update lec21 spoc discuss

related_info/lab8/sfs-homework.md

@@ -103,10 +103,10 @@ fs.data:         [(.,0) (..,0) (y,1) (z,2) (x,3)] [u] [(.,3) (..,0)] [] ...
    
 
 ## 问题1： 
-根据文件系统的状态变化信息，给出具体的文件相关操作内容
+根据[sfs文件系统的状态变化信息](https://github.com/chyyuu/ucore_lab/blob/master/related_info/lab8/sfs-states.txt)，给出具体的文件相关操作内容.
 
 ## 问题2：
-实现 `writeFile, createFile, createLink, deleteFile`，使得你的实现能够达到与问题1的正确结果一致
+在[sfs-homework.py 参考代码的基础上](https://github.com/chyyuu/ucore_lab/blob/master/related_info/lab8/sfs-homework.py)，实现 `writeFile, createFile, createLink, deleteFile`，使得你的实现能够达到与问题1的正确结果一致
 
 ## 问题3：
 实现`soft link`机制，并设计测试用例说明你实现的正确性。   

related_info/lab8/sfs_states.txt

@@ -0,0 +1,83 @@
+ARG seed 0
+ARG numInodes 8
+ARG numData 8
+ARG numRequests 10
+ARG reverse False
+ARG printFinal False
+
+Initial state
+
+inode bitmap  10000000
+inodes        [d a:0 r:2] [] [] [] [] [] [] [] 
+data bitmap   10000000
+data          [(.,0) (..,0)] [] [] [] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11000000
+inodes        [d a:0 r:3] [d a:1 r:2] [] [] [] [] [] [] 
+data bitmap   11000000
+data          [(.,0) (..,0) (g,1)] [(.,1) (..,0)] [] [] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11100000
+inodes        [d a:0 r:4] [d a:1 r:2] [f a:-1 r:1] [] [] [] [] [] 
+data bitmap   11000000
+data          [(.,0) (..,0) (g,1) (q,2)] [(.,1) (..,0)] [] [] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11110000
+inodes        [d a:0 r:5] [d a:1 r:2] [f a:-1 r:1] [f a:-1 r:1] [] [] [] [] 
+data bitmap   11000000
+data          [(.,0) (..,0) (g,1) (q,2) (u,3)] [(.,1) (..,0)] [] [] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11110000
+inodes        [d a:0 r:6] [d a:1 r:2] [f a:-1 r:1] [f a:-1 r:2] [] [] [] [] 
+data bitmap   11000000
+data          [(.,0) (..,0) (g,1) (q,2) (u,3) (x,3)] [(.,1) (..,0)] [] [] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11111000
+inodes        [d a:0 r:7] [d a:1 r:2] [f a:-1 r:1] [f a:-1 r:2] [d a:2 r:2] [] [] [] 
+data bitmap   11100000
+data          [(.,0) (..,0) (g,1) (q,2) (u,3) (x,3) (t,4)] [(.,1) (..,0)] [(.,4) (..,0)] [] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11111100
+inodes        [d a:0 r:7] [d a:1 r:3] [f a:-1 r:1] [f a:-1 r:2] [d a:2 r:2] [f a:-1 r:1] [] [] 
+data bitmap   11100000
+data          [(.,0) (..,0) (g,1) (q,2) (u,3) (x,3) (t,4)] [(.,1) (..,0) (c,5)] [(.,4) (..,0)] [] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11111100
+inodes        [d a:0 r:6] [d a:1 r:3] [f a:-1 r:1] [f a:-1 r:1] [d a:2 r:2] [f a:-1 r:1] [] [] 
+data bitmap   11100000
+data          [(.,0) (..,0) (g,1) (q,2) (u,3) (t,4)] [(.,1) (..,0) (c,5)] [(.,4) (..,0)] [] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11111110
+inodes        [d a:0 r:6] [d a:1 r:4] [f a:-1 r:1] [f a:-1 r:1] [d a:2 r:2] [f a:-1 r:1] [d a:3 r:2] [] 
+data bitmap   11110000
+data          [(.,0) (..,0) (g,1) (q,2) (u,3) (t,4)] [(.,1) (..,0) (c,5) (w,6)] [(.,4) (..,0)] [(.,6) (..,1)] [] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11111110
+inodes        [d a:0 r:6] [d a:1 r:4] [f a:-1 r:1] [f a:-1 r:1] [d a:2 r:2] [f a:4 r:1] [d a:3 r:2] [] 
+data bitmap   11111000
+data          [(.,0) (..,0) (g,1) (q,2) (u,3) (t,4)] [(.,1) (..,0) (c,5) (w,6)] [(.,4) (..,0)] [(.,6) (..,1)] [o] [] [] [] 
+
+Which operation took place?
+
+inode bitmap  11111111
+inodes        [d a:0 r:7] [d a:1 r:4] [f a:-1 r:1] [f a:-1 r:1] [d a:2 r:2] [f a:4 r:1] [d a:3 r:2] [f a:-1 r:1] 
+data bitmap   11111000
+data          [(.,0) (..,0) (g,1) (q,2) (u,3) (t,4) (n,7)] [(.,1) (..,0) (c,5) (w,6)] [(.,4) (..,0)] [(.,6) (..,1)] [o] [] [] []