What is the role of inodes, directories, and metadata in a file system?

• A. Inodes store file metadata and pointers to data blocks; directories map names to inodes; metadata enables access control, timestamps, and permissions.
• B. Inodes store file content; directories store file permissions.
• C. Directories store file data blocks; inodes store file names.
• D. File system defines data and metadata layout; inodes store file metadata and pointers to data blocks; directories map names to inodes.

Answer: (A)

In this topic, the focus is on how a file system organizes information about files. Inodes, directories, and metadata work together to make file access efficient and secure. An inode is like a container for a file’s core attributes: it stores file metadata such as size, ownership, permissions, and timestamps, and it also holds pointers to the actual data blocks on disk. It does not hold the file’s name or its content itself. Directories act as the namescape for the file system—they’re special files that map human-friendly names to inode numbers. When you look up a file by name, the directory entry tells the system which inode to open. Metadata, the attributes associated with a file (and sometimes its ACLs), governs how the file can be accessed and tracked: it includes permission bits that determine who can read, write, or execute, as well as timestamps like when the file was last accessed or modified. Together, this separation lets the system resolve a name to its data efficiently via the inode, while enforcing security and keeping an accurate history through metadata.