linux-kernel - Re: [PATCH v5 4/4] rust: samples: Add debugfs sample

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Message-ID: <d61e11e2d99659cf13d0e20f56afe319720d03b7.camel@nvidia.com>
Date: Wed, 14 May 2025 22:40:09 +0000
From: Timur Tabi <ttabi@...dia.com>
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Subject: Re: [PATCH v5 4/4] rust: samples: Add debugfs sample

On Wed, 2025-05-14 at 15:32 -0700, Matthew Maurer wrote:
> One further possibility here, which we'd need Greg to weigh in on - we
> could add a method to the debugfs API intended for Rust usage which
> specifically releases a directory or file *without* releasing any
> nested elements. This would mean we could get rid of all the lifetimes
> on directory and file handles. 

I had a conversation with Greg about this topic just the other week.

https://lore.kernel.org/linux-doc/20250429173958.3973958-1-ttabi@nvidia.com/

There are two versions of debugfs_remove:

void debugfs_remove(struct dentry *dentry);
#define debugfs_remove_recursive debugfs_remove

Unfortunately, the direction that we've been going is to get rid of debugfs_remove_recursive() and
have drivers only call debugfs_remove().  

What would solve your problem is doing the opposite: making debugfs_remove() be non-recursive and
require drivers to call debugfs_remove_recursive() if that's what they really want.

Maybe we need debugfs_remove_single()?