xfs: track directory entry updates during live nlinks fsck

Create the necessary hooks in the directory operations
(create/link/unlink/rename) code so that our live nlink scrub code can
stay up to date with link count updates in the rest of the filesystem.
This will be the means to keep our shadow link count information up to
date while the scan runs in real time.

In online fsck part 2, we'll use these same hooks to handle repairs
to directories and parent pointer information.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 31 insertions, 0 deletions

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 7bbdc7009e7d..ab46ffb3ac19 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -171,6 +171,12 @@ static inline struct inode *VFS_I(struct xfs_inode *ip)
 	return &ip->i_vnode;
 }
 
+/* convert from const xfs inode to const vfs inode */
+static inline const struct inode *VFS_IC(const struct xfs_inode *ip)
+{
+	return &ip->i_vnode;
+}
+
 /*
  * For regular files we only update the on-disk filesize when actually
  * writing data back to disk.  Until then only the copy in the VFS inode
@@ -626,4 +632,29 @@ bool xfs_ifork_zapped(const struct xfs_inode *ip, int whichfork);
 void xfs_inode_count_blocks(struct xfs_trans *tp, struct xfs_inode *ip,
 		xfs_filblks_t *dblocks, xfs_filblks_t *rblocks);
 
+struct xfs_dir_update_params {
+	const struct xfs_inode	*dp;
+	const struct xfs_inode	*ip;
+	const struct xfs_name	*name;
+	int			delta;
+};
+
+#ifdef CONFIG_XFS_LIVE_HOOKS
+void xfs_dir_update_hook(struct xfs_inode *dp, struct xfs_inode *ip,
+		int delta, const struct xfs_name *name);
+
+struct xfs_dir_hook {
+	struct xfs_hook		dirent_hook;
+};
+
+void xfs_dir_hook_disable(void);
+void xfs_dir_hook_enable(void);
+
+int xfs_dir_hook_add(struct xfs_mount *mp, struct xfs_dir_hook *hook);
+void xfs_dir_hook_del(struct xfs_mount *mp, struct xfs_dir_hook *hook);
+void xfs_dir_hook_setup(struct xfs_dir_hook *hook, notifier_fn_t mod_fn);
+#else
+# define xfs_dir_update_hook(dp, ip, delta, name)	((void)0)
+#endif /* CONFIG_XFS_LIVE_HOOKS */
+
 #endif	/* __XFS_INODE_H__ */