Midterm Exam Project File Systems

Description

In this project, you will design and implement a simplifies UNIX like file system in C or C++. This project does not use MIPS or SPIM, so it is completely independent of your other homework assignments. This will count as midterm exam for this course.

Part 1

Design a file system that uses i-nodes blocks and data blocks to keep your files. Your file system will use, a i-node structure like Fig 4.33 of your textbook (single link, double link and triple link i-nodes). Your directory, i-node block, data block structure will be similar to Fig 4.34 of the textbook. Your file attributes will include size, last modification date and time, and name of the file. No permissions or owner attributes will be kept. Write a design report that specifies the following

• Define your directory structure and directory entries;

• Define how you keep the free blocks and free i-nodes;

• Define your i-node structure

• Define your superblock that contains crucial information about the file system such as the block size, i-node positions, block positions, etc.

Your report should include the function names of your source code that handles the file system operations listed in the table of Part 3.

Part 2

Write a C/C++ program that creates an empty file system as a 1 MB Linux file. This file will include all the information about your file system including the i-nodes, data blocks, free blocks and i-nodes, directories, data, etc. The sample run of the program will be like

makeFileSystem 4 400 mySystem.dat

where 4 is the block size of the file system in KB for both data blocks and i-node blocks, and 400 is the number of free i-nodes for an empty file system. mySystem.dat is the Linux file that contains all the file system. When you work on the file system, this file contains all the information for the file system. Note that the size of mySystem.dat will be exactly 1 MB all the time whether it contains any information or not.

Part 3

You will write a program that performs file system operation on the file system. The program will work like following

fileSystemOper fileSystem.data operation parameters

where fileSystemOper is your program, fileSystem.data is the file system data file that you have created in Part 2. You will keep modifying the same fileSystem.data file for all your operations. Allowable operations and parameters for these operations are given below in the following table.

Operation	Parameters	Explanation		Example
list	Path	Lists the contents of		fileSystemOper fileSystem.data list “/”
		the directory shown by
		path on the screen.		lists the contents of the root directory. The output will
				be like ls –l
mkdir	Path and dir	Makes or removes a		fileSystemOper fileSystem.data mkdir
	name	directory		“/usr/ysa”
rmdir				makes a new directory under the directory “ysa” if
				possible. These two works exactly like mkdir and
				rmdir commands of Linux shell
dumpe2fs	None	Gives information		fileSystemOper fileSystem.data dumpe2fs
		about the file system.
				works like simplified and modified Linux dumpe2fs
				command. It will list block count, i-node count, free
				block and i-nodes, number of files and directories, and
				block size. Different from regular dumpe2fs, this
				command lists all the occupied i-nodes, blocks and the
				file names for each of them.
write	Path and	Creates and writes data		fileSystemOper fileSystem.data write
	file name	to the file		“/usr/ysa/file” linuxFile
				Creates a file named file under “/usr/ysa” in your
				file system, then copies the contents of the Linux file
				into the new file. This works very similar to Linux
				copy command.
read	Path and	Reads data from the		fileSystemOper fileSystem.data read
	file name	file		“/usr/ysa/file” linuxFile
				Reads the file named file under “/usr/ysa” in your
				file system, then writes this data to the Linux file. This
				again works very similar to Linux copy command.
del	Path and	Deletes file from the		fileSystemOper fileSystem.data del
	file name	path		“/usr/ysa/file”
				Deletes the file named file under “/usr/ysa” in
				your file system. This again works very similar to
				Linux del command.

Operations below are bonus (20 points)

ln	Source and	Hard linking between	fileSystemOper fileSystem.data ln
	destination	2 files	“/usr/ysa/file1” “/usr/ysa/file2”
	path and		Allows more than one filename to refer to the same
	file names
			file
			Linux ln command
lnsym	Source and	Symbolic linking	fileSystemOper fileSystem.data lnsym
	destination	between 2 files	“/usr/ysa/file1” “/usr/ysa/file2”
	path and		Linux ln-s command
	file names

General Homework Guidelines

1. No cheating, No copying, No peaking to other people homework

2. Follow the instructions very carefully.

3. Send required files only. Do not share your whole file system with us.

4. If you fail to implement one of the requirements, leave it be. Do not send an empty file

5. Respect the file names! Our HW grading is case-sensitive.

6. Failing to comply any of the warnings above will result in getting a 0 for your current homework.

Homework Instructions

1. Download and Install Vmware Player from Official site.

2. Download and install our virtual machine from https://drive.google.com/open?id=1YppX3lNkyTsHV_lvA4w9TomNCUkpLeEg

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