Ubuntu：内核 5.6.0-rc3：file_operations 中不支持 IOCTL？

Posted 2023-02-22

【中文标题】Ubuntu：内核 5.6.0-rc3：file_operations 中不支持 IOCTL？

【英文标题】：Ubuntu: Kernel 5.6.0-rc3: No IOCTL support in file_operations?

【发布时间】：2020-03-01 16:57:30

【问题描述】：

我使用的是 ubuntu 和内核版本 5.6.3-rc3。 我在标头的file_operations 结构中看不到任何ioctl。

是否取消了支持？什么是替代品？

从linux/fs.h 标头粘贴到下方。

struct file_operations 
        struct module *owner;
        loff_t (*llseek) (struct file *, loff_t, int);
        ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
        ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
        ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
        ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
        int (*iopoll)(struct kiocb *kiocb, bool spin);
        int (*iterate) (struct file *, struct dir_context *);
        int (*iterate_shared) (struct file *, struct dir_context *);
        __poll_t (*poll) (struct file *, struct poll_table_struct *);
        long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
        long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
        int (*mmap) (struct file *, struct vm_area_struct *);
        unsigned long mmap_supported_flags;
        int (*open) (struct inode *, struct file *);
        int (*flush) (struct file *, fl_owner_t id);
        int (*release) (struct inode *, struct file *);
        int (*fsync) (struct file *, loff_t, loff_t, int datasync);
        int (*fasync) (int, struct file *, int);
        int (*lock) (struct file *, int, struct file_lock *);
        ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t
 unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
        int (*check_flags)(int);
        int (*setfl)(struct file *, unsigned long);
        int (*flock) (struct file *, int, struct file_lock *);
        ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
        ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
        int (*setlease)(struct file *, long, struct file_lock **, void **);
        long (*fallocate)(struct file *file, int mode, loff_t offset,
                          loff_t len);
        void (*show_fdinfo)(struct seq_file *m, struct file *f);
#ifndef CONFIG_MMU
        unsigned (*mmap_capabilities)(struct file *);
#endif
        ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
                        loff_t, size_t, unsigned int);
        loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
                                   struct file *file_out, loff_t pos_out,
                                   loff_t len, unsigned int remap_flags);
        int (*fadvise)(struct file *, loff_t, loff_t, int);
 __randomize_layout;

【参考方案1】：

ioctl() 文件操作自内核 v2.6.36 以来已被删除（很久以前）。

处理 ioctl 的“新”方式是通过 unlocked_ioctl() 和 compat_ioctl()，它们是在 v2.6.11 (2005) 中引入的，并且仍然存在于最新的内核中（以及您在上面粘贴的代码中）：

long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);

建议阅读：

LWN: The new way of ioctl() ioctl removal patchwork What is the difference between ioctl(), unlocked_ioctl() and compat_ioctl()?