X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?p=pintos-anon;a=blobdiff_plain;f=doc%2Ffilesys.texi;h=eb2ba766bf8ec675d36746cf0bb268c06374328b;hp=f245daa48ea1e6d592a86146ddddf9947ca9cffe;hb=59f738d500f51ffc5f487344865b8bed69c26281;hpb=c9667cc796f96017951f8ac90978846918c184d7 diff --git a/doc/filesys.texi b/doc/filesys.texi index f245daa..eb2ba76 100644 --- a/doc/filesys.texi +++ b/doc/filesys.texi @@ -112,8 +112,8 @@ for test @var{t} is named @file{@var{t}.tar}. @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 @@ -134,6 +134,9 @@ should pass the directory tests. 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 @@ -300,7 +303,7 @@ 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 +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. @@ -311,12 +314,12 @@ 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 @@ -516,7 +519,7 @@ corresponding sector from disk when it's created. Keeping extra 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