2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
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>
25 #include "extent_map.h"
27 #include "transaction.h"
28 #include "print-tree.h"
39 struct btrfs_bio_stripe stripes[];
42 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
43 (sizeof(struct btrfs_bio_stripe) * (n)))
45 static DEFINE_MUTEX(uuid_mutex);
46 static LIST_HEAD(fs_uuids);
48 int btrfs_cleanup_fs_uuids(void)
50 struct btrfs_fs_devices *fs_devices;
51 struct list_head *uuid_cur;
52 struct list_head *devices_cur;
53 struct btrfs_device *dev;
55 list_for_each(uuid_cur, &fs_uuids) {
56 fs_devices = list_entry(uuid_cur, struct btrfs_fs_devices,
58 while(!list_empty(&fs_devices->devices)) {
59 devices_cur = fs_devices->devices.next;
60 dev = list_entry(devices_cur, struct btrfs_device,
63 close_bdev_excl(dev->bdev);
65 list_del(&dev->dev_list);
72 static struct btrfs_device *__find_device(struct list_head *head, u64 devid,
75 struct btrfs_device *dev;
76 struct list_head *cur;
78 list_for_each(cur, head) {
79 dev = list_entry(cur, struct btrfs_device, dev_list);
80 if (dev->devid == devid &&
81 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
88 static struct btrfs_fs_devices *find_fsid(u8 *fsid)
90 struct list_head *cur;
91 struct btrfs_fs_devices *fs_devices;
93 list_for_each(cur, &fs_uuids) {
94 fs_devices = list_entry(cur, struct btrfs_fs_devices, list);
95 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
101 static int device_list_add(const char *path,
102 struct btrfs_super_block *disk_super,
103 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
105 struct btrfs_device *device;
106 struct btrfs_fs_devices *fs_devices;
107 u64 found_transid = btrfs_super_generation(disk_super);
109 fs_devices = find_fsid(disk_super->fsid);
111 fs_devices = kmalloc(sizeof(*fs_devices), GFP_NOFS);
114 INIT_LIST_HEAD(&fs_devices->devices);
115 INIT_LIST_HEAD(&fs_devices->alloc_list);
116 list_add(&fs_devices->list, &fs_uuids);
117 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
118 fs_devices->latest_devid = devid;
119 fs_devices->latest_trans = found_transid;
120 fs_devices->lowest_devid = (u64)-1;
121 fs_devices->num_devices = 0;
124 device = __find_device(&fs_devices->devices, devid,
125 disk_super->dev_item.uuid);
128 device = kzalloc(sizeof(*device), GFP_NOFS);
130 /* we can safely leave the fs_devices entry around */
133 device->devid = devid;
134 memcpy(device->uuid, disk_super->dev_item.uuid,
136 device->barriers = 1;
137 spin_lock_init(&device->io_lock);
138 device->name = kstrdup(path, GFP_NOFS);
143 list_add(&device->dev_list, &fs_devices->devices);
144 list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
145 fs_devices->num_devices++;
148 if (found_transid > fs_devices->latest_trans) {
149 fs_devices->latest_devid = devid;
150 fs_devices->latest_trans = found_transid;
152 if (fs_devices->lowest_devid > devid) {
153 fs_devices->lowest_devid = devid;
155 *fs_devices_ret = fs_devices;
159 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
161 struct list_head *head = &fs_devices->devices;
162 struct list_head *cur;
163 struct btrfs_device *device;
165 mutex_lock(&uuid_mutex);
166 list_for_each(cur, head) {
167 device = list_entry(cur, struct btrfs_device, dev_list);
169 close_bdev_excl(device->bdev);
173 mutex_unlock(&uuid_mutex);
177 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
178 int flags, void *holder)
180 struct block_device *bdev;
181 struct list_head *head = &fs_devices->devices;
182 struct list_head *cur;
183 struct btrfs_device *device;
186 mutex_lock(&uuid_mutex);
187 list_for_each(cur, head) {
188 device = list_entry(cur, struct btrfs_device, dev_list);
189 bdev = open_bdev_excl(device->name, flags, holder);
192 printk("open %s failed\n", device->name);
196 if (device->devid == fs_devices->latest_devid)
197 fs_devices->latest_bdev = bdev;
198 if (device->devid == fs_devices->lowest_devid) {
199 fs_devices->lowest_bdev = bdev;
203 mutex_unlock(&uuid_mutex);
206 mutex_unlock(&uuid_mutex);
207 btrfs_close_devices(fs_devices);
211 int btrfs_scan_one_device(const char *path, int flags, void *holder,
212 struct btrfs_fs_devices **fs_devices_ret)
214 struct btrfs_super_block *disk_super;
215 struct block_device *bdev;
216 struct buffer_head *bh;
221 mutex_lock(&uuid_mutex);
223 bdev = open_bdev_excl(path, flags, holder);
230 ret = set_blocksize(bdev, 4096);
233 bh = __bread(bdev, BTRFS_SUPER_INFO_OFFSET / 4096, 4096);
238 disk_super = (struct btrfs_super_block *)bh->b_data;
239 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
240 sizeof(disk_super->magic))) {
244 devid = le64_to_cpu(disk_super->dev_item.devid);
245 transid = btrfs_super_generation(disk_super);
246 if (disk_super->label[0])
247 printk("device label %s ", disk_super->label);
249 /* FIXME, make a readl uuid parser */
250 printk("device fsid %llx-%llx ",
251 *(unsigned long long *)disk_super->fsid,
252 *(unsigned long long *)(disk_super->fsid + 8));
254 printk("devid %Lu transid %Lu %s\n", devid, transid, path);
255 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
260 close_bdev_excl(bdev);
262 mutex_unlock(&uuid_mutex);
267 * this uses a pretty simple search, the expectation is that it is
268 * called very infrequently and that a given device has a small number
