Filesystem: Review Questions - lyuanschool/SystemProgramming GitHub Wiki

Question numbers subject to change

Q1

Write a function that uses fseek and ftell to replace the middle character of a file with an 'X'

void xout(char* filename) {
  FILE *f = fopen(filename, ____ );
  


}

Q2

In an ext2 filesystem how many inodes are read from disk to access the first byte of the file /dir1/subdirA/notes.txt ? Assume the directory names and inode numbers in the root directory (but not the inodes themselves) are already in memory.

Q3

In an ext2 filesystem what is the minimum number of disk blocks that must be read from disk to access the first byte of the file /dir1/subdirA/notes.txt ? Assume the directory names and inode numbers in the root directory and all inodes are already in memory.

Q4

In an ext2 filesystem with 32 bit addresses and 4KB disk blocks, an inodes that can store 10 direct disk block numbers. What is the minimum file size required to require an single indirection table? ii) a double direction table?

Q5

Fix the shell command chmod below to set the permission of a file secret.txt so that the owner can read,write,and execute permissions the group can read and everyone else has no access.

chmod 000 secret.txt
```