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
  59         btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
  60         btrfs_mark_buffer_dirty(path->nodes[0]);
  61
  62         /* FIXME, use some real flag for selecting the extra index */
  63         if (root == root->fs_info->tree_root)
  64                 goto out;
  65
  66         btrfs_release_path(root, path);
  67
  68         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
  69         key.offset = location->objectid;
  70         ret = insert_with_overflow(trans, root, path, &key, data_size);
  71         // FIXME clear the dirindex bit
  72         if (ret)
  73                 goto out;
  74
  75         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
  76                                   path->slots[0],
  77                                   struct btrfs_dir_item);
  78         btrfs_cpu_key_to_disk(&dir_item->location, location);
  79         btrfs_set_dir_type(dir_item, type);
  80         btrfs_set_dir_flags(dir_item, 0);
  81         btrfs_set_dir_name_len(dir_item, name_len);
  82         name_ptr = (char *)(dir_item + 1);
  83         btrfs_memcpy(root, path->nodes[0]->b_data, name_ptr, name, name_len);
  84         btrfs_mark_buffer_dirty(path->nodes[0]);
  85 out:
  86         btrfs_release_path(root, path);
  87         btrfs_free_path(path);
  88         return ret;
  89 }
  90
  91 int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
  92                           *root, struct btrfs_path *path, u64 dir,
  93                           const char *name, int name_len, int mod)
  94 {
  95         int ret;
  96         struct btrfs_key key;
  97         int ins_len = mod < 0 ? -1 : 0;
  98         int cow = mod != 0;
  99         struct btrfs_disk_key *found_key;
 100         struct btrfs_leaf *leaf;
 101         u32 overflow;
 102
 103         key.objectid = dir;
 104         key.flags = 0;
 105         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 106         // btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
 107         ret = btrfs_name_hash(name, name_len, &key.offset);
 108         BUG_ON(ret);
 109         while(1) {
 110                 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 111                 if (ret < 0)
 112                         return ret;
 113                 if (ret > 0) {
 114                         if (path->slots[0] == 0)
 115                                 return 1;
 116                         path->slots[0]--;
 117                 }
 118                 leaf = btrfs_buffer_leaf(path->nodes[0]);
 119                 found_key = &leaf->items[path->slots[0]].key;
 120
 121                 if (btrfs_disk_key_objectid(found_key) != dir ||
 122                     btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
 123                     btrfs_disk_key_offset(found_key) != key.offset)
 124                         return 1;
 125
 126                 if (btrfs_match_dir_item_name(root, path, name, name_len))
 127                         return 0;
 128
 129                 overflow = btrfs_disk_key_overflow(found_key);
 130                 if (overflow == 0)
 131                         return 1;
 132                 btrfs_set_key_overflow(&key, overflow - 1);
 133                 btrfs_release_path(root, path);
 134         }
 135         return 1;
 136 }
 137
 138 int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 139                                 struct btrfs_root *root,
 140                                 struct btrfs_path *path, u64 dir,
 141                                 u64 objectid, int mod)
 142 {
 143         int ret;
 144         struct btrfs_key key;
 145         int ins_len = mod < 0 ? -1 : 0;
 146         int cow = mod != 0;
 147         struct btrfs_disk_key *found_key;
 148         struct btrfs_leaf *leaf;
 149         int overflow = 0;
 150
 151         key.objectid = dir;
 152         key.flags = 0;
 153         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 154         key.offset = objectid;
 155
 156         while(1) {
 157                 btrfs_set_key_overflow(&key, overflow);
 158                 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 159                 if (ret < 0)
 160                         return ret;
 161                 if (ret > 0) {
 162                         if (overflow >= BTRFS_KEY_OVERFLOW_MAX)
 163                                 return 1;
 164                         overflow++;
 165                         btrfs_set_key_overflow(&key, overflow);
 166                         btrfs_release_path(root, path);
 167                         continue;
 168                 } else {
 169                         /* found */
 170                         break;
 171                 }
 172         }
 173         leaf = btrfs_buffer_leaf(path->nodes[0]);
 174         found_key = &leaf->items[path->slots[0]].key;
 175
 176         if (btrfs_disk_key_objectid(found_key) != dir ||
 177             btrfs_disk_key_type(found_key) != BTRFS_DIR_INDEX_KEY)
 178                 return 1;
 179         if (btrfs_disk_key_offset(found_key) == objectid)
 180                 return 0;
 181         return 1;
 182 }
 183
 184 int btrfs_match_dir_item_name(struct btrfs_root *root,
 185                               struct btrfs_path *path,
 186                               const char *name, int name_len)
 187 {
 188         struct btrfs_dir_item *dir_item;
 189         char *name_ptr;
 190
 191         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
 192                                   path->slots[0],
 193                                   struct btrfs_dir_item);
 194         if (btrfs_dir_name_len(dir_item) != name_len)
 195                 return 0;
 196         name_ptr = (char *)(dir_item + 1);
 197         if (memcmp(name_ptr, name, name_len))
 198                 return 0;
 199         return 1;
 200 }