fs/btrfs/root-tree.c

   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
  19 #include "ctree.h"
  20 #include "transaction.h"
  21 #include "disk-io.h"
  22 #include "print-tree.h"
  23
  24 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
  25                         struct btrfs_root_item *item, struct btrfs_key *key)
  26 {
  27         struct btrfs_path *path;
  28         struct btrfs_key search_key;
  29         struct btrfs_leaf *l;
  30         int ret;
  31         int slot;
  32
  33         search_key.objectid = objectid;
  34         search_key.flags = (u32)-1;
  35         search_key.offset = (u64)-1;
  36
  37         path = btrfs_alloc_path();
  38         BUG_ON(!path);
  39         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
  40         if (ret < 0)
  41                 goto out;
  42         BUG_ON(ret == 0);
  43         l = btrfs_buffer_leaf(path->nodes[0]);
  44         BUG_ON(path->slots[0] == 0);
  45         slot = path->slots[0] - 1;
  46         if (btrfs_disk_key_objectid(&l->items[slot].key) != objectid) {
  47                 ret = 1;
  48                 goto out;
  49         }
  50         memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
  51                 sizeof(*item));
  52         btrfs_disk_key_to_cpu(key, &l->items[slot].key);
  53         ret = 0;
  54 out:
  55         btrfs_release_path(root, path);
  56         btrfs_free_path(path);
  57         return ret;
  58 }
  59
  60 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
  61                       *root, struct btrfs_key *key, struct btrfs_root_item
  62                       *item)
  63 {
  64         struct btrfs_path *path;
  65         struct btrfs_leaf *l;
  66         int ret;
  67         int slot;
  68         struct btrfs_root_item *update_item;
  69
  70         path = btrfs_alloc_path();
  71         BUG_ON(!path);
  72         ret = btrfs_search_slot(trans, root, key, path, 0, 1);
  73         if (ret < 0)
  74                 goto out;
  75         BUG_ON(ret != 0);
  76         l = btrfs_buffer_leaf(path->nodes[0]);
  77         slot = path->slots[0];
  78         update_item = btrfs_item_ptr(l, slot, struct btrfs_root_item);
  79         btrfs_memcpy(root, l, update_item, item, sizeof(*item));
  80         btrfs_mark_buffer_dirty(path->nodes[0]);
  81 out:
  82         btrfs_release_path(root, path);
  83         btrfs_free_path(path);
  84         return ret;
  85 }
  86
  87 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
  88                       *root, struct btrfs_key *key, struct btrfs_root_item
  89                       *item)
  90 {
  91         int ret;
  92         ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
  93         return ret;
  94 }
  95
  96 int btrfs_find_dead_roots(struct btrfs_root *root)
  97 {
  98         struct btrfs_root *dead_root;
  99         struct btrfs_item *item;
 100         struct btrfs_root_item *ri;
 101         struct btrfs_key key;
 102         struct btrfs_path *path;
 103         int ret;
 104         u32 nritems;
 105         struct btrfs_leaf *leaf;
 106         int slot;
 107
 108         key.objectid = 0;
 109         key.flags = 0;
 110         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 111         key.offset = 0;
 112         path = btrfs_alloc_path();
 113         if (!path)
 114                 return -ENOMEM;
 115         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 116         if (ret < 0)
 117                 goto err;
 118         while(1) {
 119                 leaf = btrfs_buffer_leaf(path->nodes[0]);
 120                 nritems = btrfs_header_nritems(&leaf->header);
 121                 slot = path->slots[0];
 122                 if (slot >= nritems) {
 123                         ret = btrfs_next_leaf(root, path);
 124                         if (ret)
 125                                 break;
 126                         leaf = btrfs_buffer_leaf(path->nodes[0]);
 127                         nritems = btrfs_header_nritems(&leaf->header);
 128                         slot = path->slots[0];
 129                 }
 130                 item = leaf->items + slot;
 131                 btrfs_disk_key_to_cpu(&key, &item->key);
 132                 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
 133                         goto next;
 134                 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
 135                 if (btrfs_root_refs(ri) != 0)
 136                         goto next;
 137                 dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
 138                 if (IS_ERR(root)) {
 139                         ret = PTR_ERR(root);
 140                         goto err;
 141                 }
 142                 ret = btrfs_add_dead_root(dead_root,
 143                                           &root->fs_info->dead_roots);
 144                 if (ret)
 145                         goto err;
 146 next:
 147                 slot++;
 148                 path->slots[0]++;
 149         }
 150         ret = 0;
 151 err:
 152         btrfs_free_path(path);
 153         return ret;
 154 }
 155
 156 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 157                    struct btrfs_key *key)
 158 {
 159         struct btrfs_path *path;
 160         int ret;
 161         u32 refs;
 162         struct btrfs_root_item *ri;
 163
 164         path = btrfs_alloc_path();
 165         BUG_ON(!path);
 166         ret = btrfs_search_slot(trans, root, key, path, -1, 1);
 167         if (ret < 0)
 168                 goto out;
 169         BUG_ON(ret != 0);
 170         ri = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
 171                             path->slots[0], struct btrfs_root_item);
 172
 173         refs = btrfs_root_refs(ri);
 174         BUG_ON(refs != 0);
 175         ret = btrfs_del_item(trans, root, path);
 176 out:
 177         btrfs_release_path(root, path);
 178         btrfs_free_path(path);
 179         return ret;
 180 }