM;
1349
1350 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1351 key.type = BTRFS_DEV_ITEM_KEY;
1352 key.offset = device->devid;
1353
1354 ret = btrfs_insert_empty_item(trans, root, path, &key,
1355 sizeof(*dev_item));
1356 if (ret)
1357 goto out;
1358
1359 leaf = path->nodes[0];
1360 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1361
1362 btrfs_set_device_id(leaf, dev_item, device->devid);
1363 btrfs_set_device_generation(leaf, dev_item, 0);
1364 btrfs_set_device_type(leaf, dev_item, device->type);
1365 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1366 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1367 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1368 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1369 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1370 btrfs_set_device_group(leaf, dev_item, 0);
1371 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1372 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1373 btrfs_set_device_start_offset(leaf, dev_item, 0);
1374
1375 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1376 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1377 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1378 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1379 btrfs_mark_buffer_dirty(leaf);
1380
1381 ret = 0;
1382 out:
1383 btrfs_free_path(path);
1384 return ret;
1385 }
1386
1387 static int btrfs_rm_dev_item(struct btrfs_root *root,
1388 struct btrfs_device *device)
1389 {
1390 int ret;
1391 struct btrfs_path *path;
1392 struct btrfs_key key;
1393 struct btrfs_trans_handle *trans;
1394
1395 root = root->fs_info->chunk_root;
1396
1397 path = btrfs_alloc_path();
1398 if (!path)
1399 return -ENOMEM;
1400
1401 trans = btrfs_start_transaction(root, 0);
1402 if (IS_ERR(trans)) {
1403 btrfs_free_path(path);
1404 return PTR_ERR(trans);
1405 }
1406 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1407 key.type = BTRFS_DEV_ITEM_KEY;
1408 key.offset = device->devid;
1409 lock_chunks(root);
1410
1411 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1412 if (ret < 0)
1413 goto out;
1414
1415 if (ret > 0) {
1416 ret = -ENOENT;
1417 goto out;
1418 }
1419
1420 ret = btrfs_del_item(trans, root, path);
1421 if (ret)
1422 goto out;
1423 out:
1424 btrfs_free_path(path);
1425 unlock_chunks(root);
1426 btrfs_commit_transaction(trans, root);
1427 return ret;
1428 }
1429
1430 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1431 {
1432 struct btrfs_device *device;
1433 struct btrfs_device *next_device;
1434 struct block_device *bdev;
1435 struct buffer_head *bh = NULL;
1436 struct btrfs_super_block *disk_super;
1437 struct btrfs_fs_devices *cur_devices;
1438 u64 all_avail;
1439 u64 devid;
1440 u64 num_devices;
1441 u8 *dev_uuid;
1442 unsigned seq;
1443 int ret = 0;
1444 bool clear_super = false;
1445
1446 mutex_lock(&uuid_mutex);
1447
1448 do {
1449 seq = read_seqbegin(&root->fs_info->profiles_lock);
1450
1451 all_avail = root->fs_info->avail_data_alloc_bits |
1452 root->fs_info->avail_system_alloc_bits |
1453 root->fs_info->avail_metadata_alloc_bits;
1454 } while (read_seqretry(&root->fs_info->profiles_lock, seq));
1455
1456 num_devices = root->fs_info->fs_devices->num_devices;
1457 btrfs_dev_replace_lock(&root->fs_info->dev_replace);
1458 if (btrfs_dev_replace_is_ongoing(&root->fs_info->dev_replace)) {
1459 WARN_ON(num_devices < 1);
1460 num_devices--;
1461 }
1462 btrfs_dev_replace_unlock(&root->fs_info->dev_replace);
1463
1464 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) && num_devices <= 4) {
1465 printk(KERN_ERR "btrfs: unable to go below four devices "
1466 "on raid10\n");
1467 ret = -EINVAL;
1468 goto out;
1469 }
1470
1471 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) && num_devices <= 2) {
1472 printk(KERN_ERR "btrfs: unable to go below two "
1473 "devices on raid1\n");
1474 ret = -EINVAL;
1475 goto out;
1476 }
1477
1478 if ((all_avail & BTRFS_BLOCK_GROUP_RAID5) &&
1479 root->fs_info->fs_devices->rw_devices <= 2) {
1480 printk(KERN_ERR "btrfs: unable to go below two "
1481 "devices on raid5\n");
1482 ret = -EINVAL;
1483 goto out;
1484 }
1485 if ((all_avail & BTRFS_BLOCK_GROUP_RAID6) &&
1486 root->fs_info->fs_devices->rw_devices <= 3) {
1487 printk(KERN_ERR "btrfs: unable to go below three "
1488 "devices on raid6\n");
1489 ret = -EINVAL;
1490 goto out;
1491 }
1492
1493 if (strcmp(device_path, "missing") == 0) {
1494 struct list_head *devices;
1495 struct btrfs_device *tmp;
1496
1497 device = NULL;
1498 devices = &root->fs_info->fs_devices->devices;
1499 /*
1500 * It is safe to read the devices since the volume_mutex
1501 * is held.
1502 */
1503 list_for_each_entry(tmp, devices, dev_list) {
1504 if (tmp->in_fs_metadata &&
1505 !tmp->is_tgtdev_for_dev_replace &&
1506 !tmp->bdev) {
1507 device = tmp;
1508 break;
1509 }
1510 }
1511 bdev = NULL;
1512 bh = NULL;
1513 disk_super = NULL;
1514 if (!device) {
1515 printk(KERN_ERR "btrfs: no missing devices found to "
1516 "remove\n");
1517 goto out;
1518 }
1519 } else {
1520 ret = btrfs_get_bdev_and_sb(device_path,
1521 FMODE_WRITE | FMODE_EXCL,
1522 root->fs_info->bdev_holder, 0,
1523 &bdev, &bh);
1524 if (ret)
1525 goto out;
1526 disk_super = (struct btrfs_super_block *)bh->b_data;
1527 devid = btrfs_stack_device_id(&disk_super->dev_item);
1528 dev_uuid = disk_super->dev_item.uuid;
1529 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1530 disk_super->fsid);
1531 if (!device) {
1532 ret = -ENOENT;
1533 goto error_brelse;
1534 }
1535 }
1536
1537 if (device->is_tgtdev_for_dev_replace) {
1538 pr_err("btrfs: unable to remove the dev_replace target dev\n");
1539 ret = -EINVAL;
1540 goto error_brelse;
1541 }
1542
1543 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1544 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1545 "device\n");
1546 ret = -EINVAL;
1547 goto error_brelse;
1548 }
1549
1550 if (device->writeable) {
1551 lock_chunks(root);
1552 list_del_init(&device->dev_alloc_list);
1553 unlock_chunks(root);
1554 root->fs_info->fs_devices->rw_devices--;
1555 clear_super = true;
1556 }
1557
1558 ret = btrfs_shrink_device(device, 0);
1559 if (ret)
1560 goto error_undo;
1561
1562 /*
1563 * TODO: the superblock still includes this device in its num_devices
1564 * counter although write_all_supers() is not locked out. This
1565 * could give a filesystem state which requires a degraded mount.
1566 */
1567 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1568 if (ret)
1569 goto error_undo;
1570
1571 spin_lock(&root->fs_info->free_chunk_lock);
1572 root->fs_info->free_chunk_space = device->total_bytes -
1573 device->bytes_used;
1574 spin_unlock(&root->fs_info->free_chunk_lock);
1575
1576 device->in_fs_metadata = 0;
1577 btrfs_scrub_cancel_dev(root->fs_info, device);
1578
1579 /*
1580 * the device list mutex makes sure that we don't change
1581 * the device list while someone else is writing out all
1582 * the device supers.
1583 */
1584
1585 cur_devices = device->fs_devices;
1586 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1587 list_del_rcu(&device->dev_list);
1588
1589 device->fs_devices->num_devices--;
1590 device->fs_devices->total_devices--;
1591
1592 if (device->missing)
1593 root->fs_info->fs_devices->missing_devices--;
1594
1595 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1596 struct btrfs_device, dev_list);
1597 if (device->bdev == root->fs_info->sb->s_bdev)
1598 root->fs_info->sb->s_bdev = next_device->bdev;
1599 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1600 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1601
1602 if (device->bdev)
1603 device->fs_devices->open_devices--;
1604
1605 call_rcu(&device->rcu, free_device);
1606 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1607
1608 num_devices = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
1609 btrfs_set_super_num_devices(root->fs_info->super_copy, num_devices);
1610
1611 if (cur_devices->open_devices == 0) {
1612 struct btrfs_fs_devices *fs_devices;
1613 fs_devices = root->fs_info->fs_devices;
1614 while (fs_devices) {
1615 if (fs_devices->seed == cur_devices)
1616 break;
1617 fs_devices = fs_devices->seed;
1618 }
1619 fs_devices->seed = cur_devices->seed;
1620 cur_devices->seed = NULL;
1621 lock_chunks(root);
1622 __btrfs_close_devices(cur_devices);
1623 unlock_chunks(root);
1624 free_fs_devices(cur_devices);
1625 }
1626
1627 root->fs_info->num_tolerated_disk_barrier_failures =
1628 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
1629
1630 /*
1631 * at this point, the device is zero sized. We want to
1632 * remove it from the devices list and zero out the old super
1633 */
1634 if (clear_super && disk_super) {
1635 /* make sure this device isn't detected as part of
1636 * the FS anymore
1637 */
1638 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1639 set_buffer_dirty(bh);
1640 sync_dirty_buffer(bh);
1641 }
1642
1643 ret = 0;
1644
1645 /* Notify udev that device has changed */
1646 if (bdev)
1647 btrfs_kobject_uevent(bdev, KOBJ_CHANGE);
1648
1649 error_brelse:
1650 brelse(bh);
1651 if (bdev)
1652 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1653 out:
1654 mutex_unlock(&uuid_mutex);
1655 return ret;
1656 error_undo:
1657 if (device->writeable) {
1658 lock_chunks(root);
1659 list_add(&device->dev_alloc_list,
1660 &root->fs_info->fs_devices->alloc_list);
1661 unlock_chunks(root);
1662 root->fs_info->fs_devices->rw_devices++;
1663 }
1664 goto error_brelse;
1665 }
1666
1667 void btrfs_rm_dev_replace_srcdev(struct btrfs_fs_info *fs_info,
1668 struct btrfs_device *srcdev)
1669 {
1670 WARN_ON(!mutex_is_locked(&fs_info->fs_devices->device_list_mutex));
1671 list_del_rcu(&srcdev->dev_list);
1672 list_del_rcu(&srcdev->dev_alloc_list);
1673 fs_info->fs_devices->num_devices--;
1674 if (srcdev->missing) {
1675 fs_info->fs_devices->missing_devices--;
1676 fs_info->fs_devices->rw_devices++;
1677 }
1678 if (srcdev->can_discard)
1679 fs_info->fs_devices->num_can_discard--;
1680 if (srcdev->bdev)
1681 fs_info->fs_devices->open_devices--;
1682
1683 call_rcu(&srcdev->rcu, free_device);
1684 }
1685
1686 void btrfs_destroy_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
1687 struct btrfs_device *tgtdev)
1688 {
1689 struct btrfs_device *next_device;
1690
1691 WARN_ON(!tgtdev);
1692 mutex_lock(&fs_info->fs_devices->device_list_mutex);
1693 if (tgtdev->bdev) {
1694 btrfs_scratch_superblock(tgtdev);
1695 fs_info->fs_devices->open_devices--;
1696 }
1697 fs_info->fs_devices->num_devices--;
1698 if (tgtdev->can_discard)
1699 fs_info->fs_devices->num_can_discard++;
1700
1701 next_device = list_entry(fs_info->fs_devices->devices.next,
1702 struct btrfs_device, dev_list);
1703 if (tgtdev->bdev == fs_info->sb->s_bdev)
1704 fs_info->sb->s_bdev = next_device->bdev;
1705 if (tgtdev->bdev == fs_info->fs_devices->latest_bdev)
1706 fs_info->fs_devices->latest_bdev = next_device->bdev;
1707 list_del_rcu(&tgtdev->dev_list);
1708
1709 call_rcu(&tgtdev->rcu, free_device);
1710
1711 mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1712 }
1713
1714 static int btrfs_find_device_by_path(struct btrfs_root *root, char *device_path,
1715 struct btrfs_device **device)
1716 {
1717 int ret = 0;
1718 struct btrfs_super_block *disk_super;
1719 u64 devid;
1720 u8 *dev_uuid;
1721 struct block_device *bdev;
1722 struct buffer_head *bh;
1723
1724 *device = NULL;
1725 ret = btrfs_get_bdev_and_sb(device_path, FMODE_READ,
1726 root->fs_info->bdev_holder, 0, &bdev, &bh);
1727 if (ret)
1728 return ret;
1729 disk_super = (struct btrfs_super_block *)bh->b_data;
1730 devid = btrfs_stack_device_id(&disk_super->dev_item);
1731 dev_uuid = disk_super->dev_item.uuid;
1732 *device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1733 disk_super->fsid);
1734 brelse(bh);
1735 if (!*device)
1736 ret = -ENOENT;
1737 blkdev_put(bdev, FMODE_READ);
1738 return ret;
1739 }
1740
1741 int btrfs_find_device_missing_or_by_path(struct btrfs_root *root,
1742 char *device_path,
1743 struct btrfs_device **device)
1744 {
1745 *device = NULL;
1746 if (strcmp(device_path, "missing") == 0) {
1747 struct list_head *devices;
1748 struct btrfs_device *tmp;
1749
1750 devices = &root->fs_info->fs_devices->devices;
1751 /*
1752 * It is safe to read the devices since the volume_mutex
1753 * is held by the caller.
1754 */
1755 list_for_each_entry(tmp, devices, dev_list) {
1756 if (tmp->in_fs_metadata && !tmp->bdev) {
1757 *device = tmp;
1758 break;
1759 }
1760 }
1761
1762 if (!*device) {
1763 pr_err("btrfs: no missing device found\n");
1764 return -ENOENT;
1765 }
1766
1767 return 0;
1768 } else {
1769 return btrfs_find_device_by_path(root, device_path, device);
1770 }
1771 }
1772
1773 /*
1774 * does all the dirty work required for changing file system's UUID.
1775 */
1776 static int btrfs_prepare_sprout(struct btrfs_root *root)
1777 {
1778 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1779 struct btrfs_fs_devices *old_devices;
1780 struct btrfs_fs_devices *seed_devices;
1781 struct btrfs_super_block *disk_super = root->fs_info->super_copy;
1782 struct btrfs_device *device;
1783 u64 super_flags;
1784
1785 BUG_ON(!mutex_is_locked(&uuid_mutex));
1786 if (!fs_devices->seeding)
1787 return -EINVAL;
1788
1789 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1790 if (!seed_devices)
1791 return -ENOMEM;
1792
1793 old_devices = clone_fs_devices(fs_devices);
1794 if (IS_ERR(old_devices)) {
1795 kfree(seed_devices);
1796 return PTR_ERR(old_devices);
1797 }
1798
1799 list_add(&old_devices->list, &fs_uuids);
1800
1801 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1802 seed_devices->opened = 1;
1803 INIT_LIST_HEAD(&seed_devices->devices);
1804 INIT_LIST_HEAD(&seed_devices->alloc_list);
1805 mutex_init(&seed_devices->device_list_mutex);
1806
1807 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1808 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1809 synchronize_rcu);
1810 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1811
1812 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1813 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1814 device->fs_devices = seed_devices;
1815 }
1816
1817 fs_devices->seeding = 0;
1818 fs_devices->num_devices = 0;
1819 fs_devices->open_devices = 0;
1820 fs_devices->total_devices = 0;
1821 fs_devices->seed = seed_devices;
1822
1823 generate_random_uuid(fs_devices->fsid);
1824 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1825 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1826 super_flags = btrfs_super_flags(disk_super) &
1827 ~BTRFS_SUPER_FLAG_SEEDING;
1828 btrfs_set_super_flags(disk_super, super_flags);
1829
1830 return 0;
1831 }
1832
1833 /*
1834 * strore the expected generation for seed devices in device items.
