SAFE public projects git trees. - safe/jmp/linux-2.6/blob - fs/btrfs/dir-item.c

   1 #include <linux/module.h>
   2 #include "ctree.h"
   3 #include "disk-io.h"
   4 #include "hash.h"
   5 #include "transaction.h"
   6
   7 static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
   8                                                    *trans,
   9                                                    struct btrfs_root *root,
  10                                                    struct btrfs_path *path,
  11                                                    struct btrfs_key *cpu_key,
  12                                                    u32 data_size)
  13 {
  14         int ret;
  15         char *ptr;
  16         struct btrfs_item *item;
  17         struct btrfs_leaf *leaf;
  18
  19         ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
  20         if (ret == -EEXIST) {
  21                 ret = btrfs_extend_item(trans, root, path, data_size);
  22                 WARN_ON(ret > 0);
  23                 if (ret)
  24                         return ERR_PTR(ret);
  25         }
  26         WARN_ON(ret > 0);
  27         leaf = btrfs_buffer_leaf(path->nodes[0]);
  28         item = leaf->items + path->slots[0];
  29         ptr = btrfs_item_ptr(leaf, path->slots[0], char);
  30         BUG_ON(data_size > btrfs_item_size(item));
  31         ptr += btrfs_item_size(item) - data_size;
  32         return (struct btrfs_dir_item *)ptr;
  33 }
  34
  35 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
  36                           *root, const char *name, int name_len, u64 dir,
  37                           struct btrfs_key *location, u8 type)
  38 {
  39         int ret = 0;
  40         struct btrfs_path *path;
  41         struct btrfs_dir_item *dir_item;
  42         char *name_ptr;
  43         struct btrfs_key key;
  44         u32 data_size;
  45
  46         key.objectid = dir;
  47         key.flags = 0;
  48         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
  49         ret = btrfs_name_hash(name, name_len, &key.offset);
  50         BUG_ON(ret);
  51         path = btrfs_alloc_path();
  52         btrfs_init_path(path);
  53         data_size = sizeof(*dir_item) + name_len;
  54         dir_item = insert_with_overflow(trans, root, path, &key, data_size);
  55         if (IS_ERR(dir_item)) {
  56                 ret = PTR_ERR(dir_item);
  57                 goto out;
  58         }
  59
  60         btrfs_cpu_key_to_disk(&dir_item->location, location);
  61         btrfs_set_dir_type(dir_item, type);
  62         btrfs_set_dir_flags(dir_item, 0);
  63         btrfs_set_dir_name_len(dir_item, name_len);
  64         name_ptr = (char *)(dir_item + 1);
  65
  66         btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
  67         btrfs_mark_buffer_dirty(path->nodes[0]);
  68
  69         /* FIXME, use some real flag for selecting the extra index */
  70         if (root == root->fs_info->tree_root) {
  71                 ret = 0;
  72                 goto out;
  73         }
  74
  75         btrfs_release_path(root, path);
  76
  77         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
  78         key.offset = location->objectid;
  79         dir_item = insert_with_overflow(trans, root, path, &key, data_size);
  80         if (IS_ERR(dir_item)) {
  81                 ret = PTR_ERR(dir_item);
  82                 goto out;
  83         }
  84         btrfs_cpu_key_to_disk(&dir_item->location, location);
  85         btrfs_set_dir_type(dir_item, type);
  86         btrfs_set_dir_flags(dir_item, 0);
  87         btrfs_set_dir_name_len(dir_item, name_len);
  88         name_ptr = (char *)(dir_item + 1);
  89         btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
  90         btrfs_mark_buffer_dirty(path->nodes[0]);
  91 out:
  92         btrfs_free_path(path);
  93         return ret;
  94 }
  95
  96 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
  97                                              struct btrfs_root *root,
  98                                              struct btrfs_path *path, u64 dir,
  99                                              const char *name, int name_len,
 100                                              int mod)
 101 {
 102         int ret;
 103         struct btrfs_key key;
 104         int ins_len = mod < 0 ? -1 : 0;
 105         int cow = mod != 0;