271 static int find_free_dev_extent(struct btrfs_trans_handle *trans,
272 struct btrfs_device *device,
273 struct btrfs_path *path,
274 u64 num_bytes, u64 *start)
276 struct btrfs_key key;
277 struct btrfs_root *root = device->dev_root;
278 struct btrfs_dev_extent *dev_extent = NULL;
281 u64 search_start = 0;
282 u64 search_end = device->total_bytes;
286 struct extent_buffer *l;
291 /* FIXME use last free of some kind */
293 /* we don't want to overwrite the superblock on the drive,
294 * so we make sure to start at an offset of at least 1MB
296 search_start = max((u64)1024 * 1024, search_start);
298 if (root->fs_info->alloc_start + num_bytes <= device->total_bytes)
299 search_start = max(root->fs_info->alloc_start, search_start);
301 key.objectid = device->devid;
302 key.offset = search_start;
303 key.type = BTRFS_DEV_EXTENT_KEY;
304 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
307 ret = btrfs_previous_item(root, path, 0, key.type);
311 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
314 slot = path->slots[0];
315 if (slot >= btrfs_header_nritems(l)) {
316 ret = btrfs_next_leaf(root, path);
323 if (search_start >= search_end) {
327 *start = search_start;
331 *start = last_byte > search_start ?
332 last_byte : search_start;
333 if (search_end <= *start) {
339 btrfs_item_key_to_cpu(l, &key, slot);
341 if (key.objectid < device->devid)
344 if (key.objectid > device->devid)
347 if (key.offset >= search_start && key.offset > last_byte &&
349 if (last_byte < search_start)
350 last_byte = search_start;
351 hole_size = key.offset - last_byte;
352 if (key.offset > last_byte &&
353 hole_size >= num_bytes) {
358 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY) {
363 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
364 last_byte = key.offset + btrfs_dev_extent_length(l, dev_extent);
370 /* we have to make sure we didn't find an extent that has already
371 * been allocated by the map tree or the original allocation
373 btrfs_release_path(root, path);
374 BUG_ON(*start < search_start);
376 if (*start + num_bytes > search_end) {
380 /* check for pending inserts here */
384 btrfs_release_path(root, path);
388 int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
389 struct btrfs_device *device,
393 struct btrfs_path *path;
394 struct btrfs_root *root = device->dev_root;
395 struct btrfs_key key;
397 path = btrfs_alloc_path();
401 key.objectid = device->devid;
403 key.type = BTRFS_DEV_EXTENT_KEY;
405 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
408 ret = btrfs_del_item(trans, root, path);
411 btrfs_free_path(path);
415 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
416 struct btrfs_device *device,
417 u64 chunk_tree, u64 chunk_objectid,
419 u64 num_bytes, u64 *start)
422 struct btrfs_path *path;
423 struct btrfs_root *root = device->dev_root;
424 struct btrfs_dev_extent *extent;
425 struct extent_buffer *leaf;
426 struct btrfs_key key;
428 path = btrfs_alloc_path();
432 ret = find_free_dev_extent(trans, device, path, num_bytes, start);
437 key.objectid = device->devid;
439 key.type = BTRFS_DEV_EXTENT_KEY;
440 ret = btrfs_insert_empty_item(trans, root, path, &key,
444 leaf = path->nodes[0];
445 extent = btrfs_item_ptr(leaf, path->slots[0],
446 struct btrfs_dev_extent);
447 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
448 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
449 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
451 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
452 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
455 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
456 btrfs_mark_buffer_dirty(leaf);
458 btrfs_free_path(path);
462 static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset)
464 struct btrfs_path *path;
466 struct btrfs_key key;
467 struct btrfs_chunk *chunk;
468 struct btrfs_key found_key;
470 path = btrfs_alloc_path();
473 key.objectid = objectid;
474 key.offset = (u64)-1;
475 key.type = BTRFS_CHUNK_ITEM_KEY;
477 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
483 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
487 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
489 if (found_key.objectid != objectid)
492 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
494 *offset = found_key.offset +
495 btrfs_chunk_length(path->nodes[0], chunk);
500 btrfs_free_path(path);
504 static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
508 struct btrfs_key key;
509 struct btrfs_key found_key;
511 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
512 key.type = BTRFS_DEV_ITEM_KEY;
513 key.offset = (u64)-1;
515 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
521 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
526 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
528 *objectid = found_key.offset + 1;
532 btrfs_release_path(root, path);
537 * the device information is stored in the chunk root
538 * the btrfs_device struct should be fully filled in
540 int btrfs_add_device(struct btrfs_trans_handle *trans,
541 struct btrfs_root *root,
542 struct btrfs_device *device)
545 struct btrfs_path *path;
546 struct btrfs_dev_item *dev_item;
547 struct extent_buffer *leaf;
548 struct btrfs_key key;
552 root = root->fs_info->chunk_root;
