linux/fs/btrfs/root-tree.c

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/*
* Copyright (C) 2007 Oracle. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include "ctree.h"
#include "transaction.h"
#include "disk-io.h"
#include "print-tree.h"
int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
struct btrfs_root_item *item, struct btrfs_key *key)
{
struct btrfs_path *path;
struct btrfs_key search_key;
struct btrfs_leaf *l;
int ret;
int slot;
search_key.objectid = objectid;
search_key.flags = (u32)-1;
search_key.offset = (u64)-1;
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
l = btrfs_buffer_leaf(path->nodes[0]);
BUG_ON(path->slots[0] == 0);
slot = path->slots[0] - 1;
if (btrfs_disk_key_objectid(&l->items[slot].key) != objectid) {
ret = 1;
goto out;
}
memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
sizeof(*item));
btrfs_disk_key_to_cpu(key, &l->items[slot].key);
ret = 0;
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}
int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_key *key, struct btrfs_root_item
*item)
{
struct btrfs_path *path;
struct btrfs_leaf *l;
int ret;
int slot;
struct btrfs_root_item *update_item;
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_search_slot(trans, root, key, path, 0, 1);
if (ret < 0)
goto out;
BUG_ON(ret != 0);
l = btrfs_buffer_leaf(path->nodes[0]);
slot = path->slots[0];
update_item = btrfs_item_ptr(l, slot, struct btrfs_root_item);
btrfs_memcpy(root, l, update_item, item, sizeof(*item));
btrfs_mark_buffer_dirty(path->nodes[0]);
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}
int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
*root, struct btrfs_key *key, struct btrfs_root_item
*item)
{
int ret;
ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
return ret;
}
int btrfs_find_dead_roots(struct btrfs_root *root)
{
struct btrfs_root *dead_root;
struct btrfs_item *item;
struct btrfs_root_item *ri;
struct btrfs_key key;
struct btrfs_path *path;
int ret;
u32 nritems;
struct btrfs_leaf *leaf;
int slot;
key.objectid = 0;
key.flags = 0;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
key.offset = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
while(1) {
leaf = btrfs_buffer_leaf(path->nodes[0]);
nritems = btrfs_header_nritems(&leaf->header);
slot = path->slots[0];
if (slot >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
break;
leaf = btrfs_buffer_leaf(path->nodes[0]);
nritems = btrfs_header_nritems(&leaf->header);
slot = path->slots[0];
}
item = leaf->items + slot;
btrfs_disk_key_to_cpu(&key, &item->key);
if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
goto next;
ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
if (btrfs_root_refs(ri) != 0)
goto next;
dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
if (IS_ERR(dead_root)) {
ret = PTR_ERR(dead_root);
goto err;
}
ret = btrfs_add_dead_root(dead_root,
&root->fs_info->dead_roots);
if (ret)
goto err;
next:
slot++;
path->slots[0]++;
}
ret = 0;
err:
btrfs_free_path(path);
return ret;
}
int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_key *key)
{
struct btrfs_path *path;
int ret;
u32 refs;
struct btrfs_root_item *ri;
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_search_slot(trans, root, key, path, -1, 1);
if (ret < 0)
goto out;
BUG_ON(ret != 0);
ri = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
path->slots[0], struct btrfs_root_item);
refs = btrfs_root_refs(ri);
BUG_ON(refs != 0);
ret = btrfs_del_item(trans, root, path);
out:
btrfs_release_path(root, path);
btrfs_free_path(path);
return ret;
}