1835 */
1836 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1837 struct btrfs_root *root)
1838 {
1839 struct btrfs_path *path;
1840 struct extent_buffer *leaf;
1841 struct btrfs_dev_item *dev_item;
1842 struct btrfs_device *device;
1843 struct btrfs_key key;
1844 u8 fs_uuid[BTRFS_UUID_SIZE];
1845 u8 dev_uuid[BTRFS_UUID_SIZE];
1846 u64 devid;
1847 int ret;
1848
1849 path = btrfs_alloc_path();
1850 if (!path)
1851 return -ENOMEM;
1852
1853 root = root->fs_info->chunk_root;
1854 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1855 key.offset = 0;
1856 key.type = BTRFS_DEV_ITEM_KEY;
1857
1858 while (1) {
1859 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1860 if (ret < 0)
1861 goto error;
1862
1863 leaf = path->nodes[0];
1864 next_slot:
1865 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1866 ret = btrfs_next_leaf(root, path);
1867 if (ret > 0)
1868 break;
1869 if (ret < 0)
1870 goto error;
1871 leaf = path->nodes[0];
1872 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1873 btrfs_release_path(path);
1874 continue;
1875 }
1876
1877 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1878 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1879 key.type != BTRFS_DEV_ITEM_KEY)
1880 break;
1881
1882 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1883 struct btrfs_dev_item);
1884 devid = btrfs_device_id(leaf, dev_item);
1885 read_extent_buffer(leaf, dev_uuid,
1886 (unsigned long)btrfs_device_uuid(dev_item),
1887 BTRFS_UUID_SIZE);
1888 read_extent_buffer(leaf, fs_uuid,
1889 (unsigned long)btrfs_device_fsid(dev_item),
1890 BTRFS_UUID_SIZE);
1891 device = btrfs_find_device(root->fs_info, devid, dev_uuid,
1892 fs_uuid);
1893 BUG_ON(!device); /* Logic error */
1894
1895 if (device->fs_devices->seeding) {
1896 btrfs_set_device_generation(leaf, dev_item,
1897 device->generation);
1898 btrfs_mark_buffer_dirty(leaf);
1899 }
1900
1901 path->slots[0]++;
1902 goto next_slot;
1903 }
1904 ret = 0;
1905 error:
1906 btrfs_free_path(path);
1907 return ret;
1908 }
1909
1910 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1911 {
1912 struct request_queue *q;
1913 struct btrfs_trans_handle *trans;
1914 struct btrfs_device *device;
1915 struct block_device *bdev;
1916 struct list_head *devices;
1917 struct super_block *sb = root->fs_info->sb;
1918 struct rcu_string *name;
1919 u64 total_bytes;
1920 int seeding_dev = 0;
1921 int ret = 0;
1922
1923 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1924 return -EROFS;
1925
1926 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
1927 root->fs_info->bdev_holder);
1928 if (IS_ERR(bdev))
1929 return PTR_ERR(bdev);
1930
1931 if (root->fs_info->fs_devices->seeding) {
1932 seeding_dev = 1;
1933 down_write(&sb->s_umount);
1934 mutex_lock(&uuid_mutex);
1935 }
1936
1937 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1938
1939 devices = &root->fs_info->fs_devices->devices;
1940
1941 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1942 list_for_each_entry(device, devices, dev_list) {
1943 if (device->bdev == bdev) {
1944 ret = -EEXIST;
1945 mutex_unlock(
1946 &root->fs_info->fs_devices->device_list_mutex);
1947 goto error;
1948 }
1949 }
1950 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1951
1952 device = kzalloc(sizeof(*device), GFP_NOFS);
1953 if (!device) {
1954 /* we can safely leave the fs_devices entry around */
1955 ret = -ENOMEM;
1956 goto error;
1957 }
1958
1959 name = rcu_string_strdup(device_path, GFP_NOFS);
1960 if (!name) {
1961 kfree(device);
1962 ret = -ENOMEM;
1963 goto error;
1964 }
1965 rcu_assign_pointer(device->name, name);
1966
1967 ret = find_next_devid(root, &device->devid);
1968 if (ret) {
1969 rcu_string_free(device->name);
1970 kfree(device);
1971 goto error;
1972 }
1973
1974 trans = btrfs_start_transaction(root, 0);
1975 if (IS_ERR(trans)) {
1976 rcu_string_free(device->name);
1977 kfree(device);
1978 ret = PTR_ERR(trans);
1979 goto error;
1980 }
1981
1982 lock_chunks(root);
1983
1984 q = bdev_get_queue(bdev);
1985 if (blk_queue_discard(q))
1986 device->can_discard = 1;
1987 device->writeable = 1;
1988 device->work.func = pending_bios_fn;
1989 generate_random_uuid(device->uuid);
1990 spin_lock_init(&device->io_lock);
1991 device->generation = trans->transid;
1992 device->io_width = root->sectorsize;
1993 device->io_align = root->sectorsize;
1994 device->sector_size = root->sectorsize;
1995 device->total_bytes = i_size_read(bdev->bd_inode);
1996 device->disk_total_bytes = device->total_bytes;
1997 device->dev_root = root->fs_info->dev_root;
1998 device->bdev = bdev;
1999 device->in_fs_metadata = 1;
2000 device->is_tgtdev_for_dev_replace = 0;
2001 device->mode = FMODE_EXCL;
2002 set_blocksize(device->bdev, 4096);
2003
2004 if (seeding_dev) {
2005 sb->s_flags &= ~MS_RDONLY;
2006 ret = btrfs_prepare_sprout(root);
2007 BUG_ON(ret); /* -ENOMEM */
2008 }
2009
2010 device->fs_devices = root->fs_info->fs_devices;
2011
2012 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2013 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
2014 list_add(&device->dev_alloc_list,
2015 &root->fs_info->fs_devices->alloc_list);
2016 root->fs_info->fs_devices->num_devices++;
2017 root->fs_info->fs_devices->open_devices++;
2018 root->fs_info->fs_devices->rw_devices++;
2019 root->fs_info->fs_devices->total_devices++;
2020 if (device->can_discard)
2021 root->fs_info->fs_devices->num_can_discard++;
2022 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
2023
2024 spin_lock(&root->fs_info->free_chunk_lock);
2025 root->fs_info->free_chunk_space += device->total_bytes;
2026 spin_unlock(&root->fs_info->free_chunk_lock);
2027
2028 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
2029 root->fs_info->fs_devices->rotating = 1;
2030
2031 total_bytes = btrfs_super_total_bytes(root->fs_info->super_copy);
2032 btrfs_set_super_total_bytes(root->fs_info->super_copy,
2033 total_bytes + device->total_bytes);
2034
2035 total_bytes = btrfs_super_num_devices(root->fs_info->super_copy);
2036 btrfs_set_super_num_devices(root->fs_info->super_copy,
2037 total_bytes + 1);
2038 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2039
2040 if (seeding_dev) {
2041 ret = init_first_rw_device(trans, root, device);
2042 if (ret) {
2043 btrfs_abort_transaction(trans, root, ret);
2044 goto error_trans;
2045 }
2046 ret = btrfs_finish_sprout(trans, root);
2047 if (ret) {
2048 btrfs_abort_transaction(trans, root, ret);
2049 goto error_trans;
2050 }
2051 } else {
2052 ret = btrfs_add_device(trans, root, device);
2053 if (ret) {
2054 btrfs_abort_transaction(trans, root, ret);
2055 goto error_trans;
2056 }
2057 }
2058
2059 /*
2060 * we've got more storage, clear any full flags on the space
2061 * infos
2062 */
2063 btrfs_clear_space_info_full(root->fs_info);
2064
2065 unlock_chunks(root);
2066 root->fs_info->num_tolerated_disk_barrier_failures =
2067 btrfs_calc_num_tolerated_disk_barrier_failures(root->fs_info);
2068 ret = btrfs_commit_transaction(trans, root);
2069
2070 if (seeding_dev) {
2071 mutex_unlock(&uuid_mutex);
2072 up_write(&sb->s_umount);
2073
2074 if (ret) /* transaction commit */
2075 return ret;
2076
2077 ret = btrfs_relocate_sys_chunks(root);
2078 if (ret < 0)
2079 btrfs_error(root->fs_info, ret,
2080 "Failed to relocate sys chunks after "
2081 "device initialization. This can be fixed "
2082 "using the \"btrfs balance\" command.");
2083 trans = btrfs_attach_transaction(root);
2084 if (IS_ERR(trans)) {
2085 if (PTR_ERR(trans) == -ENOENT)
2086 return 0;
2087 return PTR_ERR(trans);
2088 }
2089 ret = btrfs_commit_transaction(trans, root);
2090 }
2091
2092 return ret;
2093
2094 error_trans:
2095 unlock_chunks(root);
2096 btrfs_end_transaction(trans, root);
2097 rcu_string_free(device->name);
2098 kfree(device);
2099 error:
2100 blkdev_put(bdev, FMODE_EXCL);
2101 if (seeding_dev) {
2102 mutex_unlock(&uuid_mutex);
2103 up_write(&sb->s_umount);
2104 }
2105 return ret;
2106 }
2107
2108 int btrfs_init_dev_replace_tgtdev(struct btrfs_root *root, char *device_path,
2109 struct btrfs_device **device_out)
2110 {
2111 struct request_queue *q;
2112 struct btrfs_device *device;
2113 struct block_device *bdev;
2114 struct btrfs_fs_info *fs_info = root->fs_info;
2115 struct list_head *devices;
2116 struct rcu_string *name;
2117 int ret = 0;
2118
2119 *device_out = NULL;
2120 if (fs_info->fs_devices->seeding)
2121 return -EINVAL;
2122
2123 bdev = blkdev_get_by_path(device_path, FMODE_WRITE | FMODE_EXCL,
2124 fs_info->bdev_holder);
2125 if (IS_ERR(bdev))
2126 return PTR_ERR(bdev);
2127
2128 filemap_write_and_wait(bdev->bd_inode->i_mapping);
2129
2130 devices = &fs_info->fs_devices->devices;
2131 list_for_each_entry(device, devices, dev_list) {
2132 if (device->bdev == bdev) {
2133 ret = -EEXIST;
2134 goto error;
2135 }
2136 }
2137
2138 device = kzalloc(sizeof(*device), GFP_NOFS);
2139 if (!device) {
2140 ret = -ENOMEM;
2141 goto error;
2142 }
2143
2144 name = rcu_string_strdup(device_path, GFP_NOFS);
2145 if (!name) {
2146 kfree(device);
2147 ret = -ENOMEM;
2148 goto error;
2149 }
2150 rcu_assign_pointer(device->name, name);
2151
2152 q = bdev_get_queue(bdev);
2153 if (blk_queue_discard(q))
2154 device->can_discard = 1;
2155 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2156 device->writeable = 1;
2157 device->work.func = pending_bios_fn;
2158 generate_random_uuid(device->uuid);
2159 device->devid = BTRFS_DEV_REPLACE_DEVID;
2160 spin_lock_init(&device->io_lock);
2161 device->generation = 0;
2162 device->io_width = root->sectorsize;
2163 device->io_align = root->sectorsize;
2164 device->sector_size = root->sectorsize;
2165 device->total_bytes = i_size_read(bdev->bd_inode);
2166 device->disk_total_bytes = device->total_bytes;
2167 device->dev_root = fs_info->dev_root;
2168 device->bdev = bdev;
2169 device->in_fs_metadata = 1;
2170 device->is_tgtdev_for_dev_replace = 1;
2171 device->mode = FMODE_EXCL;
2172 set_blocksize(device->bdev, 4096);
2173 device->fs_devices = fs_info->fs_devices;
2174 list_add(&device->dev_list, &fs_info->fs_devices->devices);
2175 fs_info->fs_devices->num_devices++;
2176 fs_info->fs_devices->open_devices++;
2177 if (device->can_discard)
2178 fs_info->fs_devices->num_can_discard++;
2179 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2180
2181 *device_out = device;
2182 return ret;
2183
2184 error:
2185 blkdev_put(bdev, FMODE_EXCL);
2186 return ret;
2187 }
2188
2189 void btrfs_init_dev_replace_tgtdev_for_resume(struct btrfs_fs_info *fs_info,
2190 struct btrfs_device *tgtdev)
2191 {
2192 WARN_ON(fs_info->fs_devices->rw_devices == 0);
2193 tgtdev->io_width = fs_info->dev_root->sectorsize;
2194 tgtdev->io_align = fs_info->dev_root->sectorsize;
2195 tgtdev->sector_size = fs_info->dev_root->sectorsize;
2196 tgtdev->dev_root = fs_info->dev_root;
2197 tgtdev->in_fs_metadata = 1;
2198 }
2199
2200 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
2201 struct btrfs_device *device)
2202 {
2203 int ret;
2204 struct btrfs_path *path;
2205 struct btrfs_root *root;
2206 struct btrfs_dev_item *dev_item;
2207 struct extent_buffer *leaf;
2208 struct btrfs_key key;
2209
2210 root = device->dev_root->fs_info->chunk_root;
2211
2212 path = btrfs_alloc_path();
2213 if (!path)
2214 return -ENOMEM;
2215
2216 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2217 key.type = BTRFS_DEV_ITEM_KEY;
2218 key.offset = device->devid;
2219
2220 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2221 if (ret < 0)
2222 goto out;
2223
2224 if (ret > 0) {
2225 ret = -ENOENT;
2226 goto out;
2227 }
2228
2229 leaf = path->nodes[0];
2230 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
2231
2232 btrfs_set_device_id(leaf, dev_item, device->devid);
2233 btrfs_set_device_type(leaf, dev_item, device->type);
2234 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
2235 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
2236 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
2237 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
2238 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
2239 btrfs_mark_buffer_dirty(leaf);
2240
2241 out:
2242 btrfs_free_path(path);
2243 return ret;
2244 }
2245
2246 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
2247 struct btrfs_device *device, u64 new_size)
2248 {
2249 struct btrfs_super_block *super_copy =
2250 device->dev_root->fs_info->super_copy;
2251 u64 old_total = btrfs_super_total_bytes(super_copy);
2252 u64 diff = new_size - device->total_bytes;
2253
2254 if (!device->writeable)
2255 return -EACCES;
2256 if (new_size <= device->total_bytes ||
2257 device->is_tgtdev_for_dev_replace)
2258 return -EINVAL;
2259
2260 btrfs_set_super_total_bytes(super_copy, old_total + diff);
2261 device->fs_devices->total_rw_bytes += diff;
2262
2263 device->total_bytes = new_size;
2264 device->disk_total_bytes = new_size;
2265 btrfs_clear_space_info_full(device->dev_root->fs_info);
2266
2267 return btrfs_update_device(trans, device);
2268 }
2269
2270 int btrfs_grow_device(struct btrfs_trans_handle *trans,
2271 struct btrfs_device *device, u64 new_size)
2272 {
2273 int ret;
2274 lock_chunks(device->dev_root);
2275 ret = __btrfs_grow_device(trans, device, new_size);
2276 unlock_chunks(device->dev_root);
2277 return ret;
2278 }
2279
2280 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
2281 struct btrfs_root *root,
2282 u64 chunk_tree, u64 chunk_objectid,
2283 u64 chunk_offset)
2284 {
2285 int ret;
2286 struct btrfs_path *path;
2287 struct btrfs_key key;
2288
2289 root = root->fs_info->chunk_root;
2290 path = btrfs_alloc_path();
2291 if (!path)
2292 return -ENOMEM;
2293
2294 key.objectid = chunk_objectid;
2295 key.offset = chunk_offset;
2296 key.type = BTRFS_CHUNK_ITEM_KEY;
2297
2298 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2299 if (ret < 0)
2300 goto out;
2301 else if (ret > 0) { /* Logic error or corruption */
2302 btrfs_error(root->fs_info, -ENOENT,
2303 "Failed lookup while freeing chunk.");
2304 ret = -ENOENT;
2305 goto out;
2306 }
2307
2308 ret = btrfs_del_item(trans, root, path);
2309 if (ret < 0)
2310 btrfs_error(root->fs_info, ret,
2311 "Failed to delete chunk item.");
2312 out:
2313 btrfs_free_path(path);
2314 return ret;
2315 }
2316
2317 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
2318 chunk_offset)
2319 {
2320 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
2321 struct btrfs_disk_key *disk_key;
2322 struct btrfs_chunk *chunk;
2323 u8 *ptr;
2324 int ret = 0;
2325 u32 num_stripes;
2326 u32 array_size;
2327 u32 len = 0;
2328 u32 cur;
2329 struct btrfs_key key;
2330
2331 array_size = btrfs_super_sys_array_size(super_copy);
2332
2333 ptr = super_copy->sys_chunk_array;
2334 cur = 0;
2335
2336 while (cur < array_size) {
2337 disk_key = (struct btrfs_disk_key *)ptr;
2338 btrfs_disk_key_to_cpu(&key, disk_key);
2339
2340 len = sizeof(*disk_key);
2341
2342 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2343 chunk = (struct btrfs_chunk *)(ptr + len);
2344 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
2345 len += btrfs_chunk_item_size(num_stripes);
2346 } else {
2347 ret = -EIO;
2348 break;
2349 }
2350 if (key.objectid == chunk_objectid &&
2351 key.offset == chunk_offset) {
2352 memmove(ptr, ptr + len, array_size - (cur + len));
2353 array_size -= len;
2354 btrfs_set_super_sys_array_size(super_copy, array_size);
2355 } else {
2356 ptr += len;
2357 cur += len;
2358 }
2359 }
2360 return ret;
2361 }
2362
2363 static int btrfs_relocate_chunk(struct btrfs_root *root,
2364 u64 chunk_tree, u64 chunk_objectid,
2365 u64 chunk_offset)
2366 {
2367 struct extent_map_tree *em_tree;
2368 struct btrfs_root *extent_root;
2369 struct btrfs_trans_handle *trans;
2370 struct extent_map *em;
2371 struct map_lookup *map;
2372 int ret;
2373 int i;
2374
2375 root = root->fs_info->chunk_root;
2376 extent_root = root->fs_info->extent_root;
2377 em_tree = &root->fs_info->mapping_tree.map_tree;
2378
2379 ret = btrfs_can_relocate(extent_root, chunk_offset);
2380 if (ret)
2381 return -ENOSPC;
2382
2383 /* step one, relocate all the extents inside this chunk */
2384 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
2385 if (ret)
2386 return ret;
2387
2388 trans = btrfs_start_transaction(root, 0);
2389 if (IS_ERR(trans)) {
2390 ret = PTR_ERR(trans);
2391 btrfs_std_error(root->fs_info, ret);
2392 return ret;
2393 }
2394
2395 lock_chunks(root);
2396
2397 /*
2398 * step two, delete the device extents and the
2399 * chunk tree entries
2400 */
2401 read_lock(&em_tree->lock);
2402 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
2403 read_unlock(&em_tree->lock);
2404
2405 BUG_ON(!em || em->start > chunk_offset ||
2406 em->start + em->len < chunk_offset);
2407 map = (struct map_lookup *)em->bdev;
2408
2409 for (i = 0; i < map->num_stripes; i++) {
2410 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
2411 map->stripes[i].physical);
2412 BUG_ON(ret);
2413
2414 if (map->stripes[i].dev) {
2415 ret = btrfs_update_device(trans, map->stripes[i].dev);
2416 BUG_ON(ret);
2417 }
2418 }
2419 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
2420 chunk_offset);
2421
2422 BUG_ON(ret);
2423
2424 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
2425
2426 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2427 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
2428 BUG_ON(ret);
2429 }
2430
2431 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
2432 BUG_ON(ret);
2433
2434 write_lock(&em_tree->lock);
2435 remove_extent_mapping(em_tree, em);
2436 write_unlock(&em_tree->lock);
2437
2438 kfree(map);
2439 em->bdev = NULL;
2440
2441 /* once for the tree */
2442 free_extent_map(em);
2443 /* once for us */
2444 free_extent_map(em);
2445
2446 unlock_chunks(root);
2447 btrfs_end_transaction(trans, root);
2448 return 0;
2449 }
2450
2451 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
2452 {
2453 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
2454 struct btrfs_path *path;
2455 struct extent_buffer *leaf;
2456 struct btrfs_chunk *chunk;
2457 struct btrfs_key key;
2458 struct btrfs_key found_key;
2459 u64 chunk_tree = chunk_root->root_key.objectid;
2460 u64 chunk_type;
2461 bool retried = false;
2462 int failed = 0;
2463 int ret;
2464
2465 path = btrfs_alloc_path();
2466 if (!path)
2467 return -ENOMEM;
2468
2469 again:
2470 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2471 key.offset = (u64)-1;
2472 key.type = BTRFS_CHUNK_ITEM_KEY;
2473
2474 while (1) {
2475 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2476 if (ret < 0)
2477 goto error;
2478 BUG_ON(ret == 0); /* Corruption */
2479
2480 ret = btrfs_previous_item(chunk_root, path, key.objectid,
2481 key.type);
2482 if (ret < 0)
2483 goto error;
2484 if (ret > 0)
2485 break;
2486
2487 leaf = path->nodes[0];
2488 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2489
2490 chunk = btrfs_item_ptr(leaf, path->slots[0],
2491 struct btrfs_chunk);
2492 chunk_type = btrfs_chunk_type(leaf, chunk);
2493 btrfs_release_path(path);
2494
2495 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
2496 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
2497 found_key.objectid,
2498 found_key.offset);
2499 if (ret == -ENOSPC)
2500 failed++;
2501 else if (ret)
2502 BUG();
2503 }
2504
2505 if (found_key.offset == 0)
2506 break;
2507 key.offset = found_key.offset - 1;
2508 }
2509 ret = 0;
2510 if (failed && !retried) {
2511 failed = 0;
2512 retried = true;
2513 goto again;
2514 } else if (failed && retried) {
2515 WARN_ON(1);
2516 ret = -ENOSPC;
2517 }
2518 error:
2519 btrfs_free_path(path);
2520 return ret;
2521 }
2522
2523 static int insert_balance_item(struct btrfs_root *root,
2524 struct btrfs_balance_control *bctl)
2525 {
2526 struct btrfs_trans_handle *trans;
2527 struct btrfs_balance_item *item;
2528 struct btrfs_disk_balance_args disk_bargs;
2529 struct btrfs_path *path;
2530 struct extent_buffer *leaf;
2531 struct btrfs_key key;
2532 int ret, err;
2533
2534 path = btrfs_alloc_path();
2535 if (!path)
2536 return -ENOMEM;
2537
2538 trans = btrfs_start_transaction(root, 0);
2539 if (IS_ERR(trans)) {
2540 btrfs_free_path(path);
2541 return PTR_ERR(trans);
2542 }
2543
2544 key.objectid = BTRFS_BALANCE_OBJECTID;
2545 key.type = BTRFS_BALANCE_ITEM_KEY;
2546 key.offset = 0;
2547
2548 ret = btrfs_insert_empty_item(trans, root, path, &key,
2549 sizeof(*item));
2550 if (ret)
2551 goto out;
2552
2553 leaf = path->nodes[0];
2554 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
2555
2556 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
2557
2558 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data);
2559 btrfs_set_balance_data(leaf, item, &disk_bargs);
2560 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta);
2561 btrfs_set_balance_meta(leaf, item, &disk_bargs);
2562 btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys);
2563 btrfs_set_balance_sys(leaf, item, &disk_bargs);
2564
2565 btrfs_set_balance_flags(leaf, item, bctl->flags);
2566
2567 btrfs_mark_buffer_dirty(leaf);
2568 out:
2569 btrfs_free_path(path);
2570 err = btrfs_commit_transaction(trans, root);
2571 if (err && !ret)
2572 ret = err;
2573 return ret;
2574 }
2575
2576 static int del_balance_item(struct btrfs_root *root)
2577 {
2578 struct btrfs_trans_handle *trans;
2579 struct btrfs_path *path;
2580 struct btrfs_key key;
2581 int ret, err;
2582
2583 path = btrfs_alloc_path();
2584 if (!path)
2585 return -ENOMEM;
2586
2587 trans = btrfs_start_transaction(root, 0);
2588 if (IS_ERR(trans)) {
2589 btrfs_free_path(path);
2590 return PTR_ERR(trans);
2591 }
2592
2593 key.objectid = BTRFS_BALANCE_OBJECTID;
2594 key.type = BTRFS_BALANCE_ITEM_KEY;
2595 key.offset = 0;
2596
2597 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
2598 if (ret < 0)
2599 goto out;
2600 if (ret > 0) {
2601 ret = -ENOENT;
2602 goto out;
2603 }
2604
2605 ret = btrfs_del_item(trans, root, path);
2606 out:
2607 btrfs_free_path(path);
2608 err = btrfs_commit_transaction(trans, root);
2609 if (err && !ret)
2610 ret = err;
2611 return ret;
2612 }
2613
2614 /*
2615 * This is a heuristic used to reduce the number of chunks balanced on
2616 * resume after balance was interrupted.
