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);
873 * shrinking a device means finding all of the device extents past
874 * the new size, and then following the back refs to the chunks.
875 * The chunk relocation code actually frees the device extent
877 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
879 struct btrfs_trans_handle *trans;
880 struct btrfs_root *root = device->dev_root;
881 struct btrfs_dev_extent *dev_extent = NULL;
882 struct btrfs_path *path;
889 struct extent_buffer *l;
890 struct btrfs_key key;
891 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
892 u64 old_total = btrfs_super_total_bytes(super_copy);
893 u64 diff = device->total_bytes - new_size;
896 path = btrfs_alloc_path();
900 trans = btrfs_start_transaction(root, 1);
908 device->total_bytes = new_size;
909 ret = btrfs_update_device(trans, device);
911 btrfs_end_transaction(trans, root);
914 WARN_ON(diff > old_total);
915 btrfs_set_super_total_bytes(super_copy, old_total - diff);
916 btrfs_end_transaction(trans, root);
918 key.objectid = device->devid;
919 key.offset = (u64)-1;
920 key.type = BTRFS_DEV_EXTENT_KEY;
923 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
927 ret = btrfs_previous_item(root, path, 0, key.type);
936 slot = path->slots[0];
937 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
939 if (key.objectid != device->devid)
942 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
943 length = btrfs_dev_extent_length(l, dev_extent);
945 if (key.offset + length <= new_size)
948 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
949 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
950 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
951 btrfs_release_path(root, path);
953 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
960 btrfs_free_path(path);
964 int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
965 struct btrfs_root *root,
966 struct btrfs_key *key,
967 struct btrfs_chunk *chunk, int item_size)
969 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
970 struct btrfs_disk_key disk_key;
974 array_size = btrfs_super_sys_array_size(super_copy);
975 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
978 ptr = super_copy->sys_chunk_array + array_size;
979 btrfs_cpu_key_to_disk(&disk_key, key);
980 memcpy(ptr, &disk_key, sizeof(disk_key));
981 ptr += sizeof(disk_key);
982 memcpy(ptr, chunk, item_size);
983 item_size += sizeof(disk_key);
984 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
988 static u64 div_factor(u64 num, int factor)
997 static u64 chunk_bytes_by_type(u64 type, u64 calc_size, int num_stripes,
1000 if (type & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_DUP))
1002 else if (type & BTRFS_BLOCK_GROUP_RAID10)
1003 return calc_size * (num_stripes / sub_stripes);
1005 return calc_size * num_stripes;
1009 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
1010 struct btrfs_root *extent_root, u64 *start,
1011 u64 *num_bytes, u64 type)
1014 struct btrfs_fs_info *info = extent_root->fs_info;
1015 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
1016 struct btrfs_path *path;
1017 struct btrfs_stripe *stripes;
1018 struct btrfs_device *device = NULL;
1019 struct btrfs_chunk *chunk;
1020 struct list_head private_devs;
1021 struct list_head *dev_list;
1022 struct list_head *cur;
1023 struct extent_map_tree *em_tree;
1024 struct map_lookup *map;
1025 struct extent_map *em;
1026 int min_stripe_size = 1 * 1024 * 1024;
1028 u64 calc_size = 1024 * 1024 * 1024;
1029 u64 max_chunk_size = calc_size;
1034 int num_stripes = 1;
1035 int min_stripes = 1;
1036 int sub_stripes = 0;
1040 int stripe_len = 64 * 1024;
1041 struct btrfs_key key;
1043 dev_list = &extent_root->fs_info->fs_devices->alloc_list;
1044 if (list_empty(dev_list))
1047 if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
