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-rw-r--r--fs/btrfs/volumes.c2549
1 files changed, 2549 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
new file mode 100644
index 000000000000..2eed7f91f51a
--- /dev/null
+++ b/fs/btrfs/volumes.c
@@ -0,0 +1,2549 @@
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/buffer_head.h>
21#include <linux/blkdev.h>
22#include <linux/random.h>
23#include <asm/div64.h>
24#include "ctree.h"
25#include "extent_map.h"
26#include "disk-io.h"
27#include "transaction.h"
28#include "print-tree.h"
29#include "volumes.h"
30#include "async-thread.h"
31
32struct map_lookup {
33 u64 type;
34 int io_align;
35 int io_width;
36 int stripe_len;
37 int sector_size;
38 int num_stripes;
39 int sub_stripes;
40 struct btrfs_bio_stripe stripes[];
41};
42
43#define map_lookup_size(n) (sizeof(struct map_lookup) + \
44 (sizeof(struct btrfs_bio_stripe) * (n)))
45
46static DEFINE_MUTEX(uuid_mutex);
47static LIST_HEAD(fs_uuids);
48
49void btrfs_lock_volumes(void)
50{
51 mutex_lock(&uuid_mutex);
52}
53
54void btrfs_unlock_volumes(void)
55{
56 mutex_unlock(&uuid_mutex);
57}
58
59static void lock_chunks(struct btrfs_root *root)
60{
61 mutex_lock(&root->fs_info->alloc_mutex);
62 mutex_lock(&root->fs_info->chunk_mutex);
63}
64
65static void unlock_chunks(struct btrfs_root *root)
66{
67 mutex_unlock(&root->fs_info->chunk_mutex);
68 mutex_unlock(&root->fs_info->alloc_mutex);
69}
70
71int btrfs_cleanup_fs_uuids(void)
72{
73 struct btrfs_fs_devices *fs_devices;
74 struct list_head *uuid_cur;
75 struct list_head *devices_cur;
76 struct btrfs_device *dev;
77
78 list_for_each(uuid_cur, &fs_uuids) {
79 fs_devices = list_entry(uuid_cur, struct btrfs_fs_devices,
80 list);
81 while(!list_empty(&fs_devices->devices)) {
82 devices_cur = fs_devices->devices.next;
83 dev = list_entry(devices_cur, struct btrfs_device,
84 dev_list);
85 if (dev->bdev) {
86 close_bdev_excl(dev->bdev);
87 fs_devices->open_devices--;
88 }
89 list_del(&dev->dev_list);
90 kfree(dev->name);
91 kfree(dev);
92 }
93 }
94 return 0;
95}
96
97static noinline struct btrfs_device *__find_device(struct list_head *head,
98 u64 devid, u8 *uuid)
99{
100 struct btrfs_device *dev;
101 struct list_head *cur;
102
103 list_for_each(cur, head) {
104 dev = list_entry(cur, struct btrfs_device, dev_list);
105 if (dev->devid == devid &&
106 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
107 return dev;
108 }
109 }
110 return NULL;
111}
112
113static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
114{
115 struct list_head *cur;
116 struct btrfs_fs_devices *fs_devices;
117
118 list_for_each(cur, &fs_uuids) {
119 fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
120 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
121 return fs_devices;
122 }
123 return NULL;
124}
125
126/*
127 * we try to collect pending bios for a device so we don't get a large
128 * number of procs sending bios down to the same device. This greatly
129 * improves the schedulers ability to collect and merge the bios.
130 *
131 * But, it also turns into a long list of bios to process and that is sure
132 * to eventually make the worker thread block. The solution here is to
133 * make some progress and then put this work struct back at the end of
134 * the list if the block device is congested. This way, multiple devices
135 * can make progress from a single worker thread.
136 */
137static int noinline run_scheduled_bios(struct btrfs_device *device)
138{
139 struct bio *pending;
140 struct backing_dev_info *bdi;
141 struct btrfs_fs_info *fs_info;
142 struct bio *tail;
143 struct bio *cur;
144 int again = 0;
145 unsigned long num_run = 0;
146 unsigned long limit;
147
148 bdi = device->bdev->bd_inode->i_mapping->backing_dev_info;
149 fs_info = device->dev_root->fs_info;
150 limit = btrfs_async_submit_limit(fs_info);
151 limit = limit * 2 / 3;
152
153loop:
154 spin_lock(&device->io_lock);
155
156 /* take all the bios off the list at once and process them
157 * later on (without the lock held). But, remember the
158 * tail and other pointers so the bios can be properly reinserted
159 * into the list if we hit congestion
160 */
161 pending = device->pending_bios;
162 tail = device->pending_bio_tail;
163 WARN_ON(pending && !tail);
164 device->pending_bios = NULL;
165 device->pending_bio_tail = NULL;
166
167 /*
168 * if pending was null this time around, no bios need processing
169 * at all and we can stop. Otherwise it'll loop back up again
170 * and do an additional check so no bios are missed.
171 *
172 * device->running_pending is used to synchronize with the
173 * schedule_bio code.
174 */
175 if (pending) {
176 again = 1;
177 device->running_pending = 1;
178 } else {
179 again = 0;
180 device->running_pending = 0;
181 }
182 spin_unlock(&device->io_lock);
183
184 while(pending) {
185 cur = pending;
186 pending = pending->bi_next;
187 cur->bi_next = NULL;
188 atomic_dec(&fs_info->nr_async_bios);
189
190 if (atomic_read(&fs_info->nr_async_bios) < limit &&
191 waitqueue_active(&fs_info->async_submit_wait))
192 wake_up(&fs_info->async_submit_wait);
193
194 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
195 bio_get(cur);
196 submit_bio(cur->bi_rw, cur);
197 bio_put(cur);
198 num_run++;
199
200 /*
201 * we made progress, there is more work to do and the bdi
202 * is now congested. Back off and let other work structs
203 * run instead
204 */
205 if (pending && bdi_write_congested(bdi)) {
206 struct bio *old_head;
207
208 spin_lock(&device->io_lock);
209
210 old_head = device->pending_bios;
211 device->pending_bios = pending;
212 if (device->pending_bio_tail)
213 tail->bi_next = old_head;
214 else
215 device->pending_bio_tail = tail;
216
217 spin_unlock(&device->io_lock);
218 btrfs_requeue_work(&device->work);
219 goto done;
220 }
221 }
222 if (again)
223 goto loop;
224done:
225 return 0;
226}
227
228void pending_bios_fn(struct btrfs_work *work)
229{
230 struct btrfs_device *device;
231
232 device = container_of(work, struct btrfs_device, work);
233 run_scheduled_bios(device);
234}
235
236static noinline int device_list_add(const char *path,
237 struct btrfs_super_block *disk_super,
238 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
239{
240 struct btrfs_device *device;
241 struct btrfs_fs_devices *fs_devices;
242 u64 found_transid = btrfs_super_generation(disk_super);
243
244 fs_devices = find_fsid(disk_super->fsid);
245 if (!fs_devices) {
246 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
247 if (!fs_devices)
248 return -ENOMEM;
249 INIT_LIST_HEAD(&fs_devices->devices);
250 INIT_LIST_HEAD(&fs_devices->alloc_list);
251 list_add(&fs_devices->list, &fs_uuids);
252 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
253 fs_devices->latest_devid = devid;
254 fs_devices->latest_trans = found_transid;
255 device = NULL;
256 } else {
257 device = __find_device(&fs_devices->devices, devid,
258 disk_super->dev_item.uuid);
259 }
260 if (!device) {
261 device = kzalloc(sizeof(*device), GFP_NOFS);
262 if (!device) {
263 /* we can safely leave the fs_devices entry around */
264 return -ENOMEM;
265 }
266 device->devid = devid;
267 device->work.func = pending_bios_fn;
268 memcpy(device->uuid, disk_super->dev_item.uuid,
269 BTRFS_UUID_SIZE);
270 device->barriers = 1;
271 spin_lock_init(&device->io_lock);
272 device->name = kstrdup(path, GFP_NOFS);
273 if (!device->name) {
274 kfree(device);
275 return -ENOMEM;
276 }
277 list_add(&device->dev_list, &fs_devices->devices);
278 list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
279 fs_devices->num_devices++;
280 }
281
282 if (found_transid > fs_devices->latest_trans) {
283 fs_devices->latest_devid = devid;
284 fs_devices->latest_trans = found_transid;
285 }
286 *fs_devices_ret = fs_devices;
287 return 0;
288}
289
290int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
291{
292 struct list_head *head = &fs_devices->devices;
293 struct list_head *cur;
294 struct btrfs_device *device;
295
296 mutex_lock(&uuid_mutex);
297again:
298 list_for_each(cur, head) {
299 device = list_entry(cur, struct btrfs_device, dev_list);
300 if (!device->in_fs_metadata) {
301 struct block_device *bdev;
302 list_del(&device->dev_list);
303 list_del(&device->dev_alloc_list);
304 fs_devices->num_devices--;
305 if (device->bdev) {
306 bdev = device->bdev;
307 fs_devices->open_devices--;
308 mutex_unlock(&uuid_mutex);
309 close_bdev_excl(bdev);
310 mutex_lock(&uuid_mutex);
311 }
312 kfree(device->name);
313 kfree(device);
314 goto again;
315 }
316 }
317 mutex_unlock(&uuid_mutex);
318 return 0;
319}
320
321int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
322{
323 struct list_head *head = &fs_devices->devices;
324 struct list_head *cur;
325 struct btrfs_device *device;
326
327 mutex_lock(&uuid_mutex);
328 list_for_each(cur, head) {
329 device = list_entry(cur, struct btrfs_device, dev_list);
