Chris Mason | 6cbd557 | 2007-06-12 09:07:21 -0400 | [diff] [blame] | 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 | |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 19 | #include "ctree.h" |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 20 | #include "transaction.h" |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 21 | #include "disk-io.h" |
| 22 | #include "print-tree.h" |
| 23 | |
Chris Mason | bf4ef67 | 2008-05-08 13:26:18 -0400 | [diff] [blame] | 24 | /* |
Chris Mason | d352ac6 | 2008-09-29 15:18:18 -0400 | [diff] [blame] | 25 | * search forward for a root, starting with objectid 'search_start' |
| 26 | * if a root key is found, the objectid we find is filled into 'found_objectid' |
| 27 | * and 0 is returned. < 0 is returned on error, 1 if there is nothing |
| 28 | * left in the tree. |
Chris Mason | bf4ef67 | 2008-05-08 13:26:18 -0400 | [diff] [blame] | 29 | */ |
| 30 | int btrfs_search_root(struct btrfs_root *root, u64 search_start, |
| 31 | u64 *found_objectid) |
| 32 | { |
| 33 | struct btrfs_path *path; |
| 34 | struct btrfs_key search_key; |
| 35 | int ret; |
| 36 | |
| 37 | root = root->fs_info->tree_root; |
| 38 | search_key.objectid = search_start; |
| 39 | search_key.type = (u8)-1; |
| 40 | search_key.offset = (u64)-1; |
| 41 | |
| 42 | path = btrfs_alloc_path(); |
| 43 | BUG_ON(!path); |
| 44 | again: |
| 45 | ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); |
| 46 | if (ret < 0) |
| 47 | goto out; |
| 48 | if (ret == 0) { |
| 49 | ret = 1; |
| 50 | goto out; |
| 51 | } |
| 52 | if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { |
| 53 | ret = btrfs_next_leaf(root, path); |
| 54 | if (ret) |
| 55 | goto out; |
| 56 | } |
| 57 | btrfs_item_key_to_cpu(path->nodes[0], &search_key, path->slots[0]); |
| 58 | if (search_key.type != BTRFS_ROOT_ITEM_KEY) { |
| 59 | search_key.offset++; |
| 60 | btrfs_release_path(root, path); |
| 61 | goto again; |
| 62 | } |
| 63 | ret = 0; |
| 64 | *found_objectid = search_key.objectid; |
| 65 | |
| 66 | out: |
| 67 | btrfs_free_path(path); |
| 68 | return ret; |
| 69 | } |
| 70 | |
Chris Mason | d352ac6 | 2008-09-29 15:18:18 -0400 | [diff] [blame] | 71 | /* |
| 72 | * lookup the root with the highest offset for a given objectid. The key we do |
| 73 | * find is copied into 'key'. If we find something return 0, otherwise 1, < 0 |
| 74 | * on error. |
| 75 | */ |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 76 | int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, |
| 77 | struct btrfs_root_item *item, struct btrfs_key *key) |
| 78 | { |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 79 | struct btrfs_path *path; |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 80 | struct btrfs_key search_key; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 81 | struct btrfs_key found_key; |
| 82 | struct extent_buffer *l; |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 83 | int ret; |
| 84 | int slot; |
| 85 | |
| 86 | search_key.objectid = objectid; |
Chris Mason | 0660b5a | 2008-11-17 20:37:39 -0500 | [diff] [blame] | 87 | search_key.type = BTRFS_ROOT_ITEM_KEY; |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 88 | search_key.offset = (u64)-1; |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 89 | |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 90 | path = btrfs_alloc_path(); |
| 91 | BUG_ON(!path); |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 92 | ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 93 | if (ret < 0) |
| 94 | goto out; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 95 | |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 96 | BUG_ON(ret == 0); |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 97 | l = path->nodes[0]; |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 98 | BUG_ON(path->slots[0] == 0); |
| 99 | slot = path->slots[0] - 1; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 100 | btrfs_item_key_to_cpu(l, &found_key, slot); |
| 101 | if (found_key.objectid != objectid) { |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 102 | ret = 1; |
| 103 | goto out; |
| 104 | } |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 105 | read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot), |
| 106 | sizeof(*item)); |
| 107 | memcpy(key, &found_key, sizeof(found_key)); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 108 | ret = 0; |