2617 */
2618 static void update_balance_args(struct btrfs_balance_control *bctl)
2619 {
2620 /*
2621 * Turn on soft mode for chunk types that were being converted.
2622 */
2623 if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)
2624 bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT;
2625 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)
2626 bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT;
2627 if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)
2628 bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT;
2629
2630 /*
2631 * Turn on usage filter if is not already used. The idea is
2632 * that chunks that we have already balanced should be
2633 * reasonably full. Don't do it for chunks that are being
2634 * converted - that will keep us from relocating unconverted
2635 * (albeit full) chunks.
2636 */
2637 if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2638 !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2639 bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
2640 bctl->data.usage = 90;
2641 }
2642 if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2643 !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2644 bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
2645 bctl->sys.usage = 90;
2646 }
2647 if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
2648 !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
2649 bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
2650 bctl->meta.usage = 90;
2651 }
2652 }
2653
2654 /*
2655 * Should be called with both balance and volume mutexes held to
2656 * serialize other volume operations (add_dev/rm_dev/resize) with
2657 * restriper. Same goes for unset_balance_control.
2658 */
2659 static void set_balance_control(struct btrfs_balance_control *bctl)
2660 {
2661 struct btrfs_fs_info *fs_info = bctl->fs_info;
2662
2663 BUG_ON(fs_info->balance_ctl);
2664
2665 spin_lock(&fs_info->balance_lock);
2666 fs_info->balance_ctl = bctl;
2667 spin_unlock(&fs_info->balance_lock);
2668 }
2669
2670 static void unset_balance_control(struct btrfs_fs_info *fs_info)
2671 {
2672 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2673
2674 BUG_ON(!fs_info->balance_ctl);
2675
2676 spin_lock(&fs_info->balance_lock);
2677 fs_info->balance_ctl = NULL;
2678 spin_unlock(&fs_info->balance_lock);
2679
2680 kfree(bctl);
2681 }
2682
2683 /*
2684 * Balance filters. Return 1 if chunk should be filtered out
2685 * (should not be balanced).
2686 */
2687 static int chunk_profiles_filter(u64 chunk_type,
2688 struct btrfs_balance_args *bargs)
2689 {
2690 chunk_type = chunk_to_extended(chunk_type) &
2691 BTRFS_EXTENDED_PROFILE_MASK;
2692
2693 if (bargs->profiles & chunk_type)
2694 return 0;
2695
2696 return 1;
2697 }
2698
2699 static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
2700 struct btrfs_balance_args *bargs)
2701 {
2702 struct btrfs_block_group_cache *cache;
2703 u64 chunk_used, user_thresh;
2704 int ret = 1;
2705
2706 cache = btrfs_lookup_block_group(fs_info, chunk_offset);
2707 chunk_used = btrfs_block_group_used(&cache->item);
2708
2709 if (bargs->usage == 0)
2710 user_thresh = 1;
2711 else if (bargs->usage > 100)
2712 user_thresh = cache->key.offset;
2713 else
2714 user_thresh = div_factor_fine(cache->key.offset,
2715 bargs->usage);
2716
2717 if (chunk_used < user_thresh)
2718 ret = 0;
2719
2720 btrfs_put_block_group(cache);
2721 return ret;
2722 }
2723
2724 static int chunk_devid_filter(struct extent_buffer *leaf,
2725 struct btrfs_chunk *chunk,
2726 struct btrfs_balance_args *bargs)
2727 {
2728 struct btrfs_stripe *stripe;
2729 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2730 int i;
2731
2732 for (i = 0; i < num_stripes; i++) {
2733 stripe = btrfs_stripe_nr(chunk, i);
2734 if (btrfs_stripe_devid(leaf, stripe) == bargs->devid)
2735 return 0;
2736 }
2737
2738 return 1;
2739 }
2740
2741 /* [pstart, pend) */
2742 static int chunk_drange_filter(struct extent_buffer *leaf,
2743 struct btrfs_chunk *chunk,
2744 u64 chunk_offset,
2745 struct btrfs_balance_args *bargs)
2746 {
2747 struct btrfs_stripe *stripe;
2748 int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2749 u64 stripe_offset;
2750 u64 stripe_length;
2751 int factor;
2752 int i;
2753
2754 if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID))
2755 return 0;
2756
2757 if (btrfs_chunk_type(leaf, chunk) & (BTRFS_BLOCK_GROUP_DUP |
2758 BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) {
2759 factor = num_stripes / 2;
2760 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID5) {
2761 factor = num_stripes - 1;
2762 } else if (btrfs_chunk_type(leaf, chunk) & BTRFS_BLOCK_GROUP_RAID6) {
2763 factor = num_stripes - 2;
2764 } else {
2765 factor = num_stripes;
2766 }
2767
2768 for (i = 0; i < num_stripes; i++) {
2769 stripe = btrfs_stripe_nr(chunk, i);
2770 if (btrfs_stripe_devid(leaf, stripe) != bargs->devid)
2771 continue;
2772
2773 stripe_offset = btrfs_stripe_offset(leaf, stripe);
2774 stripe_length = btrfs_chunk_length(leaf, chunk);
2775 do_div(stripe_length, factor);
2776
2777 if (stripe_offset < bargs->pend &&
2778 stripe_offset + stripe_length > bargs->pstart)
2779 return 0;
2780 }
2781
2782 return 1;
2783 }
2784
2785 /* [vstart, vend) */
2786 static int chunk_vrange_filter(struct extent_buffer *leaf,
2787 struct btrfs_chunk *chunk,
2788 u64 chunk_offset,
2789 struct btrfs_balance_args *bargs)
2790 {
2791 if (chunk_offset < bargs->vend &&
2792 chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
2793 /* at least part of the chunk is inside this vrange */
2794 return 0;
2795
2796 return 1;
2797 }
2798
2799 static int chunk_soft_convert_filter(u64 chunk_type,
2800 struct btrfs_balance_args *bargs)
2801 {
2802 if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
2803 return 0;
2804
2805 chunk_type = chunk_to_extended(chunk_type) &
2806 BTRFS_EXTENDED_PROFILE_MASK;
2807
2808 if (bargs->target == chunk_type)
2809 return 1;
2810
2811 return 0;
2812 }
2813
2814 static int should_balance_chunk(struct btrfs_root *root,
2815 struct extent_buffer *leaf,
2816 struct btrfs_chunk *chunk, u64 chunk_offset)
2817 {
2818 struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
2819 struct btrfs_balance_args *bargs = NULL;
2820 u64 chunk_type = btrfs_chunk_type(leaf, chunk);
2821
2822 /* type filter */
2823 if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
2824 (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
2825 return 0;
2826 }
2827
2828 if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
2829 bargs = &bctl->data;
2830 else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
2831 bargs = &bctl->sys;
2832 else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
2833 bargs = &bctl->meta;
2834
2835 /* profiles filter */
2836 if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) &&
2837 chunk_profiles_filter(chunk_type, bargs)) {
2838 return 0;
2839 }
2840
2841 /* usage filter */
2842 if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
2843 chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
2844 return 0;
2845 }
2846
2847 /* devid filter */
2848 if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) &&
2849 chunk_devid_filter(leaf, chunk, bargs)) {
2850 return 0;
2851 }
2852
2853 /* drange filter, makes sense only with devid filter */
2854 if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) &&
2855 chunk_drange_filter(leaf, chunk, chunk_offset, bargs)) {
2856 return 0;
2857 }
2858
2859 /* vrange filter */
2860 if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
2861 chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
2862 return 0;
2863 }
2864
2865 /* soft profile changing mode */
2866 if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
2867 chunk_soft_convert_filter(chunk_type, bargs)) {
2868 return 0;
2869 }
2870
2871 return 1;
2872 }
2873
2874 static int __btrfs_balance(struct btrfs_fs_info *fs_info)
2875 {
2876 struct btrfs_balance_control *bctl = fs_info->balance_ctl;
2877 struct btrfs_root *chunk_root = fs_info->chunk_root;
2878 struct btrfs_root *dev_root = fs_info->dev_root;
2879 struct list_head *devices;
2880 struct btrfs_device *device;
2881 u64 old_size;
2882 u64 size_to_free;
2883 struct btrfs_chunk *chunk;
2884 struct btrfs_path *path;
2885 struct btrfs_key key;
2886 struct btrfs_key found_key;
2887 struct btrfs_trans_handle *trans;
2888 struct extent_buffer *leaf;
2889 int slot;
2890 int ret;
2891 int enospc_errors = 0;
2892 bool counting = true;
2893
2894 /* step one make some room on all the devices */
2895 devices = &fs_info->fs_devices->devices;
2896 list_for_each_entry(device, devices, dev_list) {
2897 old_size = device->total_bytes;
2898 size_to_free = div_factor(old_size, 1);
2899 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2900 if (!device->writeable ||
2901 device->total_bytes - device->bytes_used > size_to_free ||
2902 device->is_tgtdev_for_dev_replace)
2903 continue;
2904
2905 ret = btrfs_shrink_device(device, old_size - size_to_free);
2906 if (ret == -ENOSPC)
2907 break;
2908 BUG_ON(ret);
2909
2910 trans = btrfs_start_transaction(dev_root, 0);
2911 BUG_ON(IS_ERR(trans));
2912
2913 ret = btrfs_grow_device(trans, device, old_size);
2914 BUG_ON(ret);
2915
2916 btrfs_end_transaction(trans, dev_root);
2917 }
2918
2919 /* step two, relocate all the chunks */
2920 path = btrfs_alloc_path();
2921 if (!path) {
2922 ret = -ENOMEM;
2923 goto error;
2924 }
2925
2926 /* zero out stat counters */
2927 spin_lock(&fs_info->balance_lock);
2928 memset(&bctl->stat, 0, sizeof(bctl->stat));
2929 spin_unlock(&fs_info->balance_lock);
2930 again:
2931 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2932 key.offset = (u64)-1;
2933 key.type = BTRFS_CHUNK_ITEM_KEY;
2934
2935 while (1) {
2936 if ((!counting && atomic_read(&fs_info->balance_pause_req)) ||
2937 atomic_read(&fs_info->balance_cancel_req)) {
2938 ret = -ECANCELED;
2939 goto error;
2940 }
2941
2942 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2943 if (ret < 0)
2944 goto error;
2945
2946 /*
2947 * this shouldn't happen, it means the last relocate
2948 * failed
2949 */
2950 if (ret == 0)
2951 BUG(); /* FIXME break ? */
2952
2953 ret = btrfs_previous_item(chunk_root, path, 0,
2954 BTRFS_CHUNK_ITEM_KEY);
2955 if (ret) {
2956 ret = 0;
2957 break;
2958 }
2959
2960 leaf = path->nodes[0];
2961 slot = path->slots[0];
2962 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2963
2964 if (found_key.objectid != key.objectid)
2965 break;
2966
2967 /* chunk zero is special */
2968 if (found_key.offset == 0)
2969 break;
2970
2971 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2972
2973 if (!counting) {
2974 spin_lock(&fs_info->balance_lock);
2975 bctl->stat.considered++;
2976 spin_unlock(&fs_info->balance_lock);
2977 }
2978
2979 ret = should_balance_chunk(chunk_root, leaf, chunk,
2980 found_key.offset);
2981 btrfs_release_path(path);
2982 if (!ret)
2983 goto loop;
2984
2985 if (counting) {
2986 spin_lock(&fs_info->balance_lock);
2987 bctl->stat.expected++;
2988 spin_unlock(&fs_info->balance_lock);
2989 goto loop;
2990 }
2991
2992 ret = btrfs_relocate_chunk(chunk_root,
2993 chunk_root->root_key.objectid,
2994 found_key.objectid,
2995 found_key.offset);
2996 if (ret && ret != -ENOSPC)
2997 goto error;
2998 if (ret == -ENOSPC) {
2999 enospc_errors++;
3000 } else {
3001 spin_lock(&fs_info->balance_lock);
3002 bctl->stat.completed++;
3003 spin_unlock(&fs_info->balance_lock);
3004 }
3005 loop:
3006 key.offset = found_key.offset - 1;
3007 }
3008
3009 if (counting) {
3010 btrfs_release_path(path);
3011 counting = false;
3012 goto again;
3013 }
3014 error:
3015 btrfs_free_path(path);
3016 if (enospc_errors) {
3017 printk(KERN_INFO "btrfs: %d enospc errors during balance\n",
3018 enospc_errors);
3019 if (!ret)
3020 ret = -ENOSPC;
3021 }
3022
3023 return ret;
3024 }
3025
3026 /**
3027 * alloc_profile_is_valid - see if a given profile is valid and reduced
3028 * @flags: profile to validate
3029 * @extended: if true @flags is treated as an extended profile
3030 */
3031 static int alloc_profile_is_valid(u64 flags, int extended)
3032 {
3033 u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
3034 BTRFS_BLOCK_GROUP_PROFILE_MASK);
3035
3036 flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
3037
3038 /* 1) check that all other bits are zeroed */
3039 if (flags & ~mask)
3040 return 0;
3041
3042 /* 2) see if profile is reduced */
3043 if (flags == 0)
3044 return !extended; /* "0" is valid for usual profiles */
3045
3046 /* true if exactly one bit set */
3047 return (flags & (flags - 1)) == 0;
3048 }
3049
3050 static inline int balance_need_close(struct btrfs_fs_info *fs_info)
3051 {
3052 /* cancel requested || normal exit path */
3053 return atomic_read(&fs_info->balance_cancel_req) ||
3054 (atomic_read(&fs_info->balance_pause_req) == 0 &&
3055 atomic_read(&fs_info->balance_cancel_req) == 0);
3056 }
3057
3058 static void __cancel_balance(struct btrfs_fs_info *fs_info)
3059 {
3060 int ret;
3061
3062 unset_balance_control(fs_info);
3063 ret = del_balance_item(fs_info->tree_root);
3064 if (ret)
3065 btrfs_std_error(fs_info, ret);
3066
3067 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3068 }
3069
3070 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
3071 struct btrfs_ioctl_balance_args *bargs);
3072
3073 /*
3074 * Should be called with both balance and volume mutexes held
3075 */
3076 int btrfs_balance(struct btrfs_balance_control *bctl,
3077 struct btrfs_ioctl_balance_args *bargs)
3078 {
3079 struct btrfs_fs_info *fs_info = bctl->fs_info;
3080 u64 allowed;
3081 int mixed = 0;
3082 int ret;
3083 u64 num_devices;
3084 unsigned seq;
3085
3086 if (btrfs_fs_closing(fs_info) ||
3087 atomic_read(&fs_info->balance_pause_req) ||
3088 atomic_read(&fs_info->balance_cancel_req)) {
3089 ret = -EINVAL;
3090 goto out;
3091 }
3092
3093 allowed = btrfs_super_incompat_flags(fs_info->super_copy);
3094 if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS)
3095 mixed = 1;
3096
3097 /*
3098 * In case of mixed groups both data and meta should be picked,
3099 * and identical options should be given for both of them.
