f_test - basic concurrent filesystem test
f_test consists of three tests, 1-3, that can be specified on the command line. If nothing is specified, all three tests are run.
Test 1 writes a large file (a bit over 270k) and reads it back.
Test 2 creates and removes a directory tree, rather like dirtest.
Test 3 spawns three subprocesses that simultaneously read and write the same file.
f_test uses the following system calls:
f_test should run correctly once the file system assignment is complete.