http://blog.chinaunix.net/uid-14735472-id-2921377.htmlexplain some of the data structure of the virtual file system and the relationship between them, some places do not understandhttp://www.docin.com/p-941544538.htmlexplains the links between the various data structures created by the kernel when the process opens a file after partitioning the disk, each partition can have its own separate file system, and the physical file system can be the same or different. The way that different physical file systems organize data is certainly different, for example, ext2 file systems organize data by relying on superblock blocks, inode blocks, and block blocks of three basic units, But other file systems like the FAT file system do not organize the data in this way. This means that the underlying drivers for different file systems are definitely not the same. so the problem is, when we use these file IO functions to manipulate files, we are not concerned with the fact that the file systems on different disk partitions are not the same. For all file systems, we use the same interfaces to manipulate the files. we can do this because there is a layer of virtual file system in the middle of the application and the physical file system, the role of the virtual file system is to shield the application from the underlying various file systems, to provide a unified interface for the application. the virtual file system mainly includes superblock structure, inode structure, dentry structure, and file structure. superblock in superblock structure corresponding to file system Inode structure corresponding to inode in file systemdentry structure corresponding to the directory entry in the file systemFile struct in order to represent an open document
File io detailed (iii)---Linux virtual file system