| 109 | out: |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 110 | btrfs_free_path(path); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 111 | return ret; |
| 112 | } |
| 113 | |
Chris Mason | d352ac6 | 2008-09-29 15:18:18 -0400 | [diff] [blame] | 114 | /* |
| 115 | * copy the data in 'item' into the btree |
| 116 | */ |
Chris Mason | e089f05 | 2007-03-16 16:20:31 -0400 | [diff] [blame] | 117 | int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root |
| 118 | *root, struct btrfs_key *key, struct btrfs_root_item |
| 119 | *item) |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 120 | { |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 121 | struct btrfs_path *path; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 122 | struct extent_buffer *l; |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 123 | int ret; |
| 124 | int slot; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 125 | unsigned long ptr; |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 126 | |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 127 | path = btrfs_alloc_path(); |
| 128 | BUG_ON(!path); |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 129 | ret = btrfs_search_slot(trans, root, key, path, 0, 1); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 130 | if (ret < 0) |
| 131 | goto out; |
Chris Mason | d666746 | 2008-01-03 14:51:00 -0500 | [diff] [blame] | 132 | |
| 133 | if (ret != 0) { |
| 134 | btrfs_print_leaf(root, path->nodes[0]); |
Chris Mason | d397712 | 2009-01-05 21:25:51 -0500 | [diff] [blame^] | 135 | printk(KERN_CRIT "unable to update root key %llu %u %llu\n", |
| 136 | (unsigned long long)key->objectid, key->type, |
| 137 | (unsigned long long)key->offset); |
Chris Mason | d666746 | 2008-01-03 14:51:00 -0500 | [diff] [blame] | 138 | BUG_ON(1); |
| 139 | } |
| 140 | |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 141 | l = path->nodes[0]; |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 142 | slot = path->slots[0]; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 143 | ptr = btrfs_item_ptr_offset(l, slot); |
| 144 | write_extent_buffer(l, item, ptr, sizeof(*item)); |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 145 | btrfs_mark_buffer_dirty(path->nodes[0]); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 146 | out: |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 147 | btrfs_release_path(root, path); |
| 148 | btrfs_free_path(path); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 149 | return ret; |
| 150 | } |
| 151 | |
Chris Mason | e089f05 | 2007-03-16 16:20:31 -0400 | [diff] [blame] | 152 | int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root |
| 153 | *root, struct btrfs_key *key, struct btrfs_root_item |
| 154 | *item) |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 155 | { |
| 156 | int ret; |
Chris Mason | e089f05 | 2007-03-16 16:20:31 -0400 | [diff] [blame] | 157 | ret = btrfs_insert_item(trans, root, key, item, sizeof(*item)); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 158 | return ret; |
| 159 | } |
| 160 | |
Chris Mason | d352ac6 | 2008-09-29 15:18:18 -0400 | [diff] [blame] | 161 | /* |
| 162 | * at mount time we want to find all the old transaction snapshots that were in |
Chris Mason | d397712 | 2009-01-05 21:25:51 -0500 | [diff] [blame^] | 163 | * the process of being deleted if we crashed. This is any root item with an |
| 164 | * offset lower than the latest root. They need to be queued for deletion to |
| 165 | * finish what was happening when we crashed. |
Chris Mason | d352ac6 | 2008-09-29 15:18:18 -0400 | [diff] [blame] | 166 | */ |
Chris Mason | 5ce14bb | 2007-09-11 11:15:39 -0400 | [diff] [blame] | 167 | int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid, |
| 168 | struct btrfs_root *latest) |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 169 | { |
| 170 | struct btrfs_root *dead_root; |
| 171 | struct btrfs_item *item; |
| 172 | struct btrfs_root_item *ri; |
| 173 | struct btrfs_key key; |
Chris Mason | a7a16fd | 2008-06-26 10:34:20 -0400 | [diff] [blame] | 174 | struct btrfs_key found_key; |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 175 | struct btrfs_path *path; |
| 176 | int ret; |
| 177 | u32 nritems; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 178 | struct extent_buffer *leaf; |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 179 | int slot; |
| 180 | |