3100 */
3101 allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA;
3102 if (mixed && (bctl->flags & allowed)) {
3103 if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
3104 !(bctl->flags & BTRFS_BALANCE_METADATA) ||
3105 memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
3106 printk(KERN_ERR "btrfs: with mixed groups data and "
3107 "metadata balance options must be the same\n");
3108 ret = -EINVAL;
3109 goto out;
3110 }
3111 }
3112
3113 num_devices = fs_info->fs_devices->num_devices;
3114 btrfs_dev_replace_lock(&fs_info->dev_replace);
3115 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
3116 BUG_ON(num_devices < 1);
3117 num_devices--;
3118 }
3119 btrfs_dev_replace_unlock(&fs_info->dev_replace);
3120 allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE;
3121 if (num_devices == 1)
3122 allowed |= BTRFS_BLOCK_GROUP_DUP;
3123 else if (num_devices < 4)
3124 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
3125 else
3126 allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
3127 BTRFS_BLOCK_GROUP_RAID10 |
3128 BTRFS_BLOCK_GROUP_RAID5 |
3129 BTRFS_BLOCK_GROUP_RAID6);
3130
3131 if ((bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3132 (!alloc_profile_is_valid(bctl->data.target, 1) ||
3133 (bctl->data.target & ~allowed))) {
3134 printk(KERN_ERR "btrfs: unable to start balance with target "
3135 "data profile %llu\n",
3136 (unsigned long long)bctl->data.target);
3137 ret = -EINVAL;
3138 goto out;
3139 }
3140 if ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3141 (!alloc_profile_is_valid(bctl->meta.target, 1) ||
3142 (bctl->meta.target & ~allowed))) {
3143 printk(KERN_ERR "btrfs: unable to start balance with target "
3144 "metadata profile %llu\n",
3145 (unsigned long long)bctl->meta.target);
3146 ret = -EINVAL;
3147 goto out;
3148 }
3149 if ((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3150 (!alloc_profile_is_valid(bctl->sys.target, 1) ||
3151 (bctl->sys.target & ~allowed))) {
3152 printk(KERN_ERR "btrfs: unable to start balance with target "
3153 "system profile %llu\n",
3154 (unsigned long long)bctl->sys.target);
3155 ret = -EINVAL;
3156 goto out;
3157 }
3158
3159 /* allow dup'ed data chunks only in mixed mode */
3160 if (!mixed && (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3161 (bctl->data.target & BTRFS_BLOCK_GROUP_DUP)) {
3162 printk(KERN_ERR "btrfs: dup for data is not allowed\n");
3163 ret = -EINVAL;
3164 goto out;
3165 }
3166
3167 /* allow to reduce meta or sys integrity only if force set */
3168 allowed = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 |
3169 BTRFS_BLOCK_GROUP_RAID10 |
3170 BTRFS_BLOCK_GROUP_RAID5 |
3171 BTRFS_BLOCK_GROUP_RAID6;
3172 do {
3173 seq = read_seqbegin(&fs_info->profiles_lock);
3174
3175 if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3176 (fs_info->avail_system_alloc_bits & allowed) &&
3177 !(bctl->sys.target & allowed)) ||
3178 ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) &&
3179 (fs_info->avail_metadata_alloc_bits & allowed) &&
3180 !(bctl->meta.target & allowed))) {
3181 if (bctl->flags & BTRFS_BALANCE_FORCE) {
3182 printk(KERN_INFO "btrfs: force reducing metadata "
3183 "integrity\n");
3184 } else {
3185 printk(KERN_ERR "btrfs: balance will reduce metadata "
3186 "integrity, use force if you want this\n");
3187 ret = -EINVAL;
3188 goto out;
3189 }
3190 }
3191 } while (read_seqretry(&fs_info->profiles_lock, seq));
3192
3193 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3194 int num_tolerated_disk_barrier_failures;
3195 u64 target = bctl->sys.target;
3196
3197 num_tolerated_disk_barrier_failures =
3198 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3199 if (num_tolerated_disk_barrier_failures > 0 &&
3200 (target &
3201 (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 |
3202 BTRFS_AVAIL_ALLOC_BIT_SINGLE)))
3203 num_tolerated_disk_barrier_failures = 0;
3204 else if (num_tolerated_disk_barrier_failures > 1 &&
3205 (target &
3206 (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)))
3207 num_tolerated_disk_barrier_failures = 1;
3208
3209 fs_info->num_tolerated_disk_barrier_failures =
3210 num_tolerated_disk_barrier_failures;
3211 }
3212
3213 ret = insert_balance_item(fs_info->tree_root, bctl);
3214 if (ret && ret != -EEXIST)
3215 goto out;
3216
3217 if (!(bctl->flags & BTRFS_BALANCE_RESUME)) {
3218 BUG_ON(ret == -EEXIST);
3219 set_balance_control(bctl);
3220 } else {
3221 BUG_ON(ret != -EEXIST);
3222 spin_lock(&fs_info->balance_lock);
3223 update_balance_args(bctl);
3224 spin_unlock(&fs_info->balance_lock);
3225 }
3226
3227 atomic_inc(&fs_info->balance_running);
3228 mutex_unlock(&fs_info->balance_mutex);
3229
3230 ret = __btrfs_balance(fs_info);
3231
3232 mutex_lock(&fs_info->balance_mutex);
3233 atomic_dec(&fs_info->balance_running);
3234
3235 if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) {
3236 fs_info->num_tolerated_disk_barrier_failures =
3237 btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
3238 }
3239
3240 if (bargs) {
3241 memset(bargs, 0, sizeof(*bargs));
3242 update_ioctl_balance_args(fs_info, 0, bargs);
3243 }
3244
3245 if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
3246 balance_need_close(fs_info)) {
3247 __cancel_balance(fs_info);
3248 }
3249
3250 wake_up(&fs_info->balance_wait_q);
3251
3252 return ret;
3253 out:
3254 if (bctl->flags & BTRFS_BALANCE_RESUME)
3255 __cancel_balance(fs_info);
3256 else {
3257 kfree(bctl);
3258 atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
3259 }
3260 return ret;
3261 }
3262
3263 static int balance_kthread(void *data)
3264 {
3265 struct btrfs_fs_info *fs_info = data;
3266 int ret = 0;
3267
3268 mutex_lock(&fs_info->volume_mutex);
3269 mutex_lock(&fs_info->balance_mutex);
3270
3271 if (fs_info->balance_ctl) {
3272 printk(KERN_INFO "btrfs: continuing balance\n");
3273 ret = btrfs_balance(fs_info->balance_ctl, NULL);
3274 }
3275
3276 mutex_unlock(&fs_info->balance_mutex);
3277 mutex_unlock(&fs_info->volume_mutex);
3278
3279 return ret;
3280 }
3281
3282 int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info)
3283 {
3284 struct task_struct *tsk;
3285
3286 spin_lock(&fs_info->balance_lock);
3287 if (!fs_info->balance_ctl) {
3288 spin_unlock(&fs_info->balance_lock);
3289 return 0;
3290 }
3291 spin_unlock(&fs_info->balance_lock);
3292
3293 if (btrfs_test_opt(fs_info->tree_root, SKIP_BALANCE)) {
3294 printk(KERN_INFO "btrfs: force skipping balance\n");
3295 return 0;
3296 }
3297
3298 tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
3299 if (IS_ERR(tsk))
3300 return PTR_ERR(tsk);
3301
3302 return 0;
3303 }
3304
3305 int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
3306 {
3307 struct btrfs_balance_control *bctl;
3308 struct btrfs_balance_item *item;
3309 struct btrfs_disk_balance_args disk_bargs;
3310 struct btrfs_path *path;
3311 struct extent_buffer *leaf;
3312 struct btrfs_key key;
3313 int ret;
3314
3315 path = btrfs_alloc_path();
3316 if (!path)
3317 return -ENOMEM;
3318
3319 key.objectid = BTRFS_BALANCE_OBJECTID;
3320 key.type = BTRFS_BALANCE_ITEM_KEY;
3321 key.offset = 0;
3322
3323 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
3324 if (ret < 0)
3325 goto out;
3326 if (ret > 0) { /* ret = -ENOENT; */
3327 ret = 0;
3328 goto out;
3329 }
3330
3331 bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
3332 if (!bctl) {
3333 ret = -ENOMEM;
3334 goto out;
3335 }
3336
3337 leaf = path->nodes[0];
3338 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item);
3339
3340 bctl->fs_info = fs_info;
3341 bctl->flags = btrfs_balance_flags(leaf, item);
3342 bctl->flags |= BTRFS_BALANCE_RESUME;
3343
3344 btrfs_balance_data(leaf, item, &disk_bargs);
3345 btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs);
3346 btrfs_balance_meta(leaf, item, &disk_bargs);
3347 btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs);
3348 btrfs_balance_sys(leaf, item, &disk_bargs);
3349 btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
3350
3351 WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
3352
3353 mutex_lock(&fs_info->volume_mutex);
3354 mutex_lock(&fs_info->balance_mutex);
3355
3356 set_balance_control(bctl);
3357
3358 mutex_unlock(&fs_info->balance_mutex);
3359 mutex_unlock(&fs_info->volume_mutex);
3360 out:
3361 btrfs_free_path(path);
3362 return ret;
3363 }
3364
3365 int btrfs_pause_balance(struct btrfs_fs_info *fs_info)
3366 {
3367 int ret = 0;
3368
3369 mutex_lock(&fs_info->balance_mutex);
3370 if (!fs_info->balance_ctl) {
3371 mutex_unlock(&fs_info->balance_mutex);
3372 return -ENOTCONN;
3373 }
3374
3375 if (atomic_read(&fs_info->balance_running)) {
3376 atomic_inc(&fs_info->balance_pause_req);
3377 mutex_unlock(&fs_info->balance_mutex);
3378
3379 wait_event(fs_info->balance_wait_q,
3380 atomic_read(&fs_info->balance_running) == 0);
3381
3382 mutex_lock(&fs_info->balance_mutex);
3383 /* we are good with balance_ctl ripped off from under us */
3384 BUG_ON(atomic_read(&fs_info->balance_running));
3385 atomic_dec(&fs_info->balance_pause_req);
3386 } else {
3387 ret = -ENOTCONN;
3388 }
3389
3390 mutex_unlock(&fs_info->balance_mutex);
3391 return ret;
3392 }
3393
3394 int btrfs_cancel_balance(struct btrfs_fs_info *fs_info)
3395 {
3396 mutex_lock(&fs_info->balance_mutex);
3397 if (!fs_info->balance_ctl) {
3398 mutex_unlock(&fs_info->balance_mutex);
3399 return -ENOTCONN;
3400 }
3401
3402 atomic_inc(&fs_info->balance_cancel_req);
3403 /*
3404 * if we are running just wait and return, balance item is
3405 * deleted in btrfs_balance in this case
3406 */
3407 if (atomic_read(&fs_info->balance_running)) {
3408 mutex_unlock(&fs_info->balance_mutex);
3409 wait_event(fs_info->balance_wait_q,
3410 atomic_read(&fs_info->balance_running) == 0);
3411 mutex_lock(&fs_info->balance_mutex);
3412 } else {
3413 /* __cancel_balance needs volume_mutex */
3414 mutex_unlock(&fs_info->balance_mutex);
3415 mutex_lock(&fs_info->volume_mutex);
3416 mutex_lock(&fs_info->balance_mutex);
3417
3418 if (fs_info->balance_ctl)
3419 __cancel_balance(fs_info);
3420
3421 mutex_unlock(&fs_info->volume_mutex);
3422 }
3423
3424 BUG_ON(fs_info->balance_ctl || atomic_read(&fs_info->balance_running));
3425 atomic_dec(&fs_info->balance_cancel_req);
3426 mutex_unlock(&fs_info->balance_mutex);
3427 return 0;
3428 }
3429
3430 /*
3431 * shrinking a device means finding all of the device extents past
3432 * the new size, and then following the back refs to the chunks.
3433 * The chunk relocation code actually frees the device extent
3434 */
3435 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
3436 {
3437 struct btrfs_trans_handle *trans;
3438 struct btrfs_root *root = device->dev_root;
3439 struct btrfs_dev_extent *dev_extent = NULL;
3440 struct btrfs_path *path;
3441 u64 length;
3442 u64 chunk_tree;
3443 u64 chunk_objectid;
3444 u64 chunk_offset;
3445 int ret;
3446 int slot;
3447 int failed = 0;
3448 bool retried = false;
3449 struct extent_buffer *l;
3450 struct btrfs_key key;
3451 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3452 u64 old_total = btrfs_super_total_bytes(super_copy);
3453 u64 old_size = device->total_bytes;
3454 u64 diff = device->total_bytes - new_size;
3455
3456 if (device->is_tgtdev_for_dev_replace)
3457 return -EINVAL;
3458
3459 path = btrfs_alloc_path();
3460 if (!path)
3461 return -ENOMEM;
3462
3463 path->reada = 2;
3464
3465 lock_chunks(root);
3466
3467 device->total_bytes = new_size;
3468 if (device->writeable) {
3469 device->fs_devices->total_rw_bytes -= diff;
3470 spin_lock(&root->fs_info->free_chunk_lock);
3471 root->fs_info->free_chunk_space -= diff;
3472 spin_unlock(&root->fs_info->free_chunk_lock);
3473 }
3474 unlock_chunks(root);
3475
3476 again:
3477 key.objectid = device->devid;
3478 key.offset = (u64)-1;
3479 key.type = BTRFS_DEV_EXTENT_KEY;
3480
3481 do {
3482 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3483 if (ret < 0)
3484 goto done;
3485
3486 ret = btrfs_previous_item(root, path, 0, key.type);
3487 if (ret < 0)
3488 goto done;
3489 if (ret) {
3490 ret = 0;
3491 btrfs_release_path(path);
3492 break;
3493 }
3494
3495 l = path->nodes[0];
3496 slot = path->slots[0];
3497 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
3498
3499 if (key.objectid != device->devid) {
3500 btrfs_release_path(path);
3501 break;
3502 }
3503
3504 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
3505 length = btrfs_dev_extent_length(l, dev_extent);
3506
3507 if (key.offset + length <= new_size) {
3508 btrfs_release_path(path);
3509 break;
3510 }
3511
3512 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
3513 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
3514 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
3515 btrfs_release_path(path);
3516
3517 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
3518 chunk_offset);
3519 if (ret && ret != -ENOSPC)
3520 goto done;
3521 if (ret == -ENOSPC)
3522 failed++;
3523 } while (key.offset-- > 0);
3524
3525 if (failed && !retried) {
3526 failed = 0;
3527 retried = true;
3528 goto again;
3529 } else if (failed && retried) {
3530 ret = -ENOSPC;
3531 lock_chunks(root);
3532
3533 device->total_bytes = old_size;
3534 if (device->writeable)
3535 device->fs_devices->total_rw_bytes += diff;
3536 spin_lock(&root->fs_info->free_chunk_lock);
3537 root->fs_info->free_chunk_space += diff;
3538 spin_unlock(&root->fs_info->free_chunk_lock);
3539 unlock_chunks(root);
3540 goto done;
3541 }
3542
3543 /* Shrinking succeeded, else we would be at "done". */
3544 trans = btrfs_start_transaction(root, 0);
3545 if (IS_ERR(trans)) {
3546 ret = PTR_ERR(trans);
3547 goto done;
3548 }
3549
3550 lock_chunks(root);
3551
3552 device->disk_total_bytes = new_size;
3553 /* Now btrfs_update_device() will change the on-disk size. */
3554 ret = btrfs_update_device(trans, device);
3555 if (ret) {
3556 unlock_chunks(root);
3557 btrfs_end_transaction(trans, root);
3558 goto done;
3559 }
3560 WARN_ON(diff > old_total);
3561 btrfs_set_super_total_bytes(super_copy, old_total - diff);
3562 unlock_chunks(root);
3563 btrfs_end_transaction(trans, root);
3564 done:
3565 btrfs_free_path(path);
3566 return ret;
3567 }
3568
3569 static int btrfs_add_system_chunk(struct btrfs_root *root,
3570 struct btrfs_key *key,
3571 struct btrfs_chunk *chunk, int item_size)
3572 {
3573 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
3574 struct btrfs_disk_key disk_key;
3575 u32 array_size;
3576 u8 *ptr;
3577
3578 array_size = btrfs_super_sys_array_size(super_copy);
3579 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
3580 return -EFBIG;
3581
3582 ptr = super_copy->sys_chunk_array + array_size;
3583 btrfs_cpu_key_to_disk(&disk_key, key);
3584 memcpy(ptr, &disk_key, sizeof(disk_key));
3585 ptr += sizeof(disk_key);
3586 memcpy(ptr, chunk, item_size);
3587 item_size += sizeof(disk_key);
3588 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
3589 return 0;
3590 }
3591
3592 /*
3593 * sort the devices in descending order by max_avail, total_avail
3594 */
3595 static int btrfs_cmp_device_info(const void *a, const void *b)
3596 {
3597 const struct btrfs_device_info *di_a = a;
3598 const struct btrfs_device_info *di_b = b;
3599
3600 if (di_a->max_avail > di_b->max_avail)
3601 return -1;
3602 if (di_a->max_avail < di_b->max_avail)
3603 return 1;
3604 if (di_a->total_avail > di_b->total_avail)
3605 return -1;
3606 if (di_a->total_avail < di_b->total_avail)
3607 return 1;
3608 return 0;
3609 }
3610
3611 static struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
3612 [BTRFS_RAID_RAID10] = {
3613 .sub_stripes = 2,
3614 .dev_stripes = 1,
3615 .devs_max = 0, /* 0 == as many as possible */
3616 .devs_min = 4,
3617 .devs_increment = 2,
3618 .ncopies = 2,
3619 },
3620 [BTRFS_RAID_RAID1] = {
3621 .sub_stripes = 1,
3622 .dev_stripes = 1,
3623 .devs_max = 2,
3624 .devs_min = 2,
3625 .devs_increment = 2,
3626 .ncopies = 2,
3627 },
3628 [BTRFS_RAID_DUP] = {
3629 .sub_stripes = 1,
3630 .dev_stripes = 2,
3631 .devs_max = 1,
3632 .devs_min = 1,
3633 .devs_increment = 1,
3634 .ncopies = 2,
3635 },
3636 [BTRFS_RAID_RAID0] = {
3637 .sub_stripes = 1,
3638 .dev_stripes = 1,
3639 .devs_max = 0,
3640 .devs_min = 2,
3641 .devs_increment = 1,
3642 .ncopies = 1,
3643 },
3644 [BTRFS_RAID_SINGLE] = {
3645 .sub_stripes = 1,
3646 .dev_stripes = 1,
3647 .devs_max = 1,
3648 .devs_min = 1,
3649 .devs_increment = 1,
3650 .ncopies = 1,
3651 },
3652 [BTRFS_RAID_RAID5] = {
3653 .sub_stripes = 1,
3654 .dev_stripes = 1,
3655 .devs_max = 0,
3656 .devs_min = 2,
3657 .devs_increment = 1,
3658 .ncopies = 2,
3659 },
3660 [BTRFS_RAID_RAID6] = {
3661 .sub_stripes = 1,
3662 .dev_stripes = 1,
3663 .devs_max = 0,
3664 .devs_min = 3,
3665 .devs_increment = 1,
3666 .ncopies = 3,
3667 },
3668 };
3669
3670 static u32 find_raid56_stripe_len(u32 data_devices, u32 dev_stripe_target)
3671 {
3672 /* TODO allow them to set a preferred stripe size */
3673 return 64 * 1024;
3674 }
3675
3676 static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type)
3677 {
3678 if (!(type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)))
3679 return;
3680
3681 btrfs_set_fs_incompat(info, RAID56);
3682 }
3683
3684 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
3685 struct btrfs_root *extent_root,
3686 struct map_lookup **map_ret,
3687 u64 *num_bytes_out, u64 *stripe_size_out,
3688 u64 start, u64 type)
3689 {
3690 struct btrfs_fs_info *info = extent_root->fs_info;
3691 struct btrfs_fs_devices *fs_devices = info->fs_devices;
3692 struct list_head *cur;
3693 struct map_lookup *map = NULL;
3694 struct extent_map_tree *em_tree;
3695 struct extent_map *em;
3696 struct btrfs_device_info *devices_info = NULL;
3697 u64 total_avail;
3698 int num_stripes; /* total number of stripes to allocate */
3699 int data_stripes; /* number of stripes that count for
3700 block group size */
3701 int sub_stripes; /* sub_stripes info for map */
3702 int dev_stripes; /* stripes per dev */
3703 int devs_max; /* max devs to use */
3704 int devs_min; /* min devs needed */
3705 int devs_increment; /* ndevs has to be a multiple of this */
3706 int ncopies; /* how many copies to data has */
3707 int ret;
3708 u64 max_stripe_size;
3709 u64 max_chunk_size;
3710 u64 stripe_size;
3711 u64 num_bytes;
3712 u64 raid_stripe_len = BTRFS_STRIPE_LEN;
3713 int ndevs;
3714 int i;
3715 int j;
3716 int index;
3717
3718 BUG_ON(!alloc_profile_is_valid(type, 0));
3719
3720 if (list_empty(&fs_devices->alloc_list))
3721 return -ENOSPC;
3722
3723 index = __get_raid_index(type);
3724
3725 sub_stripes = btrfs_raid_array[index].sub_stripes;
3726 dev_stripes = btrfs_raid_array[index].dev_stripes;
3727 devs_max = btrfs_raid_array[index].devs_max;
3728 devs_min = btrfs_raid_array[index].devs_min;
3729 devs_increment = btrfs_raid_array[index].devs_increment;
3730 ncopies = btrfs_raid_array[index].ncopies;
3731
3732 if (type & BTRFS_BLOCK_GROUP_DATA) {
3733 max_stripe_size = 1024 * 1024 * 1024;
3734 max_chunk_size = 10 * max_stripe_size;
3735 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
3736 /* for larger filesystems, use larger metadata chunks */
3737 if (fs_devices->total_rw_bytes > 50ULL * 1024 * 1024 * 1024)
3738 max_stripe_size = 1024 * 1024 * 1024;
3739 else
3740 max_stripe_size = 256 * 1024 * 1024;
3741 max_chunk_size = max_stripe_size;
3742 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
3743 max_stripe_size = 32 * 1024 * 1024;
3744 max_chunk_size = 2 * max_stripe_size;
3745 } else {
3746 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
3747 type);
3748 BUG_ON(1);
3749 }
3750
3751 /* we don't want a chunk larger than 10% of writeable space */
3752 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
3753 max_chunk_size);
3754
3755 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
3756 GFP_NOFS);
3757 if (!devices_info)
3758 return -ENOMEM;
3759
3760 cur = fs_devices->alloc_list.next;
3761
3762 /*
3763 * in the first pass through the devices list, we gather information
3764 * about the available holes on each device.
