Inode - Index Node

• The index number is the unique identifier (inode number) assigned by the filesystem to every object (file/directory) upon creation. Inode numbers are dynamic and tied to the specific filesystem instance. They are not persistent across different machine images or re-formatted volumes.

Low-Level Context

The inode is a data structure in the inode table

• Stored Metadata: Permissions, UID/GID, Timestamps, Size, and Data Block Pointers.
• Missing Data: The inode does not store the filename. Filenames are stored in the directory entry (dentry), which maps a name to an inode number
• To retrieve the inode number of a specific file:`
  • ls -i <file> #ls or stat <file> #stat
• Code References (VFS)
  • struct inode in include/Linux/fs.h
  • struct dentry in include/Linux/dcache.h

Related Research

• Linux/Kernel/Filesystem/Superblocks
• Linux/Kernel/Filesystem/Dentries