Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...

[~andy/linux] / fs / btrfs / disk-io.h

diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index be69ce1b07a22ac83a2dedd808be0e6d20040333..b71acd6e1e5b1941e75ed4c5c056d47268cdc407 100644 (file)
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -63,14 +63,40 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev);
 int btrfs_commit_super(struct btrfs_root *root);
 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
                                            u64 bytenr, u32 blocksize);
-struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
-                                              struct btrfs_key *location);
+struct btrfs_root *btrfs_read_fs_root(struct btrfs_root *tree_root,
+                                     struct btrfs_key *location);
+int btrfs_init_fs_root(struct btrfs_root *root);
+int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
+                        struct btrfs_root *root);
 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
                                              struct btrfs_key *location);
 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
 void btrfs_btree_balance_dirty(struct btrfs_root *root);
 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);
-void btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
+void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
+                                struct btrfs_root *root);
+void btrfs_free_fs_root(struct btrfs_root *root);
+
+/*
+ * This function is used to grab the root, and avoid it is freed when we
+ * access it. But it doesn't ensure that the tree is not dropped.
+ *
+ * If you want to ensure the whole tree is safe, you should use
+ *     fs_info->subvol_srcu
+ */
+static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
+{
+       if (atomic_inc_not_zero(&root->refs))
+               return root;
+       return NULL;
+}
+
+static inline void btrfs_put_fs_root(struct btrfs_root *root)
+{
+       if (atomic_dec_and_test(&root->refs))
+               kfree(root);
+}
+
 void btrfs_mark_buffer_dirty(struct extent_buffer *buf);
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
                          int atomic);