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 /*
  25  * returns 0 on finding something, 1 if no more roots are there
  26  * and < 0 on error
  27  */
  28 int btrfs_search_root(struct btrfs_root *root, u64 search_start,
  29                       u64 *found_objectid)
  30 {
  31         struct btrfs_path *path;
  32         struct btrfs_key search_key;
  33         int ret;
  34
  35         root = root->fs_info->tree_root;
  36         search_key.objectid = search_start;
  37         search_key.type = (u8)-1;
  38         search_key.offset = (u64)-1;
  39
  40         path = btrfs_alloc_path();
  41         BUG_ON(!path);
  42 again:
  43         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
  44         if (ret < 0)
  45                 goto out;
  46         if (ret == 0) {
  47                 ret = 1;
  48                 goto out;
  49         }
  50         if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
  51                 ret = btrfs_next_leaf(root, path);
  52                 if (ret)
  53                         goto out;
  54         }
  55         btrfs_item_key_to_cpu(path->nodes[0], &search_key, path->slots[0]);
  56         if (search_key.type != BTRFS_ROOT_ITEM_KEY) {
  57                 search_key.offset++;
  58                 btrfs_release_path(root, path);
  59                 goto again;
  60         }
  61         ret = 0;
  62         *found_objectid = search_key.objectid;
  63
  64 out:
  65         btrfs_free_path(path);
  66         return ret;
  67 }
  68
  69 int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
  70                         struct btrfs_root_item *item, struct btrfs_key *key)
  71 {
  72         struct btrfs_path *path;
  73         struct btrfs_key search_key;
  74         struct btrfs_key found_key;
  75         struct extent_buffer *l;
  76         int ret;
  77         int slot;
  78
  79         search_key.objectid = objectid;
  80         search_key.type = (u8)-1;
  81         search_key.offset = (u64)-1;
  82
  83         path = btrfs_alloc_path();
  84         BUG_ON(!path);
  85         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
  86         if (ret < 0)
  87                 goto out;
  88
  89         BUG_ON(ret == 0);
  90         l = path->nodes[0];
  91         BUG_ON(path->slots[0] == 0);
  92         slot = path->slots[0] - 1;
  93         btrfs_item_key_to_cpu(l, &found_key, slot);
  94         if (found_key.objectid != objectid) {
  95                 ret = 1;
  96                 goto out;
  97         }
  98         read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
  99                            sizeof(*item));
 100         memcpy(key, &found_key, sizeof(found_key));
 101         ret = 0;
 102 out:
 103         btrfs_free_path(path);
 104         return ret;
 105 }
 106
 107 int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
 108                       *root, struct btrfs_key *key, struct btrfs_root_item
 109                       *item)
 110 {
 111         struct btrfs_path *path;
 112         struct extent_buffer *l;
 113         int ret;
 114         int slot;
 115         unsigned long ptr;
 116
 117         path = btrfs_alloc_path();
 118         BUG_ON(!path);
 119         ret = btrfs_search_slot(trans, root, key, path, 0, 1);
 120         if (ret < 0)
 121                 goto out;
 122
 123         if (ret != 0) {
 124                 btrfs_print_leaf(root, path->nodes[0]);
 125                 printk("unable to update root key %Lu %u %Lu\n",
 126                        key->objectid, key->type, key->offset);
 127                 BUG_ON(1);
 128         }
 129
 130         l = path->nodes[0];
 131         slot = path->slots[0];
 132         ptr = btrfs_item_ptr_offset(l, slot);
 133         write_extent_buffer(l, item, ptr, sizeof(*item));
 134         btrfs_mark_buffer_dirty(path->nodes[0]);
 135 out:
 136         btrfs_release_path(root, path);
 137         btrfs_free_path(path);
 138         return ret;
 139 }
 140
 141 int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
 142                       *root, struct btrfs_key *key, struct btrfs_root_item
 143                       *item)
 144 {
 145         int ret;
 146         ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
 147         return ret;
 148 }
 149
 150 int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
 151                           struct btrfs_root *latest)
 152 {
 153         struct btrfs_root *dead_root;
 154         struct btrfs_item *item;
 155         struct btrfs_root_item *ri;
 156         struct btrfs_key key;
 157         struct btrfs_key found_key;
 158         struct btrfs_path *path;
 159         int ret;
 160         u32 nritems;
 161         struct extent_buffer *leaf;
 162         int slot;
 163
 164         key.objectid = objectid;
 165         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
 166         key.offset = 0;
 167         path = btrfs_alloc_path();
 168         if (!path)
 169                 return -ENOMEM;
 170
 171 again:
 172         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 173         if (ret < 0)
 174                 goto err;
 175         while(1) {
 176                 leaf = path->nodes[0];
 177                 nritems = btrfs_header_nritems(leaf);
 178                 slot = path->slots[0];
 179                 if (slot >= nritems) {
 180                         ret = btrfs_next_leaf(root, path);
 181                         if (ret)
 182                                 break;
 183                         leaf = path->nodes[0];
 184                         nritems = btrfs_header_nritems(leaf);
 185                         slot = path->slots[0];
 186                 }
 187                 item = btrfs_item_nr(leaf, slot);
 188                 btrfs_item_key_to_cpu(leaf, &key, slot);
 189                 if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
 190                         goto next;
 191
 192                 if (key.objectid < objectid)
 193                         goto next;
 194
 195                 if (key.objectid > objectid)
 196                         break;
 197
 198                 ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
 199                 if (btrfs_disk_root_refs(leaf, ri) != 0)
 200                         goto next;
 201
 202                 memcpy(&found_key, &key, sizeof(key));
 203                 key.offset++;
 204                 btrfs_release_path(root, path);
 205                 dead_root = btrfs_read_fs_root_no_radix(root->fs_info,
 206                                                         &found_key);
 207                 if (IS_ERR(dead_root)) {
 208                         ret = PTR_ERR(dead_root);
 209                         goto err;
 210                 }
 211
 212                 ret = btrfs_add_dead_root(dead_root, latest,
 213                                           &root->fs_info->dead_roots);
 214                 if (ret)
 215                         goto err;
 216                 goto again;
 217 next:
 218                 slot++;
 219                 path->slots[0]++;
 220         }
 221         ret = 0;
 222 err:
 223         btrfs_free_path(path);
 224         return ret;
 225 }
 226
 227 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 228                    struct btrfs_key *key)
 229 {
 230         struct btrfs_path *path;
 231         int ret;
 232         u32 refs;
 233         struct btrfs_root_item *ri;
 234         struct extent_buffer *leaf;
 235
 236         path = btrfs_alloc_path();
 237         BUG_ON(!path);
 238         ret = btrfs_search_slot(trans, root, key, path, -1, 1);
 239         if (ret < 0)
 240                 goto out;
 241         if (ret) {
 242 btrfs_print_leaf(root, path->nodes[0]);
 243 printk("failed to del %Lu %u %Lu\n", key->objectid, key->type, key->offset);
 244
 245         }
 246         BUG_ON(ret != 0);
 247         leaf = path->nodes[0];
 248         ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
 249
 250         refs = btrfs_disk_root_refs(leaf, ri);
 251         BUG_ON(refs != 0);
 252         ret = btrfs_del_item(trans, root, path);
 253 out:
 254         btrfs_release_path(root, path);
 255         btrfs_free_path(path);
 256         return ret;
 257 }