1048 num_stripes = btrfs_super_num_devices(&info->super_copy);
1051 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
1055 if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
1056 num_stripes = min_t(u64, 2,
1057 btrfs_super_num_devices(&info->super_copy));
1058 if (num_stripes < 2)
1062 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1063 num_stripes = btrfs_super_num_devices(&info->super_copy);
1064 if (num_stripes < 4)
1066 num_stripes &= ~(u32)1;
1071 if (type & BTRFS_BLOCK_GROUP_DATA) {
1072 max_chunk_size = 10 * calc_size;
1073 min_stripe_size = 64 * 1024 * 1024;
1074 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
1075 max_chunk_size = 4 * calc_size;
1076 min_stripe_size = 32 * 1024 * 1024;
1077 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1078 calc_size = 8 * 1024 * 1024;
1079 max_chunk_size = calc_size * 2;
1080 min_stripe_size = 1 * 1024 * 1024;
1083 path = btrfs_alloc_path();
1087 /* we don't want a chunk larger than 10% of the FS */
1088 percent_max = div_factor(btrfs_super_total_bytes(&info->super_copy), 1);
1089 max_chunk_size = min(percent_max, max_chunk_size);
1092 if (calc_size * num_stripes > max_chunk_size) {
1093 calc_size = max_chunk_size;
1094 do_div(calc_size, num_stripes);
1095 do_div(calc_size, stripe_len);
1096 calc_size *= stripe_len;
1098 /* we don't want tiny stripes */
1099 calc_size = max_t(u64, min_stripe_size, calc_size);
1101 do_div(calc_size, stripe_len);
1102 calc_size *= stripe_len;
1104 INIT_LIST_HEAD(&private_devs);
1105 cur = dev_list->next;
1108 if (type & BTRFS_BLOCK_GROUP_DUP)
1109 min_free = calc_size * 2;
1111 min_free = calc_size;
1113 /* we add 1MB because we never use the first 1MB of the device */
1114 min_free += 1024 * 1024;
1116 /* build a private list of devices we will allocate from */
1117 while(index < num_stripes) {
1118 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
1120 avail = device->total_bytes - device->bytes_used;
1123 if (avail >= min_free) {
1124 u64 ignored_start = 0;
1125 ret = find_free_dev_extent(trans, device, path,
1129 list_move_tail(&device->dev_alloc_list,
1132 if (type & BTRFS_BLOCK_GROUP_DUP)
1135 } else if (avail > max_avail)
1137 if (cur == dev_list)
1140 if (index < num_stripes) {
1141 list_splice(&private_devs, dev_list);
1142 if (index >= min_stripes) {
1143 num_stripes = index;
1144 if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
1145 num_stripes /= sub_stripes;
1146 num_stripes *= sub_stripes;
1151 if (!looped && max_avail > 0) {
1153 calc_size = max_avail;
1156 btrfs_free_path(path);
1159 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1160 key.type = BTRFS_CHUNK_ITEM_KEY;
1161 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
1164 btrfs_free_path(path);
1168 chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
1170 btrfs_free_path(path);
1174 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1177 btrfs_free_path(path);
1180 btrfs_free_path(path);
1183 stripes = &chunk->stripe;
1184 *num_bytes = chunk_bytes_by_type(type, calc_size,
1185 num_stripes, sub_stripes);
1188 printk("new chunk type %Lu start %Lu size %Lu\n", type, key.offset, *num_bytes);
1189 while(index < num_stripes) {
1190 struct btrfs_stripe *stripe;
1191 BUG_ON(list_empty(&private_devs));
1192 cur = private_devs.next;
1193 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
1195 /* loop over this device again if we're doing a dup group */
1196 if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
1197 (index == num_stripes - 1))
1198 list_move_tail(&device->dev_alloc_list, dev_list);
1200 ret = btrfs_alloc_dev_extent(trans, device,
1201 info->chunk_root->root_key.objectid,
1202 BTRFS_FIRST_CHUNK_TREE_OBJECTID, key.offset,
1203 calc_size, &dev_offset);
