> diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
> index
> d17c473c1ef292875475bf3bdf62d07241c13882..d713a6445a6267145a7014f308d
> f3bb25b8c3287 100644
> --- a/include/linux/sysfs.h
> +++ b/include/linux/sysfs.h
> @@ -305,8 +305,12 @@ struct bin_attribute {
>       struct address_space *(*f_mapping)(void);
>       ssize_t (*read)(struct file *, struct kobject *, struct
> bin_attribute *,
>                       char *, loff_t, size_t);
> +     ssize_t (*read_new)(struct file *, struct kobject *, const
> struct bin_attribute *,
> +                         char *, loff_t, size_t);
>       ssize_t (*write)(struct file *, struct kobject *, struct
> bin_attribute *,
>                        char *, loff_t, size_t);
> +     ssize_t (*write_new)(struct file *, struct kobject *,
> +                          const struct bin_attribute *, char *,
> loff_t, size_t);
>       loff_t (*llseek)(struct file *, struct kobject *, const
> struct bin_attribute *,
>                        loff_t, int);
>       int (*mmap)(struct file *, struct kobject *, const struct
> bin_attribute *attr,
> @@ -325,11 +329,28 @@ struct bin_attribute {
>   */
>  #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)-
> >attr)
>  
> +typedef ssize_t __sysfs_bin_rw_handler_new(struct file *, struct
> kobject *,
> +                                        const struct
> bin_attribute *, char *, loff_t, size_t);
> +
>  /* macros to create static binary attributes easier */
>  #define __BIN_ATTR(_name, _mode, _read, _write, _size)
> {             \
>       .attr = { .name = __stringify(_name), .mode = _mode
> },            \
> -     .read   =
> _read,                                                \
> -     .write  =
> _write,                                               \
> +     .read =
> _Generic(_read,                                               \
> +             __sysfs_bin_rw_handler_new * :
> NULL,                 \
> +             default :
> _read                                         \
> +     ),                                                      
>       \
> +     .read_new =
> _Generic(_read,                                       \
> +             __sysfs_bin_rw_handler_new * :
> _read,                        \
> +             default :
> NULL                                          \
> +     ),                                                      
>       \
> +     .write =
> _Generic(_write,                                      \
> +             __sysfs_bin_rw_handler_new * :
> NULL,                 \
> +             default :
> _write                                        \
> +     ),                                                      
>       \
> +     .write_new =
> _Generic(_write,                                      \
> +             __sysfs_bin_rw_handler_new * :
> _write,                       \
> +             default :
> NULL                                          \
> +     ),                                                      
>       \
>       .size   =
> _size,                                                \
>  }

It's probably a bit late now, but you've done this the wrong way
around.  What you should have done is added the const to .read/.write
then added a .read_old/.write_old with the original function prototype
and used _Generic() to switch between them.  Then when there are no
more non const left, you can simply remove .read_old and .write_old
without getting Linus annoyed by having to do something like this:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e70140ba0d2b1a30467d4af6bcfe761327b9ec95

Regards,

James


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