Problem
What is the maximum number of disk blocks that must be read in the UNIX Fast File System to fetch the first block of a file, as a function of the number of N layers of directories (in other words, the depth of the file in the directory tree). Assume that nothing is in the file cache. Hint: To read each directory layer, at most we must read the inode, a triple indirect block, a double indirect block, an indirect block, and the data block. Then, to read the first block of the file, we must read its inode and data block.