chapter 40 - file system implementation

Question 1

What are the two main aspects to understand in a file system?

Answer 1

• Data structures (inodes, bitmaps, data blocks)
• Access methods (system call handling like open, read, write)

Question 2

What does an inode store?

Answer 2

Metadata about a file: type, size, owner, permissions, timestamps, and pointers to data blocks

Question 2

What is the role of the superblock in a file system?

Answer 2

stores metadata like the number of inodes, number of data blocks, and locations of inode/data regions

Question 3

Why do file systems use both direct and indirect pointers in inodes?

Answer 3

Direct pointers allow fast access for small files; indirect pointers enable support for large files

Question 4

What does the inode number (i-number) do?

Answer 4

It indexes into the inode table to locate a file’s metadata

Question 5

What maps human-readable file names to inode numbers?

Answer 5

Directories

Question 6

Why are bitmaps used in file systems?

Answer 6

To track which inodes and data blocks are in use or free

Question 7

How are files found on disk using inodes?

Answer 7

The inode number indexes into an inode table that contains the file’s metadata and data block pointers

Question 8

What does the Open File Table (OFT) track?

Answer 8

File inode, access mode, current offset, and reference count

Question 9

What happens when write() needs to allocate a new block?

Answer 9

The file system updates the data bitmap, modifies the inode, and writes data to the allocated block