330 if (device->bdev) {
331 close_bdev_excl(device->bdev);
332 fs_devices->open_devices--;
333 }
334 device->bdev = NULL;
335 device->in_fs_metadata = 0;
336 }
337 fs_devices->mounted = 0;
338 mutex_unlock(&uuid_mutex);
339 return 0;
340}
341
342int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
343 int flags, void *holder)
344{
345 struct block_device *bdev;
346 struct list_head *head = &fs_devices->devices;
347 struct list_head *cur;
348 struct btrfs_device *device;
349 struct block_device *latest_bdev = NULL;
350 struct buffer_head *bh;
351 struct btrfs_super_block *disk_super;
352 u64 latest_devid = 0;
353 u64 latest_transid = 0;
354 u64 transid;
355 u64 devid;
356 int ret = 0;
357
358 mutex_lock(&uuid_mutex);
359 if (fs_devices->mounted)
360 goto out;
361
362 list_for_each(cur, head) {
363 device = list_entry(cur, struct btrfs_device, dev_list);
364 if (device->bdev)
365 continue;
366
367 if (!device->name)
368 continue;
369
370 bdev = open_bdev_excl(device->name, flags, holder);
371
372 if (IS_ERR(bdev)) {
373 printk("open %s failed\n", device->name);
374 goto error;
375 }
376 set_blocksize(bdev, 4096);
377
378 bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
379 if (!bh)
380 goto error_close;
381
382 disk_super = (struct btrfs_super_block *)bh->b_data;
383 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
384 sizeof(disk_super->magic)))
385 goto error_brelse;
386
387 devid = le64_to_cpu(disk_super->dev_item.devid);
388 if (devid != device->devid)
389 goto error_brelse;
390
391 transid = btrfs_super_generation(disk_super);
392 if (!latest_transid || transid > latest_transid) {
393 latest_devid = devid;
394 latest_transid = transid;
395 latest_bdev = bdev;
396 }
397
398 device->bdev = bdev;
399 device->in_fs_metadata = 0;
400 fs_devices->open_devices++;
401 continue;
402
403error_brelse:
404 brelse(bh);
405error_close:
406 close_bdev_excl(bdev);
407error:
408 continue;
409 }
410 if (fs_devices->open_devices == 0) {
411 ret = -EIO;
412 goto out;
413 }
414 fs_devices->mounted = 1;
415 fs_devices->latest_bdev = latest_bdev;
416 fs_devices->latest_devid = latest_devid;
417 fs_devices->latest_trans = latest_transid;
418out:
419 mutex_unlock(&uuid_mutex);
420 return ret;
421}
422
423int btrfs_scan_one_device(const char *path, int flags, void *holder,
424 struct btrfs_fs_devices **fs_devices_ret)
425{
426 struct btrfs_super_block *disk_super;
427 struct block_device *bdev;
428 struct buffer_head *bh;
429 int ret;
430 u64 devid;
431 u64 transid;
432
433 mutex_lock(&uuid_mutex);
434
435 bdev = open_bdev_excl(path, flags, holder);
436
437 if (IS_ERR(bdev)) {
438 ret = PTR_ERR(bdev);
439 goto error;
440 }
441
442 ret = set_blocksize(bdev, 4096);
443 if (ret)
444 goto error_close;
445 bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
446 if (!bh) {
447 ret = -EIO;
448 goto error_close;
449 }
450 disk_super = (struct btrfs_super_block *)bh->b_data;
451 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
452 sizeof(disk_super->magic))) {
453 ret = -EINVAL;
454 goto error_brelse;
455 }
456 devid = le64_to_cpu(disk_super->dev_item.devid);
457 transid = btrfs_super_generation(disk_super);
458 if (disk_super->label[0])
459 printk("device label %s ", disk_super->label);
460 else {
461 /* FIXME, make a readl uuid parser */
462 printk("device fsid %llx-%llx ",
463 *(unsigned long long *)disk_super->fsid,
464 *(unsigned long long *)(disk_super->fsid + 8));
465 }
466 printk("devid %Lu transid %Lu %s\n", devid, transid, path);
467 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
468
469error_brelse:
470 brelse(bh);
471error_close:
472 close_bdev_excl(bdev);
473error:
474 mutex_unlock(&uuid_mutex);
475 return ret;
476}
477
478/*
479 * this uses a pretty simple search, the expectation is that it is
480 * called very infrequently and that a given device has a small number
481 * of extents
482 */
483static noinline int find_free_dev_extent(struct btrfs_trans_handle *trans,
484 struct btrfs_device *device,
485 struct btrfs_path *path,
486 u64 num_bytes, u64 *start)
487{
488 struct btrfs_key key;
489 struct btrfs_root *root = device->dev_root;
490 struct btrfs_dev_extent *dev_extent = NULL;
491 u64 hole_size = 0;
492 u64 last_byte = 0;
493 u64 search_start = 0;
494 u64 search_end = device->total_bytes;
495 int ret;
496 int slot = 0;
497 int start_found;
498 struct extent_buffer *l;
499
500 start_found = 0;
501 path->reada = 2;
502
503 /* FIXME use last free of some kind */
504
505 /* we don't want to overwrite the superblock on the drive,
506 * so we make sure to start at an offset of at least 1MB
507 */
508 search_start = max((u64)1024 * 1024, search_start);
509
510 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
511 search_start = max(root->fs_info->alloc_start, search_start);
512
513 key.objectid = device->devid;
514 key.offset = search_start;
515 key.type = BTRFS_DEV_EXTENT_KEY;
516 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
517 if (ret < 0)
518 goto error;
519 ret = btrfs_previous_item(root, path, 0, key.type);
520 if (ret < 0)
521 goto error;
522 l = path->nodes[0];
523 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
524 while (1) {
525 l = path->nodes[0];
526 slot = path->slots[0];
527 if (slot >= btrfs_header_nritems(l)) {
528 ret = btrfs_next_leaf(root, path);
529 if (ret == 0)
530 continue;
531 if (ret < 0)
532 goto error;
533no_more_items:
534 if (!start_found) {
535 if (search_start >= search_end) {
536 ret = -ENOSPC;
537 goto error;
538 }
539 *start = search_start;
540 start_found = 1;
541 goto check_pending;
542 }
543 *start = last_byte > search_start ?
544 last_byte : search_start;
545 if (search_end <= *start) {
546 ret = -ENOSPC;
547 goto error;
548 }
549 goto check_pending;
550 }
551 btrfs_item_key_to_cpu(l, &key, slot);
552
553 if (key.objectid < device->devid)
554 goto next;
555
556 if (key.objectid > device->devid)
557 goto no_more_items;
558
559 if (key.offset >= search_start && key.offset > last_byte &&
560 start_found) {
561 if (last_byte < search_start)
562 last_byte = search_start;
563 hole_size = key.offset - last_byte;
564 if (key.offset > last_byte &&
565 hole_size >= num_bytes) {
566 *start = last_byte;
567 goto check_pending;
568 }
569 }
570 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
571 goto next;
572 }
573
574 start_found = 1;
575 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
576 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
577next:
578 path->slots[0]++;
579 cond_resched();
580 }
581check_pending:
582 /* we have to make sure we didn't find an extent that has already
583 * been allocated by the map tree or the original allocation
584 */
585 btrfs_release_path(root, path);
586 BUG_ON(*start < search_start);
587
588 if (*start + num_bytes > search_end) {
589 ret = -ENOSPC;
590 goto error;
591 }
592 /* check for pending inserts here */
593 return 0;
594
595error:
596 btrfs_release_path(root, path);
597 return ret;
598}
599
600int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
601 struct btrfs_device *device,
602 u64 start)
603{
604 int ret;
605 struct btrfs_path *path;
606 struct btrfs_root *root = device->dev_root;
607 struct btrfs_key key;
608 struct btrfs_key found_key;
609 struct extent_buffer *leaf = NULL;
610 struct btrfs_dev_extent *extent = NULL;
611
612 path = btrfs_alloc_path();
613 if (!path)
614 return -ENOMEM;
615
616 key.objectid = device->devid;
617 key.offset = start;
618 key.type = BTRFS_DEV_EXTENT_KEY;
619
620 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
621 if (ret > 0) {
622 ret = btrfs_previous_item(root, path, key.objectid,
623 BTRFS_DEV_EXTENT_KEY);
624 BUG_ON(ret);
625 leaf = path->nodes[0];
626 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
627 extent = btrfs_item_ptr(leaf, path->slots[0],
628 struct btrfs_dev_extent);
629 BUG_ON(found_key.offset > start || found_key.offset +
630 btrfs_dev_extent_length(leaf, extent) < start);
631 ret = 0;
632 } else if (ret == 0) {
633 leaf = path->nodes[0];
634 extent = btrfs_item_ptr(leaf, path->slots[0],
635 struct btrfs_dev_extent);
636 }
637 BUG_ON(ret);
638
639 if (device->bytes_used > 0)
640 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
641 ret = btrfs_del_item(trans, root, path);
642 BUG_ON(ret);
643
644 btrfs_free_path(path);
645 return ret;
646}
647
648int noinline btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
649 struct btrfs_device *device,
650 u64 chunk_tree, u64 chunk_objectid,
651 u64 chunk_offset,
652 u64 num_bytes, u64 *start)
653{
654 int ret;
655 struct btrfs_path *path;
656 struct btrfs_root *root = device->dev_root;
657 struct btrfs_dev_extent *extent;
658 struct extent_buffer *leaf;
659 struct btrfs_key key;
660
661 WARN_ON(!device->in_fs_metadata);
662 path = btrfs_alloc_path();
663 if (!path)
664 return -ENOMEM;
665
