Figure 13.9 shows an inode data structure. Suppose a file system that uses this structure has filled up the blocks stemming from the doubly indirect pointers. How many disk accesses will it take to write one more byte to the file? Assume that the inode and free block bitmap are both completely in memory, but there is no buffer cache. Also assume that blocks do not have to be initialized.

Inode File control block Data blocks Data block pointers Data blocks Data block pointers Indirect pointer Doubly indirect pointer Triply indirect pointer Indirect pointers Data block pointers Data block pointers Data block pointers Data blocks -Doubly indirectpointersl Indirect pointers Indirect pointers Data block pointers Data block pointers Data block pointers Data block pointers Data blocks Figure 13.9 |Inode structure. Inode File control block Data blocks Data block pointers Data blocks Data block pointers Indirect pointer Doubly indirect pointer Triply indirect pointer Indirect pointers Data block pointers Data block pointers Data block pointers Data blocks -Doubly indirectpointersl Indirect pointers Indirect pointers Data block pointers Data block pointers Data block pointers Data block pointers Data blocks Figure 13.9 |Inode structure