课程列表

• 电子线路计算机辅助设计
• 嵌入式系统设计
• SOPC系统设计

基本问题

• 自制计算机

开源资源

• 开源cpu
• gcc

好好学习天天向上

Linux驱动file_operations{}结构

在ARM-Linux操作系统的fs.h文件中定义了file_operations结构。

struct file_operations {

    struct module *owner;

    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 *, struct poll_table_struct *);

    int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);

    int (*mmap) (struct file *, struct vm_area_struct *);

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

    int (*flush) (struct file *);

    int (*release) (struct inode *, struct file *);

    int (*fsync) (struct file *, struct dentry *, int datasync);

    int (*fasync) (int, struct file *, int);

    int (*lock) (struct file *, int, struct file_lock *);

    ssize_t (*readv) (struct file *, const struct iovec *, unsigned long, loff_t *);

    ssize_t (*writev) (struct file *, const struct iovec *, unsigned long, loff_t *);

    ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);

    unsigned long (*get_unmapped_area)(struct file *, unsigned long,

unsigned long, unsigned long, unsigned long);

    #ifdef MAGIC_ROM_PTR

    int (*romptr) (struct file *, struct vm_area_struct *);

    #endif /* MAGIC_ROM_PTR */

};

表6.1描述了file_operations 结构体中主要成员作用。

表6.1  file_operations结构体成员变量

file_operations结构是Linux内核的重要数据结构，也是file{}、inode{}结构的重要成员。结构file{}和inode{}均定义在/include/linux/fs.h 中。

在file结构体中定义成员变量f_op。

   struct file_operations *f_op;

在inode结构体中定义成员变量i_fop。

   const   struct file_operations  *i_fop