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 "disk-io.h" 21 #include "transaction.h" 22 23 static int find_name_in_backref(struct btrfs_path *path, const char *name, 24 int name_len, struct btrfs_inode_ref **ref_ret) 25 { 26 struct extent_buffer *leaf; 27 struct btrfs_inode_ref *ref; 28 unsigned long ptr; 29 unsigned long name_ptr; 30 u32 item_size; 31 u32 cur_offset = 0; 32 int len; 33 34 leaf = path->nodes[0]; 35 item_size = btrfs_item_size_nr(leaf, path->slots[0]); 36 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); 37 while (cur_offset < item_size) { 38 ref = (struct btrfs_inode_ref *)(ptr + cur_offset); 39 len = btrfs_inode_ref_name_len(leaf, ref); 40 name_ptr = (unsigned long)(ref + 1); 41 cur_offset += len + sizeof(*ref); 42 if (len != name_len) 43 continue; 44 if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) { 45 *ref_ret = ref; 46 return 1; 47 } 48 } 49 return 0; 50 } 51 52 int btrfs_del_inode_ref(struct btrfs_trans_handle *trans, 53 struct btrfs_root *root, 54 const char *name, int name_len, 55 u64 inode_objectid, u64 ref_objectid, u64 *index) 56 { 57 struct btrfs_path *path; 58 struct btrfs_key key; 59 struct btrfs_inode_ref *ref; 60 struct extent_buffer *leaf; 61 unsigned long ptr; 62 unsigned long item_start; 63 u32 item_size; 64 u32 sub_item_len; 65 int ret; 66 int del_len = name_len + sizeof(*ref); 67 68 key.objectid = inode_objectid; 69 key.offset = ref_objectid; 70 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY); 71 72 path = btrfs_alloc_path(); 73 if (!path) 74 return -ENOMEM; 75 76 ret = btrfs_search_slot(trans, root, &key, path, -1, 1); 77 if (ret > 0) { 78 ret = -ENOENT; 79 goto out; 80 } else if (ret < 0) { 81 goto out; 82 } 83 if (!find_name_in_backref(path, name, name_len, &ref)) { 84 ret = -ENOENT; 85 goto out; 86 } 87 leaf = path->nodes[0]; 88 item_size = btrfs_item_size_nr(leaf, path->slots[0]); 89 90 if (index) 91 *index = btrfs_inode_ref_index(leaf, ref); 92 93 if (del_len == item_size) { 94 ret = btrfs_del_item(trans, root, path); 95 goto out; 96 } 97 ptr = (unsigned long)ref; 98 sub_item_len = name_len + sizeof(*ref); 99 item_start = btrfs_item_ptr_offset(leaf, path->slots[0]); 100 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len, 101 item_size - (ptr + sub_item_len - item_start)); 102 ret = btrfs_truncate_item(trans, root, path, 103 item_size - sub_item_len, 1); 104 BUG_ON(ret); 105 out: 106 btrfs_free_path(path); 107 return ret; 108 } 109 110 int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans, 111 struct btrfs_root *root, 112 const char *name, int name_len, 113 u64 inode_objectid, u64 ref_objectid, u64 index) 114 { 115 struct btrfs_path *path; 116 struct btrfs_key key; 117 struct btrfs_inode_ref *ref; 118 unsigned long ptr; 119 int ret; 120 int ins_len = name_len + sizeof(*ref); 121 122 key.objectid = inode_objectid; 123 key.offset = ref_objectid; 124 btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY); 125 126 path = btrfs_alloc_path(); 127 if (!path) 128 return -ENOMEM; 129 130 ret = btrfs_insert_empty_item(trans, root, path, &key, 131 ins_len); 132 if (ret == -EEXIST) { 133 u32 old_size; 134 135 if (find_name_in_backref(path, name, name_len, &ref)) 136 goto out; 137 138 old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); 139 ret = btrfs_extend_item(trans, root, path, ins_len); 140 BUG_ON(ret); 141 ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 142 struct btrfs_inode_ref); 143 ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size); 144 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 145 btrfs_set_inode_ref_index(path->nodes[0], ref, index); 146 ptr = (unsigned long)(ref + 1); 147 ret = 0; 148 } else if (ret < 0) { 149 goto out; 150 } else { 151 ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 152 struct btrfs_inode_ref); 153 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); 154 btrfs_set_inode_ref_index(path->nodes[0], ref, index); 155 ptr = (unsigned long)(ref + 1); 156 } 157 write_extent_buffer(path->nodes[0], name, ptr, name_len); 158 btrfs_mark_buffer_dirty(path->nodes[0]); 159 160 out: 161 btrfs_free_path(path); 162 return ret; 163 } 164 165 int btrfs_insert_empty_inode(struct btrfs_trans_handle *trans, 166 struct btrfs_root *root, 167 struct btrfs_path *path, u64 objectid) 168 { 169 struct btrfs_key key; 170 int ret; 171 key.objectid = objectid; 172 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); 173 key.offset = 0; 174 175 ret = btrfs_insert_empty_item(trans, root, path, &key, 176 sizeof(struct btrfs_inode_item)); 177 if (ret == 0 && objectid > root->highest_inode) 178 root->highest_inode = objectid; 179 return ret; 180 } 181 182 int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root 183 *root, struct btrfs_path *path, 184 struct btrfs_key *location, int mod) 185 { 186 int ins_len = mod < 0 ? -1 : 0; 187 int cow = mod != 0; 188 int ret; 189 int slot; 190 struct extent_buffer *leaf; 191 struct btrfs_key found_key; 192 193 ret = btrfs_search_slot(trans, root, location, path, ins_len, cow); 194 if (ret > 0 && btrfs_key_type(location) == BTRFS_ROOT_ITEM_KEY && 195 location->offset == (u64)-1 && path->slots[0] != 0) { 196 slot = path->slots[0] - 1; 197 leaf = path->nodes[0]; 198 btrfs_item_key_to_cpu(leaf, &found_key, slot); 199 if (found_key.objectid == location->objectid && 200 btrfs_key_type(&found_key) == btrfs_key_type(location)) { 201 path->slots[0]--; 202 return 0; 203 } 204 } 205 return ret; 206 } 207