Each instance of struct inode represents a file in rootfs. VFS defines this structure as an abstraction for filesystem-specific inodes. Irrespective of the type of inode structure and its representation on disk, each filesystem needs to enumerate its files as struct inode into rootfs for a common file view. This structure is defined in <linux/fs.h>:
struct inode { umode_t i_mode; unsigned short i_opflags; kuid_t i_uid; kgid_t i_gid; unsigned int i_flags;#ifdef CONFIG_FS_POSIX_ACL struct posix_acl *i_acl; struct posix_acl *i_default_acl;#endif const struct inode_operations *i_op; struct super_block *i_sb; struct address_space *i_mapping;#ifdef CONFIG_SECURITY void *i_security;#endif /* Stat data, not accessed from path walking ...