666 ret = find_free_dev_extent(trans, device, path, num_bytes, start);
667 if (ret) {
668 goto err;
669 }
670
671 key.objectid = device->devid;
672 key.offset = *start;
673 key.type = BTRFS_DEV_EXTENT_KEY;
674 ret = btrfs_insert_empty_item(trans, root, path, &key,
675 sizeof(*extent));
676 BUG_ON(ret);
677
678 leaf = path->nodes[0];
679 extent = btrfs_item_ptr(leaf, path->slots[0],
680 struct btrfs_dev_extent);
681 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
682 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
683 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
684
685 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
686 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
687 BTRFS_UUID_SIZE);
688
689 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
690 btrfs_mark_buffer_dirty(leaf);
691err:
692 btrfs_free_path(path);
693 return ret;
694}
695
696static noinline int find_next_chunk(struct btrfs_root *root,
697 u64 objectid, u64 *offset)
698{
699 struct btrfs_path *path;
700 int ret;
701 struct btrfs_key key;
702 struct btrfs_chunk *chunk;
703 struct btrfs_key found_key;
704
705 path = btrfs_alloc_path();
706 BUG_ON(!path);
707
708 key.objectid = objectid;
709 key.offset = (u64)-1;
710 key.type = BTRFS_CHUNK_ITEM_KEY;
711
712 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
713 if (ret < 0)
714 goto error;
715
716 BUG_ON(ret == 0);
717
718 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
719 if (ret) {
720 *offset = 0;
721 } else {
722 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
723 path->slots[0]);
724 if (found_key.objectid != objectid)
725 *offset = 0;
726 else {
727 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
728 struct btrfs_chunk);
729 *offset = found_key.offset +
730 btrfs_chunk_length(path->nodes[0], chunk);
731 }
732 }
733 ret = 0;
734error:
735 btrfs_free_path(path);
736 return ret;
737}
738
739static noinline int find_next_devid(struct btrfs_root *root,
740 struct btrfs_path *path, u64 *objectid)
741{
742 int ret;
743 struct btrfs_key key;
744 struct btrfs_key found_key;
745
746 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
747 key.type = BTRFS_DEV_ITEM_KEY;
748 key.offset = (u64)-1;
749
750 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
751 if (ret < 0)
752 goto error;
753
754 BUG_ON(ret == 0);
755
756 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
757 BTRFS_DEV_ITEM_KEY);
758 if (ret) {
759 *objectid = 1;
760 } else {
761 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
762 path->slots[0]);
763 *objectid = found_key.offset + 1;
764 }
765 ret = 0;
766error:
767 btrfs_release_path(root, path);
768 return ret;
769}
770
771/*
772 * the device information is stored in the chunk root
773 * the btrfs_device struct should be fully filled in
774 */
775int btrfs_add_device(struct btrfs_trans_handle *trans,
776 struct btrfs_root *root,
777 struct btrfs_device *device)
778{
779 int ret;
780 struct btrfs_path *path;
781 struct btrfs_dev_item *dev_item;
782 struct extent_buffer *leaf;
783 struct btrfs_key key;
784 unsigned long ptr;
785 u64 free_devid = 0;
786
787 root = root->fs_info->chunk_root;
788
789 path = btrfs_alloc_path();
790 if (!path)
791 return -ENOMEM;
792
793 ret = find_next_devid(root, path, &free_devid);
794 if (ret)
795 goto out;
796
797 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
798 key.type = BTRFS_DEV_ITEM_KEY;
799 key.offset = free_devid;
800
801 ret = btrfs_insert_empty_item(trans, root, path, &key,
802 sizeof(*dev_item));
803 if (ret)
804 goto out;
805
806 leaf = path->nodes[0];
807 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
808
809 device->devid = free_devid;
810 btrfs_set_device_id(leaf, dev_item, device->devid);
811 btrfs_set_device_type(leaf, dev_item, device->type);
812 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
813 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
814 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
815 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
816 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
817 btrfs_set_device_group(leaf, dev_item, 0);
818 btrfs_set_device_seek_speed(leaf, dev_item, 0);
819 btrfs_set_device_bandwidth(leaf, dev_item, 0);
820
821 ptr = (unsigned long)btrfs_device_uuid(dev_item);
822 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
823 btrfs_mark_buffer_dirty(leaf);
824 ret = 0;
825
826out:
827 btrfs_free_path(path);
828 return ret;
829}
830
831static int btrfs_rm_dev_item(struct btrfs_root *root,
832 struct btrfs_device *device)
833{
834 int ret;
835 struct btrfs_path *path;
836 struct block_device *bdev = device->bdev;
837 struct btrfs_device *next_dev;
838 struct btrfs_key key;
839 u64 total_bytes;
840 struct btrfs_fs_devices *fs_devices;
841 struct btrfs_trans_handle *trans;
842
843 root = root->fs_info->chunk_root;
844
845 path = btrfs_alloc_path();
846 if (!path)
847 return -ENOMEM;
848
849 trans = btrfs_start_transaction(root, 1);
850 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
851 key.type = BTRFS_DEV_ITEM_KEY;
852 key.offset = device->devid;
853 lock_chunks(root);
854
855 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
856 if (ret < 0)
857 goto out;
858
859 if (ret > 0) {
860 ret = -ENOENT;
861 goto out;
862 }
863
864 ret = btrfs_del_item(trans, root, path);
865 if (ret)
866 goto out;
867
868 /*
869 * at this point, the device is zero sized. We want to
870 * remove it from the devices list and zero out the old super
871 */
872 list_del_init(&device->dev_list);
873 list_del_init(&device->dev_alloc_list);
874 fs_devices = root->fs_info->fs_devices;
875
876 next_dev = list_entry(fs_devices->devices.next, struct btrfs_device,
877 dev_list);
878 if (bdev == root->fs_info->sb->s_bdev)
879 root->fs_info->sb->s_bdev = next_dev->bdev;
880 if (bdev == fs_devices->latest_bdev)
881 fs_devices->latest_bdev = next_dev->bdev;
882
883 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
884 btrfs_set_super_num_devices(&root->fs_info->super_copy,
885 total_bytes - 1);
886out:
887 btrfs_free_path(path);
888 unlock_chunks(root);
889 btrfs_commit_transaction(trans, root);
890 return ret;
891}
892
893int btrfs_rm_device(struct btrfs_root *root, char *device_path)
894{
895 struct btrfs_device *device;
896 struct block_device *bdev;
897 struct buffer_head *bh = NULL;
898 struct btrfs_super_block *disk_super;
899 u64 all_avail;
900 u64 devid;
901 int ret = 0;
902
903 mutex_lock(&uuid_mutex);
904 mutex_lock(&root->fs_info->volume_mutex);
905
906 all_avail = root->fs_info->avail_data_alloc_bits |
907 root->fs_info->avail_system_alloc_bits |
908 root->fs_info->avail_metadata_alloc_bits;
909
910 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
911 btrfs_super_num_devices(&root->fs_info->super_copy) <= 4) {
912 printk("btrfs: unable to go below four devices on raid10\n");
913 ret = -EINVAL;
914 goto out;
915 }
916
917 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
918 btrfs_super_num_devices(&root->fs_info->super_copy) <= 2) {
919 printk("btrfs: unable to go below two devices on raid1\n");
920 ret = -EINVAL;
921 goto out;
922 }
923
924 if (strcmp(device_path, "missing") == 0) {
925 struct list_head *cur;
926 struct list_head *devices;
927 struct btrfs_device *tmp;
928
929 device = NULL;
930 devices = &root->fs_info->fs_devices->devices;
931 list_for_each(cur, devices) {
932 tmp = list_entry(cur, struct btrfs_device, dev_list);
933 if (tmp->in_fs_metadata && !tmp->bdev) {
934 device = tmp;
935 break;
936 }
937 }
938 bdev = NULL;
939 bh = NULL;
940 disk_super = NULL;
941 if (!device) {
942 printk("btrfs: no missing devices found to remove\n");
943 goto out;
944 }
945
946 } else {
947 bdev = open_bdev_excl(device_path, 0,
948 root->fs_info->bdev_holder);
949 if (IS_ERR(bdev)) {
950 ret = PTR_ERR(bdev);
951 goto out;
952 }
953
954 bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
955 if (!bh) {
956 ret = -EIO;
957 goto error_close;
958 }
959 disk_super = (struct btrfs_super_block *)bh->b_data;
960 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
961 sizeof(disk_super->magic))) {
962 ret = -ENOENT;
963 goto error_brelse;
964 }
965 if (memcmp(disk_super->fsid, root->fs_info->fsid,
966 BTRFS_FSID_SIZE)) {
967 ret = -ENOENT;
968 goto error_brelse;
969 }
970 devid = le64_to_cpu(disk_super->dev_item.devid);
971 device = btrfs_find_device(root, devid, NULL);
972 if (!device) {
973 ret = -ENOENT;
974 goto error_brelse;
975 }
976
977 }
978 root->fs_info->fs_devices->num_devices--;
979 root->fs_info->fs_devices->open_devices--;
980
981 ret = btrfs_shrink_device(device, 0);
982 if (ret)
983 goto error_brelse;
984
985
986 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
987 if (ret)
988 goto error_brelse;
989
990 if (bh) {
991 /* make sure this device isn't detected as part of
992 * the FS anymore
993 */