Chris Mason | 5ce14bb | 2007-09-11 11:15:39 -0400 | [diff] [blame] | 181 | key.objectid = objectid; |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 182 | btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); |
| 183 | key.offset = 0; |
| 184 | path = btrfs_alloc_path(); |
| 185 | if (!path) |
| 186 | return -ENOMEM; |
Chris Mason | a7a16fd | 2008-06-26 10:34:20 -0400 | [diff] [blame] | 187 | |
| 188 | again: |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 189 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| 190 | if (ret < 0) |
| 191 | goto err; |
Chris Mason | d397712 | 2009-01-05 21:25:51 -0500 | [diff] [blame^] | 192 | while (1) { |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 193 | leaf = path->nodes[0]; |
| 194 | nritems = btrfs_header_nritems(leaf); |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 195 | slot = path->slots[0]; |
| 196 | if (slot >= nritems) { |
| 197 | ret = btrfs_next_leaf(root, path); |
| 198 | if (ret) |
| 199 | break; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 200 | leaf = path->nodes[0]; |
| 201 | nritems = btrfs_header_nritems(leaf); |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 202 | slot = path->slots[0]; |
| 203 | } |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 204 | item = btrfs_item_nr(leaf, slot); |
| 205 | btrfs_item_key_to_cpu(leaf, &key, slot); |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 206 | if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY) |
| 207 | goto next; |
Chris Mason | 5ce14bb | 2007-09-11 11:15:39 -0400 | [diff] [blame] | 208 | |
| 209 | if (key.objectid < objectid) |
| 210 | goto next; |
| 211 | |
| 212 | if (key.objectid > objectid) |
| 213 | break; |
| 214 | |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 215 | ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item); |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 216 | if (btrfs_disk_root_refs(leaf, ri) != 0) |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 217 | goto next; |
Chris Mason | 5ce14bb | 2007-09-11 11:15:39 -0400 | [diff] [blame] | 218 | |
Chris Mason | a7a16fd | 2008-06-26 10:34:20 -0400 | [diff] [blame] | 219 | memcpy(&found_key, &key, sizeof(key)); |
| 220 | key.offset++; |
| 221 | btrfs_release_path(root, path); |
Chris Mason | e02119d | 2008-09-05 16:13:11 -0400 | [diff] [blame] | 222 | dead_root = |
| 223 | btrfs_read_fs_root_no_radix(root->fs_info->tree_root, |
| 224 | &found_key); |
Aneesh | a1f3963 | 2007-07-11 10:03:27 -0400 | [diff] [blame] | 225 | if (IS_ERR(dead_root)) { |
| 226 | ret = PTR_ERR(dead_root); |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 227 | goto err; |
| 228 | } |
Chris Mason | 5ce14bb | 2007-09-11 11:15:39 -0400 | [diff] [blame] | 229 | |
Zheng Yan | 1a40e23 | 2008-09-26 10:09:34 -0400 | [diff] [blame] | 230 | if (objectid == BTRFS_TREE_RELOC_OBJECTID) |
| 231 | ret = btrfs_add_dead_reloc_root(dead_root); |
| 232 | else |
| 233 | ret = btrfs_add_dead_root(dead_root, latest); |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 234 | if (ret) |
| 235 | goto err; |
Chris Mason | a7a16fd | 2008-06-26 10:34:20 -0400 | [diff] [blame] | 236 | goto again; |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 237 | next: |
| 238 | slot++; |
| 239 | path->slots[0]++; |
| 240 | } |
| 241 | ret = 0; |
| 242 | err: |
| 243 | btrfs_free_path(path); |
| 244 | return ret; |
| 245 | } |
| 246 | |
Chris Mason | d352ac6 | 2008-09-29 15:18:18 -0400 | [diff] [blame] | 247 | /* drop the root item for 'key' from 'root' */ |
Chris Mason | e089f05 | 2007-03-16 16:20:31 -0400 | [diff] [blame] | 248 | int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| 249 | struct btrfs_key *key) |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 250 | { |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 251 | struct btrfs_path *path; |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 252 | int ret; |
Chris Mason | c5739bb | 2007-04-10 09:27:04 -0400 | [diff] [blame] | 253 | u32 refs; |
| 254 | struct btrfs_root_item *ri; |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 255 | struct extent_buffer *leaf; |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 256 | |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 257 | path = btrfs_alloc_path(); |
| 258 | BUG_ON(!path); |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 259 | ret = btrfs_search_slot(trans, root, key, path, -1, 1); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 260 | if (ret < 0) |
| 261 | goto out; |