3765 */
3766 ndevs = 0;
3767 while (cur != &fs_devices->alloc_list) {
3768 struct btrfs_device *device;
3769 u64 max_avail;
3770 u64 dev_offset;
3771
3772 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
3773
3774 cur = cur->next;
3775
3776 if (!device->writeable) {
3777 WARN(1, KERN_ERR
3778 "btrfs: read-only device in alloc_list\n");
3779 continue;
3780 }
3781
3782 if (!device->in_fs_metadata ||
3783 device->is_tgtdev_for_dev_replace)
3784 continue;
3785
3786 if (device->total_bytes > device->bytes_used)
3787 total_avail = device->total_bytes - device->bytes_used;
3788 else
3789 total_avail = 0;
3790
3791 /* If there is no space on this device, skip it. */
3792 if (total_avail == 0)
3793 continue;
3794
3795 ret = find_free_dev_extent(device,
3796 max_stripe_size * dev_stripes,
3797 &dev_offset, &max_avail);
3798 if (ret && ret != -ENOSPC)
3799 goto error;
3800
3801 if (ret == 0)
3802 max_avail = max_stripe_size * dev_stripes;
3803
3804 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
3805 continue;
3806
3807 if (ndevs == fs_devices->rw_devices) {
3808 WARN(1, "%s: found more than %llu devices\n",
3809 __func__, fs_devices->rw_devices);
3810 break;
3811 }
3812 devices_info[ndevs].dev_offset = dev_offset;
3813 devices_info[ndevs].max_avail = max_avail;
3814 devices_info[ndevs].total_avail = total_avail;
3815 devices_info[ndevs].dev = device;
3816 ++ndevs;
3817 }
3818
3819 /*
3820 * now sort the devices by hole size / available space
3821 */
3822 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
3823 btrfs_cmp_device_info, NULL);
3824
3825 /* round down to number of usable stripes */
3826 ndevs -= ndevs % devs_increment;
3827
3828 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
3829 ret = -ENOSPC;
3830 goto error;
3831 }
3832
3833 if (devs_max && ndevs > devs_max)
3834 ndevs = devs_max;
3835 /*
3836 * the primary goal is to maximize the number of stripes, so use as many
3837 * devices as possible, even if the stripes are not maximum sized.
3838 */
3839 stripe_size = devices_info[ndevs-1].max_avail;
3840 num_stripes = ndevs * dev_stripes;
3841
3842 /*
3843 * this will have to be fixed for RAID1 and RAID10 over
3844 * more drives
3845 */
3846 data_stripes = num_stripes / ncopies;
3847
3848 if (type & BTRFS_BLOCK_GROUP_RAID5) {
3849 raid_stripe_len = find_raid56_stripe_len(ndevs - 1,
3850 btrfs_super_stripesize(info->super_copy));
3851 data_stripes = num_stripes - 1;
3852 }
3853 if (type & BTRFS_BLOCK_GROUP_RAID6) {
3854 raid_stripe_len = find_raid56_stripe_len(ndevs - 2,
3855 btrfs_super_stripesize(info->super_copy));
3856 data_stripes = num_stripes - 2;
3857 }
3858
3859 /*
3860 * Use the number of data stripes to figure out how big this chunk
3861 * is really going to be in terms of logical address space,
3862 * and compare that answer with the max chunk size
3863 */
3864 if (stripe_size * data_stripes > max_chunk_size) {
3865 u64 mask = (1ULL << 24) - 1;
3866 stripe_size = max_chunk_size;
3867 do_div(stripe_size, data_stripes);
3868
3869 /* bump the answer up to a 16MB boundary */
3870 stripe_size = (stripe_size + mask) & ~mask;
3871
3872 /* but don't go higher than the limits we found
3873 * while searching for free extents
3874 */
3875 if (stripe_size > devices_info[ndevs-1].max_avail)
3876 stripe_size = devices_info[ndevs-1].max_avail;
3877 }
3878
3879 do_div(stripe_size, dev_stripes);
3880
3881 /* align to BTRFS_STRIPE_LEN */
3882 do_div(stripe_size, raid_stripe_len);
3883 stripe_size *= raid_stripe_len;
3884
3885 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3886 if (!map) {
3887 ret = -ENOMEM;
3888 goto error;
3889 }
3890 map->num_stripes = num_stripes;
3891
3892 for (i = 0; i < ndevs; ++i) {
3893 for (j = 0; j < dev_stripes; ++j) {
3894 int s = i * dev_stripes + j;
3895 map->stripes[s].dev = devices_info[i].dev;
3896 map->stripes[s].physical = devices_info[i].dev_offset +
3897 j * stripe_size;
3898 }
3899 }
3900 map->sector_size = extent_root->sectorsize;
3901 map->stripe_len = raid_stripe_len;
3902 map->io_align = raid_stripe_len;
3903 map->io_width = raid_stripe_len;
3904 map->type = type;
3905 map->sub_stripes = sub_stripes;
3906
3907 *map_ret = map;
3908 num_bytes = stripe_size * data_stripes;
3909
3910 *stripe_size_out = stripe_size;
3911 *num_bytes_out = num_bytes;
3912
3913 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
3914
3915 em = alloc_extent_map();
3916 if (!em) {
3917 ret = -ENOMEM;
3918 goto error;
3919 }
3920 em->bdev = (struct block_device *)map;
3921 em->start = start;
3922 em->len = num_bytes;
3923 em->block_start = 0;
3924 em->block_len = em->len;
3925
3926 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
3927 write_lock(&em_tree->lock);
3928 ret = add_extent_mapping(em_tree, em, 0);
3929 write_unlock(&em_tree->lock);
3930 if (ret) {
3931 free_extent_map(em);
3932 goto error;
3933 }
3934
3935 for (i = 0; i < map->num_stripes; ++i) {
3936 struct btrfs_device *device;
3937 u64 dev_offset;
3938
3939 device = map->stripes[i].dev;
3940 dev_offset = map->stripes[i].physical;
3941
3942 ret = btrfs_alloc_dev_extent(trans, device,
3943 info->chunk_root->root_key.objectid,
3944 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3945 start, dev_offset, stripe_size);
3946 if (ret)
3947 goto error_dev_extent;
3948 }
3949
3950 ret = btrfs_make_block_group(trans, extent_root, 0, type,
3951 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
3952 start, num_bytes);
3953 if (ret) {
3954 i = map->num_stripes - 1;
3955 goto error_dev_extent;
3956 }
3957
3958 free_extent_map(em);
3959 check_raid56_incompat_flag(extent_root->fs_info, type);
3960
3961 kfree(devices_info);
3962 return 0;
3963
3964 error_dev_extent:
3965 for (; i >= 0; i--) {
3966 struct btrfs_device *device;
3967 int err;
3968
3969 device = map->stripes[i].dev;
3970 err = btrfs_free_dev_extent(trans, device, start);
3971 if (err) {
3972 btrfs_abort_transaction(trans, extent_root, err);
3973 break;
3974 }
3975 }
3976 write_lock(&em_tree->lock);
3977 remove_extent_mapping(em_tree, em);
3978 write_unlock(&em_tree->lock);
3979
3980 /* One for our allocation */
3981 free_extent_map(em);
3982 /* One for the tree reference */
3983 free_extent_map(em);
3984 error:
3985 kfree(map);
3986 kfree(devices_info);
3987 return ret;
3988 }
3989
3990 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
3991 struct btrfs_root *extent_root,
3992 struct map_lookup *map, u64 chunk_offset,
3993 u64 chunk_size, u64 stripe_size)
3994 {
3995 u64 dev_offset;
3996 struct btrfs_key key;
3997 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
3998 struct btrfs_device *device;
3999 struct btrfs_chunk *chunk;
4000 struct btrfs_stripe *stripe;
4001 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
4002 int index = 0;
4003 int ret;
4004
4005 chunk = kzalloc(item_size, GFP_NOFS);
4006 if (!chunk)
4007 return -ENOMEM;
4008
4009 index = 0;
4010 while (index < map->num_stripes) {
4011 device = map->stripes[index].dev;
4012 device->bytes_used += stripe_size;
4013 ret = btrfs_update_device(trans, device);
4014 if (ret)
4015 goto out_free;
4016 index++;
4017 }
4018
4019 spin_lock(&extent_root->fs_info->free_chunk_lock);
4020 extent_root->fs_info->free_chunk_space -= (stripe_size *
4021 map->num_stripes);
4022 spin_unlock(&extent_root->fs_info->free_chunk_lock);
4023
4024 index = 0;
4025 stripe = &chunk->stripe;
4026 while (index < map->num_stripes) {
4027 device = map->stripes[index].dev;
4028 dev_offset = map->stripes[index].physical;
4029
4030 btrfs_set_stack_stripe_devid(stripe, device->devid);
4031 btrfs_set_stack_stripe_offset(stripe, dev_offset);
4032 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
4033 stripe++;
4034 index++;
4035 }
4036
4037 btrfs_set_stack_chunk_length(chunk, chunk_size);
4038 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
4039 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
4040 btrfs_set_stack_chunk_type(chunk, map->type);
4041 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
4042 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
4043 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
4044 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
4045 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
4046
4047 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
4048 key.type = BTRFS_CHUNK_ITEM_KEY;
4049 key.offset = chunk_offset;
4050
4051 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
4052
4053 if (ret == 0 && map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
4054 /*
4055 * TODO: Cleanup of inserted chunk root in case of
4056 * failure.
4057 */
4058 ret = btrfs_add_system_chunk(chunk_root, &key, chunk,
4059 item_size);
4060 }
4061
4062 out_free:
4063 kfree(chunk);
4064 return ret;
4065 }
4066
4067 /*
4068 * Chunk allocation falls into two parts. The first part does works
4069 * that make the new allocated chunk useable, but not do any operation
4070 * that modifies the chunk tree. The second part does the works that
4071 * require modifying the chunk tree. This division is important for the
4072 * bootstrap process of adding storage to a seed btrfs.
4073 */
4074 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
4075 struct btrfs_root *extent_root, u64 type)
4076 {
4077 u64 chunk_offset;
4078 u64 chunk_size;
4079 u64 stripe_size;
4080 struct map_lookup *map;
4081 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
4082 int ret;
4083
4084 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
4085 &chunk_offset);
4086 if (ret)
4087 return ret;
4088
4089 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
4090 &stripe_size, chunk_offset, type);
4091 if (ret)
4092 return ret;
4093
4094 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
4095 chunk_size, stripe_size);
4096 if (ret)
4097 return ret;
4098 return 0;
4099 }
4100
4101 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
4102 struct btrfs_root *root,
4103 struct btrfs_device *device)
4104 {
4105 u64 chunk_offset;
4106 u64 sys_chunk_offset;
4107 u64 chunk_size;
4108 u64 sys_chunk_size;
4109 u64 stripe_size;
4110 u64 sys_stripe_size;
4111 u64 alloc_profile;
4112 struct map_lookup *map;
4113 struct map_lookup *sys_map;
4114 struct btrfs_fs_info *fs_info = root->fs_info;
4115 struct btrfs_root *extent_root = fs_info->extent_root;
4116 int ret;
4117
4118 ret = find_next_chunk(fs_info->chunk_root,
4119 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
4120 if (ret)
4121 return ret;
4122
4123 alloc_profile = btrfs_get_alloc_profile(extent_root, 0);
4124 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
4125 &stripe_size, chunk_offset, alloc_profile);
4126 if (ret)
4127 return ret;
4128
4129 sys_chunk_offset = chunk_offset + chunk_size;
4130
4131 alloc_profile = btrfs_get_alloc_profile(fs_info->chunk_root, 0);
4132 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
4133 &sys_chunk_size, &sys_stripe_size,
4134 sys_chunk_offset, alloc_profile);
4135 if (ret) {
4136 btrfs_abort_transaction(trans, root, ret);
4137 goto out;
4138 }
4139
4140 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
4141 if (ret) {
4142 btrfs_abort_transaction(trans, root, ret);
4143 goto out;
4144 }
4145
4146 /*
4147 * Modifying chunk tree needs allocating new blocks from both
4148 * system block group and metadata block group. So we only can
4149 * do operations require modifying the chunk tree after both
4150 * block groups were created.
4151 */
4152 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
4153 chunk_size, stripe_size);
4154 if (ret) {
4155 btrfs_abort_transaction(trans, root, ret);
4156 goto out;
4157 }
4158
4159 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
4160 sys_chunk_offset, sys_chunk_size,
4161 sys_stripe_size);
4162 if (ret)
4163 btrfs_abort_transaction(trans, root, ret);
4164
4165 out:
4166
4167 return ret;
4168 }
4169
4170 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
4171 {
4172 struct extent_map *em;
4173 struct map_lookup *map;
4174 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
4175 int readonly = 0;
4176 int i;
4177
4178 read_lock(&map_tree->map_tree.lock);
4179 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
4180 read_unlock(&map_tree->map_tree.lock);
4181 if (!em)
4182 return 1;
4183
4184 if (btrfs_test_opt(root, DEGRADED)) {
4185 free_extent_map(em);
4186 return 0;
4187 }
4188
4189 map = (struct map_lookup *)em->bdev;
4190 for (i = 0; i < map->num_stripes; i++) {
4191 if (!map->stripes[i].dev->writeable) {
4192 readonly = 1;
4193 break;
4194 }
4195 }
4196 free_extent_map(em);
4197 return readonly;
4198 }
4199
4200 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
4201 {
4202 extent_map_tree_init(&tree->map_tree);
4203 }
4204
4205 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
4206 {
4207 struct extent_map *em;
4208
4209 while (1) {
4210 write_lock(&tree->map_tree.lock);
4211 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
4212 if (em)
4213 remove_extent_mapping(&tree->map_tree, em);
4214 write_unlock(&tree->map_tree.lock);
4215 if (!em)
4216 break;
4217 kfree(em->bdev);
4218 /* once for us */
4219 free_extent_map(em);
4220 /* once for the tree */
4221 free_extent_map(em);
4222 }
4223 }
4224
4225 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len)
4226 {
4227 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4228 struct extent_map *em;
4229 struct map_lookup *map;
4230 struct extent_map_tree *em_tree = &map_tree->map_tree;
4231 int ret;
4232
4233 read_lock(&em_tree->lock);
4234 em = lookup_extent_mapping(em_tree, logical, len);
4235 read_unlock(&em_tree->lock);
4236
4237 /*
4238 * We could return errors for these cases, but that could get ugly and
4239 * we'd probably do the same thing which is just not do anything else
4240 * and exit, so return 1 so the callers don't try to use other copies.
4241 */
4242 if (!em) {
4243 btrfs_emerg(fs_info, "No mapping for %Lu-%Lu\n", logical,
4244 logical+len);
4245 return 1;
4246 }
4247
4248 if (em->start > logical || em->start + em->len < logical) {
4249 btrfs_emerg(fs_info, "Invalid mapping for %Lu-%Lu, got "
4250 "%Lu-%Lu\n", logical, logical+len, em->start,
4251 em->start + em->len);
4252 return 1;
4253 }
4254
4255 map = (struct map_lookup *)em->bdev;
4256 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
4257 ret = map->num_stripes;
4258 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4259 ret = map->sub_stripes;
4260 else if (map->type & BTRFS_BLOCK_GROUP_RAID5)
4261 ret = 2;
4262 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4263 ret = 3;
4264 else
4265 ret = 1;
4266 free_extent_map(em);
4267
4268 btrfs_dev_replace_lock(&fs_info->dev_replace);
4269 if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))
4270 ret++;
4271 btrfs_dev_replace_unlock(&fs_info->dev_replace);
4272
4273 return ret;
4274 }
4275
4276 unsigned long btrfs_full_stripe_len(struct btrfs_root *root,
4277 struct btrfs_mapping_tree *map_tree,
4278 u64 logical)
4279 {
4280 struct extent_map *em;
4281 struct map_lookup *map;
4282 struct extent_map_tree *em_tree = &map_tree->map_tree;
4283 unsigned long len = root->sectorsize;
4284
4285 read_lock(&em_tree->lock);
4286 em = lookup_extent_mapping(em_tree, logical, len);
4287 read_unlock(&em_tree->lock);
4288 BUG_ON(!em);
4289
4290 BUG_ON(em->start > logical || em->start + em->len < logical);
4291 map = (struct map_lookup *)em->bdev;
4292 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4293 BTRFS_BLOCK_GROUP_RAID6)) {
4294 len = map->stripe_len * nr_data_stripes(map);
4295 }
4296 free_extent_map(em);
4297 return len;
4298 }
4299
4300 int btrfs_is_parity_mirror(struct btrfs_mapping_tree *map_tree,
4301 u64 logical, u64 len, int mirror_num)
4302 {
4303 struct extent_map *em;
4304 struct map_lookup *map;
4305 struct extent_map_tree *em_tree = &map_tree->map_tree;
4306 int ret = 0;
4307
4308 read_lock(&em_tree->lock);
4309 em = lookup_extent_mapping(em_tree, logical, len);
4310 read_unlock(&em_tree->lock);
4311 BUG_ON(!em);
4312
4313 BUG_ON(em->start > logical || em->start + em->len < logical);
4314 map = (struct map_lookup *)em->bdev;
4315 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4316 BTRFS_BLOCK_GROUP_RAID6))
4317 ret = 1;
4318 free_extent_map(em);
4319 return ret;
4320 }
4321
4322 static int find_live_mirror(struct btrfs_fs_info *fs_info,
4323 struct map_lookup *map, int first, int num,
4324 int optimal, int dev_replace_is_ongoing)
4325 {
4326 int i;
4327 int tolerance;
4328 struct btrfs_device *srcdev;
4329
4330 if (dev_replace_is_ongoing &&
4331 fs_info->dev_replace.cont_reading_from_srcdev_mode ==
4332 BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID)
4333 srcdev = fs_info->dev_replace.srcdev;
4334 else
4335 srcdev = NULL;
4336
4337 /*
4338 * try to avoid the drive that is the source drive for a
4339 * dev-replace procedure, only choose it if no other non-missing
4340 * mirror is available
4341 */
4342 for (tolerance = 0; tolerance < 2; tolerance++) {
4343 if (map->stripes[optimal].dev->bdev &&
4344 (tolerance || map->stripes[optimal].dev != srcdev))
4345 return optimal;
4346 for (i = first; i < first + num; i++) {
4347 if (map->stripes[i].dev->bdev &&
4348 (tolerance || map->stripes[i].dev != srcdev))
4349 return i;
4350 }
4351 }
4352
4353 /* we couldn't find one that doesn't fail. Just return something
4354 * and the io error handling code will clean up eventually
4355 */
4356 return optimal;
4357 }
4358
4359 static inline int parity_smaller(u64 a, u64 b)
4360 {
4361 return a > b;
4362 }
4363
4364 /* Bubble-sort the stripe set to put the parity/syndrome stripes last */
4365 static void sort_parity_stripes(struct btrfs_bio *bbio, u64 *raid_map)
4366 {
4367 struct btrfs_bio_stripe s;
4368 int i;
4369 u64 l;
4370 int again = 1;
4371
4372 while (again) {
4373 again = 0;
4374 for (i = 0; i < bbio->num_stripes - 1; i++) {
4375 if (parity_smaller(raid_map[i], raid_map[i+1])) {
4376 s = bbio->stripes[i];
4377 l = raid_map[i];
4378 bbio->stripes[i] = bbio->stripes[i+1];
4379 raid_map[i] = raid_map[i+1];
4380 bbio->stripes[i+1] = s;
4381 raid_map[i+1] = l;
4382 again = 1;
4383 }
4384 }
4385 }
4386 }
4387
4388 static int __btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4389 u64 logical, u64 *length,
4390 struct btrfs_bio **bbio_ret,
4391 int mirror_num, u64 **raid_map_ret)
4392 {
4393 struct extent_map *em;
4394 struct map_lookup *map;
4395 struct btrfs_mapping_tree *map_tree = &fs_info->mapping_tree;
4396 struct extent_map_tree *em_tree = &map_tree->map_tree;
4397 u64 offset;
4398 u64 stripe_offset;
4399 u64 stripe_end_offset;
4400 u64 stripe_nr;
4401 u64 stripe_nr_orig;
4402 u64 stripe_nr_end;
4403 u64 stripe_len;
4404 u64 *raid_map = NULL;
4405 int stripe_index;
4406 int i;
4407 int ret = 0;
4408 int num_stripes;
4409 int max_errors = 0;
4410 struct btrfs_bio *bbio = NULL;
4411 struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
4412 int dev_replace_is_ongoing = 0;
4413 int num_alloc_stripes;
4414 int patch_the_first_stripe_for_dev_replace = 0;
4415 u64 physical_to_patch_in_first_stripe = 0;
4416 u64 raid56_full_stripe_start = (u64)-1;
4417
4418 read_lock(&em_tree->lock);
4419 em = lookup_extent_mapping(em_tree, logical, *length);
4420 read_unlock(&em_tree->lock);
4421
4422 if (!em) {
4423 btrfs_crit(fs_info, "unable to find logical %llu len %llu",
4424 (unsigned long long)logical,
4425 (unsigned long long)*length);
4426 return -EINVAL;
4427 }
4428
4429 if (em->start > logical || em->start + em->len < logical) {
4430 btrfs_crit(fs_info, "found a bad mapping, wanted %Lu, "
4431 "found %Lu-%Lu\n", logical, em->start,
4432 em->start + em->len);
4433 return -EINVAL;
4434 }
4435
4436 map = (struct map_lookup *)em->bdev;
4437 offset = logical - em->start;
4438
4439 if (mirror_num > map->num_stripes)
4440 mirror_num = 0;
4441
4442 stripe_len = map->stripe_len;
4443 stripe_nr = offset;
4444 /*
4445 * stripe_nr counts the total number of stripes we have to stride
4446 * to get to this block
4447 */
4448 do_div(stripe_nr, stripe_len);
4449
4450 stripe_offset = stripe_nr * stripe_len;
4451 BUG_ON(offset < stripe_offset);
4452
4453 /* stripe_offset is the offset of this block in its stripe*/
4454 stripe_offset = offset - stripe_offset;
4455
4456 /* if we're here for raid56, we need to know the stripe aligned start */
4457 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4458 unsigned long full_stripe_len = stripe_len * nr_data_stripes(map);
4459 raid56_full_stripe_start = offset;
4460
4461 /* allow a write of a full stripe, but make sure we don't
4462 * allow straddling of stripes
4463 */
4464 do_div(raid56_full_stripe_start, full_stripe_len);
4465 raid56_full_stripe_start *= full_stripe_len;
4466 }
4467
4468 if (rw & REQ_DISCARD) {
4469 /* we don't discard raid56 yet */
4470 if (map->type &
4471 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) {
4472 ret = -EOPNOTSUPP;
4473 goto out;
4474 }
4475 *length = min_t(u64, em->len - offset, *length);
4476 } else if (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
4477 u64 max_len;
4478 /* For writes to RAID[56], allow a full stripeset across all disks.