1205 printk("alloc chunk start %Lu size %Lu from dev %Lu type %Lu\n", key.offset, calc_size, device->devid, type);
1206 device->bytes_used += calc_size;
1207 ret = btrfs_update_device(trans, device);
1210 map->stripes[index].dev = device;
1211 map->stripes[index].physical = dev_offset;
1212 stripe = stripes + index;
1213 btrfs_set_stack_stripe_devid(stripe, device->devid);
1214 btrfs_set_stack_stripe_offset(stripe, dev_offset);
1215 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
1216 physical = dev_offset;
1219 BUG_ON(!list_empty(&private_devs));
1221 /* key was set above */
1222 btrfs_set_stack_chunk_length(chunk, *num_bytes);
1223 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
1224 btrfs_set_stack_chunk_stripe_len(chunk, stripe_len);
1225 btrfs_set_stack_chunk_type(chunk, type);
1226 btrfs_set_stack_chunk_num_stripes(chunk, num_stripes);
1227 btrfs_set_stack_chunk_io_align(chunk, stripe_len);
1228 btrfs_set_stack_chunk_io_width(chunk, stripe_len);
1229 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
1230 btrfs_set_stack_chunk_sub_stripes(chunk, sub_stripes);
1231 map->sector_size = extent_root->sectorsize;
1232 map->stripe_len = stripe_len;
1233 map->io_align = stripe_len;
1234 map->io_width = stripe_len;
1236 map->num_stripes = num_stripes;
1237 map->sub_stripes = sub_stripes;
1239 ret = btrfs_insert_item(trans, chunk_root, &key, chunk,
1240 btrfs_chunk_item_size(num_stripes));
1242 *start = key.offset;;
1244 em = alloc_extent_map(GFP_NOFS);
1247 em->bdev = (struct block_device *)map;
1248 em->start = key.offset;
1249 em->len = *num_bytes;
1250 em->block_start = 0;
1252 if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
1253 ret = btrfs_add_system_chunk(trans, chunk_root, &key,
1254 chunk, btrfs_chunk_item_size(num_stripes));
1259 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
1260 spin_lock(&em_tree->lock);
1261 ret = add_extent_mapping(em_tree, em);
1262 spin_unlock(&em_tree->lock);
1264 free_extent_map(em);
1268 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
1270 extent_map_tree_init(&tree->map_tree, GFP_NOFS);
1273 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
1275 struct extent_map *em;
1278 spin_lock(&tree->map_tree.lock);
1279 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
1281 remove_extent_mapping(&tree->map_tree, em);
1282 spin_unlock(&tree->map_tree.lock);
1287 free_extent_map(em);
1288 /* once for the tree */
1289 free_extent_map(em);
1293 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
1295 struct extent_map *em;
1296 struct map_lookup *map;
1297 struct extent_map_tree *em_tree = &map_tree->map_tree;
1300 spin_lock(&em_tree->lock);
1301 em = lookup_extent_mapping(em_tree, logical, len);
1302 spin_unlock(&em_tree->lock);
1305 BUG_ON(em->start > logical || em->start + em->len < logical);
1306 map = (struct map_lookup *)em->bdev;
1307 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
1308 ret = map->num_stripes;
1309 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
1310 ret = map->sub_stripes;
1313 free_extent_map(em);
1317 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1318 u64 logical, u64 *length,
1319 struct btrfs_multi_bio **multi_ret,
1320 int mirror_num, struct page *unplug_page)
1322 struct extent_map *em;
1323 struct map_lookup *map;
1324 struct extent_map_tree *em_tree = &map_tree->map_tree;
1328 int stripes_allocated = 8;
1329 int stripes_required = 1;
1333 struct btrfs_multi_bio *multi = NULL;
1335 if (multi_ret && !(rw & (1 << BIO_RW))) {
1336 stripes_allocated = 1;
1340 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
1346 spin_lock(&em_tree->lock);
1347 em = lookup_extent_mapping(em_tree, logical, *length);
1348 spin_unlock(&em_tree->lock);
1350 if (!em && unplug_page)
1354 printk("unable to find logical %Lu\n", logical);
1358 BUG_ON(em->start > logical || em->start + em->len < logical);
