Proper way to get device file minor number from struct file

[Matwey V. Kornilov]

Hello,

I am looking through some legacy out of tree custom linux kernel device
driver.

It is full of lines like the following:

iminor(fp->f_dentry->d_inode)

here struct file *fp is an argument of callback of struct file_operations.

Documentation/filesystems/porting says:

"f_dentry is gone; use f_path.dentry, or, better yet, see if you can
avoid it entirely"

So, is there a proper compatible way to do the same?