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Date: Wed, 10 Jan 2024 09:45:27 +0000
To: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>, Wedson Almeida Filho <wedsonaf@gmail.com>
From: Benno Lossin <benno.lossin@proton.me>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>, Christian Brauner <brauner@kernel.org>, Matthew Wilcox <willy@infradead.org>, Kent Overstreet <kent.overstreet@gmail.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-fsdevel@vger.kernel.org, rust-for-linux@vger.kernel.org, Wedson Almeida Filho <walmeida@microsoft.com>
Subject: Re: [RFC PATCH 05/19] rust: fs: introduce `INode<T>`
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In-Reply-To: <87sf3e5v55.fsf@metaspace.dk>
References: <20231018122518.128049-1-wedsonaf@gmail.com> <20231018122518.128049-6-wedsonaf@gmail.com> <87sf3e5v55.fsf@metaspace.dk>
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On 03.01.24 13:54, Andreas Hindborg (Samsung) wrote:
> Wedson Almeida Filho <wedsonaf@gmail.com> writes:
>> +    /// Returns the super-block that owns the inode.
>> +    pub fn super_block(&self) -> &SuperBlock<T> {
>> +        // SAFETY: `i_sb` is immutable, and `self` is guaranteed to be =
valid by the existence of a
>> +        // shared reference (&self) to it.
>> +        unsafe { &*(*self.0.get()).i_sb.cast() }
>> +    }
>=20
> I think the safety comment should talk about the pointee rather than the
> pointer? "The pointee of `i_sb` is immutable, and ..."

I think in this case it would be a very good idea to just split
the `unsafe` block into two parts. That would solve the issue
of "what does this safety comment justify?".

--=20
Cheers,
Benno