Chris Mason | edbd8d4 | 2007-12-21 16:27:24 -0500 | [diff] [blame] | 262 | |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 263 | BUG_ON(ret != 0); |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 264 | leaf = path->nodes[0]; |
| 265 | ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item); |
Chris Mason | c5739bb | 2007-04-10 09:27:04 -0400 | [diff] [blame] | 266 | |
Chris Mason | 5f39d39 | 2007-10-15 16:14:19 -0400 | [diff] [blame] | 267 | refs = btrfs_disk_root_refs(leaf, ri); |
Chris Mason | 5eda7b5 | 2007-06-22 14:16:25 -0400 | [diff] [blame] | 268 | BUG_ON(refs != 0); |
| 269 | ret = btrfs_del_item(trans, root, path); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 270 | out: |
Chris Mason | 5caf2a0 | 2007-04-02 11:20:42 -0400 | [diff] [blame] | 271 | btrfs_release_path(root, path); |
| 272 | btrfs_free_path(path); |
Chris Mason | 3768f36 | 2007-03-13 16:47:54 -0400 | [diff] [blame] | 273 | return ret; |
| 274 | } |
Chris Mason | 0660b5a | 2008-11-17 20:37:39 -0500 | [diff] [blame] | 275 | |
Christoph Hellwig | b295086 | 2008-12-02 09:54:17 -0500 | [diff] [blame] | 276 | #if 0 /* this will get used when snapshot deletion is implemented */ |
Chris Mason | 0660b5a | 2008-11-17 20:37:39 -0500 | [diff] [blame] | 277 | int btrfs_del_root_ref(struct btrfs_trans_handle *trans, |
| 278 | struct btrfs_root *tree_root, |
| 279 | u64 root_id, u8 type, u64 ref_id) |
| 280 | { |
| 281 | struct btrfs_key key; |
| 282 | int ret; |
| 283 | struct btrfs_path *path; |
| 284 | |
| 285 | path = btrfs_alloc_path(); |
| 286 | |
| 287 | key.objectid = root_id; |
| 288 | key.type = type; |
| 289 | key.offset = ref_id; |
| 290 | |
| 291 | ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); |
| 292 | BUG_ON(ret); |
| 293 | |
| 294 | ret = btrfs_del_item(trans, tree_root, path); |
| 295 | BUG_ON(ret); |
| 296 | |
| 297 | btrfs_free_path(path); |
| 298 | return ret; |
| 299 | } |
Christoph Hellwig | b295086 | 2008-12-02 09:54:17 -0500 | [diff] [blame] | 300 | #endif |
Chris Mason | 0660b5a | 2008-11-17 20:37:39 -0500 | [diff] [blame] | 301 | |
Chris Mason | ea9e8b1 | 2008-11-17 21:14:24 -0500 | [diff] [blame] | 302 | int btrfs_find_root_ref(struct btrfs_root *tree_root, |
| 303 | struct btrfs_path *path, |
| 304 | u64 root_id, u64 ref_id) |
| 305 | { |
| 306 | struct btrfs_key key; |
| 307 | int ret; |
| 308 | |
| 309 | key.objectid = root_id; |
| 310 | key.type = BTRFS_ROOT_REF_KEY; |
| 311 | key.offset = ref_id; |
| 312 | |
| 313 | ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); |
| 314 | return ret; |
| 315 | } |
| 316 | |
| 317 | |
Chris Mason | 0660b5a | 2008-11-17 20:37:39 -0500 | [diff] [blame] | 318 | /* |
| 319 | * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY |
| 320 | * or BTRFS_ROOT_BACKREF_KEY. |
| 321 | * |
| 322 | * The dirid, sequence, name and name_len refer to the directory entry |
| 323 | * that is referencing the root. |
| 324 | * |
| 325 | * For a forward ref, the root_id is the id of the tree referencing |
| 326 | * the root and ref_id is the id of the subvol or snapshot. |
| 327 | * |
| 328 | * For a back ref the root_id is the id of the subvol or snapshot and |
| 329 | * ref_id is the id of the tree referencing it. |
| 330 | */ |
| 331 | int btrfs_add_root_ref(struct btrfs_trans_handle *trans, |
| 332 | struct btrfs_root *tree_root, |
| 333 | u64 root_id, u8 type, u64 ref_id, |
| 334 | u64 dirid, u64 sequence, |
| 335 | const char *name, int name_len) |
| 336 | { |
| 337 | struct btrfs_key key; |
| 338 | int ret; |
| 339 | struct btrfs_path *path; |
| 340 | struct btrfs_root_ref *ref; |
| 341 | struct extent_buffer *leaf; |
| 342 | unsigned long ptr; |
| 343 | |
| 344 | |
| 345 | path = btrfs_alloc_path(); |
| 346 | |
| 347 | key.objectid = root_id; |
| 348 | key.type = type; |
| 349 | key.offset = ref_id; |
| 350 | |
| 351 | ret = btrfs_insert_empty_item(trans, tree_root, path, &key, |
| 352 | sizeof(*ref) + name_len); |
| 353 | BUG_ON(ret); |
| 354 | |
| 355 | leaf = path->nodes[0]; |
| 356 | ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); |
| 357 | btrfs_set_root_ref_dirid(leaf, ref, dirid); |
| 358 | btrfs_set_root_ref_sequence(leaf, ref, sequence); |
| 359 | btrfs_set_root_ref_name_len(leaf, ref, name_len); |
| 360 | ptr = (unsigned long)(ref + 1); |
| 361 | write_extent_buffer(leaf, name, ptr, name_len); |
| 362 | btrfs_mark_buffer_dirty(leaf); |
| 363 | |
| 364 | btrfs_free_path(path); |
| 365 | return ret; |
| 366 | } |