@file{filesys/Make.vars} to enable VM functionality. You can receive up
to 5% extra credit if you do enable VM.
+The tests for project 4 (and later projects) will probably run faster if
+you use the qemu emulator, e.g.@: via @code{make check
+PINTOSOPTS='--qemu'}.
+
@menu
* Project 4 Background::
* Project 4 Requirements::
-* Project 4 FAQ::
+* Project 4 FAQ::
@end menu
@node Project 4 Background
free. Eliminate this problem by
modifying the on-disk inode structure. In practice, this probably means using
an index structure with direct, indirect, and doubly indirect blocks.
-(You are welcome to choose a different scheme as long as you explain the
+You are welcome to choose a different scheme as long as you explain the
rationale for it in your design documentation, and as long as it does
-not suffer from external fragmentation.)
+not suffer from external fragmentation (as does the extent-based file
+system we provide).
You can assume that the disk will not be larger than 8 MB. You must
support files as large as the disk (minus metadata). Each inode is
it, at your option. You must allow full path names to be
much longer than 14 characters.
-The current directory is maintained separately for each process. At
-startup, the initial process's current directory is the root directory.
+Maintain a separate current directory for each process. At
+startup, set the root as the initial process's current directory.
When one process starts another with the @code{exec} system call, the
child process inherits its parent's current directory. After that, the
two processes' current directories are independent, so that either
changing its own current directory has no effect on the other.
+(This is why, under Unix, the @command{cd} command is a shell built-in,
+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 @code{remove} system call so that it can delete empty
directories in addition to regular files. Directories can only be
@end deftypefn
We have provided @command{ls} and @command{mkdir} user programs, which
-are straightforward once the above syscalls are implemented. In Unix,
-these are programs rather than built-in shell commands, but
-@command{cd} is a shell command.
+are straightforward once the above syscalls are implemented.
The @code{pintos} @option{put} and @option{get} commands should now
accept full path names, assuming that the directories used in the
No, @code{DISK_SECTOR_SIZE} is fixed at 512. This is a fixed property
of IDE disk hardware.
-
-@item What's the directory separator character?
-
-Forward slash (@samp{/}).
@end table
@menu
* Indexed Files FAQ::
-* Subdirectories FAQ::
* Buffer Cache FAQ::
@end menu
You'll need to consider this when deciding your inode organization.
@end table
-@node Subdirectories FAQ
-@subsection Subdirectories FAQ
-
-@table @b
-@item Why is @command{cd} a shell command?
-
-The current directory of each process is independent. A @command{cd}
-program could change its own current directory, but that would have no
-effect on the shell. In fact, Unix-like systems don't provide any way
-for one process to change another's current working directory.
-@end table
-
@node Buffer Cache FAQ
@subsection Buffer Cache FAQ
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}, if you want,
-and you can store other information to help you find the inode when you
+You can store a pointer to inode data in @struct{inode}, but it 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
need it. Similarly, you may store some metadata along each of your 64
cache entries.
projects / pintos-anon / blobdiff