4479 For other RAID types and for RAID[56] reads, just allow a single
4480 stripe (on a single disk). */
4481 if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6) &&
4482 (rw & REQ_WRITE)) {
4483 max_len = stripe_len * nr_data_stripes(map) -
4484 (offset - raid56_full_stripe_start);
4485 } else {
4486 /* we limit the length of each bio to what fits in a stripe */
4487 max_len = stripe_len - stripe_offset;
4488 }
4489 *length = min_t(u64, em->len - offset, max_len);
4490 } else {
4491 *length = em->len - offset;
4492 }
4493
4494 /* This is for when we're called from btrfs_merge_bio_hook() and all
4495 it cares about is the length */
4496 if (!bbio_ret)
4497 goto out;
4498
4499 btrfs_dev_replace_lock(dev_replace);
4500 dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
4501 if (!dev_replace_is_ongoing)
4502 btrfs_dev_replace_unlock(dev_replace);
4503
4504 if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
4505 !(rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) &&
4506 dev_replace->tgtdev != NULL) {
4507 /*
4508 * in dev-replace case, for repair case (that's the only
4509 * case where the mirror is selected explicitly when
4510 * calling btrfs_map_block), blocks left of the left cursor
4511 * can also be read from the target drive.
4512 * For REQ_GET_READ_MIRRORS, the target drive is added as
4513 * the last one to the array of stripes. For READ, it also
4514 * needs to be supported using the same mirror number.
4515 * If the requested block is not left of the left cursor,
4516 * EIO is returned. This can happen because btrfs_num_copies()
4517 * returns one more in the dev-replace case.
4518 */
4519 u64 tmp_length = *length;
4520 struct btrfs_bio *tmp_bbio = NULL;
4521 int tmp_num_stripes;
4522 u64 srcdev_devid = dev_replace->srcdev->devid;
4523 int index_srcdev = 0;
4524 int found = 0;
4525 u64 physical_of_found = 0;
4526
4527 ret = __btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS,
4528 logical, &tmp_length, &tmp_bbio, 0, NULL);
4529 if (ret) {
4530 WARN_ON(tmp_bbio != NULL);
4531 goto out;
4532 }
4533
4534 tmp_num_stripes = tmp_bbio->num_stripes;
4535 if (mirror_num > tmp_num_stripes) {
4536 /*
4537 * REQ_GET_READ_MIRRORS does not contain this
4538 * mirror, that means that the requested area
4539 * is not left of the left cursor
4540 */
4541 ret = -EIO;
4542 kfree(tmp_bbio);
4543 goto out;
4544 }
4545
4546 /*
4547 * process the rest of the function using the mirror_num
4548 * of the source drive. Therefore look it up first.
4549 * At the end, patch the device pointer to the one of the
4550 * target drive.
4551 */
4552 for (i = 0; i < tmp_num_stripes; i++) {
4553 if (tmp_bbio->stripes[i].dev->devid == srcdev_devid) {
4554 /*
4555 * In case of DUP, in order to keep it
4556 * simple, only add the mirror with the
4557 * lowest physical address
4558 */
4559 if (found &&
4560 physical_of_found <=
4561 tmp_bbio->stripes[i].physical)
4562 continue;
4563 index_srcdev = i;
4564 found = 1;
4565 physical_of_found =
4566 tmp_bbio->stripes[i].physical;
4567 }
4568 }
4569
4570 if (found) {
4571 mirror_num = index_srcdev + 1;
4572 patch_the_first_stripe_for_dev_replace = 1;
4573 physical_to_patch_in_first_stripe = physical_of_found;
4574 } else {
4575 WARN_ON(1);
4576 ret = -EIO;
4577 kfree(tmp_bbio);
4578 goto out;
4579 }
4580
4581 kfree(tmp_bbio);
4582 } else if (mirror_num > map->num_stripes) {
4583 mirror_num = 0;
4584 }
4585
4586 num_stripes = 1;
4587 stripe_index = 0;
4588 stripe_nr_orig = stripe_nr;
4589 stripe_nr_end = ALIGN(offset + *length, map->stripe_len);
4590 do_div(stripe_nr_end, map->stripe_len);
4591 stripe_end_offset = stripe_nr_end * map->stripe_len -
4592 (offset + *length);
4593
4594 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4595 if (rw & REQ_DISCARD)
4596 num_stripes = min_t(u64, map->num_stripes,
4597 stripe_nr_end - stripe_nr_orig);
4598 stripe_index = do_div(stripe_nr, map->num_stripes);
4599 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
4600 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS))
4601 num_stripes = map->num_stripes;
4602 else if (mirror_num)
4603 stripe_index = mirror_num - 1;
4604 else {
4605 stripe_index = find_live_mirror(fs_info, map, 0,
4606 map->num_stripes,
4607 current->pid % map->num_stripes,
4608 dev_replace_is_ongoing);
4609 mirror_num = stripe_index + 1;
4610 }
4611
4612 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
4613 if (rw & (REQ_WRITE | REQ_DISCARD | REQ_GET_READ_MIRRORS)) {
4614 num_stripes = map->num_stripes;
4615 } else if (mirror_num) {
4616 stripe_index = mirror_num - 1;
4617 } else {
4618 mirror_num = 1;
4619 }
4620
4621 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4622 int factor = map->num_stripes / map->sub_stripes;
4623
4624 stripe_index = do_div(stripe_nr, factor);
4625 stripe_index *= map->sub_stripes;
4626
4627 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS))
4628 num_stripes = map->sub_stripes;
4629 else if (rw & REQ_DISCARD)
4630 num_stripes = min_t(u64, map->sub_stripes *
4631 (stripe_nr_end - stripe_nr_orig),
4632 map->num_stripes);
4633 else if (mirror_num)
4634 stripe_index += mirror_num - 1;
4635 else {
4636 int old_stripe_index = stripe_index;
4637 stripe_index = find_live_mirror(fs_info, map,
4638 stripe_index,
4639 map->sub_stripes, stripe_index +
4640 current->pid % map->sub_stripes,
4641 dev_replace_is_ongoing);
4642 mirror_num = stripe_index - old_stripe_index + 1;
4643 }
4644
4645 } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4646 BTRFS_BLOCK_GROUP_RAID6)) {
4647 u64 tmp;
4648
4649 if (bbio_ret && ((rw & REQ_WRITE) || mirror_num > 1)
4650 && raid_map_ret) {
4651 int i, rot;
4652
4653 /* push stripe_nr back to the start of the full stripe */
4654 stripe_nr = raid56_full_stripe_start;
4655 do_div(stripe_nr, stripe_len);
4656
4657 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4658
4659 /* RAID[56] write or recovery. Return all stripes */
4660 num_stripes = map->num_stripes;
4661 max_errors = nr_parity_stripes(map);
4662
4663 raid_map = kmalloc(sizeof(u64) * num_stripes,
4664 GFP_NOFS);
4665 if (!raid_map) {
4666 ret = -ENOMEM;
4667 goto out;
4668 }
4669
4670 /* Work out the disk rotation on this stripe-set */
4671 tmp = stripe_nr;
4672 rot = do_div(tmp, num_stripes);
4673
4674 /* Fill in the logical address of each stripe */
4675 tmp = stripe_nr * nr_data_stripes(map);
4676 for (i = 0; i < nr_data_stripes(map); i++)
4677 raid_map[(i+rot) % num_stripes] =
4678 em->start + (tmp + i) * map->stripe_len;
4679
4680 raid_map[(i+rot) % map->num_stripes] = RAID5_P_STRIPE;
4681 if (map->type & BTRFS_BLOCK_GROUP_RAID6)
4682 raid_map[(i+rot+1) % num_stripes] =
4683 RAID6_Q_STRIPE;
4684
4685 *length = map->stripe_len;
4686 stripe_index = 0;
4687 stripe_offset = 0;
4688 } else {
4689 /*
4690 * Mirror #0 or #1 means the original data block.
4691 * Mirror #2 is RAID5 parity block.
4692 * Mirror #3 is RAID6 Q block.
4693 */
4694 stripe_index = do_div(stripe_nr, nr_data_stripes(map));
4695 if (mirror_num > 1)
4696 stripe_index = nr_data_stripes(map) +
4697 mirror_num - 2;
4698
4699 /* We distribute the parity blocks across stripes */
4700 tmp = stripe_nr + stripe_index;
4701 stripe_index = do_div(tmp, map->num_stripes);
4702 }
4703 } else {
4704 /*
4705 * after this do_div call, stripe_nr is the number of stripes
4706 * on this device we have to walk to find the data, and
4707 * stripe_index is the number of our device in the stripe array
4708 */
4709 stripe_index = do_div(stripe_nr, map->num_stripes);
4710 mirror_num = stripe_index + 1;
4711 }
4712 BUG_ON(stripe_index >= map->num_stripes);
4713
4714 num_alloc_stripes = num_stripes;
4715 if (dev_replace_is_ongoing) {
4716 if (rw & (REQ_WRITE | REQ_DISCARD))
4717 num_alloc_stripes <<= 1;
4718 if (rw & REQ_GET_READ_MIRRORS)
4719 num_alloc_stripes++;
4720 }
4721 bbio = kzalloc(btrfs_bio_size(num_alloc_stripes), GFP_NOFS);
4722 if (!bbio) {
4723 ret = -ENOMEM;
4724 goto out;
4725 }
4726 atomic_set(&bbio->error, 0);
4727
4728 if (rw & REQ_DISCARD) {
4729 int factor = 0;
4730 int sub_stripes = 0;
4731 u64 stripes_per_dev = 0;
4732 u32 remaining_stripes = 0;
4733 u32 last_stripe = 0;
4734
4735 if (map->type &
4736 (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
4737 if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4738 sub_stripes = 1;
4739 else
4740 sub_stripes = map->sub_stripes;
4741
4742 factor = map->num_stripes / sub_stripes;
4743 stripes_per_dev = div_u64_rem(stripe_nr_end -
4744 stripe_nr_orig,
4745 factor,
4746 &remaining_stripes);
4747 div_u64_rem(stripe_nr_end - 1, factor, &last_stripe);
4748 last_stripe *= sub_stripes;
4749 }
4750
4751 for (i = 0; i < num_stripes; i++) {
4752 bbio->stripes[i].physical =
4753 map->stripes[stripe_index].physical +
4754 stripe_offset + stripe_nr * map->stripe_len;
4755 bbio->stripes[i].dev = map->stripes[stripe_index].dev;
4756
4757 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
4758 BTRFS_BLOCK_GROUP_RAID10)) {
4759 bbio->stripes[i].length = stripes_per_dev *
4760 map->stripe_len;
4761
4762 if (i / sub_stripes < remaining_stripes)
4763 bbio->stripes[i].length +=
4764 map->stripe_len;
4765
4766 /*
4767 * Special for the first stripe and
4768 * the last stripe:
4769 *
4770 * |-------|...|-------|
4771 * |----------|
4772 * off end_off
4773 */
4774 if (i < sub_stripes)
4775 bbio->stripes[i].length -=
4776 stripe_offset;
4777
4778 if (stripe_index >= last_stripe &&
4779 stripe_index <= (last_stripe +
4780 sub_stripes - 1))
4781 bbio->stripes[i].length -=
4782 stripe_end_offset;
4783
4784 if (i == sub_stripes - 1)
4785 stripe_offset = 0;
4786 } else
4787 bbio->stripes[i].length = *length;
4788
4789 stripe_index++;
4790 if (stripe_index == map->num_stripes) {
4791 /* This could only happen for RAID0/10 */
4792 stripe_index = 0;
4793 stripe_nr++;
4794 }
4795 }
4796 } else {
4797 for (i = 0; i < num_stripes; i++) {
4798 bbio->stripes[i].physical =
4799 map->stripes[stripe_index].physical +
4800 stripe_offset +
4801 stripe_nr * map->stripe_len;
4802 bbio->stripes[i].dev =
4803 map->stripes[stripe_index].dev;
4804 stripe_index++;
4805 }
4806 }
4807
4808 if (rw & (REQ_WRITE | REQ_GET_READ_MIRRORS)) {
4809 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
4810 BTRFS_BLOCK_GROUP_RAID10 |
4811 BTRFS_BLOCK_GROUP_RAID5 |
4812 BTRFS_BLOCK_GROUP_DUP)) {
4813 max_errors = 1;
4814 } else if (map->type & BTRFS_BLOCK_GROUP_RAID6) {
4815 max_errors = 2;
4816 }
4817 }
4818
4819 if (dev_replace_is_ongoing && (rw & (REQ_WRITE | REQ_DISCARD)) &&
4820 dev_replace->tgtdev != NULL) {
4821 int index_where_to_add;
4822 u64 srcdev_devid = dev_replace->srcdev->devid;
4823
4824 /*
4825 * duplicate the write operations while the dev replace
4826 * procedure is running. Since the copying of the old disk
4827 * to the new disk takes place at run time while the
4828 * filesystem is mounted writable, the regular write
4829 * operations to the old disk have to be duplicated to go
4830 * to the new disk as well.
4831 * Note that device->missing is handled by the caller, and
4832 * that the write to the old disk is already set up in the
4833 * stripes array.
4834 */
4835 index_where_to_add = num_stripes;
4836 for (i = 0; i < num_stripes; i++) {
4837 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4838 /* write to new disk, too */
4839 struct btrfs_bio_stripe *new =
4840 bbio->stripes + index_where_to_add;
4841 struct btrfs_bio_stripe *old =
4842 bbio->stripes + i;
4843
4844 new->physical = old->physical;
4845 new->length = old->length;
4846 new->dev = dev_replace->tgtdev;
4847 index_where_to_add++;
4848 max_errors++;
4849 }
4850 }
4851 num_stripes = index_where_to_add;
4852 } else if (dev_replace_is_ongoing && (rw & REQ_GET_READ_MIRRORS) &&
4853 dev_replace->tgtdev != NULL) {
4854 u64 srcdev_devid = dev_replace->srcdev->devid;
4855 int index_srcdev = 0;
4856 int found = 0;
4857 u64 physical_of_found = 0;
4858
4859 /*
4860 * During the dev-replace procedure, the target drive can
4861 * also be used to read data in case it is needed to repair
4862 * a corrupt block elsewhere. This is possible if the
4863 * requested area is left of the left cursor. In this area,
4864 * the target drive is a full copy of the source drive.