994 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
995 set_buffer_dirty(bh);
996 sync_dirty_buffer(bh);
997
998 brelse(bh);
999 }
1000
1001 if (device->bdev) {
1002 /* one close for the device struct or super_block */
1003 close_bdev_excl(device->bdev);
1004 }
1005 if (bdev) {
1006 /* one close for us */
1007 close_bdev_excl(bdev);
1008 }
1009 kfree(device->name);
1010 kfree(device);
1011 ret = 0;
1012 goto out;
1013
1014error_brelse:
1015 brelse(bh);
1016error_close:
1017 if (bdev)
1018 close_bdev_excl(bdev);
1019out:
1020 mutex_unlock(&root->fs_info->volume_mutex);
1021 mutex_unlock(&uuid_mutex);
1022 return ret;
1023}
1024
1025int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1026{
1027 struct btrfs_trans_handle *trans;
1028 struct btrfs_device *device;
1029 struct block_device *bdev;
1030 struct list_head *cur;
1031 struct list_head *devices;
1032 u64 total_bytes;
1033 int ret = 0;
1034
1035
1036 bdev = open_bdev_excl(device_path, 0, root->fs_info->bdev_holder);
1037 if (!bdev) {
1038 return -EIO;
1039 }
1040
1041 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1042 mutex_lock(&root->fs_info->volume_mutex);
1043
1044 trans = btrfs_start_transaction(root, 1);
1045 lock_chunks(root);
1046 devices = &root->fs_info->fs_devices->devices;
1047 list_for_each(cur, devices) {
1048 device = list_entry(cur, struct btrfs_device, dev_list);
1049 if (device->bdev == bdev) {
1050 ret = -EEXIST;
1051 goto out;
1052 }
1053 }
1054
1055 device = kzalloc(sizeof(*device), GFP_NOFS);
1056 if (!device) {
1057 /* we can safely leave the fs_devices entry around */
1058 ret = -ENOMEM;
1059 goto out_close_bdev;
1060 }
1061
1062 device->barriers = 1;
1063 device->work.func = pending_bios_fn;
1064 generate_random_uuid(device->uuid);
1065 spin_lock_init(&device->io_lock);
1066 device->name = kstrdup(device_path, GFP_NOFS);
1067 if (!device->name) {
1068 kfree(device);
1069 goto out_close_bdev;
1070 }
1071 device->io_width = root->sectorsize;
1072 device->io_align = root->sectorsize;
1073 device->sector_size = root->sectorsize;
1074 device->total_bytes = i_size_read(bdev->bd_inode);
1075 device->dev_root = root->fs_info->dev_root;
1076 device->bdev = bdev;
1077 device->in_fs_metadata = 1;
1078
1079 ret = btrfs_add_device(trans, root, device);
1080 if (ret)
1081 goto out_close_bdev;
1082
1083 set_blocksize(device->bdev, 4096);
1084
1085 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1086 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1087 total_bytes + device->total_bytes);
1088
1089 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1090 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1091 total_bytes + 1);
1092
1093 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
1094 list_add(&device->dev_alloc_list,
1095 &root->fs_info->fs_devices->alloc_list);
1096 root->fs_info->fs_devices->num_devices++;
1097 root->fs_info->fs_devices->open_devices++;
1098out:
1099 unlock_chunks(root);
1100 btrfs_end_transaction(trans, root);
1101 mutex_unlock(&root->fs_info->volume_mutex);
1102
1103 return ret;
1104
1105out_close_bdev:
1106 close_bdev_excl(bdev);
1107 goto out;
1108}
1109
1110int noinline btrfs_update_device(struct btrfs_trans_handle *trans,
1111 struct btrfs_device *device)
1112{
1113 int ret;
1114 struct btrfs_path *path;
1115 struct btrfs_root *root;
1116 struct btrfs_dev_item *dev_item;
1117 struct extent_buffer *leaf;
1118 struct btrfs_key key;
1119
1120 root = device->dev_root->fs_info->chunk_root;
1121
1122 path = btrfs_alloc_path();
1123 if (!path)
1124 return -ENOMEM;
1125
1126 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1127 key.type = BTRFS_DEV_ITEM_KEY;
1128 key.offset = device->devid;
1129
1130 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1131 if (ret < 0)
1132 goto out;
1133
1134 if (ret > 0) {
1135 ret = -ENOENT;
1136 goto out;
1137 }
1138
1139 leaf = path->nodes[0];
1140 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1141
1142 btrfs_set_device_id(leaf, dev_item, device->devid);
1143 btrfs_set_device_type(leaf, dev_item, device->type);
1144 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1145 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1146 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1147 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1148 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1149 btrfs_mark_buffer_dirty(leaf);
1150
1151out:
1152 btrfs_free_path(path);
1153 return ret;
1154}
1155
1156static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1157 struct btrfs_device *device, u64 new_size)
1158{
1159 struct btrfs_super_block *super_copy =
1160 &device->dev_root->fs_info->super_copy;
1161 u64 old_total = btrfs_super_total_bytes(super_copy);
1162 u64 diff = new_size - device->total_bytes;
1163
1164 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1165 return btrfs_update_device(trans, device);
1166}
1167
1168int btrfs_grow_device(struct btrfs_trans_handle *trans,
1169 struct btrfs_device *device, u64 new_size)
1170{
1171 int ret;
1172 lock_chunks(device->dev_root);
1173 ret = __btrfs_grow_device(trans, device, new_size);
1174 unlock_chunks(device->dev_root);
1175 return ret;
1176}
1177
1178static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1179 struct btrfs_root *root,
1180 u64 chunk_tree, u64 chunk_objectid,
1181 u64 chunk_offset)
1182{
1183 int ret;
1184 struct btrfs_path *path;
1185 struct btrfs_key key;
1186
1187 root = root->fs_info->chunk_root;
1188 path = btrfs_alloc_path();
1189 if (!path)
1190 return -ENOMEM;
1191
1192 key.objectid = chunk_objectid;
1193 key.offset = chunk_offset;
1194 key.type = BTRFS_CHUNK_ITEM_KEY;
1195
1196 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1197 BUG_ON(ret);
1198
1199 ret = btrfs_del_item(trans, root, path);
1200 BUG_ON(ret);
1201
1202 btrfs_free_path(path);
1203 return 0;
1204}
1205
1206int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1207 chunk_offset)
1208{
1209 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1210 struct btrfs_disk_key *disk_key;
1211 struct btrfs_chunk *chunk;
1212 u8 *ptr;
1213 int ret = 0;
1214 u32 num_stripes;
1215 u32 array_size;
1216 u32 len = 0;
1217 u32 cur;
1218 struct btrfs_key key;
1219
1220 array_size = btrfs_super_sys_array_size(super_copy);
1221
1222 ptr = super_copy->sys_chunk_array;
1223 cur = 0;
1224
1225 while (cur < array_size) {
1226 disk_key = (struct btrfs_disk_key *)ptr;
1227 btrfs_disk_key_to_cpu(&key, disk_key);
1228
1229 len = sizeof(*disk_key);
1230
1231 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1232 chunk = (struct btrfs_chunk *)(ptr + len);
1233 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1234 len += btrfs_chunk_item_size(num_stripes);
1235 } else {
1236 ret = -EIO;
1237 break;
1238 }
1239 if (key.objectid == chunk_objectid &&
1240 key.offset == chunk_offset) {
1241 memmove(ptr, ptr + len, array_size - (cur + len));
1242 array_size -= len;
1243 btrfs_set_super_sys_array_size(super_copy, array_size);
1244 } else {
1245 ptr += len;
1246 cur += len;
1247 }
1248 }
1249 return ret;
1250}
1251
1252
1253int btrfs_relocate_chunk(struct btrfs_root *root,
1254 u64 chunk_tree, u64 chunk_objectid,
1255 u64 chunk_offset)
1256{
1257 struct extent_map_tree *em_tree;
1258 struct btrfs_root *extent_root;
1259 struct btrfs_trans_handle *trans;
1260 struct extent_map *em;
1261 struct map_lookup *map;
1262 int ret;
1263 int i;
1264
1265 printk("btrfs relocating chunk %llu\n",
1266 (unsigned long long)chunk_offset);
1267 root = root->fs_info->chunk_root;
1268 extent_root = root->fs_info->extent_root;
1269 em_tree = &root->fs_info->mapping_tree.map_tree;
1270
1271 /* step one, relocate all the extents inside this chunk */
1272 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1273 BUG_ON(ret);
1274
1275 trans = btrfs_start_transaction(root, 1);
1276 BUG_ON(!trans);
1277
1278 lock_chunks(root);
1279
1280 /*
1281 * step two, delete the device extents and the
1282 * chunk tree entries
1283 */
1284 spin_lock(&em_tree->lock);
1285 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1286 spin_unlock(&em_tree->lock);
1287
1288 BUG_ON(em->start > chunk_offset ||
1289 em->start + em->len < chunk_offset);
1290 map = (struct map_lookup *)em->bdev;
1291
1292 for (i = 0; i < map->num_stripes; i++) {
1293 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1294 map->stripes[i].physical);
1295 BUG_ON(ret);
1296
1297 if (map->stripes[i].dev) {
1298 ret = btrfs_update_device(trans, map->stripes[i].dev);
1299 BUG_ON(ret);
1300 }
1301 }
1302 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1303 chunk_offset);
1304
1305 BUG_ON(ret);
1306
1307 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1308 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1309 BUG_ON(ret);
1310 }
1311
1312 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1313 BUG_ON(ret);
1314