554 path = btrfs_alloc_path();
558 ret = find_next_devid(root, path, &free_devid);
562 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
563 key.type = BTRFS_DEV_ITEM_KEY;
564 key.offset = free_devid;
566 ret = btrfs_insert_empty_item(trans, root, path, &key,
571 leaf = path->nodes[0];
572 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
574 device->devid = free_devid;
575 btrfs_set_device_id(leaf, dev_item, device->devid);
576 btrfs_set_device_type(leaf, dev_item, device->type);
577 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
578 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
579 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
580 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
581 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
582 btrfs_set_device_group(leaf, dev_item, 0);
583 btrfs_set_device_seek_speed(leaf, dev_item, 0);
584 btrfs_set_device_bandwidth(leaf, dev_item, 0);
586 ptr = (unsigned long)btrfs_device_uuid(dev_item);
587 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
588 btrfs_mark_buffer_dirty(leaf);
592 btrfs_free_path(path);
596 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
598 struct btrfs_trans_handle *trans;
599 struct btrfs_device *device;
600 struct block_device *bdev;
601 struct list_head *cur;
602 struct list_head *devices;
607 bdev = open_bdev_excl(device_path, 0, root->fs_info->bdev_holder);
611 mutex_lock(&root->fs_info->fs_mutex);
612 trans = btrfs_start_transaction(root, 1);
613 devices = &root->fs_info->fs_devices->devices;
614 list_for_each(cur, devices) {
615 device = list_entry(cur, struct btrfs_device, dev_list);
616 if (device->bdev == bdev) {
622 device = kzalloc(sizeof(*device), GFP_NOFS);
624 /* we can safely leave the fs_devices entry around */
629 device->barriers = 1;
630 generate_random_uuid(device->uuid);
631 spin_lock_init(&device->io_lock);
632 device->name = kstrdup(device_path, GFP_NOFS);
637 device->io_width = root->sectorsize;
638 device->io_align = root->sectorsize;
639 device->sector_size = root->sectorsize;
640 device->total_bytes = i_size_read(bdev->bd_inode);
641 device->dev_root = root->fs_info->dev_root;
644 ret = btrfs_add_device(trans, root, device);
648 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
649 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
650 total_bytes + device->total_bytes);
652 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
653 btrfs_set_super_num_devices(&root->fs_info->super_copy,
656 list_add(&device->dev_list, &root->fs_info->fs_devices->devices);
657 list_add(&device->dev_alloc_list,
658 &root->fs_info->fs_devices->alloc_list);
659 root->fs_info->fs_devices->num_devices++;
661 btrfs_end_transaction(trans, root);
662 mutex_unlock(&root->fs_info->fs_mutex);
666 close_bdev_excl(bdev);
670 int btrfs_update_device(struct btrfs_trans_handle *trans,
671 struct btrfs_device *device)
674 struct btrfs_path *path;
675 struct btrfs_root *root;
676 struct btrfs_dev_item *dev_item;
677 struct extent_buffer *leaf;
678 struct btrfs_key key;
680 root = device->dev_root->fs_info->chunk_root;
682 path = btrfs_alloc_path();
686 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
687 key.type = BTRFS_DEV_ITEM_KEY;
688 key.offset = device->devid;
690 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
699 leaf = path->nodes[0];
700 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
702 btrfs_set_device_id(leaf, dev_item, device->devid);
703 btrfs_set_device_type(leaf, dev_item, device->type);
704 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
705 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
706 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
707 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
708 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
709 btrfs_mark_buffer_dirty(leaf);
712 btrfs_free_path(path);
716 int btrfs_grow_device(struct btrfs_trans_handle *trans,
717 struct btrfs_device *device, u64 new_size)
719 struct btrfs_super_block *super_copy =
720 &device->dev_root->fs_info->super_copy;
721 u64 old_total = btrfs_super_total_bytes(super_copy);
722 u64 diff = new_size - device->total_bytes;
724 btrfs_set_super_total_bytes(super_copy, old_total + diff);
725 return btrfs_update_device(trans, device);
728 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
729 struct btrfs_root *root,
730 u64 chunk_tree, u64 chunk_objectid,
734 struct btrfs_path *path;
735 struct btrfs_key key;
737 root = root->fs_info->chunk_root;
738 path = btrfs_alloc_path();
742 key.objectid = chunk_objectid;
743 key.offset = chunk_offset;
744 key.type = BTRFS_CHUNK_ITEM_KEY;
746 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
749 ret = btrfs_del_item(trans, root, path);
752 btrfs_free_path(path);
756 int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
759 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
760 struct btrfs_disk_key *disk_key;
761 struct btrfs_chunk *chunk;
768 struct btrfs_key key;
770 array_size = btrfs_super_sys_array_size(super_copy);
772 ptr = super_copy->sys_chunk_array;
775 while (cur < array_size) {
776 disk_key = (struct btrfs_disk_key *)ptr;
777 btrfs_disk_key_to_cpu(&key, disk_key);
779 len = sizeof(*disk_key);
781 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
782 chunk = (struct btrfs_chunk *)(ptr + len);
