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 int insert_with_overflow(struct btrfs_trans_handle *trans, struct btrfs_root
   8                             *root, struct btrfs_path *path, struct btrfs_key
   9                             *cpu_key, u32 data_size)
  10 {
  11         int overflow;
  12         int ret;
  13
  14         ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
  15         overflow = btrfs_key_overflow(cpu_key);
  16
  17         while(ret == -EEXIST && overflow < BTRFS_KEY_OVERFLOW_MAX) {
  18                 overflow++;
  19                 btrfs_set_key_overflow(cpu_key, overflow);
  20                 btrfs_release_path(root, path);
  21                 ret = btrfs_insert_empty_item(trans, root, path, cpu_key,
  22                                               data_size);
  23         }
  24         return ret;
  25 }
  26
  27 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
  28                           *root, const char *name, int name_len, u64 dir,
  29                           struct btrfs_key *location, u8 type)
  30 {
  31         int ret = 0;
  32         struct btrfs_path *path;
  33         struct btrfs_dir_item *dir_item;
  34         char *name_ptr;
  35         struct btrfs_key key;
  36         u32 data_size;
  37
  38         key.objectid = dir;
  39         key.flags = 0;
  40         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
  41         ret = btrfs_name_hash(name, name_len, &key.offset);
  42         BUG_ON(ret);
  43         path = btrfs_alloc_path();
  44         btrfs_init_path(path);
  45         data_size = sizeof(*dir_item) + name_len;
  46         ret = insert_with_overflow(trans, root, path, &key, data_size);
  47         if (ret)
  48                 goto out;
  49
  50         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
  51                                   path->slots[0],
  52                                   struct btrfs_dir_item);
  53         btrfs_cpu_key_to_disk(&dir_item->location, location);
  54         btrfs_set_dir_type(dir_item, type);
  55         btrfs_set_dir_flags(dir_item, 0);
  56         btrfs_set_dir_name_len(dir_item, name_len);
  57         name_ptr = (char *)(dir_item + 1);
  58         /* FIXME, use some real flag for selecting the extra index */
  59         if (root == root->fs_info->tree_root)
  60                 goto out;
  61
  62         btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
  63         btrfs_mark_buffer_dirty(path->nodes[0]);
  64         btrfs_release_path(root, path);
  65
  66         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
  67         key.offset = location->objectid;
  68         ret = insert_with_overflow(trans, root, path, &key, data_size);
  69         // FIXME clear the dirindex bit
  70         if (ret)
  71                 goto out;
  72
  73         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
  74                                   path->slots[0],
  75                                   struct btrfs_dir_item);
  76         btrfs_cpu_key_to_disk(&dir_item->location, location);
  77         btrfs_set_dir_type(dir_item, type);
  78         btrfs_set_dir_flags(dir_item, 0);
  79         btrfs_set_dir_name_len(dir_item, name_len);
  80         name_ptr = (char *)(dir_item + 1);
  81         btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
  82         btrfs_mark_buffer_dirty(path->nodes[0]);
  83 out:
  84         btrfs_release_path(root, path);
  85         btrfs_free_path(path);
  86         return ret;
  87 }
  88
  89 int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
  90                           *root, struct btrfs_path *path, u64 dir,
  91                           const char *name, int name_len, int mod)
  92 {
  93         int ret;
  94         struct btrfs_key key;
  95         int ins_len = mod < 0 ? -1 : 0;
  96         int cow = mod != 0;
  97         struct btrfs_disk_key *found_key;
  98         struct btrfs_leaf *leaf;
  99         u32 overflow;
 100
 101         key.objectid = dir;
 102         key.flags = 0;
 103         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 104         btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
 105         ret = btrfs_name_hash(name, name_len, &key.offset);
 106         BUG_ON(ret);
 107         while(1) {
 108                 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 109                 if (ret < 0)
 110                         return ret;
 111                 if (ret > 0) {
 112                         if (path->slots[0] == 0)
 113                                 return 1;
 114                         path->slots[0]--;
 115                 }
 116                 leaf = btrfs_buffer_leaf(path->nodes[0]);
 117                 found_key = &leaf->items[path->slots[0]].key;
 118
 119                 if (btrfs_disk_key_objectid(found_key) != dir ||
 120                     btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
 121                     btrfs_disk_key_offset(found_key) != key.offset)
 122                         return 1;
 123
 124                 if (btrfs_match_dir_item_name(root, path, name, name_len))
 125                         return 0;
 126
 127                 overflow = btrfs_disk_key_overflow(found_key);
 128                 if (overflow == 0)
 129                         return 1;
 130                 btrfs_set_key_overflow(&key, overflow - 1);
 131                 btrfs_release_path(root, path);
 132         }
 133         return 1;
 134 }
 135
 136 int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 137                                 struct btrfs_root *root,
 138                                 struct btrfs_path *path, u64 dir,
 139                                 u64 objectid, int mod)
 140 {
 141         int ret;
 142         struct btrfs_key key;
 143         int ins_len = mod < 0 ? -1 : 0;
 144         int cow = mod != 0;
 145         struct btrfs_disk_key *found_key;
 146         struct btrfs_leaf *leaf;
 147
 148         key.objectid = dir;
 149         key.flags = 0;
 150         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 151         btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
 152         key.offset = objectid;
 153         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 154         if (ret < 0)
 155                 return ret;
 156         if (ret > 0) {
 157                 if (path->slots[0] == 0)
 158                         return 1;
 159                 path->slots[0]--;
 160         }
 161         leaf = btrfs_buffer_leaf(path->nodes[0]);
 162         found_key = &leaf->items[path->slots[0]].key;
 163
 164         if (btrfs_disk_key_objectid(found_key) != dir ||
 165             btrfs_disk_key_type(found_key) != BTRFS_DIR_INDEX_KEY)
 166                 return 1;
 167         if (btrfs_disk_key_offset(found_key) == objectid)
 168                 return 0;
 169         return 1;
 170 }
 171
 172 int btrfs_match_dir_item_name(struct btrfs_root *root,
 173                               struct btrfs_path *path,
 174                               const char *name, int name_len)
 175 {
 176         struct btrfs_dir_item *dir_item;
 177         char *name_ptr;
 178
 179         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
 180                                   path->slots[0],
 181                                   struct btrfs_dir_item);
 182         if (btrfs_dir_name_len(dir_item) != name_len)
 183                 return 0;
 184         name_ptr = (char *)(dir_item + 1);
 185         if (memcmp(name_ptr, name, name_len))
 186                 return 0;
 187         return 1;
 188 }