4865 */
4866 for (i = 0; i < num_stripes; i++) {
4867 if (bbio->stripes[i].dev->devid == srcdev_devid) {
4868 /*
4869 * In case of DUP, in order to keep it
4870 * simple, only add the mirror with the
4871 * lowest physical address
4872 */
4873 if (found &&
4874 physical_of_found <=
4875 bbio->stripes[i].physical)
4876 continue;
4877 index_srcdev = i;
4878 found = 1;
4879 physical_of_found = bbio->stripes[i].physical;
4880 }
4881 }
4882 if (found) {
4883 u64 length = map->stripe_len;
4884
4885 if (physical_of_found + length <=
4886 dev_replace->cursor_left) {
4887 struct btrfs_bio_stripe *tgtdev_stripe =
4888 bbio->stripes + num_stripes;
4889
4890 tgtdev_stripe->physical = physical_of_found;
4891 tgtdev_stripe->length =
4892 bbio->stripes[index_srcdev].length;
4893 tgtdev_stripe->dev = dev_replace->tgtdev;
4894
4895 num_stripes++;
4896 }
4897 }
4898 }
4899
4900 *bbio_ret = bbio;
4901 bbio->num_stripes = num_stripes;
4902 bbio->max_errors = max_errors;
4903 bbio->mirror_num = mirror_num;
4904
4905 /*
4906 * this is the case that REQ_READ && dev_replace_is_ongoing &&
4907 * mirror_num == num_stripes + 1 && dev_replace target drive is
4908 * available as a mirror
4909 */
4910 if (patch_the_first_stripe_for_dev_replace && num_stripes > 0) {
4911 WARN_ON(num_stripes > 1);
4912 bbio->stripes[0].dev = dev_replace->tgtdev;
4913 bbio->stripes[0].physical = physical_to_patch_in_first_stripe;
4914 bbio->mirror_num = map->num_stripes + 1;
4915 }
4916 if (raid_map) {
4917 sort_parity_stripes(bbio, raid_map);
4918 *raid_map_ret = raid_map;
4919 }
4920 out:
4921 if (dev_replace_is_ongoing)
4922 btrfs_dev_replace_unlock(dev_replace);
4923 free_extent_map(em);
4924 return ret;
4925 }
4926
4927 int btrfs_map_block(struct btrfs_fs_info *fs_info, int rw,
4928 u64 logical, u64 *length,
4929 struct btrfs_bio **bbio_ret, int mirror_num)
4930 {
4931 return __btrfs_map_block(fs_info, rw, logical, length, bbio_ret,
4932 mirror_num, NULL);
4933 }
4934
4935 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
4936 u64 chunk_start, u64 physical, u64 devid,
4937 u64 **logical, int *naddrs, int *stripe_len)
4938 {
4939 struct extent_map_tree *em_tree = &map_tree->map_tree;
4940 struct extent_map *em;
4941 struct map_lookup *map;
4942 u64 *buf;
4943 u64 bytenr;
4944 u64 length;
4945 u64 stripe_nr;
4946 u64 rmap_len;
4947 int i, j, nr = 0;
4948
4949 read_lock(&em_tree->lock);
4950 em = lookup_extent_mapping(em_tree, chunk_start, 1);
4951 read_unlock(&em_tree->lock);
4952
4953 if (!em) {
4954 printk(KERN_ERR "btrfs: couldn't find em for chunk %Lu\n",
4955 chunk_start);
4956 return -EIO;
4957 }
4958
4959 if (em->start != chunk_start) {
4960 printk(KERN_ERR "btrfs: bad chunk start, em=%Lu, wanted=%Lu\n",
4961 em->start, chunk_start);
4962 free_extent_map(em);
4963 return -EIO;
4964 }
4965 map = (struct map_lookup *)em->bdev;
4966
4967 length = em->len;
4968 rmap_len = map->stripe_len;
4969
4970 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
4971 do_div(length, map->num_stripes / map->sub_stripes);
4972 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
4973 do_div(length, map->num_stripes);
4974 else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 |
4975 BTRFS_BLOCK_GROUP_RAID6)) {
4976 do_div(length, nr_data_stripes(map));
4977 rmap_len = map->stripe_len * nr_data_stripes(map);
4978 }
4979
4980 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
4981 BUG_ON(!buf); /* -ENOMEM */
4982
4983 for (i = 0; i < map->num_stripes; i++) {
4984 if (devid && map->stripes[i].dev->devid != devid)
4985 continue;
4986 if (map->stripes[i].physical > physical ||
4987 map->stripes[i].physical + length <= physical)
4988 continue;
4989
4990 stripe_nr = physical - map->stripes[i].physical;
4991 do_div(stripe_nr, map->stripe_len);
4992
4993 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
4994 stripe_nr = stripe_nr * map->num_stripes + i;
4995 do_div(stripe_nr, map->sub_stripes);
4996 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
4997 stripe_nr = stripe_nr * map->num_stripes + i;
4998 } /* else if RAID[56], multiply by nr_data_stripes().
4999 * Alternatively, just use rmap_len below instead of
5000 * map->stripe_len */
5001
5002 bytenr = chunk_start + stripe_nr * rmap_len;
5003 WARN_ON(nr >= map->num_stripes);
5004 for (j = 0; j < nr; j++) {
5005 if (buf[j] == bytenr)
5006 break;
5007 }
5008 if (j == nr) {
5009 WARN_ON(nr >= map->num_stripes);
5010 buf[nr++] = bytenr;
5011 }
5012 }
5013
5014 *logical = buf;
5015 *naddrs = nr;
5016 *stripe_len = rmap_len;
5017
5018 free_extent_map(em);
5019 return 0;
5020 }
5021
5022 static void *merge_stripe_index_into_bio_private(void *bi_private,
5023 unsigned int stripe_index)
5024 {
5025 /*
5026 * with single, dup, RAID0, RAID1 and RAID10, stripe_index is
5027 * at most 1.
5028 * The alternative solution (instead of stealing bits from the
5029 * pointer) would be to allocate an intermediate structure
5030 * that contains the old private pointer plus the stripe_index.
5031 */
5032 BUG_ON((((uintptr_t)bi_private) & 3) != 0);
5033 BUG_ON(stripe_index > 3);
5034 return (void *)(((uintptr_t)bi_private) | stripe_index);
5035 }
5036
5037 static struct btrfs_bio *extract_bbio_from_bio_private(void *bi_private)
5038 {
5039 return (struct btrfs_bio *)(((uintptr_t)bi_private) & ~((uintptr_t)3));
5040 }
5041
5042 static unsigned int extract_stripe_index_from_bio_private(void *bi_private)
5043 {
5044 return (unsigned int)((uintptr_t)bi_private) & 3;
5045 }
5046
5047 static void btrfs_end_bio(struct bio *bio, int err)
5048 {
5049 struct btrfs_bio *bbio = extract_bbio_from_bio_private(bio->bi_private);
5050 int is_orig_bio = 0;
5051
5052 if (err) {
5053 atomic_inc(&bbio->error);
5054 if (err == -EIO || err == -EREMOTEIO) {
5055 unsigned int stripe_index =
5056 extract_stripe_index_from_bio_private(
5057 bio->bi_private);
5058 struct btrfs_device *dev;
5059
5060 BUG_ON(stripe_index >= bbio->num_stripes);
5061 dev = bbio->stripes[stripe_index].dev;
5062 if (dev->bdev) {
5063 if (bio->bi_rw & WRITE)
5064 btrfs_dev_stat_inc(dev,
5065 BTRFS_DEV_STAT_WRITE_ERRS);
5066 else
5067 btrfs_dev_stat_inc(dev,
5068 BTRFS_DEV_STAT_READ_ERRS);
5069 if ((bio->bi_rw & WRITE_FLUSH) == WRITE_FLUSH)
5070 btrfs_dev_stat_inc(dev,
5071 BTRFS_DEV_STAT_FLUSH_ERRS);
5072 btrfs_dev_stat_print_on_error(dev);
5073 }
5074 }
5075 }
5076
5077 if (bio == bbio->orig_bio)
5078 is_orig_bio = 1;
5079
5080 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5081 if (!is_orig_bio) {
5082 bio_put(bio);
5083 bio = bbio->orig_bio;
5084 }
5085 bio->bi_private = bbio->private;
5086 bio->bi_end_io = bbio->end_io;
5087 bio->bi_bdev = (struct block_device *)
5088 (unsigned long)bbio->mirror_num;
5089 /* only send an error to the higher layers if it is
5090 * beyond the tolerance of the btrfs bio
5091 */
5092 if (atomic_read(&bbio->error) > bbio->max_errors) {
5093 err = -EIO;
5094 } else {
5095 /*
5096 * this bio is actually up to date, we didn't
5097 * go over the max number of errors
5098 */
5099 set_bit(BIO_UPTODATE, &bio->bi_flags);
5100 err = 0;
5101 }
5102 kfree(bbio);
5103
5104 bio_endio(bio, err);
5105 } else if (!is_orig_bio) {
5106 bio_put(bio);
5107 }
5108 }
5109
5110 struct async_sched {
5111 struct bio *bio;
5112 int rw;
5113 struct btrfs_fs_info *info;
5114 struct btrfs_work work;
5115 };
5116
5117 /*
5118 * see run_scheduled_bios for a description of why bios are collected for
5119 * async submit.
5120 *
5121 * This will add one bio to the pending list for a device and make sure
5122 * the work struct is scheduled.
5123 */
5124 static noinline void btrfs_schedule_bio(struct btrfs_root *root,
5125 struct btrfs_device *device,
5126 int rw, struct bio *bio)
5127 {
5128 int should_queue = 1;
5129 struct btrfs_pending_bios *pending_bios;
5130
5131 if (device->missing || !device->bdev) {
5132 bio_endio(bio, -EIO);
5133 return;
5134 }
5135
5136 /* don't bother with additional async steps for reads, right now */
5137 if (!(rw & REQ_WRITE)) {
5138 bio_get(bio);
5139 btrfsic_submit_bio(rw, bio);
5140 bio_put(bio);
5141 return;
5142 }
5143
5144 /*
5145 * nr_async_bios allows us to reliably return congestion to the
5146 * higher layers. Otherwise, the async bio makes it appear we have
5147 * made progress against dirty pages when we've really just put it
5148 * on a queue for later
5149 */
5150 atomic_inc(&root->fs_info->nr_async_bios);
5151 WARN_ON(bio->bi_next);
5152 bio->bi_next = NULL;
5153 bio->bi_rw |= rw;
5154
5155 spin_lock(&device->io_lock);
5156 if (bio->bi_rw & REQ_SYNC)
5157 pending_bios = &device->pending_sync_bios;
5158 else
5159 pending_bios = &device->pending_bios;
5160
5161 if (pending_bios->tail)
5162 pending_bios->tail->bi_next = bio;
5163
5164 pending_bios->tail = bio;
5165 if (!pending_bios->head)
5166 pending_bios->head = bio;
5167 if (device->running_pending)
5168 should_queue = 0;
5169
5170 spin_unlock(&device->io_lock);
5171
5172 if (should_queue)
5173 btrfs_queue_worker(&root->fs_info->submit_workers,
5174 &device->work);
5175 }
5176
5177 static int bio_size_ok(struct block_device *bdev, struct bio *bio,
5178 sector_t sector)
5179 {
5180 struct bio_vec *prev;
5181 struct request_queue *q = bdev_get_queue(bdev);
5182 unsigned short max_sectors = queue_max_sectors(q);
5183 struct bvec_merge_data bvm = {
5184 .bi_bdev = bdev,
5185 .bi_sector = sector,
5186 .bi_rw = bio->bi_rw,
5187 };
5188
5189 if (bio->bi_vcnt == 0) {
5190 WARN_ON(1);
5191 return 1;
5192 }
5193
5194 prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
5195 if (bio_sectors(bio) > max_sectors)
5196 return 0;
5197
5198 if (!q->merge_bvec_fn)
5199 return 1;
5200
5201 bvm.bi_size = bio->bi_size - prev->bv_len;
5202 if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len)
5203 return 0;
5204 return 1;
5205 }
5206
5207 static void submit_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5208 struct bio *bio, u64 physical, int dev_nr,
5209 int rw, int async)
5210 {
5211 struct btrfs_device *dev = bbio->stripes[dev_nr].dev;
5212
5213 bio->bi_private = bbio;
5214 bio->bi_private = merge_stripe_index_into_bio_private(
5215 bio->bi_private, (unsigned int)dev_nr);
5216 bio->bi_end_io = btrfs_end_bio;
5217 bio->bi_sector = physical >> 9;
5218 #ifdef DEBUG
5219 {
5220 struct rcu_string *name;
5221
5222 rcu_read_lock();
5223 name = rcu_dereference(dev->name);
5224 pr_debug("btrfs_map_bio: rw %d, sector=%llu, dev=%lu "
5225 "(%s id %llu), size=%u\n", rw,
5226 (u64)bio->bi_sector, (u_long)dev->bdev->bd_dev,
5227 name->str, dev->devid, bio->bi_size);
5228 rcu_read_unlock();
5229 }
5230 #endif
5231 bio->bi_bdev = dev->bdev;
5232 if (async)
5233 btrfs_schedule_bio(root, dev, rw, bio);
5234 else
5235 btrfsic_submit_bio(rw, bio);
5236 }
5237
5238 static int breakup_stripe_bio(struct btrfs_root *root, struct btrfs_bio *bbio,
5239 struct bio *first_bio, struct btrfs_device *dev,
5240 int dev_nr, int rw, int async)
5241 {
5242 struct bio_vec *bvec = first_bio->bi_io_vec;
5243 struct bio *bio;
5244 int nr_vecs = bio_get_nr_vecs(dev->bdev);
5245 u64 physical = bbio->stripes[dev_nr].physical;
5246
5247 again:
5248 bio = btrfs_bio_alloc(dev->bdev, physical >> 9, nr_vecs, GFP_NOFS);
5249 if (!bio)
5250 return -ENOMEM;
5251
5252 while (bvec <= (first_bio->bi_io_vec + first_bio->bi_vcnt - 1)) {
5253 if (bio_add_page(bio, bvec->bv_page, bvec->bv_len,
5254 bvec->bv_offset) < bvec->bv_len) {
5255 u64 len = bio->bi_size;
5256
5257 atomic_inc(&bbio->stripes_pending);
5258 submit_stripe_bio(root, bbio, bio, physical, dev_nr,
5259 rw, async);
5260 physical += len;
5261 goto again;
5262 }
5263 bvec++;
5264 }
5265
5266 submit_stripe_bio(root, bbio, bio, physical, dev_nr, rw, async);
5267 return 0;
5268 }
5269
5270 static void bbio_error(struct btrfs_bio *bbio, struct bio *bio, u64 logical)
5271 {
5272 atomic_inc(&bbio->error);
5273 if (atomic_dec_and_test(&bbio->stripes_pending)) {
5274 bio->bi_private = bbio->private;
5275 bio->bi_end_io = bbio->end_io;
5276 bio->bi_bdev = (struct block_device *)
5277 (unsigned long)bbio->mirror_num;
5278 bio->bi_sector = logical >> 9;
5279 kfree(bbio);
5280 bio_endio(bio, -EIO);
5281 }
5282 }
5283
5284 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
5285 int mirror_num, int async_submit)
5286 {
5287 struct btrfs_device *dev;
5288 struct bio *first_bio = bio;
5289 u64 logical = (u64)bio->bi_sector << 9;
5290 u64 length = 0;
5291 u64 map_length;
5292 u64 *raid_map = NULL;
5293 int ret;
5294 int dev_nr = 0;
5295 int total_devs = 1;
5296 struct btrfs_bio *bbio = NULL;
5297
5298 length = bio->bi_size;
5299 map_length = length;
5300
5301 ret = __btrfs_map_block(root->fs_info, rw, logical, &map_length, &bbio,
5302 mirror_num, &raid_map);
5303 if (ret) /* -ENOMEM */
5304 return ret;
5305
5306 total_devs = bbio->num_stripes;
5307 bbio->orig_bio = first_bio;
5308 bbio->private = first_bio->bi_private;
5309 bbio->end_io = first_bio->bi_end_io;
5310 atomic_set(&bbio->stripes_pending, bbio->num_stripes);
5311
5312 if (raid_map) {
5313 /* In this case, map_length has been set to the length of
5314 a single stripe; not the whole write */
5315 if (rw & WRITE) {
5316 return raid56_parity_write(root, bio, bbio,
5317 raid_map, map_length);
5318 } else {
5319 return raid56_parity_recover(root, bio, bbio,
5320 raid_map, map_length,
5321 mirror_num);
5322 }
5323 }
5324
5325 if (map_length < length) {
5326 btrfs_crit(root->fs_info, "mapping failed logical %llu bio len %llu len %llu",
5327 (unsigned long long)logical,
5328 (unsigned long long)length,
5329 (unsigned long long)map_length);
5330 BUG();
5331 }
5332
5333 while (dev_nr < total_devs) {
5334 dev = bbio->stripes[dev_nr].dev;
5335 if (!dev || !dev->bdev || (rw & WRITE && !dev->writeable)) {
5336 bbio_error(bbio, first_bio, logical);
5337 dev_nr++;
5338 continue;
5339 }
5340
5341 /*
5342 * Check and see if we're ok with this bio based on it's size
5343 * and offset with the given device.