1359 map = (struct map_lookup *)em->bdev;
1360 offset = logical - em->start;
1362 if (mirror_num > map->num_stripes)
1365 /* if our multi bio struct is too small, back off and try again */
1366 if (rw & (1 << BIO_RW)) {
1367 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
1368 BTRFS_BLOCK_GROUP_DUP)) {
1369 stripes_required = map->num_stripes;
1370 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1371 stripes_required = map->sub_stripes;
1374 if (multi_ret && rw == WRITE &&
1375 stripes_allocated < stripes_required) {
1376 stripes_allocated = map->num_stripes;
1377 free_extent_map(em);
1383 * stripe_nr counts the total number of stripes we have to stride
1384 * to get to this block
1386 do_div(stripe_nr, map->stripe_len);
1388 stripe_offset = stripe_nr * map->stripe_len;
1389 BUG_ON(offset < stripe_offset);
1391 /* stripe_offset is the offset of this block in its stripe*/
1392 stripe_offset = offset - stripe_offset;
1394 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 |
1395 BTRFS_BLOCK_GROUP_RAID10 |
1396 BTRFS_BLOCK_GROUP_DUP)) {
1397 /* we limit the length of each bio to what fits in a stripe */
1398 *length = min_t(u64, em->len - offset,
1399 map->stripe_len - stripe_offset);
1401 *length = em->len - offset;
1404 if (!multi_ret && !unplug_page)
1409 if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
1410 if (unplug_page || (rw & (1 << BIO_RW)))
1411 num_stripes = map->num_stripes;
1412 else if (mirror_num) {
1413 stripe_index = mirror_num - 1;
1415 u64 orig_stripe_nr = stripe_nr;
1416 stripe_index = do_div(orig_stripe_nr, num_stripes);
1418 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
1419 if (rw & (1 << BIO_RW))
1420 num_stripes = map->num_stripes;
1421 else if (mirror_num)
1422 stripe_index = mirror_num - 1;
1423 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
1424 int factor = map->num_stripes / map->sub_stripes;
1426 stripe_index = do_div(stripe_nr, factor);
1427 stripe_index *= map->sub_stripes;
1429 if (unplug_page || (rw & (1 << BIO_RW)))
1430 num_stripes = map->sub_stripes;
1431 else if (mirror_num)
1432 stripe_index += mirror_num - 1;
1434 u64 orig_stripe_nr = stripe_nr;
1435 stripe_index += do_div(orig_stripe_nr,
1440 * after this do_div call, stripe_nr is the number of stripes
1441 * on this device we have to walk to find the data, and
1442 * stripe_index is the number of our device in the stripe array
1444 stripe_index = do_div(stripe_nr, map->num_stripes);
1446 BUG_ON(stripe_index >= map->num_stripes);
1448 for (i = 0; i < num_stripes; i++) {
1450 struct btrfs_device *device;
1451 struct backing_dev_info *bdi;
1453 device = map->stripes[stripe_index].dev;
1454 bdi = blk_get_backing_dev_info(device->bdev);
1455 if (bdi->unplug_io_fn) {
1456 bdi->unplug_io_fn(bdi, unplug_page);
1459 multi->stripes[i].physical =
1460 map->stripes[stripe_index].physical +
1461 stripe_offset + stripe_nr * map->stripe_len;
1462 multi->stripes[i].dev = map->stripes[stripe_index].dev;
1468 multi->num_stripes = num_stripes;
1471 free_extent_map(em);
1475 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
1476 u64 logical, u64 *length,
1477 struct btrfs_multi_bio **multi_ret, int mirror_num)
1479 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
1483 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
1484 u64 logical, struct page *page)
1486 u64 length = PAGE_CACHE_SIZE;
1487 return __btrfs_map_block(map_tree, READ, logical, &length,
1492 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
1493 static void end_bio_multi_stripe(struct bio *bio, int err)
1495 static int end_bio_multi_stripe(struct bio *bio,
1496 unsigned int bytes_done, int err)
1499 struct btrfs_multi_bio *multi = bio->bi_private;
1501 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1508 if (atomic_dec_and_test(&multi->stripes_pending)) {