 106         struct btrfs_disk_key *found_key;
 107         struct btrfs_leaf *leaf;
 108
 109         key.objectid = dir;
 110         key.flags = 0;
 111         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 112         ret = btrfs_name_hash(name, name_len, &key.offset);
 113         BUG_ON(ret);
 114         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 115         if (ret < 0)
 116                 return ERR_PTR(ret);
 117         if (ret > 0) {
 118                 if (path->slots[0] == 0)
 119                         return NULL;
 120                 path->slots[0]--;
 121         }
 122         leaf = btrfs_buffer_leaf(path->nodes[0]);
 123         found_key = &leaf->items[path->slots[0]].key;
 124
 125         if (btrfs_disk_key_objectid(found_key) != dir ||
 126             btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
 127             btrfs_disk_key_offset(found_key) != key.offset)
 128                 return NULL;
 129
 130         return btrfs_match_dir_item_name(root, path, name, name_len);
 131 }
 132
 133 struct btrfs_dir_item *
 134 btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 135                             struct btrfs_root *root,
 136                             struct btrfs_path *path, u64 dir,
 137                             u64 objectid, const char *name, int name_len,
 138                             int mod)
 139 {
 140         int ret;
 141         struct btrfs_key key;
 142         int ins_len = mod < 0 ? -1 : 0;
 143         int cow = mod != 0;
 144
 145         key.objectid = dir;
 146         key.flags = 0;
 147         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 148         key.offset = objectid;
 149
 150         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 151         if (ret < 0)
 152                 return ERR_PTR(ret);
 153         if (ret > 0)
 154                 return ERR_PTR(-ENOENT);
 155         return btrfs_match_dir_item_name(root, path, name, name_len);
 156 }
 157
 158 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
 159                               struct btrfs_path *path,
 160                               const char *name, int name_len)
 161 {
 162         struct btrfs_dir_item *dir_item;
 163         char *name_ptr;
 164         u32 total_len;
 165         u32 cur = 0;
 166         u32 this_len;
 167         struct btrfs_leaf *leaf;
 168
 169         leaf = btrfs_buffer_leaf(path->nodes[0]);
 170         dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
 171         total_len = btrfs_item_size(leaf->items + path->slots[0]);
 172         while(cur < total_len) {
 173                 this_len = sizeof(*dir_item) + btrfs_dir_name_len(dir_item);
 174                 name_ptr = (char *)(dir_item + 1);
 175
 176                 if (btrfs_dir_name_len(dir_item) == name_len &&
 177                     memcmp(name_ptr, name, name_len) == 0)
 178                         return dir_item;
 179
 180                 cur += this_len;
 181                 dir_item = (struct btrfs_dir_item *)((char *)dir_item +
 182                                                      this_len);
 183         }
 184         return NULL;
 185 }
 186
 187 int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
 188                               struct btrfs_root *root,
 189                               struct btrfs_path *path,
 190                               struct btrfs_dir_item *di)
 191 {
 192
 193         struct btrfs_leaf *leaf;
 194         u32 sub_item_len;
 195         u32 item_len;
 196         int ret;
 197
 198         leaf = btrfs_buffer_leaf(path->nodes[0]);
 199         sub_item_len = sizeof(*di) + btrfs_dir_name_len(di);
 200         item_len = btrfs_item_size(leaf->items + path->slots[0]);
 201         if (sub_item_len == btrfs_item_size(leaf->items + path->slots[0])) {
 202                 ret = btrfs_del_item(trans, root, path);
 203                 BUG_ON(ret);
 204         } else {
 205                 char *ptr = (char *)di;
 206                 char *start = btrfs_item_ptr(leaf, path->slots[0], char);
 207                 btrfs_memmove(root, leaf, ptr, ptr + sub_item_len,
 208                         item_len - (ptr + sub_item_len - start));
 209                 ret = btrfs_truncate_item(trans, root, path,
 210                                           item_len - sub_item_len);
 211                 BUG_ON(ret);
 212         }
 213         return 0;
 214 }
 215