chmod

• So what does chmod do?

 int result = chmod("blookus", 0644);

• blookus is looked up as usual

• The result is an inode (or some error condition)

• The owner of the inode is checked against the owner of the process

• If they match, the kernel sets the mode in the inode:

 umode_t i_mode; drwxr-xr-x

• Also it updates the "ctime":

 struct timespec i_ctime;