1509 bio->bi_private = multi->private;
1510 bio->bi_end_io = multi->end_io;
1512 if (!err && multi->error)
1516 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1517 bio_endio(bio, bio->bi_size, err);
1519 bio_endio(bio, err);
1524 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1529 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
1532 struct btrfs_mapping_tree *map_tree;
1533 struct btrfs_device *dev;
1534 struct bio *first_bio = bio;
1535 u64 logical = bio->bi_sector << 9;
1538 struct btrfs_multi_bio *multi = NULL;
1543 length = bio->bi_size;
1544 map_tree = &root->fs_info->mapping_tree;
1545 map_length = length;
1547 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
1551 total_devs = multi->num_stripes;
1552 if (map_length < length) {
1553 printk("mapping failed logical %Lu bio len %Lu "
1554 "len %Lu\n", logical, length, map_length);
1557 multi->end_io = first_bio->bi_end_io;
1558 multi->private = first_bio->bi_private;
1559 atomic_set(&multi->stripes_pending, multi->num_stripes);
1561 while(dev_nr < total_devs) {
1562 if (total_devs > 1) {
1563 if (dev_nr < total_devs - 1) {
1564 bio = bio_clone(first_bio, GFP_NOFS);
1569 bio->bi_private = multi;
1570 bio->bi_end_io = end_bio_multi_stripe;
1572 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
1573 dev = multi->stripes[dev_nr].dev;
1575 bio->bi_bdev = dev->bdev;
1576 spin_lock(&dev->io_lock);
1578 spin_unlock(&dev->io_lock);
1579 submit_bio(rw, bio);
1582 if (total_devs == 1)
1587 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
1590 struct list_head *head = &root->fs_info->fs_devices->devices;
1592 return __find_device(head, devid, uuid);
1595 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
1596 struct extent_buffer *leaf,
1597 struct btrfs_chunk *chunk)
1599 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
1600 struct map_lookup *map;
1601 struct extent_map *em;
1605 u8 uuid[BTRFS_UUID_SIZE];
1610 logical = key->offset;
1611 length = btrfs_chunk_length(leaf, chunk);
1612 spin_lock(&map_tree->map_tree.lock);
1613 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
1614 spin_unlock(&map_tree->map_tree.lock);
1616 /* already mapped? */
1617 if (em && em->start <= logical && em->start + em->len > logical) {
1618 free_extent_map(em);
1621 free_extent_map(em);
1624 map = kzalloc(sizeof(*map), GFP_NOFS);
1628 em = alloc_extent_map(GFP_NOFS);
1631 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
1632 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
1634 free_extent_map(em);
1638 em->bdev = (struct block_device *)map;
1639 em->start = logical;
1641 em->block_start = 0;
1643 map->num_stripes = num_stripes;
1644 map->io_width = btrfs_chunk_io_width(leaf, chunk);
1645 map->io_align = btrfs_chunk_io_align(leaf, chunk);
1646 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
1647 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
1648 map->type = btrfs_chunk_type(leaf, chunk);
1649 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
1650 for (i = 0; i < num_stripes; i++) {
1651 map->stripes[i].physical =
1652 btrfs_stripe_offset_nr(leaf, chunk, i);
1653 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
1654 read_extent_buffer(leaf, uuid, (unsigned long)
1655 btrfs_stripe_dev_uuid_nr(chunk, i),
1657 map->stripes[i].dev = btrfs_find_device(root, devid, uuid);
1658 if (!map->stripes[i].dev) {
1660 free_extent_map(em);
1665 spin_lock(&map_tree->map_tree.lock);
1666 ret = add_extent_mapping(&map_tree->map_tree, em);
1667 spin_unlock(&map_tree->map_tree.lock);
1669 free_extent_map(em);
1674 static int fill_device_from_item(struct extent_buffer *leaf,
1675 struct btrfs_dev_item *dev_item,
1676 struct btrfs_device *device)
1680 device->devid = btrfs_device_id(leaf, dev_item);
1681 device->total_bytes = btrfs_device_total_bytes(leaf, dev_item);
