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)
 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                 if (ret == -EEXIST)
 132                         goto second_insert;
 133                 goto out;
 134         }
 135
 136         leaf = path->nodes[0];
 137         btrfs_cpu_key_to_disk(&disk_key, location);
 138         btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 139         btrfs_set_dir_type(leaf, dir_item, type);
 140         btrfs_set_dir_data_len(leaf, dir_item, 0);
 141         btrfs_set_dir_name_len(leaf, dir_item, name_len);
 142         name_ptr = (unsigned long)(dir_item + 1);
 143
 144         write_extent_buffer(leaf, name, name_ptr, name_len);
 145         btrfs_mark_buffer_dirty(leaf);
 146
 147 second_insert:
 148         /* FIXME, use some real flag for selecting the extra index */
 149         if (root == root->fs_info->tree_root) {
 150                 ret = 0;
 151                 goto out;
 152         }
 153         btrfs_release_path(root, path);
 154
 155         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 156         key.offset = location->objectid;
 157         dir_item = insert_with_overflow(trans, root, path, &key, data_size,
 158                                         name, name_len);
 159         if (IS_ERR(dir_item)) {
 160                 ret2 = PTR_ERR(dir_item);
 161                 goto out;
 162         }
 163         leaf = path->nodes[0];
 164         btrfs_cpu_key_to_disk(&disk_key, location);
 165         btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
 166         btrfs_set_dir_type(leaf, dir_item, type);
 167         btrfs_set_dir_data_len(leaf, dir_item, 0);
 168         btrfs_set_dir_name_len(leaf, dir_item, name_len);
 169         name_ptr = (unsigned long)(dir_item + 1);
 170         write_extent_buffer(leaf, name, name_ptr, name_len);
 171         btrfs_mark_buffer_dirty(leaf);
 172 out:
 173         btrfs_free_path(path);
 174         if (ret)
 175                 return ret;
 176         if (ret2)
 177                 return ret2;
 178         return 0;
 179 }
 180
 181 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
 182                                              struct btrfs_root *root,
 183                                              struct btrfs_path *path, u64 dir,
 184                                              const char *name, int name_len,
 185                                              int mod)
 186 {
 187         int ret;
 188         struct btrfs_key key;
 189         int ins_len = mod < 0 ? -1 : 0;
 190         int cow = mod != 0;
 191         struct btrfs_key found_key;
 192         struct extent_buffer *leaf;
 193
 194         key.objectid = dir;
 195         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 196
 197         key.offset = btrfs_name_hash(name, name_len);
 198
 199         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 200         if (ret < 0)
 201                 return ERR_PTR(ret);
 202         if (ret > 0) {
 203                 if (path->slots[0] == 0)
 204                         return NULL;
 205                 path->slots[0]--;
 206         }
 207
 208         leaf = path->nodes[0];
 209         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 210
 211         if (found_key.objectid != dir ||
 212             btrfs_key_type(&found_key) != BTRFS_DIR_ITEM_KEY ||
 213             found_key.offset != key.offset)
 214                 return NULL;
 215
 216         return btrfs_match_dir_item_name(root, path, name, name_len);
 217 }
 218
 219 struct btrfs_dir_item *
 220 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 221                             struct btrfs_root *root,
 222                             struct btrfs_path *path, u64 dir,
 223                             u64 objectid, const char *name, int name_len,
 224                             int mod)
 225 {
 226         int ret;
 227         struct btrfs_key key;
 228         int ins_len = mod < 0 ? -1 : 0;
 229         int cow = mod != 0;
 230
 231         key.objectid = dir;
 232         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 233         key.offset = objectid;
 234
 235         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 236         if (ret < 0)
 237                 return ERR_PTR(ret);
 238         if (ret > 0)
 239                 return ERR_PTR(-ENOENT);
 240         return btrfs_match_dir_item_name(root, path, name, name_len);
 241 }
 242
 243 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
 244                                           struct btrfs_root *root,
 245                                           struct btrfs_path *path, u64 dir,
 246                                           const char *name, u16 name_len,
 247                                           int mod)
 248 {
 249         int ret;
 250         struct btrfs_key key;
 251         int ins_len = mod < 0 ? -1 : 0;
 252         int cow = mod != 0;
 253         struct btrfs_key found_key;
 254         struct extent_buffer *leaf;
 255
 256         key.objectid = dir;
 257         btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
 258         key.offset = btrfs_name_hash(name, name_len);
 259         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 260         if (ret < 0)
 261                 return ERR_PTR(ret);
 262         if (ret > 0) {
 263                 if (path->slots[0] == 0)
 264                         return NULL;
 265                 path->slots[0]--;
 266         }
 267
 268         leaf = path->nodes[0];
 269         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
 270
 271         if (found_key.objectid != dir ||
 272             btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY ||
 273             found_key.offset != key.offset)
 274                 return NULL;
 275
 276         return btrfs_match_dir_item_name(root, path, name, name_len);
 277 }
 278
 279 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 280                               struct btrfs_path *path,
 281                               const char *name, int name_len)
 282 {
 283         struct btrfs_dir_item *dir_item;
 284         unsigned long name_ptr;
 285         u32 total_len;
 286         u32 cur = 0;
 287         u32 this_len;
 288         struct extent_buffer *leaf;
 289
 290         leaf = path->nodes[0];
 291         dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
 292         total_len = btrfs_item_size_nr(leaf, path->slots[0]);
 293         while(cur < total_len) {
 294                 this_len = sizeof(*dir_item) +
 295                         btrfs_dir_name_len(leaf, dir_item) +
 296                         btrfs_dir_data_len(leaf, dir_item);
 297                 name_ptr = (unsigned long)(dir_item + 1);
 298
 299                 if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
 300                     memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
 301                         return dir_item;
 302
 303                 cur += this_len;
 304                 dir_item = (struct btrfs_dir_item *)((char *)dir_item +
 305                                                      this_len);
 306         }
 307         return NULL;
 308 }
 309
 310 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 311                               struct btrfs_root *root,
 312                               struct btrfs_path *path,
 313                               struct btrfs_dir_item *di)
 314 {
 315
 316         struct extent_buffer *leaf;
 317         u32 sub_item_len;
 318         u32 item_len;
 319         int ret = 0;
 320
 321         leaf = path->nodes[0];
 322         sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
 323                 btrfs_dir_data_len(leaf, di);
 324         item_len = btrfs_item_size_nr(leaf, path->slots[0]);
 325         if (sub_item_len == item_len) {
 326                 ret = btrfs_del_item(trans, root, path);
 327         } else {
 328                 /* MARKER */
 329                 unsigned long ptr = (unsigned long)di;
 330                 unsigned long start;
 331
 332                 start = btrfs_item_ptr_offset(leaf, path->slots[0]);
 333                 memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
 334                         item_len - (ptr + sub_item_len - start));
 335                 ret = btrfs_truncate_item(trans, root, path,
 336                                           item_len - sub_item_len, 1);
 337         }
 338         return 0;
 339 }