dir-item.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 "disk-io.h"
  21 #include "hash.h"
  22 #include "transaction.h"
  23
  24 static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
  25                                                    *trans,
  26                                                    struct btrfs_root *root,
  27                                                    struct btrfs_path *path,
  28                                                    struct btrfs_key *cpu_key,
  29                                                    u32 data_size,
  30                                                    const char *name,
  31                                                    int name_len)
  32 {
  33         int ret;
  34         char *ptr;
  35         struct btrfs_item *item;
  36         struct extent_buffer *leaf;
  37
  38         ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
  39         if (ret == -EEXIST) {
  40                 struct btrfs_dir_item *di;
  41                 di = btrfs_match_dir_item_name(root, path, name, name_len);
  42                 if (di)
  43                         return ERR_PTR(-EEXIST);
  44                 ret = btrfs_extend_item(trans, root, path, data_size);
  45                 WARN_ON(ret > 0);
  46         }
  47         if (ret < 0)
  48                 return ERR_PTR(ret);
  49         WARN_ON(ret > 0);
  50         leaf = path->nodes[0];
  51         item = btrfs_item_nr(leaf, path->slots[0]);
  52         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
  53         BUG_ON(data_size > btrfs_item_size(leaf, item));
  54         ptr += btrfs_item_size(leaf, item) - data_size;
  55         return (struct btrfs_dir_item *)ptr;
  56 }
  57
  58 int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
  59                             struct btrfs_root *root, const char *name,
  60                             u16 name_len, const void *data, u16 data_len,
  61                             u64 dir)
  62 {
  63         int ret = 0;
  64         struct btrfs_path *path;
  65         struct btrfs_dir_item *dir_item;
  66         unsigned long name_ptr, data_ptr;
  67         struct btrfs_key key, location;
  68         struct btrfs_disk_key disk_key;
  69         struct extent_buffer *leaf;
  70         u32 data_size;
  71
  72         key.objectid = dir;
  73         btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
  74         key.offset = btrfs_name_hash(name, name_len);
  75         path = btrfs_alloc_path();
  76         if (!path)
  77                 return -ENOMEM;
  78
  79         data_size = sizeof(*dir_item) + name_len + data_len;
  80         dir_item = insert_with_overflow(trans, root, path, &key, data_size,
  81                                         name, name_len);
  82         /*
  83          * FIXME: at some point we should handle xattr's that are larger than
  84          * what we can fit in our leaf.  We set location to NULL b/c we arent
  85          * pointing at anything else, that will change if we store the xattr
  86          * data in a separate inode.
  87          */
  88         BUG_ON(IS_ERR(dir_item));
  89         memset(&location, 0, sizeof(location));
  90
  91         leaf = path->nodes[0];
  92         btrfs_cpu_key_to_disk(&disk_key, &location);
  93         btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
  94         btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
  95         btrfs_set_dir_name_len(leaf, dir_item, name_len);
  96         btrfs_set_dir_data_len(leaf, dir_item, data_len);
  97         name_ptr = (unsigned long)(dir_item + 1);
  98         data_ptr = (unsigned long)((char *)name_ptr + name_len);
  99
 100         write_extent_buffer(leaf, name, name_ptr, name_len);
 101         write_extent_buffer(leaf, data, data_ptr, data_len);
 102         btrfs_mark_buffer_dirty(path->nodes[0]);
 103
 104         btrfs_free_path(path);
 105         return ret;
 106 }
 107
 108 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
 109                           *root, const char *name, int name_len, u64 dir,
 110                           struct btrfs_key *location, u8 type, u64 index)
 111 {
 112         int ret = 0;
 113         int ret2 = 0;
 114         struct btrfs_path *path;
 115         struct btrfs_dir_item *dir_item;
 116         struct extent_buffer *leaf;
 117         unsigned long name_ptr;
 118         struct btrfs_key key;
 119         struct btrfs_disk_key disk_key;
 120         u32 data_size;
 121
 122         key.objectid = dir;
 123         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 124         key.offset = btrfs_name_hash(name, name_len);
 125         path = btrfs_alloc_path();
 126         data_size = sizeof(*dir_item) + name_len;
 127         dir_item = insert_with_overflow(trans, root, path, &key, data_size,
 128                                         name, name_len);
 129         if (IS_ERR(dir_item)) {
 130                 ret = PTR_ERR(dir_item);
 131                 goto out;
 132         }
 133
 134         leaf = path->nodes[0];
 135         btrfs_cpu_key_to_disk(&disk_key, location);
 136         btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 137         btrfs_set_dir_type(leaf, dir_item, type);
 138         btrfs_set_dir_data_len(leaf, dir_item, 0);
 139         btrfs_set_dir_name_len(leaf, dir_item, name_len);
 140         name_ptr = (unsigned long)(dir_item + 1);
 141
 142         write_extent_buffer(leaf, name, name_ptr, name_len);
 143         btrfs_mark_buffer_dirty(leaf);
 144
 145         /* FIXME, use some real flag for selecting the extra index */
 146         if (root == root->fs_info->tree_root) {
 147                 ret = 0;
 148                 goto out;
 149         }
 150         btrfs_release_path(root, path);
 151
 152         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 153         key.offset = index;
 154         dir_item = insert_with_overflow(trans, root, path, &key, data_size,
 155                                         name, name_len);
 156         if (IS_ERR(dir_item)) {
 157                 ret2 = PTR_ERR(dir_item);
 158                 goto out;
 159         }
 160         leaf = path->nodes[0];
 161         btrfs_cpu_key_to_disk(&disk_key, location);
 162         btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 163         btrfs_set_dir_type(leaf, dir_item, type);
 164         btrfs_set_dir_data_len(leaf, dir_item, 0);
 165         btrfs_set_dir_name_len(leaf, dir_item, name_len);
 166         name_ptr = (unsigned long)(dir_item + 1);
 167         write_extent_buffer(leaf, name, name_ptr, name_len);
