File system project updates:

[pintos-anon] / doc / filesys.texi

diff --git a/doc/filesys.texi b/doc/filesys.texi
index 8e4dc4f964b4f352f7ffc30c6b672f2bda8573c5..49117a502ae1fad37b20f1ba9ff1a77b3cb79c44 100644 (file)
--- a/doc/filesys.texi
+++ b/doc/filesys.texi
@@ -176,18 +176,17 @@ not an external program.)
 Update the existing system calls so that, anywhere a file name is
 provided by the caller, an absolute or relative path name may used.
 The directory separator character is forward slash (@samp{/}).
 Update the existing system calls so that, anywhere a file name is
 provided by the caller, an absolute or relative path name may used.
 The directory separator character is forward slash (@samp{/}).

-You may support @file{.} and @file{..} for a small amount of extra
-credit.
+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
 
 Update the @code{remove} system call so that it can delete empty

-directories in addition to regular files.  Directories can only be
-deleted if they do not contain any files or subdirectories.
+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.
 
 Update the @code{open} system call so that it can also open directories.

-Passing @file{.} as the argument to @code{open} must open the current
-directory, regardless of whether @file{.} and @file{..} are fully
-implemented.  Of the existing system calls, only @code{close} needs to
-accept a file descriptor for a directory.
+Of the existing system calls, only @code{close} needs to accept a file
+descriptor for a directory.

 
 Implement the following new system calls:
 
 
 Implement the following new system calls:
 


@@ -213,8 +212,7 @@ name in @var{name}, which must have room for @code{READDIR_MAX_LEN + 1}
 bytes, and returns true.  If no entries are left in the directory,
 returns false.
 
 bytes, and returns true.  If no entries are left in the directory,
 returns false.
 

-@file{.} and @file{..} should not be returned by @code{readdir},
-regardless of whether they are implemented.
+@file{.} and @file{..} should not be returned by @code{readdir}.

 
 If the directory changes while it is open, then it is acceptable for
 some entries not to be read at all or to be read multiple times.
 
 If the directory changes while it is open, then it is acceptable for
 some entries not to be read at all or to be read multiple times.


@@ -230,14 +228,24 @@ Returns true if @var{fd} represents a directory,
 false if it represents an ordinary file.
 @end deftypefn
 
 false if it represents an ordinary file.
 @end deftypefn
 

+@deftypefn {System Call} int inumber (int @var{fd})
+Returns the @dfn{inode number} of the inode associated with @var{fd}.
+Applicable to file descriptors for both files and directories.
+
+An inode number persistently identifies a file or directory.  It is
+unique during the file's existence.  In Pintos, the sector number of the
+inode is suitable for use as an inode number.
+@end deftypefn
+

 We have provided @command{ls} and @command{mkdir} user programs, which
 We have provided @command{ls} and @command{mkdir} user programs, which

-are straightforward once the above syscalls are implemented.  The
-@command{shell} program implements @command{cd} internally.
+are straightforward once the above syscalls are implemented.  
+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
 accept full path names, assuming that the directories used in the
 
 The @code{pintos} @option{put} and @option{get} commands should now
 accept full path names, assuming that the directories used in the

-paths have already been created.  This should not require any extra
-effort on your part.
+paths have already been created.  This should not require any significant
+extra effort on your part.

 
 @node Buffer Cache
 @subsection Buffer Cache
 
 @node Buffer Cache
 @subsection Buffer Cache


@@ -385,13 +393,6 @@ modified by the reference solution.
  30 files changed, 2721 insertions(+), 286 deletions(-)
 @end verbatim
 
  30 files changed, 2721 insertions(+), 286 deletions(-)
 @end verbatim
 

-@item What extra credit opportunities are available?
-
-You may implement Unix-style support for @file{.} and @file{..} in
-relative paths in their projects.
-
-You may submit with VM enabled.
-

 @item Can @code{DISK_SECTOR_SIZE} change?
 
 No, @code{DISK_SECTOR_SIZE} is fixed at 512.  This is a fixed property
 @item Can @code{DISK_SECTOR_SIZE} change?
 
 No, @code{DISK_SECTOR_SIZE} is fixed at 512.  This is a fixed property


@@ -419,16 +420,20 @@ You'll need to consider this when deciding your inode organization.
 @subsection Subdirectories FAQ
 
 @table @b
 @subsection Subdirectories FAQ
 
 @table @b

-@item How should a file name like @samp{//a//b} be interpreted?
+@item How should a file name like @samp{a//b} be interpreted?

 
 Multiple consecutive slashes are equivalent to a single slash, so this
 
 Multiple consecutive slashes are equivalent to a single slash, so this

-file name is the same as @samp{/a/b}.
+file name is the same as @samp{a/b}.

 
 @item How about a file name like @samp{/../x}?
 
 
 @item How about a file name like @samp{/../x}?
 

-If you don't implement @file{.} and @file{..}, then this is not a
-special case.  If you do, then it is equivalent to @samp{/x}.  That is,
-the root directory is its own parent.
+The root directory is its own parent, so it is equivalent to @samp{/x}.
+
+@item How should a file name that ends in @samp{/} be treated?
+
+Most Unix systems allow a slash at the end of the name for a directory,
+and reject other names that end in slashes.  We will allow this
+behavior, as well as simply rejecting a name that ends in a slash.

 @end table
 
 @node Buffer Cache FAQ
 @end table
 
 @node Buffer Cache FAQ