1315 spin_lock(&em_tree->lock);
1316 remove_extent_mapping(em_tree, em);
1317 spin_unlock(&em_tree->lock);
1318
1319 kfree(map);
1320 em->bdev = NULL;
1321
1322 /* once for the tree */
1323 free_extent_map(em);
1324 /* once for us */
1325 free_extent_map(em);
1326
1327 unlock_chunks(root);
1328 btrfs_end_transaction(trans, root);
1329 return 0;
1330}
1331
1332static u64 div_factor(u64 num, int factor)
1333{
1334 if (factor == 10)
1335 return num;
1336 num *= factor;
1337 do_div(num, 10);
1338 return num;
1339}
1340
1341
1342int btrfs_balance(struct btrfs_root *dev_root)
1343{
1344 int ret;
1345 struct list_head *cur;
1346 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
1347 struct btrfs_device *device;
1348 u64 old_size;
1349 u64 size_to_free;
1350 struct btrfs_path *path;
1351 struct btrfs_key key;
1352 struct btrfs_chunk *chunk;
1353 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
1354 struct btrfs_trans_handle *trans;
1355 struct btrfs_key found_key;
1356
1357
1358 mutex_lock(&dev_root->fs_info->volume_mutex);
1359 dev_root = dev_root->fs_info->dev_root;
1360
1361 /* step one make some room on all the devices */
1362 list_for_each(cur, devices) {
1363 device = list_entry(cur, struct btrfs_device, dev_list);
1364 old_size = device->total_bytes;
1365 size_to_free = div_factor(old_size, 1);
1366 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
1367 if (device->total_bytes - device->bytes_used > size_to_free)
1368 continue;
1369
1370 ret = btrfs_shrink_device(device, old_size - size_to_free);
1371 BUG_ON(ret);
1372
1373 trans = btrfs_start_transaction(dev_root, 1);
1374 BUG_ON(!trans);
1375
1376 ret = btrfs_grow_device(trans, device, old_size);
1377 BUG_ON(ret);
1378
1379 btrfs_end_transaction(trans, dev_root);
1380 }
1381
1382 /* step two, relocate all the chunks */
1383 path = btrfs_alloc_path();
1384 BUG_ON(!path);
1385
1386 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1387 key.offset = (u64)-1;
1388 key.type = BTRFS_CHUNK_ITEM_KEY;
1389
1390 while(1) {
1391 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1392 if (ret < 0)
1393 goto error;
1394
1395 /*
1396 * this shouldn't happen, it means the last relocate
1397 * failed
1398 */
1399 if (ret == 0)
1400 break;
1401
1402 ret = btrfs_previous_item(chunk_root, path, 0,
1403 BTRFS_CHUNK_ITEM_KEY);
1404 if (ret)
1405 break;
1406
1407 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1408 path->slots[0]);
1409 if (found_key.objectid != key.objectid)
1410 break;
1411
1412 chunk = btrfs_item_ptr(path->nodes[0],
1413 path->slots[0],
1414 struct btrfs_chunk);
1415 key.offset = found_key.offset;
1416 /* chunk zero is special */
1417 if (key.offset == 0)
1418 break;
1419
1420 btrfs_release_path(chunk_root, path);
1421 ret = btrfs_relocate_chunk(chunk_root,
1422 chunk_root->root_key.objectid,
1423 found_key.objectid,
1424 found_key.offset);
1425 BUG_ON(ret);
1426 }
1427 ret = 0;
1428error:
1429 btrfs_free_path(path);
1430 mutex_unlock(&dev_root->fs_info->volume_mutex);
1431 return ret;
1432}
1433
1434/*
1435 * shrinking a device means finding all of the device extents past
1436 * the new size, and then following the back refs to the chunks.
1437 * The chunk relocation code actually frees the device extent
1438 */
1439int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
1440{
1441 struct btrfs_trans_handle *trans;
1442 struct btrfs_root *root = device->dev_root;
1443 struct btrfs_dev_extent *dev_extent = NULL;
1444 struct btrfs_path *path;
1445 u64 length;
1446 u64 chunk_tree;
1447 u64 chunk_objectid;
1448 u64 chunk_offset;
1449 int ret;
1450 int slot;
1451 struct extent_buffer *l;
1452 struct btrfs_key key;
1453 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1454 u64 old_total = btrfs_super_total_bytes(super_copy);
1455 u64 diff = device->total_bytes - new_size;
1456
1457
1458 path = btrfs_alloc_path();
1459 if (!path)
1460 return -ENOMEM;
1461
1462 trans = btrfs_start_transaction(root, 1);
1463 if (!trans) {
1464 ret = -ENOMEM;
1465 goto done;
1466 }
1467
1468 path->reada = 2;
1469
1470 lock_chunks(root);
1471
1472 device->total_bytes = new_size;
1473 ret = btrfs_update_device(trans, device);
1474 if (ret) {
1475 unlock_chunks(root);
1476 btrfs_end_transaction(trans, root);
1477 goto done;
1478 }
1479 WARN_ON(diff > old_total);
1480 btrfs_set_super_total_bytes(super_copy, old_total - diff);
1481 unlock_chunks(root);
1482 btrfs_end_transaction(trans, root);
1483
1484 key.objectid = device->devid;
1485 key.offset = (u64)-1;
1486 key.type = BTRFS_DEV_EXTENT_KEY;
1487
1488 while (1) {
1489 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1490 if (ret < 0)
1491 goto done;
1492
1493 ret = btrfs_previous_item(root, path, 0, key.type);
1494 if (ret < 0)
1495 goto done;
1496 if (ret) {
1497 ret = 0;
1498 goto done;
1499 }
1500
1501 l = path->nodes[0];
1502 slot = path->slots[0];
1503 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1504
1505 if (key.objectid != device->devid)
1506 goto done;
1507
1508 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1509 length = btrfs_dev_extent_length(l, dev_extent);
1510
1511 if (key.offset + length <= new_size)
1512 goto done;
1513
1514 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1515 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1516 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1517 btrfs_release_path(root, path);
1518
1519 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
1520 chunk_offset);
1521 if (ret)
1522 goto done;
1523 }
1524
1525done:
1526 btrfs_free_path(path);
1527 return ret;
1528}
1529
1530int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
1531 struct btrfs_root *root,
1532 struct btrfs_key *key,
1533 struct btrfs_chunk *chunk, int item_size)
1534{
1535 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1536 struct btrfs_disk_key disk_key;
1537 u32 array_size;
1538 u8 *ptr;
1539
1540 array_size = btrfs_super_sys_array_size(super_copy);
1541 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
1542 return -EFBIG;
1543
1544 ptr = super_copy->sys_chunk_array + array_size;
1545 btrfs_cpu_key_to_disk(&disk_key, key);
1546 memcpy(ptr, &disk_key, sizeof(disk_key));
1547 ptr += sizeof(disk_key);
1548 memcpy(ptr, chunk, item_size);
1549 item_size += sizeof(disk_key);
1550 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
1551 return 0;
1552}
1553
1554static u64 noinline chunk_bytes_by_type(u64 type, u64 calc_size,
1555 int num_stripes, int sub_stripes)
1556{
1557 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
1558 return calc_size;
1559 else if (type & BTRFS_BLOCK_GROUP_RAID10)
1560 return calc_size * (num_stripes / sub_stripes);
1561 else
1562 return calc_size * num_stripes;
1563}
1564
1565
1566int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
1567 struct btrfs_root *extent_root, u64 *start,
1568 u64 *num_bytes, u64 type)
1569{
1570 u64 dev_offset;
1571 struct btrfs_fs_info *info = extent_root->fs_info;
1572 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
1573 struct btrfs_path *path;
1574 struct btrfs_stripe *stripes;
1575 struct btrfs_device *device = NULL;
1576 struct btrfs_chunk *chunk;
1577 struct list_head private_devs;
1578 struct list_head *dev_list;
1579 struct list_head *cur;
1580 struct extent_map_tree *em_tree;
1581 struct map_lookup *map;
1582 struct extent_map *em;
1583 int min_stripe_size = 1 * 1024 * 1024;
1584 u64 physical;
1585 u64 calc_size = 1024 * 1024 * 1024;
1586 u64 max_chunk_size = calc_size;
1587 u64 min_free;
1588 u64 avail;
1589 u64 max_avail = 0;
1590 u64 percent_max;
1591 int num_stripes = 1;
1592 int min_stripes = 1;
1593 int sub_stripes = 0;
1594 int looped = 0;
1595 int ret;
1596 int index;
1597 int stripe_len = 64 * 1024;
1598 struct btrfs_key key;
1599
1600 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
1601 (type & BTRFS_BLOCK_GROUP_DUP)) {
1602 WARN_ON(1);
1603 type &= ~BTRFS_BLOCK_GROUP_DUP;
1604 }
1605 dev_list = &extent_root->fs_info->fs_devices->alloc_list;
1606 if (list_empty(dev_list))
1607 return -ENOSPC;
1608
1609 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
1610 num_stripes = extent_root->fs_info->fs_devices->open_devices;
1611 min_stripes = 2;
1612 }
1613 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
1614 num_stripes = 2;
1615 min_stripes = 2;
1616 }
1617 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
1618 num_stripes = min_t(u64, 2,
1619 extent_root->fs_info->fs_devices->open_devices);
1620 if (num_stripes < 2)
1621 return -ENOSPC;
1622 min_stripes = 2;
1623 }
1624 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1625 num_stripes = extent_root->fs_info->fs_devices->open_devices;
1626 if (num_stripes < 4)
1627 return -ENOSPC;
1628 num_stripes &= ~(u32)1;
1629 sub_stripes = 2;
1630 min_stripes = 4;
1631 }
1632
1633 if (type & BTRFS_BLOCK_GROUP_DATA) {
1634 max_chunk_size = 10 * calc_size;