 168         btrfs_mark_buffer_dirty(leaf);
 169 out:
 170         btrfs_free_path(path);
 171         if (ret)
 172                 return ret;
 173         if (ret2)
 174                 return ret2;
 175         return 0;
 176 }
 177
 178 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 179                                              struct btrfs_root *root,
 180                                              struct btrfs_path *path, u64 dir,
 181                                              const char *name, int name_len,
 182                                              int mod)
 183 {
 184         int ret;
 185         struct btrfs_key key;
 186         int ins_len = mod < 0 ? -1 : 0;
 187         int cow = mod != 0;
 188         struct btrfs_key found_key;
 189         struct extent_buffer *leaf;
 190
 191         key.objectid = dir;
 192         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 193
 194         key.offset = btrfs_name_hash(name, name_len);
 195
 196         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 197         if (ret < 0)
 198                 return ERR_PTR(ret);
 199         if (ret > 0) {
 200                 if (path->slots[0] == 0)
 201                         return NULL;
 202                 path->slots[0]--;
 203         }
 204
 205         leaf = path->nodes[0];
 206         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 207
 208         if (found_key.objectid != dir ||
 209             btrfs_key_type(&found_key) != BTRFS_DIR_ITEM_KEY ||
 210             found_key.offset != key.offset)
 211                 return NULL;
 212
 213         return btrfs_match_dir_item_name(root, path, name, name_len);
 214 }
 215
 216 struct btrfs_dir_item *
 217 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 218                             struct btrfs_root *root,
 219                             struct btrfs_path *path, u64 dir,
 220                             u64 objectid, const char *name, int name_len,
 221                             int mod)
 222 {
 223         int ret;
 224         struct btrfs_key key;
 225         int ins_len = mod < 0 ? -1 : 0;
 226         int cow = mod != 0;
 227
 228         key.objectid = dir;
 229         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 230         key.offset = objectid;
 231
 232         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 233         if (ret < 0)
 234                 return ERR_PTR(ret);
 235         if (ret > 0)
 236                 return ERR_PTR(-ENOENT);
 237         return btrfs_match_dir_item_name(root, path, name, name_len);
 238 }
 239
 240 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 241                                           struct btrfs_root *root,
 242                                           struct btrfs_path *path, u64 dir,
 243                                           const char *name, u16 name_len,
 244                                           int mod)
 245 {
 246         int ret;
 247         struct btrfs_key key;
 248         int ins_len = mod < 0 ? -1 : 0;
 249         int cow = mod != 0;
 250         struct btrfs_key found_key;
 251         struct extent_buffer *leaf;
 252
 253         key.objectid = dir;
 254         btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
 255         key.offset = btrfs_name_hash(name, name_len);
 256         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 257         if (ret < 0)
 258                 return ERR_PTR(ret);
 259         if (ret > 0) {
 260                 if (path->slots[0] == 0)
 261                         return NULL;
 262                 path->slots[0]--;
 263         }
 264
 265         leaf = path->nodes[0];
 266         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 267
 268         if (found_key.objectid != dir ||
 269             btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY ||
 270             found_key.offset != key.offset)
 271                 return NULL;
 272
 273         return btrfs_match_dir_item_name(root, path, name, name_len);
 274 }
 275
 276 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 277                               struct btrfs_path *path,
 278                               const char *name, int name_len)
 279 {
 280         struct btrfs_dir_item *dir_item;
 281         unsigned long name_ptr;
 282         u32 total_len;
 283         u32 cur = 0;
 284         u32 this_len;
 285         struct extent_buffer *leaf;
 286
 287         leaf = path->nodes[0];
 288         dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
 289         total_len = btrfs_item_size_nr(leaf, path->slots[0]);
 290         while(cur < total_len) {
 291                 this_len = sizeof(*dir_item) +
 292                         btrfs_dir_name_len(leaf, dir_item) +
 293                         btrfs_dir_data_len(leaf, dir_item);
 294                 name_ptr = (unsigned long)(dir_item + 1);
 295
 296                 if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
 297                     memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
 298                         return dir_item;
 299
 300                 cur += this_len;
 301                 dir_item = (struct btrfs_dir_item *)((char *)dir_item +
 302                                                      this_len);
 303         }
 304         return NULL;
 305 }
 306
 307 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 308                               struct btrfs_root *root,
 309                               struct btrfs_path *path,
 310                               struct btrfs_dir_item *di)
 311 {
 312
 313         struct extent_buffer *leaf;
 314         u32 sub_item_len;
 315         u32 item_len;
 316         int ret = 0;
 317
 318         leaf = path->nodes[0];
 319         sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
 320                 btrfs_dir_data_len(leaf, di);
 321         item_len = btrfs_item_size_nr(leaf, path->slots[0]);
 322         if (sub_item_len == item_len) {
 323                 ret = btrfs_del_item(trans, root, path);
 324         } else {
 325                 /* MARKER */
 326                 unsigned long ptr = (unsigned long)di;
 327                 unsigned long start;
 328
 329                 start = btrfs_item_ptr_offset(leaf, path->slots[0]);
 330                 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
 331                         item_len - (ptr + sub_item_len - start));
 332                 ret = btrfs_truncate_item(trans, root, path,
 333                                           item_len - sub_item_len, 1);
 334         }
 335         return ret;
 336 }