爲什麼VFS函數同時獲得結構inode和文件？

Question

看來，struct file包含struct inode *，但都被傳遞給VFS功能。爲什麼不單純通過struct file *？

例如， int (*open) (struct inode *, struct file *);

Answer 1

簡短回答：由於歷史原因。

他們開始從file_operations參數在Linux 2.1的刪除struct inode* - 即看一看2.1.60承諾：

http://repo.or.cz/w/davej-history.git/blobdiff/1018aab0cbe3c20a69685bfa5d217d3535067686..be6cc637f086b24887a11bd4bcc7445220c9b0ff:/include/linux/fs.h

@@ -533,9 +534,9 @@ struct super_block { 
typedef int (*filldir_t)(void *, const char *, int, off_t, ino_t); 

struct file_operations { 
-  long long (*llseek) (struct file *, long long, int); 
-  long (*read) (struct inode *, struct file *, char *, unsigned long); 
-  long (*write) (struct inode *, struct file *, const char *, unsigned long); 
+  loff_t (*llseek) (struct file *, loff_t, int); 
+  ssize_t (*read) (struct file *, char *, size_t, loff_t *); 
+  ssize_t (*write) (struct file *, const char *, size_t, loff_t *); 
     int (*readdir) (struct file *, void *, filldir_t); 
     unsigned int (*poll) (struct file *, poll_table *); 
     int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long); 

我不知道爲什麼他們沒有做對於(*open)() - 可能是因爲在我們打開文件的時候，struct file*初始化未完成。

在現代性的核心do_dentry_open()這是否叫(*open)()，所以它是最基本的功能之前。