From 01a6c054d548d9fff8bbdfac4d3f3de4ae8677a1 Mon Sep 17 00:00:00 2001 From: Austin Clements Date: Wed, 7 Sep 2011 11:49:14 -0400 Subject: Remove web directory; all cruft or moved to 6.828 repo --- web/xv6-disk.html | 63 ------------------------------------------------------- 1 file changed, 63 deletions(-) delete mode 100644 web/xv6-disk.html (limited to 'web/xv6-disk.html') diff --git a/web/xv6-disk.html b/web/xv6-disk.html deleted file mode 100644 index 65bcf8f..0000000 --- a/web/xv6-disk.html +++ /dev/null @@ -1,63 +0,0 @@ - - -Homework: Files and Disk I/O - - - -

Homework: Files and Disk I/O

- -

-Read: bio.c, fd.c, fs.c, and ide.c - -

-This homework should be turned in at the beginning of lecture. - -

-File and Disk I/O - -

Insert a print statement in bwrite so that you get a -print every time a block is written to disk: - -

-  cprintf("bwrite sector %d\n", sector);
-

- -

Build and boot a new kernel and run these three commands at the shell: -

-  echo >a
-  echo >a
-  rm a
-  mkdir d
-

- -(You can try rm d if you are curious, but it should look -almost identical to rm a.) - -

You should see a sequence of bwrite prints after running each command. -Record the list and annotate it with the calling function and -what block is being written. -For example, this is the second echo >a: - -

-$ echo >a
-bwrite sector 121  # writei  (data block)
-bwrite sector 3    # iupdate (inode block)
-$ 
-

- -

Hint: the easiest way to get the name of the -calling function is to add a string argument to bwrite, -edit all the calls to bwrite to pass the name of the -calling function, and just print it. -You should be able to reason about what kind of -block is being written just from the calling function. - -

You need not write the following up, but try to -understand why each write is happening. This will -help your understanding of the file system layout -and the code. - -

-This completes the homework. - - -- cgit v1.2.3