5344 */
5345 if (!bio_size_ok(dev->bdev, first_bio,
5346 bbio->stripes[dev_nr].physical >> 9)) {
5347 ret = breakup_stripe_bio(root, bbio, first_bio, dev,
5348 dev_nr, rw, async_submit);
5349 BUG_ON(ret);
5350 dev_nr++;
5351 continue;
5352 }
5353
5354 if (dev_nr < total_devs - 1) {
5355 bio = bio_clone(first_bio, GFP_NOFS);
5356 BUG_ON(!bio); /* -ENOMEM */
5357 } else {
5358 bio = first_bio;
5359 }
5360
5361 submit_stripe_bio(root, bbio, bio,
5362 bbio->stripes[dev_nr].physical, dev_nr, rw,
5363 async_submit);
5364 dev_nr++;
5365 }
5366 return 0;
5367 }
5368
5369 struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
5370 u8 *uuid, u8 *fsid)
5371 {
5372 struct btrfs_device *device;
5373 struct btrfs_fs_devices *cur_devices;
5374
5375 cur_devices = fs_info->fs_devices;
5376 while (cur_devices) {
5377 if (!fsid ||
5378 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5379 device = __find_device(&cur_devices->devices,
5380 devid, uuid);
5381 if (device)
5382 return device;
5383 }
5384 cur_devices = cur_devices->seed;
5385 }
5386 return NULL;
5387 }
5388
5389 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
5390 u64 devid, u8 *dev_uuid)
5391 {
5392 struct btrfs_device *device;
5393 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5394
5395 device = kzalloc(sizeof(*device), GFP_NOFS);
5396 if (!device)
5397 return NULL;
5398 list_add(&device->dev_list,
5399 &fs_devices->devices);
5400 device->dev_root = root->fs_info->dev_root;
5401 device->devid = devid;
5402 device->work.func = pending_bios_fn;
5403 device->fs_devices = fs_devices;
5404 device->missing = 1;
5405 fs_devices->num_devices++;
5406 fs_devices->missing_devices++;
5407 spin_lock_init(&device->io_lock);
5408 INIT_LIST_HEAD(&device->dev_alloc_list);
5409 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
5410 return device;
5411 }
5412
5413 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
5414 struct extent_buffer *leaf,
5415 struct btrfs_chunk *chunk)
5416 {
5417 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
5418 struct map_lookup *map;
5419 struct extent_map *em;
5420 u64 logical;
5421 u64 length;
5422 u64 devid;
5423 u8 uuid[BTRFS_UUID_SIZE];
5424 int num_stripes;
5425 int ret;
5426 int i;
5427
5428 logical = key->offset;
5429 length = btrfs_chunk_length(leaf, chunk);
5430
5431 read_lock(&map_tree->map_tree.lock);
5432 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
5433 read_unlock(&map_tree->map_tree.lock);
5434
5435 /* already mapped? */
5436 if (em && em->start <= logical && em->start + em->len > logical) {
5437 free_extent_map(em);
5438 return 0;
5439 } else if (em) {
5440 free_extent_map(em);
5441 }
5442
5443 em = alloc_extent_map();
5444 if (!em)
5445 return -ENOMEM;
5446 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
5447 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
5448 if (!map) {
5449 free_extent_map(em);
5450 return -ENOMEM;
5451 }
5452
5453 em->bdev = (struct block_device *)map;
5454 em->start = logical;
5455 em->len = length;
5456 em->orig_start = 0;
5457 em->block_start = 0;
5458 em->block_len = em->len;
5459
5460 map->num_stripes = num_stripes;
5461 map->io_width = btrfs_chunk_io_width(leaf, chunk);
5462 map->io_align = btrfs_chunk_io_align(leaf, chunk);
5463 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
5464 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
5465 map->type = btrfs_chunk_type(leaf, chunk);
5466 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
5467 for (i = 0; i < num_stripes; i++) {
5468 map->stripes[i].physical =
5469 btrfs_stripe_offset_nr(leaf, chunk, i);
5470 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
5471 read_extent_buffer(leaf, uuid, (unsigned long)
5472 btrfs_stripe_dev_uuid_nr(chunk, i),
5473 BTRFS_UUID_SIZE);
5474 map->stripes[i].dev = btrfs_find_device(root->fs_info, devid,
5475 uuid, NULL);
5476 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
5477 kfree(map);
5478 free_extent_map(em);
5479 return -EIO;
5480 }
5481 if (!map->stripes[i].dev) {
5482 map->stripes[i].dev =
5483 add_missing_dev(root, devid, uuid);
5484 if (!map->stripes[i].dev) {
5485 kfree(map);
5486 free_extent_map(em);
5487 return -EIO;
5488 }
5489 }
5490 map->stripes[i].dev->in_fs_metadata = 1;
5491 }
5492
5493 write_lock(&map_tree->map_tree.lock);
5494 ret = add_extent_mapping(&map_tree->map_tree, em, 0);
5495 write_unlock(&map_tree->map_tree.lock);
5496 BUG_ON(ret); /* Tree corruption */
5497 free_extent_map(em);
5498
5499 return 0;
5500 }
5501
5502 static void fill_device_from_item(struct extent_buffer *leaf,
5503 struct btrfs_dev_item *dev_item,
5504 struct btrfs_device *device)
5505 {
5506 unsigned long ptr;
5507
5508 device->devid = btrfs_device_id(leaf, dev_item);
5509 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
5510 device->total_bytes = device->disk_total_bytes;
5511 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
5512 device->type = btrfs_device_type(leaf, dev_item);
5513 device->io_align = btrfs_device_io_align(leaf, dev_item);
5514 device->io_width = btrfs_device_io_width(leaf, dev_item);
5515 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
5516 WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID);
5517 device->is_tgtdev_for_dev_replace = 0;
5518
5519 ptr = (unsigned long)btrfs_device_uuid(dev_item);
5520 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
5521 }
5522
5523 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
5524 {
5525 struct btrfs_fs_devices *fs_devices;
5526 int ret;
5527
5528 BUG_ON(!mutex_is_locked(&uuid_mutex));
5529
5530 fs_devices = root->fs_info->fs_devices->seed;
5531 while (fs_devices) {
5532 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
5533 ret = 0;
5534 goto out;
5535 }
5536 fs_devices = fs_devices->seed;
5537 }
5538
5539 fs_devices = find_fsid(fsid);
5540 if (!fs_devices) {
5541 ret = -ENOENT;
5542 goto out;
5543 }
5544
5545 fs_devices = clone_fs_devices(fs_devices);
5546 if (IS_ERR(fs_devices)) {
5547 ret = PTR_ERR(fs_devices);
5548 goto out;
5549 }
5550
5551 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
5552 root->fs_info->bdev_holder);
5553 if (ret) {
5554 free_fs_devices(fs_devices);
5555 goto out;
5556 }
5557
5558 if (!fs_devices->seeding) {
5559 __btrfs_close_devices(fs_devices);
5560 free_fs_devices(fs_devices);
5561 ret = -EINVAL;
5562 goto out;
5563 }
5564
5565 fs_devices->seed = root->fs_info->fs_devices->seed;
5566 root->fs_info->fs_devices->seed = fs_devices;
5567 out:
5568 return ret;
5569 }
5570
5571 static int read_one_dev(struct btrfs_root *root,
5572 struct extent_buffer *leaf,
5573 struct btrfs_dev_item *dev_item)
5574 {
5575 struct btrfs_device *device;
5576 u64 devid;
5577 int ret;
5578 u8 fs_uuid[BTRFS_UUID_SIZE];
5579 u8 dev_uuid[BTRFS_UUID_SIZE];
5580
5581 devid = btrfs_device_id(leaf, dev_item);
5582 read_extent_buffer(leaf, dev_uuid,
5583 (unsigned long)btrfs_device_uuid(dev_item),
5584 BTRFS_UUID_SIZE);
5585 read_extent_buffer(leaf, fs_uuid,
5586 (unsigned long)btrfs_device_fsid(dev_item),
5587 BTRFS_UUID_SIZE);
5588
5589 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
5590 ret = open_seed_devices(root, fs_uuid);
5591 if (ret && !btrfs_test_opt(root, DEGRADED))
5592 return ret;
5593 }
5594
5595 device = btrfs_find_device(root->fs_info, devid, dev_uuid, fs_uuid);
5596 if (!device || !device->bdev) {
5597 if (!btrfs_test_opt(root, DEGRADED))
5598 return -EIO;
5599
5600 if (!device) {
5601 btrfs_warn(root->fs_info, "devid %llu missing",
5602 (unsigned long long)devid);
5603 device = add_missing_dev(root, devid, dev_uuid);
5604 if (!device)
5605 return -ENOMEM;
5606 } else if (!device->missing) {
5607 /*
5608 * this happens when a device that was properly setup
5609 * in the device info lists suddenly goes bad.
5610 * device->bdev is NULL, and so we have to set
5611 * device->missing to one here
5612 */
5613 root->fs_info->fs_devices->missing_devices++;
5614 device->missing = 1;
5615 }
5616 }
5617
5618 if (device->fs_devices != root->fs_info->fs_devices) {
5619 BUG_ON(device->writeable);
5620 if (device->generation !=
5621 btrfs_device_generation(leaf, dev_item))
5622 return -EINVAL;
5623 }
5624
5625 fill_device_from_item(leaf, dev_item, device);
5626 device->dev_root = root->fs_info->dev_root;
5627 device->in_fs_metadata = 1;
5628 if (device->writeable && !device->is_tgtdev_for_dev_replace) {
5629 device->fs_devices->total_rw_bytes += device->total_bytes;
5630 spin_lock(&root->fs_info->free_chunk_lock);
5631 root->fs_info->free_chunk_space += device->total_bytes -
5632 device->bytes_used;
5633 spin_unlock(&root->fs_info->free_chunk_lock);
5634 }
5635 ret = 0;
5636 return ret;
5637 }
5638
5639 int btrfs_read_sys_array(struct btrfs_root *root)
5640 {
5641 struct btrfs_super_block *super_copy = root->fs_info->super_copy;
5642 struct extent_buffer *sb;
5643 struct btrfs_disk_key *disk_key;
5644 struct btrfs_chunk *chunk;
5645 u8 *ptr;
5646 unsigned long sb_ptr;
5647 int ret = 0;
5648 u32 num_stripes;
5649 u32 array_size;
5650 u32 len = 0;
5651 u32 cur;
5652 struct btrfs_key key;
5653
5654 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
5655 BTRFS_SUPER_INFO_SIZE);
5656 if (!sb)
5657 return -ENOMEM;
5658 btrfs_set_buffer_uptodate(sb);
5659 btrfs_set_buffer_lockdep_class(root->root_key.objectid, sb, 0);
5660 /*
5661 * The sb extent buffer is artifical and just used to read the system array.
5662 * btrfs_set_buffer_uptodate() call does not properly mark all it's
5663 * pages up-to-date when the page is larger: extent does not cover the
5664 * whole page and consequently check_page_uptodate does not find all
5665 * the page's extents up-to-date (the hole beyond sb),
5666 * write_extent_buffer then triggers a WARN_ON.
5667 *
5668 * Regular short extents go through mark_extent_buffer_dirty/writeback cycle,
5669 * but sb spans only this function. Add an explicit SetPageUptodate call
5670 * to silence the warning eg. on PowerPC 64.
5671 */
5672 if (PAGE_CACHE_SIZE > BTRFS_SUPER_INFO_SIZE)
5673 SetPageUptodate(sb->pages[0]);
5674
5675 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
5676 array_size = btrfs_super_sys_array_size(super_copy);
5677
5678 ptr = super_copy->sys_chunk_array;
5679 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
5680 cur = 0;
5681
5682 while (cur < array_size) {
5683 disk_key = (struct btrfs_disk_key *)ptr;
5684 btrfs_disk_key_to_cpu(&key, disk_key);
5685
5686 len = sizeof(*disk_key); ptr += len;
5687 sb_ptr += len;
5688 cur += len;
5689
5690 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
5691 chunk = (struct btrfs_chunk *)sb_ptr;
5692 ret = read_one_chunk(root, &key, sb, chunk);
5693 if (ret)
5694 break;
5695 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
5696 len = btrfs_chunk_item_size(num_stripes);
5697 } else {
5698 ret = -EIO;
5699 break;
5700 }
5701 ptr += len;
5702 sb_ptr += len;
5703 cur += len;
5704 }
5705 free_extent_buffer(sb);
5706 return ret;
5707 }
5708
5709 int btrfs_read_chunk_tree(struct btrfs_root *root)
5710 {
5711 struct btrfs_path *path;
5712 struct extent_buffer *leaf;
5713 struct btrfs_key key;
5714 struct btrfs_key found_key;
5715 int ret;
5716 int slot;
5717
5718 root = root->fs_info->chunk_root;
5719
5720 path = btrfs_alloc_path();
5721 if (!path)
5722 return -ENOMEM;
5723
5724 mutex_lock(&uuid_mutex);
5725 lock_chunks(root);
5726
5727 /* first we search for all of the device items, and then we
5728 * read in all of the chunk items. This way we can create chunk
5729 * mappings that reference all of the devices that are afound
5730 */
5731 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
5732 key.offset = 0;
5733 key.type = 0;
5734 again:
5735 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5736 if (ret < 0)
5737 goto error;
5738 while (1) {
5739 leaf = path->nodes[0];
5740 slot = path->slots[0];
5741 if (slot >= btrfs_header_nritems(leaf)) {
5742 ret = btrfs_next_leaf(root, path);
5743 if (ret == 0)
5744 continue;
5745 if (ret < 0)
5746 goto error;
5747 break;
5748 }
5749 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5750 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5751 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
5752 break;
5753 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
5754 struct btrfs_dev_item *dev_item;
5755 dev_item = btrfs_item_ptr(leaf, slot,
5756 struct btrfs_dev_item);
5757 ret = read_one_dev(root, leaf, dev_item);
5758 if (ret)
5759 goto error;
5760 }
5761 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
5762 struct btrfs_chunk *chunk;
5763 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
5764 ret = read_one_chunk(root, &found_key, leaf, chunk);
5765 if (ret)
5766 goto error;
5767 }
5768 path->slots[0]++;
5769 }
5770 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
5771 key.objectid = 0;
5772 btrfs_release_path(path);
5773 goto again;
5774 }
5775 ret = 0;
5776 error:
5777 unlock_chunks(root);
5778 mutex_unlock(&uuid_mutex);
5779
5780 btrfs_free_path(path);
5781 return ret;
5782 }
5783
5784 static void __btrfs_reset_dev_stats(struct btrfs_device *dev)
5785 {
5786 int i;
5787
5788 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5789 btrfs_dev_stat_reset(dev, i);
5790 }
5791
5792 int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info)
5793 {
5794 struct btrfs_key key;
5795 struct btrfs_key found_key;
5796 struct btrfs_root *dev_root = fs_info->dev_root;
5797 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5798 struct extent_buffer *eb;
5799 int slot;
5800 int ret = 0;
5801 struct btrfs_device *device;
5802 struct btrfs_path *path = NULL;
5803 int i;
5804
5805 path = btrfs_alloc_path();
5806 if (!path) {
5807 ret = -ENOMEM;
5808 goto out;
5809 }
5810
5811 mutex_lock(&fs_devices->device_list_mutex);
5812 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5813 int item_size;
5814 struct btrfs_dev_stats_item *ptr;
5815
5816 key.objectid = 0;
5817 key.type = BTRFS_DEV_STATS_KEY;
5818 key.offset = device->devid;
5819 ret = btrfs_search_slot(NULL, dev_root, &key, path, 0, 0);
5820 if (ret) {
5821 __btrfs_reset_dev_stats(device);
5822 device->dev_stats_valid = 1;
5823 btrfs_release_path(path);
5824 continue;
5825 }
5826 slot = path->slots[0];
5827 eb = path->nodes[0];
5828 btrfs_item_key_to_cpu(eb, &found_key, slot);
5829 item_size = btrfs_item_size_nr(eb, slot);
5830
5831 ptr = btrfs_item_ptr(eb, slot,
5832 struct btrfs_dev_stats_item);
5833
5834 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
5835 if (item_size >= (1 + i) * sizeof(__le64))
5836 btrfs_dev_stat_set(device, i,
5837 btrfs_dev_stats_value(eb, ptr, i));
5838 else
5839 btrfs_dev_stat_reset(device, i);
5840 }
5841
5842 device->dev_stats_valid = 1;
5843 btrfs_dev_stat_print_on_load(device);
5844 btrfs_release_path(path);
5845 }
5846 mutex_unlock(&fs_devices->device_list_mutex);
5847
5848 out:
5849 btrfs_free_path(path);
5850 return ret < 0 ? ret : 0;
5851 }
5852
5853 static int update_dev_stat_item(struct btrfs_trans_handle *trans,
5854 struct btrfs_root *dev_root,
5855 struct btrfs_device *device)
5856 {
5857 struct btrfs_path *path;
5858 struct btrfs_key key;
5859 struct extent_buffer *eb;
5860 struct btrfs_dev_stats_item *ptr;
5861 int ret;
5862 int i;
5863
5864 key.objectid = 0;
5865 key.type = BTRFS_DEV_STATS_KEY;
5866 key.offset = device->devid;
5867
5868 path = btrfs_alloc_path();
5869 BUG_ON(!path);
5870 ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1);
5871 if (ret < 0) {
5872 printk_in_rcu(KERN_WARNING "btrfs: error %d while searching for dev_stats item for device %s!\n",
5873 ret, rcu_str_deref(device->name));
5874 goto out;
5875 }
5876
5877 if (ret == 0 &&
5878 btrfs_item_size_nr(path->nodes[0], path->slots[0]) < sizeof(*ptr)) {
5879 /* need to delete old one and insert a new one */
5880 ret = btrfs_del_item(trans, dev_root, path);
5881 if (ret != 0) {
5882 printk_in_rcu(KERN_WARNING "btrfs: delete too small dev_stats item for device %s failed %d!\n",
5883 rcu_str_deref(device->name), ret);
5884 goto out;
5885 }
5886 ret = 1;
5887 }
5888
5889 if (ret == 1) {
5890 /* need to insert a new item */
5891 btrfs_release_path(path);
5892 ret = btrfs_insert_empty_item(trans, dev_root, path,
5893 &key, sizeof(*ptr));
5894 if (ret < 0) {
5895 printk_in_rcu(KERN_WARNING "btrfs: insert dev_stats item for device %s failed %d!\n",
5896 rcu_str_deref(device->name), ret);
5897 goto out;
5898 }
5899 }
5900
5901 eb = path->nodes[0];
5902 ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item);
5903 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5904 btrfs_set_dev_stats_value(eb, ptr, i,
5905 btrfs_dev_stat_read(device, i));
5906 btrfs_mark_buffer_dirty(eb);
5907
5908 out:
5909 btrfs_free_path(path);
5910 return ret;
5911 }
5912
5913 /*
5914 * called from commit_transaction. Writes all changed device stats to disk.
5915 */
5916 int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
5917 struct btrfs_fs_info *fs_info)
5918 {
5919 struct btrfs_root *dev_root = fs_info->dev_root;
5920 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
5921 struct btrfs_device *device;
5922 int ret = 0;
5923
5924 mutex_lock(&fs_devices->device_list_mutex);
5925 list_for_each_entry(device, &fs_devices->devices, dev_list) {
5926 if (!device->dev_stats_valid || !device->dev_stats_dirty)
5927 continue;
5928
5929 ret = update_dev_stat_item(trans, dev_root, device);
5930 if (!ret)
5931 device->dev_stats_dirty = 0;
5932 }
5933 mutex_unlock(&fs_devices->device_list_mutex);
5934
5935 return ret;
5936 }
5937
5938 void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index)
5939 {
5940 btrfs_dev_stat_inc(dev, index);
5941 btrfs_dev_stat_print_on_error(dev);
5942 }
5943
5944 static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev)
5945 {
5946 if (!dev->dev_stats_valid)
5947 return;
5948 printk_ratelimited_in_rcu(KERN_ERR
5949 "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5950 rcu_str_deref(dev->name),
5951 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5952 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5953 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5954 btrfs_dev_stat_read(dev,
5955 BTRFS_DEV_STAT_CORRUPTION_ERRS),
5956 btrfs_dev_stat_read(dev,
5957 BTRFS_DEV_STAT_GENERATION_ERRS));
5958 }
5959
5960 static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev)
5961 {
5962 int i;
5963
5964 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
5965 if (btrfs_dev_stat_read(dev, i) != 0)
5966 break;
5967 if (i == BTRFS_DEV_STAT_VALUES_MAX)
5968 return; /* all values == 0, suppress message */
5969
5970 printk_in_rcu(KERN_INFO "btrfs: bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u\n",
5971 rcu_str_deref(dev->name),
5972 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS),
5973 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS),
5974 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS),
5975 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS),
5976 btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS));
5977 }
5978
5979 int btrfs_get_dev_stats(struct btrfs_root *root,
5980 struct btrfs_ioctl_get_dev_stats *stats)
5981 {
5982 struct btrfs_device *dev;
5983 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
5984 int i;
5985
5986 mutex_lock(&fs_devices->device_list_mutex);
5987 dev = btrfs_find_device(root->fs_info, stats->devid, NULL, NULL);
5988 mutex_unlock(&fs_devices->device_list_mutex);
5989
5990 if (!dev) {
5991 printk(KERN_WARNING
5992 "btrfs: get dev_stats failed, device not found\n");
5993 return -ENODEV;
5994 } else if (!dev->dev_stats_valid) {
5995 printk(KERN_WARNING
5996 "btrfs: get dev_stats failed, not yet valid\n");
5997 return -ENODEV;
5998 } else if (stats->flags & BTRFS_DEV_STATS_RESET) {
5999 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) {
6000 if (stats->nr_items > i)
6001 stats->values[i] =
6002 btrfs_dev_stat_read_and_reset(dev, i);
6003 else
6004 btrfs_dev_stat_reset(dev, i);
6005 }
6006 } else {
6007 for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++)
6008 if (stats->nr_items > i)
6009 stats->values[i] = btrfs_dev_stat_read(dev, i);
6010 }
6011 if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX)
6012 stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX;
6013 return 0;
6014 }
6015
6016 int btrfs_scratch_superblock(struct btrfs_device *device)
6017 {
6018 struct buffer_head *bh;
6019 struct btrfs_super_block *disk_super;
6020
6021 bh = btrfs_read_dev_super(device->bdev);
6022 if (!bh)
6023 return -EINVAL;
6024 disk_super = (struct btrfs_super_block *)bh->b_data;
6025
6026 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
6027 set_buffer_dirty(bh);
6028 sync_dirty_buffer(bh);
6029 brelse(bh);
6030
6031 return 0;
6032 }
(deprecated) Btrfs devel tree