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_key found_key;
  30         struct extent_buffer *l;
  31         int ret;
  32         int slot;
  33
  34         search_key.objectid = objectid;
  35         search_key.type = (u8)-1;
  36         search_key.offset = (u64)-1;
  37
  38         path = btrfs_alloc_path();
  39         BUG_ON(!path);
  40         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
  41         if (ret < 0)
  42                 goto out;
  43
  44         BUG_ON(ret == 0);
  45         l = path->nodes[0];
  46         BUG_ON(path->slots[0] == 0);
  47         slot = path->slots[0] - 1;
  48         btrfs_item_key_to_cpu(l, &found_key, slot);
  49         if (found_key.objectid != objectid) {
  50                 ret = 1;
  51                 goto out;
  52         }
  53         read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
  54                            sizeof(*item));
  55         memcpy(key, &found_key, sizeof(found_key));
  56         ret = 0;
  57 out:
  58         btrfs_release_path(root, path);
  59         btrfs_free_path(path);
  60         return ret;
  61 }
  62
  63 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
  64                       *root, struct btrfs_key *key, struct btrfs_root_item
  65                       *item)
  66 {
  67         struct btrfs_path *path;
  68         struct extent_buffer *l;
  69         int ret;
  70         int slot;
  71         unsigned long ptr;
  72
  73         path = btrfs_alloc_path();
  74         BUG_ON(!path);
  75         ret = btrfs_search_slot(trans, root, key, path, 0, 1);
  76         if (ret < 0)
  77                 goto out;
  78         BUG_ON(ret != 0);
  79         l = path->nodes[0];
  80         slot = path->slots[0];
  81         ptr = btrfs_item_ptr_offset(l, slot);
  82         write_extent_buffer(l, item, ptr, sizeof(*item));
  83         btrfs_mark_buffer_dirty(path->nodes[0]);
  84 out:
  85         btrfs_release_path(root, path);
  86         btrfs_free_path(path);
  87         return ret;
  88 }
  89
  90 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
  91                       *root, struct btrfs_key *key, struct btrfs_root_item
  92                       *item)
  93 {
  94         int ret;
  95         ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
  96         return ret;
  97 }
  98
  99 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
 100                           struct btrfs_root *latest)
 101 {
 102         struct btrfs_root *dead_root;
 103         struct btrfs_item *item;
 104         struct btrfs_root_item *ri;
 105         struct btrfs_key key;
 106         struct btrfs_path *path;
 107         int ret;
 108         u32 nritems;
 109         struct extent_buffer *leaf;
 110         int slot;
 111
 112         key.objectid = objectid;
 113         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 114         key.offset = 0;
 115         path = btrfs_alloc_path();
 116         if (!path)
 117                 return -ENOMEM;
 118         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 119         if (ret < 0)
 120                 goto err;
 121         while(1) {
 122                 leaf = path->nodes[0];
 123                 nritems = btrfs_header_nritems(leaf);
 124                 slot = path->slots[0];
 125                 if (slot >= nritems) {
 126                         ret = btrfs_next_leaf(root, path);
 127                         if (ret)
 128                                 break;
 129                         leaf = path->nodes[0];
 130                         nritems = btrfs_header_nritems(leaf);
 131                         slot = path->slots[0];
 132                 }
 133                 item = btrfs_item_nr(leaf, slot);
 134                 btrfs_item_key_to_cpu(leaf, &key, slot);
 135                 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
 136                         goto next;
 137
 138                 if (key.objectid < objectid)
 139                         goto next;
 140
 141                 if (key.objectid > objectid)
 142                         break;
 143
 144                 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
 145                 if (btrfs_disk_root_refs(leaf, ri) != 0)
 146                         goto next;
 147
 148                 dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
 149                 if (IS_ERR(dead_root)) {
 150                         ret = PTR_ERR(dead_root);
 151                         goto err;
 152                 }
 153
 154                 ret = btrfs_add_dead_root(dead_root, latest,
 155                                           &root->fs_info->dead_roots);
 156                 if (ret)
 157                         goto err;
 158 next:
 159                 slot++;
 160                 path->slots[0]++;
 161         }
 162         ret = 0;
 163 err:
 164         btrfs_free_path(path);
 165         return ret;
 166 }
 167
 168 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 169                    struct btrfs_key *key)
 170 {
 171         struct btrfs_path *path;
 172         int ret;
 173         u32 refs;
 174         struct btrfs_root_item *ri;
 175         struct extent_buffer *leaf;
 176
 177         path = btrfs_alloc_path();
 178         BUG_ON(!path);
 179         ret = btrfs_search_slot(trans, root, key, path, -1, 1);
 180         if (ret < 0)
 181                 goto out;
 182         if (ret) {
 183 btrfs_print_leaf(root, path->nodes[0]);
 184 printk("failed to del %Lu %u %Lu\n", key->objectid, key->type, key->offset);
 185
 186         }
 187         BUG_ON(ret != 0);
 188         leaf = path->nodes[0];
 189         ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
 190
 191         refs = btrfs_disk_root_refs(leaf, ri);
 192         BUG_ON(refs != 0);
 193         ret = btrfs_del_item(trans, root, path);
 194 out:
 195         btrfs_release_path(root, path);
 196         btrfs_free_path(path);
 197         return ret;
 198 }