X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Ffilesys.texi;h=db4d94810b63426f91ee03c6783bd63b5c1060be;hb=b51bfd75c7f55f008d67ec13d895694fbfa22430;hp=a93481cca37da657cf8ec50890691e12f2d39dfe;hpb=73389b59f54bfed8eb0cb370a5ffec1223686a9e;p=pintos-anon

diff --git a/doc/filesys.texi b/doc/filesys.texi
index a93481c..db4d948 100644
--- a/doc/filesys.texi
+++ b/doc/filesys.texi
@@ -25,6 +25,7 @@ to 5% extra credit if you do enable VM.
 
 @menu
 * File System New Code::        
+* Testing File System Persistence::  
 @end menu
 
 @node File System New Code
@@ -78,6 +79,35 @@ which you will remove.
 While most of your work will be in @file{filesys}, you should be
 prepared for interactions with all previous parts.
 
+@node Testing File System Persistence
+@subsection Testing File System Persistence
+
+By now, you should be familiar with the basic process of running the
+Pintos tests.  @xref{Testing}, for review, if necessary.
+
+Until now, each test invoked Pintos just once.  However, an important
+purpose of a file system is to ensure that data remains accessible from
+one boot to another.  Thus, the tests that are part of the file system
+project invoke Pintos a second time.  The second run combines all the
+files and directories in the file system into a single file, then copies
+that file out of the Pintos file system into the host (Unix) file
+system.
+
+The grading scripts check the file system's correctness based on the
+contents of the file copied out in the second run.  This means that your
+project will not pass any of the extended file system tests until the
+file system is implemented well enough to support @program{tar}, the
+Pintos user program that produces the file that is copied out.  The
+@program{tar} program is fairly demanding (it requires both extensible
+file and subdirectory support), so this will take some work.  Until
+then, you can ignore errors from @command{make check} regarding the
+extracted file system.
+
+Incidentally, as you may have surmised, the file format used for copying
+out the file system contents is the standard Unix ``tar'' format.  You
+can use the Unix @command{tar} program to examine them.  The tar file
+for test @var{t} is named @file{@var{t}.tar}.
+
 @node Project 4 Requirements
 @section Requirements
 
@@ -175,15 +205,19 @@ The directory separator character is forward slash (@samp{/}).
 You must also support special file names @file{.} and @file{..}, which
 have the same meanings as they do in Unix.
 
-Update the @code{remove} system call so that it can delete empty
-directories in addition to regular files.  Directories may only be
-deleted if they do not contain any files or subdirectories (other than
-@file{.} and @file{..}).
-
 Update the @code{open} system call so that it can also open directories.
 Of the existing system calls, only @code{close} needs to accept a file
 descriptor for a directory.
 
+Update the @code{remove} system call so that it can delete empty
+directories (other than the root) in addition to regular files.
+Directories may only be deleted if they do not contain any files or
+subdirectories (other than @file{.} and @file{..}).  You may decide
+whether to allow deletion of a directory that is open by a process or in
+use as a process's current working directory.  If it is allowed, then
+attempts to open files (including @file{.} and @file{..}) or create new
+files in a deleted directory must be disallowed.
+
 Implement the following new system calls:
 
 @deftypefn {System Call} bool chdir (const char *@var{dir})