@node Project 4 Suggested Order of Implementation
@section Suggested Order of Implementation
-We suggest implementing the parts of this project in the following
-order to make your job easier:
+To make your job easier, we suggest implementing the parts of this
+project in the following order:
@enumerate
@item
Remaining miscellaneous items.
@end enumerate
+You can implement extensible files and subdirectories in parallel if
+you temporarily make the number of entries in new directories fixed.
+
You should think about synchronization throughout.
@node Project 4 Requirements
We have also provided @command{pwd}, which is not so straightforward.
The @command{shell} program implements @command{cd} internally.
-The @code{pintos} @option{put} and @option{get} commands should now
+The @code{pintos} @option{extract} and @option{append} commands should now
accept full path names, assuming that the directories used in the
paths have already been created. This should not require any significant
extra effort on your part.
Modify the file system to keep a cache of file blocks. When a request
is made to read or write a block, check to see if it is in the
cache, and if so, use the cached data without going to
-disk. Otherwise, fetch the block from disk into cache, evicting an
+disk. Otherwise, fetch the block from disk into the cache, evicting an
older entry if necessary. You are limited to a cache no greater than 64
sectors in size.
You must implement a cache replacement algorithm that is at least as
-good as the ``clock'' algorithm. Your algorithm must also account for
+good as the ``clock'' algorithm. We encourage you to account for
the generally greater value of metadata compared to data. Experiment
to see what combination of accessed, dirty, and other information
results in the best performance, as measured by the number of disk
copies of inodes would subvert the 64-block limitation that we place
on your cache.
-You can store a pointer to inode data in @struct{inode}, but it you do
+You can store a pointer to inode data in @struct{inode}, but if you do
so you should carefully make sure that this does not limit your OS to 64
simultaneously open files.
You can also store other information to help you find the inode when you