Re: [RFC 1/2] rwsem: introduce upgrade_read interface

[Christoph Hellwig]

On Wed, Oct 16, 2024 at 12:35:59PM +0800, lizhe.67@xxxxxxxxxxxxx wrote:
> From: Li Zhe <lizhe.67@xxxxxxxxxxxxx>
> 
> Introduce a new rwsem interface upgrade_read(). We can call it

It's obviously a try_upgrade_read, right?

> +extern int upgrade_read(struct rw_semaphore *sem);

No need for the extern.  Also please make any new advanced funtionality
like this an EXPORT_SYMBO_GPL.  That is if you actually had a modular
user, the current one is built-in.  (although we could use this in
XFS if it lands).