783 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
784 len += btrfs_chunk_item_size(num_stripes);
789 if (key.objectid == chunk_objectid &&
790 key.offset == chunk_offset) {
791 memmove(ptr, ptr + len, array_size - (cur + len));
793 btrfs_set_super_sys_array_size(super_copy, array_size);
803 int btrfs_relocate_chunk(struct btrfs_root *root,
804 u64 chunk_tree, u64 chunk_objectid,
807 struct extent_map_tree *em_tree;
808 struct btrfs_root *extent_root;
809 struct btrfs_trans_handle *trans;
810 struct extent_map *em;
811 struct map_lookup *map;
815 root = root->fs_info->chunk_root;
816 extent_root = root->fs_info->extent_root;
817 em_tree = &root->fs_info->mapping_tree.map_tree;
819 /* step one, relocate all the extents inside this chunk */
820 ret = btrfs_shrink_extent_tree(extent_root, chunk_offset);
823 trans = btrfs_start_transaction(root, 1);
827 * step two, delete the device extents and the
830 spin_lock(&em_tree->lock);
831 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
832 spin_unlock(&em_tree->lock);
834 BUG_ON(em->start > chunk_offset || em->start + em->len < chunk_offset);
835 map = (struct map_lookup *)em->bdev;
837 for (i = 0; i < map->num_stripes; i++) {
838 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
839 map->stripes[i].physical);
842 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
847 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
848 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
855 spin_lock(&em_tree->lock);
856 remove_extent_mapping(em_tree, em);
860 /* once for the tree */
862 spin_unlock(&em_tree->lock);
868 btrfs_end_transaction(trans, root);
872 static u64 div_factor(u64 num, int factor)
882 int btrfs_balance(struct btrfs_root *dev_root)
885 struct list_head *cur;
886 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
887 struct btrfs_device *device;
890 struct btrfs_path *path;
891 struct btrfs_key key;
892 struct btrfs_chunk *chunk;
893 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
894 struct btrfs_trans_handle *trans;
895 struct btrfs_key found_key;
898 dev_root = dev_root->fs_info->dev_root;
900 mutex_lock(&dev_root->fs_info->fs_mutex);
901 /* step one make some room on all the devices */
902 list_for_each(cur, devices) {
903 device = list_entry(cur, struct btrfs_device, dev_list);
904 old_size = device->total_bytes;
905 size_to_free = div_factor(old_size, 1);
906 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
907 if (device->total_bytes - device->bytes_used > size_to_free)
910 ret = btrfs_shrink_device(device, old_size - size_to_free);
913 trans = btrfs_start_transaction(dev_root, 1);
916 ret = btrfs_grow_device(trans, device, old_size);
919 btrfs_end_transaction(trans, dev_root);
922 /* step two, relocate all the chunks */
923 path = btrfs_alloc_path();
926 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
927 key.offset = (u64)-1;
928 key.type = BTRFS_CHUNK_ITEM_KEY;
931 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
936 * this shouldn't happen, it means the last relocate
942 ret = btrfs_previous_item(chunk_root, path, 0,
943 BTRFS_CHUNK_ITEM_KEY);
947 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
949 if (found_key.objectid != key.objectid)
951 chunk = btrfs_item_ptr(path->nodes[0],
954 key.offset = found_key.offset;
955 /* chunk zero is special */
959 ret = btrfs_relocate_chunk(chunk_root,
960 chunk_root->root_key.objectid,
964 btrfs_release_path(chunk_root, path);
968 btrfs_free_path(path);
969 mutex_unlock(&dev_root->fs_info->fs_mutex);
974 * shrinking a device means finding all of the device extents past
975 * the new size, and then following the back refs to the chunks.
976 * The chunk relocation code actually frees the device extent
978 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
980 struct btrfs_trans_handle *trans;
981 struct btrfs_root *root = device->dev_root;
982 struct btrfs_dev_extent *dev_extent = NULL;
983 struct btrfs_path *path;
990 struct extent_buffer *l;
991 struct btrfs_key key;
992 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
993 u64 old_total = btrfs_super_total_bytes(super_copy);
994 u64 diff = device->total_bytes - new_size;
997 path = btrfs_alloc_path();
1001 trans = btrfs_start_transaction(root, 1);
1009 device->total_bytes = new_size;
1010 ret = btrfs_update_device(trans, device);
1012 btrfs_end_transaction(trans, root);
1015 WARN_ON(diff > old_total);
1016 btrfs_set_super_total_bytes(super_copy, old_total - diff);
1017 btrfs_end_transaction(trans, root);
1019 key.objectid = device->devid;
1020 key.offset = (u64)-1;
1021 key.type = BTRFS_DEV_EXTENT_KEY;
1024 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1028 ret = btrfs_previous_item(root, path, 0, key.type);
1037 slot = path->slots[0];
1038 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
1040 if (key.objectid != device->devid)
1043 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
1044 length = btrfs_dev_extent_length(l, dev_extent);
1046 if (key.offset + length <= new_size)
1049 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
1050 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
1051 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
1052 btrfs_release_path(root, path);
1054 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
