VFS: Comment mount following code (f015f126) · Commits · 戴 / test

fs/namei.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -672,6 +672,16 @@ static int follow_up_rcu(struct path *path)
		return 1;
		}

		/*
		* follow_up - Find the mountpoint of path's vfsmount
		*
		* Given a path, find the mountpoint of its source file system.
		* Replace @path with the path of the mountpoint in the parent mount.
		* Up is towards /.
		*
		* Return 1 if we went up a level and 0 if we were already at the
		* root.
		*/
		int follow_up(struct path *path)
		{
		struct mount *mnt = real_mount(path->mnt);

+14 −2

Original line number	Diff line number	Diff line
		@@ -515,8 +515,20 @@ struct mount __lookup_mnt(struct vfsmount mnt, struct dentry *dentry,
		}

		/*
		* lookup_mnt increments the ref count before returning
		* the vfsmount struct.
		* lookup_mnt - Return the first child mount mounted at path
		*
		* "First" means first mounted chronologically. If you create the
		* following mounts:
		*
		* mount /dev/sda1 /mnt
		* mount /dev/sda2 /mnt
		* mount /dev/sda3 /mnt
		*
		* Then lookup_mnt() on the base /mnt dentry in the root mount will
		* return successively the root dentry and vfsmount of /dev/sda1, then
		* /dev/sda2, then /dev/sda3, then NULL.
		*
		* lookup_mnt takes a reference to the found vfsmount.
		*/
		struct vfsmount lookup_mnt(struct path path)
		{