1635 min_stripe_size = 64 * 1024 * 1024;
1636 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
1637 max_chunk_size = 4 * calc_size;
1638 min_stripe_size = 32 * 1024 * 1024;
1639 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1640 calc_size = 8 * 1024 * 1024;
1641 max_chunk_size = calc_size * 2;
1642 min_stripe_size = 1 * 1024 * 1024;
1643 }
1644
1645 path = btrfs_alloc_path();
1646 if (!path)
1647 return -ENOMEM;
1648
1649 /* we don't want a chunk larger than 10% of the FS */
1650 percent_max = div_factor(btrfs_super_total_bytes(&info->super_copy), 1);
1651 max_chunk_size = min(percent_max, max_chunk_size);
1652
1653again:
1654 if (calc_size * num_stripes > max_chunk_size) {
1655 calc_size = max_chunk_size;
1656 do_div(calc_size, num_stripes);
1657 do_div(calc_size, stripe_len);
1658 calc_size *= stripe_len;
1659 }
1660 /* we don't want tiny stripes */
1661 calc_size = max_t(u64, min_stripe_size, calc_size);
1662
1663 do_div(calc_size, stripe_len);
1664 calc_size *= stripe_len;
1665
1666 INIT_LIST_HEAD(&private_devs);
1667 cur = dev_list->next;
1668 index = 0;
1669
1670 if (type & BTRFS_BLOCK_GROUP_DUP)
1671 min_free = calc_size * 2;
1672 else
1673 min_free = calc_size;
1674
1675 /*
1676 * we add 1MB because we never use the first 1MB of the device, unless
1677 * we've looped, then we are likely allocating the maximum amount of
1678 * space left already
1679 */
1680 if (!looped)
1681 min_free += 1024 * 1024;
1682
1683 /* build a private list of devices we will allocate from */
1684 while(index < num_stripes) {
1685 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
1686
1687 if (device->total_bytes > device->bytes_used)
1688 avail = device->total_bytes - device->bytes_used;
1689 else
1690 avail = 0;
1691 cur = cur->next;
1692
1693 if (device->in_fs_metadata && avail >= min_free) {
1694 u64 ignored_start = 0;
1695 ret = find_free_dev_extent(trans, device, path,
1696 min_free,
1697 &ignored_start);
1698 if (ret == 0) {
1699 list_move_tail(&device->dev_alloc_list,
1700 &private_devs);
1701 index++;
1702 if (type & BTRFS_BLOCK_GROUP_DUP)
1703 index++;
1704 }
1705 } else if (device->in_fs_metadata && avail > max_avail)
1706 max_avail = avail;
1707 if (cur == dev_list)
1708 break;
1709 }
1710 if (index < num_stripes) {
1711 list_splice(&private_devs, dev_list);
1712 if (index >= min_stripes) {
1713 num_stripes = index;
1714 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1715 num_stripes /= sub_stripes;
1716 num_stripes *= sub_stripes;
1717 }
1718 looped = 1;
1719 goto again;
1720 }
1721 if (!looped && max_avail > 0) {
1722 looped = 1;
1723 calc_size = max_avail;
1724 goto again;
1725 }
1726 btrfs_free_path(path);
1727 return -ENOSPC;
1728 }
1729 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1730 key.type = BTRFS_CHUNK_ITEM_KEY;
1731 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
1732 &key.offset);
1733 if (ret) {
1734 btrfs_free_path(path);
1735 return ret;
1736 }
1737
1738 chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
1739 if (!chunk) {
1740 btrfs_free_path(path);
1741 return -ENOMEM;
1742 }
1743
1744 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1745 if (!map) {
1746 kfree(chunk);
1747 btrfs_free_path(path);
1748 return -ENOMEM;
1749 }
1750 btrfs_free_path(path);
1751 path = NULL;
1752
1753 stripes = &chunk->stripe;
1754 *num_bytes = chunk_bytes_by_type(type, calc_size,
1755 num_stripes, sub_stripes);
1756
1757 index = 0;
1758 while(index < num_stripes) {
1759 struct btrfs_stripe *stripe;
1760 BUG_ON(list_empty(&private_devs));
1761 cur = private_devs.next;
1762 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
1763
1764 /* loop over this device again if we're doing a dup group */
1765 if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
1766 (index == num_stripes - 1))
1767 list_move_tail(&device->dev_alloc_list, dev_list);
1768
1769 ret = btrfs_alloc_dev_extent(trans, device,
1770 info->chunk_root->root_key.objectid,
1771 BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
1772 calc_size, &dev_offset);
1773 BUG_ON(ret);
1774 device->bytes_used += calc_size;
1775 ret = btrfs_update_device(trans, device);
1776 BUG_ON(ret);
1777
1778 map->stripes[index].dev = device;
1779 map->stripes[index].physical = dev_offset;
1780 stripe = stripes + index;
1781 btrfs_set_stack_stripe_devid(stripe, device->devid);
1782 btrfs_set_stack_stripe_offset(stripe, dev_offset);
1783 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
1784 physical = dev_offset;
1785 index++;
1786 }
1787 BUG_ON(!list_empty(&private_devs));
1788
1789 /* key was set above */
1790 btrfs_set_stack_chunk_length(chunk, *num_bytes);
1791 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
1792 btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
1793 btrfs_set_stack_chunk_type(chunk, type);
1794 btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
1795 btrfs_set_stack_chunk_io_align(chunk, stripe_len);
1796 btrfs_set_stack_chunk_io_width(chunk, stripe_len);
1797 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
1798 btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
1799 map->sector_size = extent_root->sectorsize;
1800 map->stripe_len = stripe_len;
1801 map->io_align = stripe_len;
1802 map->io_width = stripe_len;
1803 map->type = type;
1804 map->num_stripes = num_stripes;
1805 map->sub_stripes = sub_stripes;
1806
1807 ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
1808 btrfs_chunk_item_size(num_stripes));
1809 BUG_ON(ret);
1810 *start = key.offset;;
1811
1812 em = alloc_extent_map(GFP_NOFS);
1813 if (!em)
1814 return -ENOMEM;
1815 em->bdev = (struct block_device *)map;
1816 em->start = key.offset;
1817 em->len = *num_bytes;
1818 em->block_start = 0;
1819
1820 if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1821 ret = btrfs_add_system_chunk(trans, chunk_root, &key,
1822 chunk, btrfs_chunk_item_size(num_stripes));
1823 BUG_ON(ret);
1824 }
1825 kfree(chunk);
1826
1827 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
1828 spin_lock(&em_tree->lock);
1829 ret = add_extent_mapping(em_tree, em);
1830 spin_unlock(&em_tree->lock);
1831 BUG_ON(ret);
1832 free_extent_map(em);
1833 return ret;
1834}
1835
1836void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
1837{
1838 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
1839}
1840
1841void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
1842{
1843 struct extent_map *em;
1844
1845 while(1) {
1846 spin_lock(&tree->map_tree.lock);
1847 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
1848 if (em)
1849 remove_extent_mapping(&tree->map_tree, em);
1850 spin_unlock(&tree->map_tree.lock);
1851 if (!em)
1852 break;
1853 kfree(em->bdev);
1854 /* once for us */
1855 free_extent_map(em);
1856 /* once for the tree */
1857 free_extent_map(em);
1858 }
1859}
1860
1861int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
1862{
1863 struct extent_map *em;
1864 struct map_lookup *map;
1865 struct extent_map_tree *em_tree = &map_tree->map_tree;
1866 int ret;
1867
1868 spin_lock(&em_tree->lock);
1869 em = lookup_extent_mapping(em_tree, logical, len);
1870 spin_unlock(&em_tree->lock);
1871 BUG_ON(!em);
1872
1873 BUG_ON(em->start > logical || em->start + em->len < logical);
1874 map = (struct map_lookup *)em->bdev;
1875 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
1876 ret = map->num_stripes;
1877 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
1878 ret = map->sub_stripes;
1879 else
1880 ret = 1;
1881 free_extent_map(em);
1882 return ret;
1883}
1884
1885static int find_live_mirror(struct map_lookup *map, int first, int num,
1886 int optimal)
1887{
1888 int i;
1889 if (map->stripes[optimal].dev->bdev)
1890 return optimal;
1891 for (i = first; i < first + num; i++) {
1892 if (map->stripes[i].dev->bdev)
1893 return i;
1894 }
1895 /* we couldn't find one that doesn't fail. Just return something
1896 * and the io error handling code will clean up eventually
1897 */
1898 return optimal;
1899}
1900
1901static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1902 u64 logical, u64 *length,
1903 struct btrfs_multi_bio **multi_ret,
1904 int mirror_num, struct page *unplug_page)
1905{
1906 struct extent_map *em;
1907 struct map_lookup *map;
1908 struct extent_map_tree *em_tree = &map_tree->map_tree;
1909 u64 offset;
1910 u64 stripe_offset;
1911 u64 stripe_nr;
1912 int stripes_allocated = 8;
1913 int stripes_required = 1;
1914 int stripe_index;
1915 int i;
1916 int num_stripes;
1917 int max_errors = 0;
1918 struct btrfs_multi_bio *multi = NULL;
1919
1920 if (multi_ret && !(rw & (1 << BIO_RW))) {
1921 stripes_allocated = 1;
1922 }
1923again:
1924 if (multi_ret) {
1925 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
1926 GFP_NOFS);
1927 if (!multi)
1928 return -ENOMEM;
1929
1930 atomic_set(&multi->error, 0);
1931 }
1932
1933 spin_lock(&em_tree->lock);
