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 out:
  62         btrfs_release_path(root, path);
  63         btrfs_free_path(path);
  64         return ret;
  65 }
  66
  67 int btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
  68                           *root, struct btrfs_path *path, u64 dir,
  69                           const char *name, int name_len, int mod)
  70 {
  71         int ret;
  72         struct btrfs_key key;
  73         int ins_len = mod < 0 ? -1 : 0;
  74         int cow = mod != 0;
  75         struct btrfs_disk_key *found_key;
  76         struct btrfs_leaf *leaf;
  77         u32 overflow;
  78
  79         key.objectid = dir;
  80         key.flags = 0;
  81         btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
  82         // btrfs_set_key_overflow(&key, BTRFS_KEY_OVERFLOW_MAX - 1);
  83         ret = btrfs_name_hash(name, name_len, &key.offset);
  84         BUG_ON(ret);
  85         while(1) {
  86                 ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
  87                 if (ret < 0)
  88                         return ret;
  89                 if (ret > 0) {
  90                         if (path->slots[0] == 0)
  91                                 return 1;
  92                         path->slots[0]--;
  93                 }
  94                 leaf = btrfs_buffer_leaf(path->nodes[0]);
  95                 found_key = &leaf->items[path->slots[0]].key;
  96
  97                 if (btrfs_disk_key_objectid(found_key) != dir ||
  98                     btrfs_disk_key_type(found_key) != BTRFS_DIR_ITEM_KEY ||
  99                     btrfs_disk_key_offset(found_key) != key.offset)
 100                         return 1;
 101
 102                 if (btrfs_match_dir_item_name(root, path, name, name_len))
 103                         return 0;
 104
 105                 overflow = btrfs_disk_key_overflow(found_key);
 106                 if (overflow == 0)
 107                         return 1;
 108                 btrfs_set_key_overflow(&key, overflow - 1);
 109                 btrfs_release_path(root, path);
 110         }
 111         return 1;
 112 }
 113
 114 int btrfs_match_dir_item_name(struct btrfs_root *root,
 115                               struct btrfs_path *path,
 116                               const char *name, int name_len)
 117 {
 118         struct btrfs_dir_item *dir_item;
 119         char *name_ptr;
 120
 121         dir_item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
 122                                   path->slots[0],
 123                                   struct btrfs_dir_item);
 124         if (btrfs_dir_name_len(dir_item) != name_len)
 125                 return 0;
 126         name_ptr = (char *)(dir_item + 1);
 127         if (memcmp(name_ptr, name, name_len))
 128                 return 0;
 129         return 1;
 130 }