tailieunhanh - Lecture Operating system concepts - Chapter 12: File system implementation

This chapter is primarily concerned with issues surrounding file storage and access on the most common secondary-storage medium, the disk. We explore ways to structure file use, to allocate disk space, to recover freed space, to track the locations of data, and to interface other parts of the operating system to secondary storage. Performance issues are considered throughout the chapter. | Chapter 12: File System Implementation I File System Structure I File System Implementation I Directory Implementation I Allocation Methods I Free-Space Management I Efficiency and Performance I Recovery I Log-Structured File Systems I NFS Operating System Concepts Silberschatz, Galvin and Gagne 2002 File-System Structure I File structure ✦ Logical storage unit ✦ Collection of related information I File system resides on secondary storage (disks). I File system organized into layers. I File control block – storage structure consisting of information about a file. Operating System Concepts Silberschatz, Galvin and Gagne 2002 Layered File System Operating System Concepts Silberschatz, Galvin and Gagne 2002 A Typical File Control Block Operating System Concepts Silberschatz, Galvin and Gagne 2002 In-Memory File System Structures I The following figure illustrates the necessary file system structures provided by the operating systems. I Figure 12-3(a) refers to opening a file. I Figure 12-3(b) refers to reading a file. Operating System Concepts Silberschatz, Galvin and Gagne 2002 In-Memory File System Structures Operating System Concepts Silberschatz, Galvin and Gagne 2002 Virtual File Systems I Virtual File Systems (VFS) provide an object-oriented way of implementing file systems. I VFS allows the same system call interface (the API) to be used for different types of file systems. I The API is to the VFS interface, rather than any specific type of file system. Operating System Concepts Silberschatz, Galvin and Gagne 2002 Schematic View of Virtual File System Operating System Concepts Silberschatz, Galvin and Gagne 2002 Directory Implementation I Linear list of file names with pointer to the data blocks. ✦ simple to program ✦ time-consuming to execute I Hash Table – linear list with hash data structure. ✦ decreases directory search time ✦ collisions – situations where two file .

• Hệ điều hành
• Operating system concepts
• Lecture Operating system concepts
• Operating system
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• Operating system structure
• Hệ điều hành
• Operating system services
• Operating system structures
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• Operating System Debugging
• Operating System Generation
• Types of System Calls
• Computer system structures
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• File system implementation
• Computer system architecture
• The Linux system