Re: [PATCH RFC v12 1/3] fs/lock: add new callback, lm_lock_conflict, to lock_manager_operations

["J. Bruce Fields" <bfields@fieldses.org>]

On Wed, Feb 09, 2022 at 08:52:07PM -0800, Dai Ngo wrote:
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index bbf812ce89a8..726d0005e32f 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1068,6 +1068,14 @@ struct lock_manager_operations {
>  	int (*lm_change)(struct file_lock *, int, struct list_head *);
>  	void (*lm_setup)(struct file_lock *, void **);
>  	bool (*lm_breaker_owns_lease)(struct file_lock *);
> +	/*
> +	 * This callback function is called after a lock conflict is
> +	 * detected. This allows the lock manager of the lock that
> +	 * causes the conflict to see if the conflict can be resolved
> +	 * somehow. If it can then this callback returns false; the
> +	 * conflict was resolved, else returns true.
> +	 */
> +	bool (*lm_lock_conflict)(struct file_lock *cfl);
>  };

I don't love that name.  The function isn't checking for a lock
conflict--it'd have to know *what* the lock is conflicting with.  It's
being told whether the lock is still valid.

I'd prefer lm_lock_expired(), with the opposite return values.

(Apologies if this has already been woodshedded to death, I haven't been
following.)

--b.