1061 btrfs_free_path(path);
1065 int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
1066 struct btrfs_root *root,
1067 struct btrfs_key *key,
1068 struct btrfs_chunk *chunk, int item_size)
1070 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1071 struct btrfs_disk_key disk_key;
1075 array_size = btrfs_super_sys_array_size(super_copy);
1076 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
1079 ptr = super_copy->sys_chunk_array + array_size;
1080 btrfs_cpu_key_to_disk(&disk_key, key);
1081 memcpy(ptr, &disk_key, sizeof(disk_key));
1082 ptr += sizeof(disk_key);
1083 memcpy(ptr, chunk, item_size);
1084 item_size += sizeof(disk_key);
1085 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
1089 static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
1092 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
1094 else if (type & BTRFS_BLOCK_GROUP_RAID10)
1095 return calc_size * (num_stripes / sub_stripes);
1097 return calc_size * num_stripes;
1101 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
1102 struct btrfs_root *extent_root, u64 *start,
1103 u64 *num_bytes, u64 type)
1106 struct btrfs_fs_info *info = extent_root->fs_info;
1107 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
1108 struct btrfs_path *path;
1109 struct btrfs_stripe *stripes;
1110 struct btrfs_device *device = NULL;
1111 struct btrfs_chunk *chunk;
1112 struct list_head private_devs;
1113 struct list_head *dev_list;
1114 struct list_head *cur;
1115 struct extent_map_tree *em_tree;
1116 struct map_lookup *map;
1117 struct extent_map *em;
1118 int min_stripe_size = 1 * 1024 * 1024;
1120 u64 calc_size = 1024 * 1024 * 1024;
1121 u64 max_chunk_size = calc_size;
1126 int num_stripes = 1;
1127 int min_stripes = 1;
1128 int sub_stripes = 0;
1132 int stripe_len = 64 * 1024;
1133 struct btrfs_key key;
1135 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
1136 (type & BTRFS_BLOCK_GROUP_DUP)) {
1138 type &= ~BTRFS_BLOCK_GROUP_DUP;
1140 dev_list = &extent_root->fs_info->fs_devices->alloc_list;
1141 if (list_empty(dev_list))
1144 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
1145 num_stripes = btrfs_super_num_devices(&info->super_copy);
1148 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
1152 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
1153 num_stripes = min_t(u64, 2,
1154 btrfs_super_num_devices(&info->super_copy));
1155 if (num_stripes < 2)
1159 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1160 num_stripes = btrfs_super_num_devices(&info->super_copy);
1161 if (num_stripes < 4)
1163 num_stripes &= ~(u32)1;
1168 if (type & BTRFS_BLOCK_GROUP_DATA) {
1169 max_chunk_size = 10 * calc_size;
1170 min_stripe_size = 64 * 1024 * 1024;
1171 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
1172 max_chunk_size = 4 * calc_size;
1173 min_stripe_size = 32 * 1024 * 1024;
1174 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1175 calc_size = 8 * 1024 * 1024;
1176 max_chunk_size = calc_size * 2;
1177 min_stripe_size = 1 * 1024 * 1024;
1180 path = btrfs_alloc_path();
1184 /* we don't want a chunk larger than 10% of the FS */
1185 percent_max = div_factor(btrfs_super_total_bytes(&info->super_copy), 1);
1186 max_chunk_size = min(percent_max, max_chunk_size);
1189 if (calc_size * num_stripes > max_chunk_size) {
1190 calc_size = max_chunk_size;
1191 do_div(calc_size, num_stripes);
1192 do_div(calc_size, stripe_len);
1193 calc_size *= stripe_len;
1195 /* we don't want tiny stripes */
1196 calc_size = max_t(u64, min_stripe_size, calc_size);
1198 do_div(calc_size, stripe_len);
1199 calc_size *= stripe_len;
1201 INIT_LIST_HEAD(&private_devs);
1202 cur = dev_list->next;
1205 if (type & BTRFS_BLOCK_GROUP_DUP)
1206 min_free = calc_size * 2;
1208 min_free = calc_size;
1210 /* we add 1MB because we never use the first 1MB of the device */
1211 min_free += 1024 * 1024;
1213 /* build a private list of devices we will allocate from */
1214 while(index < num_stripes) {
1215 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
1217 avail = device->total_bytes - device->bytes_used;
1220 if (avail >= min_free) {
1221 u64 ignored_start = 0;
1222 ret = find_free_dev_extent(trans, device, path,
1226 list_move_tail(&device->dev_alloc_list,
1229 if (type & BTRFS_BLOCK_GROUP_DUP)
1232 } else if (avail > max_avail)
1234 if (cur == dev_list)
1237 if (index < num_stripes) {
1238 list_splice(&private_devs, dev_list);
1239 if (index >= min_stripes) {
1240 num_stripes = index;
1241 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1242 num_stripes /= sub_stripes;
1243 num_stripes *= sub_stripes;
1248 if (!looped && max_avail > 0) {
1250 calc_size = max_avail;
1253 btrfs_free_path(path);
1256 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1257 key.type = BTRFS_CHUNK_ITEM_KEY;
1258 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
1261 btrfs_free_path(path);
1265 chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
1267 btrfs_free_path(path);
1271 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1274 btrfs_free_path(path);
1277 btrfs_free_path(path);
1280 stripes = &chunk->stripe;
1281 *num_bytes = chunk_bytes_by_type(type, calc_size,
1282 num_stripes, sub_stripes);
1285 while(index < num_stripes) {
1286 struct btrfs_stripe *stripe;
1287 BUG_ON(list_empty(&private_devs));