1934 em = lookup_extent_mapping(em_tree, logical, *length);
1935 spin_unlock(&em_tree->lock);
1936
1937 if (!em && unplug_page)
1938 return 0;
1939
1940 if (!em) {
1941 printk("unable to find logical %Lu len %Lu\n", logical, *length);
1942 BUG();
1943 }
1944
1945 BUG_ON(em->start > logical || em->start + em->len < logical);
1946 map = (struct map_lookup *)em->bdev;
1947 offset = logical - em->start;
1948
1949 if (mirror_num > map->num_stripes)
1950 mirror_num = 0;
1951
1952 /* if our multi bio struct is too small, back off and try again */
1953 if (rw & (1 << BIO_RW)) {
1954 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
1955 BTRFS_BLOCK_GROUP_DUP)) {
1956 stripes_required = map->num_stripes;
1957 max_errors = 1;
1958 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1959 stripes_required = map->sub_stripes;
1960 max_errors = 1;
1961 }
1962 }
1963 if (multi_ret && rw == WRITE &&
1964 stripes_allocated < stripes_required) {
1965 stripes_allocated = map->num_stripes;
1966 free_extent_map(em);
1967 kfree(multi);
1968 goto again;
1969 }
1970 stripe_nr = offset;
1971 /*
1972 * stripe_nr counts the total number of stripes we have to stride
1973 * to get to this block
1974 */
1975 do_div(stripe_nr, map->stripe_len);
1976
1977 stripe_offset = stripe_nr * map->stripe_len;
1978 BUG_ON(offset < stripe_offset);
1979
1980 /* stripe_offset is the offset of this block in its stripe*/
1981 stripe_offset = offset - stripe_offset;
1982
1983 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1984 BTRFS_BLOCK_GROUP_RAID10 |
1985 BTRFS_BLOCK_GROUP_DUP)) {
1986 /* we limit the length of each bio to what fits in a stripe */
1987 *length = min_t(u64, em->len - offset,
1988 map->stripe_len - stripe_offset);
1989 } else {
1990 *length = em->len - offset;
1991 }
1992
1993 if (!multi_ret && !unplug_page)
1994 goto out;
1995
1996 num_stripes = 1;
1997 stripe_index = 0;
1998 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1999 if (unplug_page || (rw & (1 << BIO_RW)))
2000 num_stripes = map->num_stripes;
2001 else if (mirror_num)
2002 stripe_index = mirror_num - 1;
2003 else {
2004 stripe_index = find_live_mirror(map, 0,
2005 map->num_stripes,
2006 current->pid % map->num_stripes);
2007 }
2008
2009 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2010 if (rw & (1 << BIO_RW))
2011 num_stripes = map->num_stripes;
2012 else if (mirror_num)
2013 stripe_index = mirror_num - 1;
2014
2015 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2016 int factor = map->num_stripes / map->sub_stripes;
2017
2018 stripe_index = do_div(stripe_nr, factor);
2019 stripe_index *= map->sub_stripes;
2020
2021 if (unplug_page || (rw & (1 << BIO_RW)))
2022 num_stripes = map->sub_stripes;
2023 else if (mirror_num)
2024 stripe_index += mirror_num - 1;
2025 else {
2026 stripe_index = find_live_mirror(map, stripe_index,
2027 map->sub_stripes, stripe_index +
2028 current->pid % map->sub_stripes);
2029 }
2030 } else {
2031 /*
2032 * after this do_div call, stripe_nr is the number of stripes
2033 * on this device we have to walk to find the data, and
2034 * stripe_index is the number of our device in the stripe array
2035 */
2036 stripe_index = do_div(stripe_nr, map->num_stripes);
2037 }
2038 BUG_ON(stripe_index >= map->num_stripes);
2039
2040 for (i = 0; i < num_stripes; i++) {
2041 if (unplug_page) {
2042 struct btrfs_device *device;
2043 struct backing_dev_info *bdi;
2044
2045 device = map->stripes[stripe_index].dev;
2046 if (device->bdev) {
2047 bdi = blk_get_backing_dev_info(device->bdev);
2048 if (bdi->unplug_io_fn) {
2049 bdi->unplug_io_fn(bdi, unplug_page);
2050 }
2051 }
2052 } else {
2053 multi->stripes[i].physical =
2054 map->stripes[stripe_index].physical +
2055 stripe_offset + stripe_nr * map->stripe_len;
2056 multi->stripes[i].dev = map->stripes[stripe_index].dev;
2057 }
2058 stripe_index++;
2059 }
2060 if (multi_ret) {
2061 *multi_ret = multi;
2062 multi->num_stripes = num_stripes;
2063 multi->max_errors = max_errors;
2064 }
2065out:
2066 free_extent_map(em);
2067 return 0;
2068}
2069
2070int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2071 u64 logical, u64 *length,
2072 struct btrfs_multi_bio **multi_ret, int mirror_num)
2073{
2074 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
2075 mirror_num, NULL);
2076}
2077
2078int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
2079 u64 logical, struct page *page)
2080{
2081 u64 length = PAGE_CACHE_SIZE;
2082 return __btrfs_map_block(map_tree, READ, logical, &length,
2083 NULL, 0, page);
2084}
2085
2086
2087static void end_bio_multi_stripe(struct bio *bio, int err)
2088{
2089 struct btrfs_multi_bio *multi = bio->bi_private;
2090 int is_orig_bio = 0;
2091
2092 if (err)
2093 atomic_inc(&multi->error);
2094
2095 if (bio == multi->orig_bio)
2096 is_orig_bio = 1;
2097
2098 if (atomic_dec_and_test(&multi->stripes_pending)) {
2099 if (!is_orig_bio) {
2100 bio_put(bio);
2101 bio = multi->orig_bio;
2102 }
2103 bio->bi_private = multi->private;
2104 bio->bi_end_io = multi->end_io;
2105 /* only send an error to the higher layers if it is
2106 * beyond the tolerance of the multi-bio
2107 */
2108 if (atomic_read(&multi->error) > multi->max_errors) {
2109 err = -EIO;
2110 } else if (err) {
2111 /*
2112 * this bio is actually up to date, we didn't
2113 * go over the max number of errors
2114 */
2115 set_bit(BIO_UPTODATE, &bio->bi_flags);
2116 err = 0;
2117 }
2118 kfree(multi);
2119
2120 bio_endio(bio, err);
2121 } else if (!is_orig_bio) {
2122 bio_put(bio);
2123 }
2124}
2125
2126struct async_sched {
2127 struct bio *bio;
2128 int rw;
2129 struct btrfs_fs_info *info;
2130 struct btrfs_work work;
2131};
2132
2133/*
2134 * see run_scheduled_bios for a description of why bios are collected for
2135 * async submit.
2136 *
2137 * This will add one bio to the pending list for a device and make sure
2138 * the work struct is scheduled.
2139 */
2140static int noinline schedule_bio(struct btrfs_root *root,
2141 struct btrfs_device *device,
2142 int rw, struct bio *bio)
2143{
2144 int should_queue = 1;
2145
2146 /* don't bother with additional async steps for reads, right now */
2147 if (!(rw & (1 << BIO_RW))) {
2148 bio_get(bio);
2149 submit_bio(rw, bio);
2150 bio_put(bio);
2151 return 0;
2152 }
2153
2154 /*
2155 * nr_async_bios allows us to reliably return congestion to the
2156 * higher layers. Otherwise, the async bio makes it appear we have
2157 * made progress against dirty pages when we've really just put it
2158 * on a queue for later
2159 */
2160 atomic_inc(&root->fs_info->nr_async_bios);
2161 WARN_ON(bio->bi_next);
2162 bio->bi_next = NULL;
2163 bio->bi_rw |= rw;
2164
2165 spin_lock(&device->io_lock);
2166
2167 if (device->pending_bio_tail)
2168 device->pending_bio_tail->bi_next = bio;
2169
2170 device->pending_bio_tail = bio;
2171 if (!device->pending_bios)
2172 device->pending_bios = bio;
2173 if (device->running_pending)
2174 should_queue = 0;
2175
2176 spin_unlock(&device->io_lock);
2177
2178 if (should_queue)
2179 btrfs_queue_worker(&root->fs_info->submit_workers,
2180 &device->work);
2181 return 0;
2182}
2183
2184int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
2185 int mirror_num, int async_submit)
2186{
2187 struct btrfs_mapping_tree *map_tree;
2188 struct btrfs_device *dev;
2189 struct bio *first_bio = bio;
2190 u64 logical = (u64)bio->bi_sector << 9;
2191 u64 length = 0;
2192 u64 map_length;
2193 struct btrfs_multi_bio *multi = NULL;
2194 int ret;
2195 int dev_nr = 0;
2196 int total_devs = 1;
2197
2198 length = bio->bi_size;
2199 map_tree = &root->fs_info->mapping_tree;
2200 map_length = length;
2201
2202 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
2203 mirror_num);
2204 BUG_ON(ret);
2205
2206 total_devs = multi->num_stripes;
2207 if (map_length < length) {
2208 printk("mapping failed logical %Lu bio len %Lu "
2209 "len %Lu\n", logical, length, map_length);
2210 BUG();
2211 }
2212 multi->end_io = first_bio->bi_end_io;
2213 multi->private = first_bio->bi_private;
2214 multi->orig_bio = first_bio;
2215 atomic_set(&multi->stripes_pending, multi->num_stripes);
2216
2217 while(dev_nr < total_devs) {
2218 if (total_devs > 1) {
2219 if (dev_nr < total_devs - 1) {
2220 bio = bio_clone(first_bio, GFP_NOFS);
2221 BUG_ON(!bio);
2222 } else {
2223 bio = first_bio;
2224 }
2225 bio->bi_private = multi;
2226 bio->bi_end_io = end_bio_multi_stripe;
2227 }
2228 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
2229 dev = multi->stripes[dev_nr].dev;
2230 if (dev && dev->bdev) {
2231 bio->bi_bdev = dev->bdev;
2232 if (async_submit)
2233 schedule_bio(root, dev, rw, bio);
2234 else
2235 submit_bio(rw, bio);
2236 } else {
2237 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
2238 bio->bi_sector = logical >> 9;
2239 bio_endio(bio, -EIO);
2240 }
2241 dev_nr++;
2242 }
2243 if (total_devs == 1)
2244 kfree(multi);
2245 return 0;
