Pileus Git - ~andy/linux/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, u64
  29                           objectid, 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_set_dir_objectid(dir_item, objectid);
  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         btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
  59         btrfs_mark_buffer_dirty(path->nodes[0]);
  60         btrfs_release_path(root, path);
  61
  62         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
  63         key.offset = objectid;
  64         ret = insert_with_overflow(trans, root, path, &key, data_size);
  65         // FIXME clear the dirindex bit
  66         if (ret)
  67                 goto out;
  68
  69         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
  70                                   path->slots[0],
  71                                   struct btrfs_dir_item);
  72         btrfs_set_dir_objectid(dir_item, objectid);
  73         btrfs_set_dir_type(dir_item, type);
  74         btrfs_set_dir_flags(dir_item, 0);
  75         btrfs_set_dir_name_len(dir_item, name_len);
  76         name_ptr = (char *)(dir_item + 1);
  77         btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
  78         btrfs_mark_buffer_dirty(path->nodes[0]);
  79 out:
  80         btrfs_release_path(root, path);
  81         btrfs_free_path(path);
  82         return ret;
  83 }
  84
  85 int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
  86                           *root, struct btrfs_path *path, u64 dir,
  87                           const char *name, int name_len, int mod)
  88 {
  89         int ret;
  90         struct btrfs_key key;
  91         int ins_len = mod < 0 ? -1 : 0;
  92         int cow = mod != 0;
  93         struct btrfs_disk_key *found_key;
  94         struct btrfs_leaf *leaf;
  95
  96         key.objectid = dir;
  97         key.flags = 0;
  98         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
  99         btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
 100         ret = btrfs_name_hash(name, name_len, &key.offset);
 101         BUG_ON(ret);
 102         while(1) {
 103                 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 104                 if (ret < 0)
 105                         return ret;
 106                 if (ret > 0) {
 107                         if (path->slots[0] == 0)
 108                                 return 1;
 109                         path->slots[0]--;
 110                 }
 111                 leaf = btrfs_buffer_leaf(path->nodes[0]);
 112                 found_key = &leaf->items[path->slots[0]].key;
 113
 114                 if (btrfs_disk_key_objectid(found_key) != dir ||
 115                     btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
 116                     btrfs_disk_key_offset(found_key) != key.offset)
 117                         return 1;
 118
 119                 if (btrfs_match_dir_item_name(root, path, name, name_len))
 120                         return 0;
 121
 122                 if (btrfs_disk_key_overflow(found_key) == 0)
 123                         return 1;
 124                 btrfs_release_path(root, path);
 125         }
 126         return 1;
 127 }
 128
 129 int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 130                                 struct btrfs_root *root,
 131                                 struct btrfs_path *path, u64 dir,
 132                                 u64 objectid, int mod)
 133 {
 134         int ret;
 135         struct btrfs_key key;
 136         int ins_len = mod < 0 ? -1 : 0;
 137         int cow = mod != 0;
 138         struct btrfs_disk_key *found_key;
 139         struct btrfs_leaf *leaf;
 140
 141         key.objectid = dir;
 142         key.flags = 0;
 143         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 144         btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
 145         key.offset = objectid;
 146         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 147         if (ret < 0)
 148                 return ret;
 149         if (ret > 0) {
 150                 if (path->slots[0] == 0)
 151                         return 1;
 152                 path->slots[0]--;
 153         }
 154         leaf = btrfs_buffer_leaf(path->nodes[0]);
 155         found_key = &leaf->items[path->slots[0]].key;
 156
 157         if (btrfs_disk_key_objectid(found_key) != dir ||
 158             btrfs_disk_key_type(found_key) != BTRFS_DIR_INDEX_KEY)
 159                 return 1;
 160         if (btrfs_disk_key_offset(found_key) == objectid)
 161                 return 0;
 162         return 1;
 163 }
 164
 165 int btrfs_match_dir_item_name(struct btrfs_root *root,
 166                               struct btrfs_path *path,
 167                               const char *name, int name_len)
 168 {
 169         struct btrfs_dir_item *dir_item;
 170         char *name_ptr;
 171
 172         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
 173                                   path->slots[0],
 174                                   struct btrfs_dir_item);
 175         if (btrfs_dir_name_len(dir_item) != name_len)
 176                 return 0;
 177         name_ptr = (char *)(dir_item + 1);
 178         if (memcmp(name_ptr, name, name_len))
 179                 return 0;
 180         return 1;
 181 }