1288 cur = private_devs.next;
1289 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
1291 /* loop over this device again if we're doing a dup group */
1292 if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
1293 (index == num_stripes - 1))
1294 list_move_tail(&device->dev_alloc_list, dev_list);
1296 ret = btrfs_alloc_dev_extent(trans, device,
1297 info->chunk_root->root_key.objectid,
1298 BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
1299 calc_size, &dev_offset);
1301 device->bytes_used += calc_size;
1302 ret = btrfs_update_device(trans, device);
1305 map->stripes[index].dev = device;
1306 map->stripes[index].physical = dev_offset;
1307 stripe = stripes + index;
1308 btrfs_set_stack_stripe_devid(stripe, device->devid);
1309 btrfs_set_stack_stripe_offset(stripe, dev_offset);
1310 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
1311 physical = dev_offset;
1314 BUG_ON(!list_empty(&private_devs));
1316 /* key was set above */
1317 btrfs_set_stack_chunk_length(chunk, *num_bytes);
1318 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
1319 btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
1320 btrfs_set_stack_chunk_type(chunk, type);
1321 btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
1322 btrfs_set_stack_chunk_io_align(chunk, stripe_len);
1323 btrfs_set_stack_chunk_io_width(chunk, stripe_len);
1324 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
1325 btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
1326 map->sector_size = extent_root->sectorsize;
1327 map->stripe_len = stripe_len;
1328 map->io_align = stripe_len;
1329 map->io_width = stripe_len;
1331 map->num_stripes = num_stripes;
1332 map->sub_stripes = sub_stripes;
1334 ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
1335 btrfs_chunk_item_size(num_stripes));
1337 *start = key.offset;;
1339 em = alloc_extent_map(GFP_NOFS);
1342 em->bdev = (struct block_device *)map;
1343 em->start = key.offset;
1344 em->len = *num_bytes;
1345 em->block_start = 0;
1347 if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1348 ret = btrfs_add_system_chunk(trans, chunk_root, &key,
1349 chunk, btrfs_chunk_item_size(num_stripes));
1354 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
1355 spin_lock(&em_tree->lock);
1356 ret = add_extent_mapping(em_tree, em);
1357 spin_unlock(&em_tree->lock);
1359 free_extent_map(em);
1363 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
1365 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
1368 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
1370 struct extent_map *em;
1373 spin_lock(&tree->map_tree.lock);
1374 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
1376 remove_extent_mapping(&tree->map_tree, em);
1377 spin_unlock(&tree->map_tree.lock);
1382 free_extent_map(em);
1383 /* once for the tree */
1384 free_extent_map(em);
1388 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
1390 struct extent_map *em;
1391 struct map_lookup *map;
1392 struct extent_map_tree *em_tree = &map_tree->map_tree;
1395 spin_lock(&em_tree->lock);
1396 em = lookup_extent_mapping(em_tree, logical, len);
1397 spin_unlock(&em_tree->lock);
1400 BUG_ON(em->start > logical || em->start + em->len < logical);
1401 map = (struct map_lookup *)em->bdev;
1402 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
1403 ret = map->num_stripes;
1404 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
1405 ret = map->sub_stripes;
1408 free_extent_map(em);
1412 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1413 u64 logical, u64 *length,
1414 struct btrfs_multi_bio **multi_ret,
1415 int mirror_num, struct page *unplug_page)
1417 struct extent_map *em;
1418 struct map_lookup *map;
1419 struct extent_map_tree *em_tree = &map_tree->map_tree;
1423 int stripes_allocated = 8;
1424 int stripes_required = 1;
1429 struct btrfs_multi_bio *multi = NULL;
1431 if (multi_ret && !(rw & (1 << BIO_RW))) {
1432 stripes_allocated = 1;
1436 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
1441 atomic_set(&multi->error, 0);
1444 spin_lock(&em_tree->lock);
1445 em = lookup_extent_mapping(em_tree, logical, *length);
1446 spin_unlock(&em_tree->lock);
1448 if (!em && unplug_page)
1452 printk("unable to find logical %Lu\n", logical);
1456 BUG_ON(em->start > logical || em->start + em->len < logical);
1457 map = (struct map_lookup *)em->bdev;
1458 offset = logical - em->start;
1460 if (mirror_num > map->num_stripes)
1463 /* if our multi bio struct is too small, back off and try again */
1464 if (rw & (1 << BIO_RW)) {
1465 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
1466 BTRFS_BLOCK_GROUP_DUP)) {
1467 stripes_required = map->num_stripes;
1469 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1470 stripes_required = map->sub_stripes;
1474 if (multi_ret && rw == WRITE &&
1475 stripes_allocated < stripes_required) {
1476 stripes_allocated = map->num_stripes;
1477 free_extent_map(em);
1483 * stripe_nr counts the total number of stripes we have to stride
1484 * to get to this block
1486 do_div(stripe_nr, map->stripe_len);
1488 stripe_offset = stripe_nr * map->stripe_len;
1489 BUG_ON(offset < stripe_offset);
1491 /* stripe_offset is the offset of this block in its stripe*/
1492 stripe_offset = offset - stripe_offset;