2246}
2247
2248struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
2249 u8 *uuid)
2250{
2251 struct list_head *head = &root->fs_info->fs_devices->devices;
2252
2253 return __find_device(head, devid, uuid);
2254}
2255
2256static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
2257 u64 devid, u8 *dev_uuid)
2258{
2259 struct btrfs_device *device;
2260 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
2261
2262 device = kzalloc(sizeof(*device), GFP_NOFS);
2263 list_add(&device->dev_list,
2264 &fs_devices->devices);
2265 list_add(&device->dev_alloc_list,
2266 &fs_devices->alloc_list);
2267 device->barriers = 1;
2268 device->dev_root = root->fs_info->dev_root;
2269 device->devid = devid;
2270 device->work.func = pending_bios_fn;
2271 fs_devices->num_devices++;
2272 spin_lock_init(&device->io_lock);
2273 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
2274 return device;
2275}
2276
2277
2278static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
2279 struct extent_buffer *leaf,
2280 struct btrfs_chunk *chunk)
2281{
2282 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2283 struct map_lookup *map;
2284 struct extent_map *em;
2285 u64 logical;
2286 u64 length;
2287 u64 devid;
2288 u8 uuid[BTRFS_UUID_SIZE];
2289 int num_stripes;
2290 int ret;
2291 int i;
2292
2293 logical = key->offset;
2294 length = btrfs_chunk_length(leaf, chunk);
2295
2296 spin_lock(&map_tree->map_tree.lock);
2297 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
2298 spin_unlock(&map_tree->map_tree.lock);
2299
2300 /* already mapped? */
2301 if (em && em->start <= logical && em->start + em->len > logical) {
2302 free_extent_map(em);
2303 return 0;
2304 } else if (em) {
2305 free_extent_map(em);
2306 }
2307
2308 map = kzalloc(sizeof(*map), GFP_NOFS);
2309 if (!map)
2310 return -ENOMEM;
2311
2312 em = alloc_extent_map(GFP_NOFS);
2313 if (!em)
2314 return -ENOMEM;
2315 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
2316 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2317 if (!map) {
2318 free_extent_map(em);
2319 return -ENOMEM;
2320 }
2321
2322 em->bdev = (struct block_device *)map;
2323 em->start = logical;
2324 em->len = length;
2325 em->block_start = 0;
2326
2327 map->num_stripes = num_stripes;
2328 map->io_width = btrfs_chunk_io_width(leaf, chunk);
2329 map->io_align = btrfs_chunk_io_align(leaf, chunk);
2330 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
2331 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
2332 map->type = btrfs_chunk_type(leaf, chunk);
2333 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
2334 for (i = 0; i < num_stripes; i++) {
2335 map->stripes[i].physical =
2336 btrfs_stripe_offset_nr(leaf, chunk, i);
2337 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
2338 read_extent_buffer(leaf, uuid, (unsigned long)
2339 btrfs_stripe_dev_uuid_nr(chunk, i),
2340 BTRFS_UUID_SIZE);
2341 map->stripes[i].dev = btrfs_find_device(root, devid, uuid);
2342
2343 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
2344 kfree(map);
2345 free_extent_map(em);
2346 return -EIO;
2347 }
2348 if (!map->stripes[i].dev) {
2349 map->stripes[i].dev =
2350 add_missing_dev(root, devid, uuid);
2351 if (!map->stripes[i].dev) {
2352 kfree(map);
2353 free_extent_map(em);
2354 return -EIO;
2355 }
2356 }
2357 map->stripes[i].dev->in_fs_metadata = 1;
2358 }
2359
2360 spin_lock(&map_tree->map_tree.lock);
2361 ret = add_extent_mapping(&map_tree->map_tree, em);
2362 spin_unlock(&map_tree->map_tree.lock);
2363 BUG_ON(ret);
2364 free_extent_map(em);
2365
2366 return 0;
2367}
2368
2369static int fill_device_from_item(struct extent_buffer *leaf,
2370 struct btrfs_dev_item *dev_item,
2371 struct btrfs_device *device)
2372{
2373 unsigned long ptr;
2374
2375 device->devid = btrfs_device_id(leaf, dev_item);
2376 device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
2377 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
2378 device->type = btrfs_device_type(leaf, dev_item);
2379 device->io_align = btrfs_device_io_align(leaf, dev_item);
2380 device->io_width = btrfs_device_io_width(leaf, dev_item);
2381 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
2382
2383 ptr = (unsigned long)btrfs_device_uuid(dev_item);
2384 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
2385
2386 return 0;
2387}
2388
2389static int read_one_dev(struct btrfs_root *root,
2390 struct extent_buffer *leaf,
2391 struct btrfs_dev_item *dev_item)
2392{
2393 struct btrfs_device *device;
2394 u64 devid;
2395 int ret;
2396 u8 dev_uuid[BTRFS_UUID_SIZE];
2397
2398 devid = btrfs_device_id(leaf, dev_item);
2399 read_extent_buffer(leaf, dev_uuid,
2400 (unsigned long)btrfs_device_uuid(dev_item),
2401 BTRFS_UUID_SIZE);
2402 device = btrfs_find_device(root, devid, dev_uuid);
2403 if (!device) {
2404 printk("warning devid %Lu missing\n", devid);
2405 device = add_missing_dev(root, devid, dev_uuid);
2406 if (!device)
2407 return -ENOMEM;
2408 }
2409
2410 fill_device_from_item(leaf, dev_item, device);
2411 device->dev_root = root->fs_info->dev_root;
2412 device->in_fs_metadata = 1;
2413 ret = 0;
2414#if 0
2415 ret = btrfs_open_device(device);
2416 if (ret) {
2417 kfree(device);
2418 }
2419#endif
2420 return ret;
2421}
2422
2423int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
2424{
2425 struct btrfs_dev_item *dev_item;
2426
2427 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
2428 dev_item);
2429 return read_one_dev(root, buf, dev_item);
2430}
2431
2432int btrfs_read_sys_array(struct btrfs_root *root)
2433{
2434 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2435 struct extent_buffer *sb;
2436 struct btrfs_disk_key *disk_key;
2437 struct btrfs_chunk *chunk;
2438 u8 *ptr;
2439 unsigned long sb_ptr;
2440 int ret = 0;
2441 u32 num_stripes;
2442 u32 array_size;
2443 u32 len = 0;
2444 u32 cur;
2445 struct btrfs_key key;
2446
2447 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
2448 BTRFS_SUPER_INFO_SIZE);
2449 if (!sb)
2450 return -ENOMEM;
2451 btrfs_set_buffer_uptodate(sb);
2452 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
2453 array_size = btrfs_super_sys_array_size(super_copy);
2454
2455 ptr = super_copy->sys_chunk_array;
2456 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
2457 cur = 0;
2458
2459 while (cur < array_size) {
2460 disk_key = (struct btrfs_disk_key *)ptr;
2461 btrfs_disk_key_to_cpu(&key, disk_key);
2462
2463 len = sizeof(*disk_key); ptr += len;
2464 sb_ptr += len;
2465 cur += len;
2466
2467 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
2468 chunk = (struct btrfs_chunk *)sb_ptr;
2469 ret = read_one_chunk(root, &key, sb, chunk);
2470 if (ret)
2471 break;
2472 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
2473 len = btrfs_chunk_item_size(num_stripes);
2474 } else {
2475 ret = -EIO;
2476 break;
2477 }
2478 ptr += len;
2479 sb_ptr += len;
2480 cur += len;
2481 }
2482 free_extent_buffer(sb);
2483 return ret;
2484}
2485
2486int btrfs_read_chunk_tree(struct btrfs_root *root)
2487{
2488 struct btrfs_path *path;
2489 struct extent_buffer *leaf;
2490 struct btrfs_key key;
2491 struct btrfs_key found_key;
2492 int ret;
2493 int slot;
2494
2495 root = root->fs_info->chunk_root;
2496
2497 path = btrfs_alloc_path();
2498 if (!path)
2499 return -ENOMEM;
2500
2501 /* first we search for all of the device items, and then we
2502 * read in all of the chunk items. This way we can create chunk
2503 * mappings that reference all of the devices that are afound
2504 */
2505 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
2506 key.offset = 0;
2507 key.type = 0;
2508again:
2509 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2510 while(1) {
2511 leaf = path->nodes[0];
2512 slot = path->slots[0];
2513 if (slot >= btrfs_header_nritems(leaf)) {
2514 ret = btrfs_next_leaf(root, path);
2515 if (ret == 0)
2516 continue;
2517 if (ret < 0)
2518 goto error;
2519 break;
2520 }
2521 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2522 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
2523 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
2524 break;
2525 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
2526 struct btrfs_dev_item *dev_item;
2527 dev_item = btrfs_item_ptr(leaf, slot,
2528 struct btrfs_dev_item);
2529 ret = read_one_dev(root, leaf, dev_item);
2530 BUG_ON(ret);
2531 }
2532 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
2533 struct btrfs_chunk *chunk;
2534 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
2535 ret = read_one_chunk(root, &found_key, leaf, chunk);
2536 }
2537 path->slots[0]++;
2538 }
2539 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
2540 key.objectid = 0;
2541 btrfs_release_path(root, path);
2542 goto again;
2543 }
2544
2545 btrfs_free_path(path);
2546 ret = 0;
2547error:
2548 return ret;
2549}
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-08 07:40:23 -0500