Btrfs: deny sys_link across subvolumes.

[cascardo/linux.git] / fs / btrfs / dir-item.c

diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 1d70236..e9103b3 100644 (file)
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -68,12 +68,12 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
  * into the tree
  */
 int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
-                           struct btrfs_root *root, const char *name,
-                           u16 name_len, const void *data, u16 data_len,
-                           u64 dir)
+                           struct btrfs_root *root,
+                           struct btrfs_path *path, u64 objectid,
+                           const char *name, u16 name_len,
+                           const void *data, u16 data_len)
 {
        int ret = 0;
-       struct btrfs_path *path;
        struct btrfs_dir_item *dir_item;
        unsigned long name_ptr, data_ptr;
        struct btrfs_key key, location;
@@ -81,15 +81,11 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
        struct extent_buffer *leaf;
        u32 data_size;
 
-       key.objectid = dir;
+       BUG_ON(name_len + data_len > BTRFS_MAX_XATTR_SIZE(root));
+
+       key.objectid = objectid;
        btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
        key.offset = btrfs_name_hash(name, name_len);
-       path = btrfs_alloc_path();
-       if (!path)
-               return -ENOMEM;
-       if (name_len + data_len + sizeof(struct btrfs_dir_item) >
-           BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item))
-               return -ENOSPC;
 
        data_size = sizeof(*dir_item) + name_len + data_len;
        dir_item = insert_with_overflow(trans, root, path, &key, data_size,
@@ -117,7 +113,6 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
        write_extent_buffer(leaf, data, data_ptr, data_len);
        btrfs_mark_buffer_dirty(path->nodes[0]);
 
-       btrfs_free_path(path);
        return ret;
 }
 
@@ -281,6 +276,53 @@ btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
        return btrfs_match_dir_item_name(root, path, name, name_len);
 }
 
+struct btrfs_dir_item *
+btrfs_search_dir_index_item(struct btrfs_root *root,
+                           struct btrfs_path *path, u64 dirid,
+                           const char *name, int name_len)
+{
+       struct extent_buffer *leaf;
+       struct btrfs_dir_item *di;
+       struct btrfs_key key;
+       u32 nritems;
+       int ret;
+
+       key.objectid = dirid;
+       key.type = BTRFS_DIR_INDEX_KEY;
+       key.offset = 0;
+
+       ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+       if (ret < 0)
+               return ERR_PTR(ret);
+
+       leaf = path->nodes[0];
+       nritems = btrfs_header_nritems(leaf);
+
+       while (1) {
+               if (path->slots[0] >= nritems) {
+                       ret = btrfs_next_leaf(root, path);
+                       if (ret < 0)
+                               return ERR_PTR(ret);
+                       if (ret > 0)
+                               break;
+                       leaf = path->nodes[0];
+                       nritems = btrfs_header_nritems(leaf);
+                       continue;
+               }
+
+               btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+               if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY)
+                       break;
+
+               di = btrfs_match_dir_item_name(root, path, name, name_len);
+               if (di)
+                       return di;
+
+               path->slots[0]++;
+       }
+       return NULL;
+}
+
 struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
                                          struct btrfs_root *root,
                                          struct btrfs_path *path, u64 dir,