1494 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1495 BTRFS_BLOCK_GROUP_RAID10 |
1496 BTRFS_BLOCK_GROUP_DUP)) {
1497 /* we limit the length of each bio to what fits in a stripe */
1498 *length = min_t(u64, em->len - offset,
1499 map->stripe_len - stripe_offset);
1501 *length = em->len - offset;
1504 if (!multi_ret && !unplug_page)
1509 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1510 if (unplug_page || (rw & (1 << BIO_RW)))
1511 num_stripes = map->num_stripes;
1512 else if (mirror_num)
1513 stripe_index = mirror_num - 1;
1515 stripe_index = current->pid % map->num_stripes;
1517 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1518 if (rw & (1 << BIO_RW))
1519 num_stripes = map->num_stripes;
1520 else if (mirror_num)
1521 stripe_index = mirror_num - 1;
1523 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1524 int factor = map->num_stripes / map->sub_stripes;
1526 stripe_index = do_div(stripe_nr, factor);
1527 stripe_index *= map->sub_stripes;
1529 if (unplug_page || (rw & (1 << BIO_RW)))
1530 num_stripes = map->sub_stripes;
1531 else if (mirror_num)
1532 stripe_index += mirror_num - 1;
1534 stripe_index += current->pid % map->sub_stripes;
1537 * after this do_div call, stripe_nr is the number of stripes
1538 * on this device we have to walk to find the data, and
1539 * stripe_index is the number of our device in the stripe array
1541 stripe_index = do_div(stripe_nr, map->num_stripes);
1543 BUG_ON(stripe_index >= map->num_stripes);
1545 for (i = 0; i < num_stripes; i++) {
1547 struct btrfs_device *device;
1548 struct backing_dev_info *bdi;
1550 device = map->stripes[stripe_index].dev;
1551 bdi = blk_get_backing_dev_info(device->bdev);
1552 if (bdi->unplug_io_fn) {
1553 bdi->unplug_io_fn(bdi, unplug_page);
1556 multi->stripes[i].physical =
1557 map->stripes[stripe_index].physical +
1558 stripe_offset + stripe_nr * map->stripe_len;
1559 multi->stripes[i].dev = map->stripes[stripe_index].dev;
1565 multi->num_stripes = num_stripes;
1566 multi->max_errors = max_errors;
1569 free_extent_map(em);
1573 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1574 u64 logical, u64 *length,
1575 struct btrfs_multi_bio **multi_ret, int mirror_num)
1577 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
1581 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
1582 u64 logical, struct page *page)
1584 u64 length = PAGE_CACHE_SIZE;
1585 return __btrfs_map_block(map_tree, READ, logical, &length,
1590 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1591 static void end_bio_multi_stripe(struct bio *bio, int err)
1593 static int end_bio_multi_stripe(struct bio *bio,
1594 unsigned int bytes_done, int err)
1597 struct btrfs_multi_bio *multi = bio->bi_private;
1599 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1604 atomic_inc(&multi->error);
1606 if (atomic_dec_and_test(&multi->stripes_pending)) {
1607 bio->bi_private = multi->private;
1608 bio->bi_end_io = multi->end_io;
1610 /* only send an error to the higher layers if it is
1611 * beyond the tolerance of the multi-bio
1613 if (atomic_read(&multi->error) > multi->max_errors)
1619 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1620 bio_endio(bio, bio->bi_size, err);
1622 bio_endio(bio, err);
1627 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1632 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
1635 struct btrfs_mapping_tree *map_tree;
1636 struct btrfs_device *dev;
1637 struct bio *first_bio = bio;
1638 u64 logical = bio->bi_sector << 9;
1641 struct btrfs_multi_bio *multi = NULL;
1646 length = bio->bi_size;
1647 map_tree = &root->fs_info->mapping_tree;
1648 map_length = length;
1650 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
1654 total_devs = multi->num_stripes;
1655 if (map_length < length) {
1656 printk("mapping failed logical %Lu bio len %Lu "
1657 "len %Lu\n", logical, length, map_length);
1660 multi->end_io = first_bio->bi_end_io;
1661 multi->private = first_bio->bi_private;
1662 atomic_set(&multi->stripes_pending, multi->num_stripes);
1664 while(dev_nr < total_devs) {
1665 if (total_devs > 1) {
1666 if (dev_nr < total_devs - 1) {
1667 bio = bio_clone(first_bio, GFP_NOFS);
1672 bio->bi_private = multi;
1673 bio->bi_end_io = end_bio_multi_stripe;
1675 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
1676 dev = multi->stripes[dev_nr].dev;
1678 bio->bi_bdev = dev->bdev;
1679 spin_lock(&dev->io_lock);
1681 spin_unlock(&dev->io_lock);
1682 submit_bio(rw, bio);
1685 if (total_devs == 1)
1690 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
1693 struct list_head *head = &root->fs_info->fs_devices->devices;
1695 return __find_device(head, devid, uuid);
1698 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
1699 struct extent_buffer *leaf,
1700 struct btrfs_chunk *chunk)
1702 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1703 struct map_lookup *map;
1704 struct extent_map *em;
1708 u8 uuid[BTRFS_UUID_SIZE];
1713 logical = key->offset;
1714 length = btrfs_chunk_length(leaf, chunk);
1715 spin_lock(&map_tree->map_tree.lock);
1716 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
1717 spin_unlock(&map_tree->map_tree.lock);
1719 /* already mapped? */
1720 if (em && em->start <= logical && em->start + em->len > logical) {
1721 free_extent_map(em);
1724 free_extent_map(em);
