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, 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         u32 overflow;
  96
  97         key.objectid = dir;
  98         key.flags = 0;
  99         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
 100         btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
 101         ret = btrfs_name_hash(name, name_len, &key.offset);
 102         BUG_ON(ret);
 103         while(1) {
 104                 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 105                 if (ret < 0)
 106                         return ret;
 107                 if (ret > 0) {
 108                         if (path->slots[0] == 0)
 109                                 return 1;
 110                         path->slots[0]--;
 111                 }
 112                 leaf = btrfs_buffer_leaf(path->nodes[0]);
 113                 found_key = &leaf->items[path->slots[0]].key;
 114
 115                 if (btrfs_disk_key_objectid(found_key) != dir ||
 116                     btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
 117                     btrfs_disk_key_offset(found_key) != key.offset)
 118                         return 1;
 119
 120                 if (btrfs_match_dir_item_name(root, path, name, name_len))
 121                         return 0;
 122
 123                 overflow = btrfs_disk_key_overflow(found_key);
 124                 if (overflow == 0)
 125                         return 1;
 126                 btrfs_set_key_overflow(&key, overflow - 1);
 127                 btrfs_release_path(root, path);
 128         }
 129         return 1;
 130 }
 131
 132 int btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
 133                                 struct btrfs_root *root,
 134                                 struct btrfs_path *path, u64 dir,
 135                                 u64 objectid, int mod)
 136 {
 137         int ret;
 138         struct btrfs_key key;
 139         int ins_len = mod < 0 ? -1 : 0;
 140         int cow = mod != 0;
 141         struct btrfs_disk_key *found_key;
 142         struct btrfs_leaf *leaf;
 143
 144         key.objectid = dir;
 145         key.flags = 0;
 146         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
 147         btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
 148         key.offset = objectid;
 149         ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
 150         if (ret < 0)
 151                 return ret;
 152         if (ret > 0) {
 153                 if (path->slots[0] == 0)
 154                         return 1;
 155                 path->slots[0]--;
 156         }
 157         leaf = btrfs_buffer_leaf(path->nodes[0]);
 158         found_key = &leaf->items[path->slots[0]].key;
 159
 160         if (btrfs_disk_key_objectid(found_key) != dir ||
 161             btrfs_disk_key_type(found_key) != BTRFS_DIR_INDEX_KEY)
 162                 return 1;
 163         if (btrfs_disk_key_offset(found_key) == objectid)
 164                 return 0;
 165         return 1;
 166 }
 167
 168 int btrfs_match_dir_item_name(struct btrfs_root *root,
 169                               struct btrfs_path *path,
 170                               const char *name, int name_len)
 171 {
 172         struct btrfs_dir_item *dir_item;
 173         char *name_ptr;
 174
 175         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
 176                                   path->slots[0],
 177                                   struct btrfs_dir_item);
 178         if (btrfs_dir_name_len(dir_item) != name_len)
 179                 return 0;
 180         name_ptr = (char *)(dir_item + 1);
 181         if (memcmp(name_ptr, name, name_len))
 182                 return 0;
 183         return 1;
 184 }