1682 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
1683 device->type = btrfs_device_type(leaf, dev_item);
1684 device->io_align = btrfs_device_io_align(leaf, dev_item);
1685 device->io_width = btrfs_device_io_width(leaf, dev_item);
1686 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
1688 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1689 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1694 static int read_one_dev(struct btrfs_root *root,
1695 struct extent_buffer *leaf,
1696 struct btrfs_dev_item *dev_item)
1698 struct btrfs_device *device;
1701 u8 dev_uuid[BTRFS_UUID_SIZE];
1703 devid = btrfs_device_id(leaf, dev_item);
1704 read_extent_buffer(leaf, dev_uuid,
1705 (unsigned long)btrfs_device_uuid(dev_item),
1707 device = btrfs_find_device(root, devid, dev_uuid);
1709 printk("warning devid %Lu not found already\n", devid);
1710 device = kzalloc(sizeof(*device), GFP_NOFS);
1713 list_add(&device->dev_list,
1714 &root->fs_info->fs_devices->devices);
1715 list_add(&device->dev_alloc_list,
1716 &root->fs_info->fs_devices->alloc_list);
1717 device->barriers = 1;
1718 spin_lock_init(&device->io_lock);
1721 fill_device_from_item(leaf, dev_item, device);
1722 device->dev_root = root->fs_info->dev_root;
1725 ret = btrfs_open_device(device);
1733 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf)
1735 struct btrfs_dev_item *dev_item;
1737 dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
1739 return read_one_dev(root, buf, dev_item);
1742 int btrfs_read_sys_array(struct btrfs_root *root)
1744 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1745 struct extent_buffer *sb = root->fs_info->sb_buffer;
1746 struct btrfs_disk_key *disk_key;
1747 struct btrfs_chunk *chunk;
1749 unsigned long sb_ptr;
1755 struct btrfs_key key;
1757 array_size = btrfs_super_sys_array_size(super_copy);
1759 ptr = super_copy->sys_chunk_array;
1760 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
1763 while (cur < array_size) {
1764 disk_key = (struct btrfs_disk_key *)ptr;
1765 btrfs_disk_key_to_cpu(&key, disk_key);
1767 len = sizeof(*disk_key);
1772 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1773 chunk = (struct btrfs_chunk *)sb_ptr;
1774 ret = read_one_chunk(root, &key, sb, chunk);
1777 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
1778 len = btrfs_chunk_item_size(num_stripes);
1790 int btrfs_read_chunk_tree(struct btrfs_root *root)
1792 struct btrfs_path *path;
1793 struct extent_buffer *leaf;
1794 struct btrfs_key key;
1795 struct btrfs_key found_key;
1799 root = root->fs_info->chunk_root;
1801 path = btrfs_alloc_path();
1805 /* first we search for all of the device items, and then we
1806 * read in all of the chunk items. This way we can create chunk
1807 * mappings that reference all of the devices that are afound
1809 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1813 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1815 leaf = path->nodes[0];
1816 slot = path->slots[0];
1817 if (slot >= btrfs_header_nritems(leaf)) {
1818 ret = btrfs_next_leaf(root, path);
1825 btrfs_item_key_to_cpu(leaf, &found_key, slot);
1826 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
1827 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
1829 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
1830 struct btrfs_dev_item *dev_item;
1831 dev_item = btrfs_item_ptr(leaf, slot,
1832 struct btrfs_dev_item);
1833 ret = read_one_dev(root, leaf, dev_item);
1836 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
1837 struct btrfs_chunk *chunk;
1838 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
1839 ret = read_one_chunk(root, &found_key, leaf, chunk);
1843 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
1845 btrfs_release_path(root, path);
1849 btrfs_free_path(path);