1727 map = kzalloc(sizeof(*map), GFP_NOFS);
1731 em = alloc_extent_map(GFP_NOFS);
1734 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
1735 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1737 free_extent_map(em);
1741 em->bdev = (struct block_device *)map;
1742 em->start = logical;
1744 em->block_start = 0;
1746 map->num_stripes = num_stripes;
1747 map->io_width = btrfs_chunk_io_width(leaf, chunk);
1748 map->io_align = btrfs_chunk_io_align(leaf, chunk);
1749 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
1750 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
1751 map->type = btrfs_chunk_type(leaf, chunk);
1752 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
1753 for (i = 0; i < num_stripes; i++) {
1754 map->stripes[i].physical =
1755 btrfs_stripe_offset_nr(leaf, chunk, i);
1756 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
1757 read_extent_buffer(leaf, uuid, (unsigned long)
1758 btrfs_stripe_dev_uuid_nr(chunk, i),
1760 map->stripes[i].dev = btrfs_find_device(root, devid, uuid);
1761 if (!map->stripes[i].dev) {
1763 free_extent_map(em);
1768 spin_lock(&map_tree->map_tree.lock);
1769 ret = add_extent_mapping(&map_tree->map_tree, em);
1770 spin_unlock(&map_tree->map_tree.lock);
1772 free_extent_map(em);
1777 static int fill_device_from_item(struct extent_buffer *leaf,
1778 struct btrfs_dev_item *dev_item,
1779 struct btrfs_device *device)
1783 device->devid = btrfs_device_id(leaf, dev_item);
1784 device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
1785 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
1786 device->type = btrfs_device_type(leaf, dev_item);
1787 device->io_align = btrfs_device_io_align(leaf, dev_item);
1788 device->io_width = btrfs_device_io_width(leaf, dev_item);
1789 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
1791 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1792 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1797 static int read_one_dev(struct btrfs_root *root,
1798 struct extent_buffer *leaf,
1799 struct btrfs_dev_item *dev_item)
1801 struct btrfs_device *device;
1804 u8 dev_uuid[BTRFS_UUID_SIZE];
1806 devid = btrfs_device_id(leaf, dev_item);
1807 read_extent_buffer(leaf, dev_uuid,
1808 (unsigned long)btrfs_device_uuid(dev_item),
1810 device = btrfs_find_device(root, devid, dev_uuid);
1812 printk("warning devid %Lu not found already\n", devid);
1813 device = kzalloc(sizeof(*device), GFP_NOFS);
1816 list_add(&device->dev_list,
1817 &root->fs_info->fs_devices->devices);
1818 list_add(&device->dev_alloc_list,
1819 &root->fs_info->fs_devices->alloc_list);
1820 device->barriers = 1;
1821 spin_lock_init(&device->io_lock);
1824 fill_device_from_item(leaf, dev_item, device);
1825 device->dev_root = root->fs_info->dev_root;
1828 ret = btrfs_open_device(device);
1836 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
1838 struct btrfs_dev_item *dev_item;
1840 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
1842 return read_one_dev(root, buf, dev_item);
1845 int btrfs_read_sys_array(struct btrfs_root *root)
1847 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1848 struct extent_buffer *sb = root->fs_info->sb_buffer;
1849 struct btrfs_disk_key *disk_key;
1850 struct btrfs_chunk *chunk;
1852 unsigned long sb_ptr;
1858 struct btrfs_key key;
1860 array_size = btrfs_super_sys_array_size(super_copy);
1862 ptr = super_copy->sys_chunk_array;
1863 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
1866 while (cur < array_size) {
1867 disk_key = (struct btrfs_disk_key *)ptr;
1868 btrfs_disk_key_to_cpu(&key, disk_key);
1870 len = sizeof(*disk_key);
1875 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1876 chunk = (struct btrfs_chunk *)sb_ptr;
1877 ret = read_one_chunk(root, &key, sb, chunk);
1880 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
1881 len = btrfs_chunk_item_size(num_stripes);
1893 int btrfs_read_chunk_tree(struct btrfs_root *root)
1895 struct btrfs_path *path;
1896 struct extent_buffer *leaf;
1897 struct btrfs_key key;
1898 struct btrfs_key found_key;
1902 root = root->fs_info->chunk_root;
1904 path = btrfs_alloc_path();
1908 /* first we search for all of the device items, and then we
1909 * read in all of the chunk items. This way we can create chunk
1910 * mappings that reference all of the devices that are afound
1912 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1916 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1918 leaf = path->nodes[0];
1919 slot = path->slots[0];
1920 if (slot >= btrfs_header_nritems(leaf)) {
1921 ret = btrfs_next_leaf(root, path);
1928 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1929 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
1930 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
1932 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
1933 struct btrfs_dev_item *dev_item;
1934 dev_item = btrfs_item_ptr(leaf, slot,
1935 struct btrfs_dev_item);
1936 ret = read_one_dev(root, leaf, dev_item);
1939 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
1940 struct btrfs_chunk *chunk;
1941 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
1942 ret = read_one_chunk(root, &found_key, leaf, chunk);
1946 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
1948 btrfs_release_path(root, path);
1952 btrfs_free_path(path);