• Study and enhance the File System Simulator
- See the FS_sim slide deck
• New features
- blockinfo - a new application that displays the information about the blocks in the file system
- ctime - implement ctime (creation time) in the inode
• Test and analysis
- Examine the file system simulator
• Feature 1: blockinfo
- This is a new application for the FS simulator. Its function is to print out the number of data blocks and the number of free blocks in the file system
- You need to write a simple design specification where you describe
• how you find all the data blocks
• how you find all the free blocks
- There are more than one solutions and you can use any solution
- Usage example
java blockinfo
The number of data blocks: 18
The number of free blocks: 5
• Feature 2: ctime
- The ctime is a field in an inode. It is used by the file system to record the creation time of a file (or a directory)
- Detailed design
• Modify the creat method in the Kernel class. Need to record the creation time when this method is called
• Modify ls to display the creation time. Name your ls program myls
- Usage example
java myls
inode_numberr file_size ctime file_name
• Test the FS simulator
- Execute the following commands
1. java mkfs filesys.dat 256 40
2. java mkdir /termproj
3. echo "This is file1, a small file for testing" | java tee /termproj/file1.txt
4. echo "This is a file2, a big file for testing. The cs506 term project is not difficult at all if I work hard on it. I like to work on a project with my friend. I am working hard to complete the project on time with high quality." | java tee /termproj/file2.txt
5. java myls /termproj
6. java myls /termproj/file2
7. java blockinfo filesys.dat
8. java mydump filesys.dat
• Deliverables
- Project report
1. blockinfo design specification
2. Test report
• screen shot of your testing
• answers to the questions, including the dump
- Software - only your code
1. Source file (blockinfo.java, myls.java, kernel.java)
2. Executable file (blockinfo.class, myls.class, kernel.class)
- Answer the following questions
1. What are the block number and address range of the superblock? Explain the content of the superblock.
2. What are the block number and address range of the free list block? Explain the content of the free list block.
3. What are the block number range and the address range of the inode blcoks? How many inodes are used? List all the inodes that are used and their corresponding directories and files. Explain the content of all the inodes.
4. What are the block number and the address range of the data block of directory termproj? Explain the content of this data block.
5. What are the block number and address range of the data block of file file1?
6. What are the block number range and the address range of the data blocks of file file2?