Re: [PATCH v2] rust: file: optimize rust symbol generation for FileDescriptorReservation

Re: [PATCH v2] rust: file: optimize rust symbol generation for FileDescriptorReservation

[Alice Ryhl]

Adding Christian Brauner who originally merged the
rust/kernel/fs/file.rs file.

On Mon, Mar 17, 2025 at 10:37:02AM +0800, Kunwu Chan wrote:
> From: Kunwu Chan <kunwu.chan@hotmail.com>
> 
> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> with ARCH=arm64, the following symbols are generated:
> 
> $ nm vmlinux | grep ' _R'.*FileDescriptorReservation | rustfilt
> ... T <kernel::fs::file::FileDescriptorReservation>::fd_install
> ... T <kernel::fs::file::FileDescriptorReservation>::get_unused_fd_flags
> ... T <kernel::fs::file::FileDescriptorReservation as core::ops::drop::Drop>::drop
> 
> These Rust symbols are trivial wrappers around the C functions
> fd_install, put_unused_fd and put_task_struct. It
> doesn't make sense to go through a trivial wrapper for these
> functions, so mark them inline.
> 
> Link: https://github.com/Rust-for-Linux/linux/issues/1145
> Suggested-by: Alice Ryhl <aliceryhl@google.com>
> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>

Re: [PATCH v2] rust: file: optimize rust symbol generation for FileDescriptorReservation

[Christian Brauner]

On Mon, Mar 17, 2025 at 10:24:15AM +0000, Alice Ryhl wrote:
> Adding Christian Brauner who originally merged the
> rust/kernel/fs/file.rs file.
> 
> On Mon, Mar 17, 2025 at 10:37:02AM +0800, Kunwu Chan wrote:
> > From: Kunwu Chan <kunwu.chan@hotmail.com>
> > 
> > When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> > with ARCH=arm64, the following symbols are generated:
> > 
> > $ nm vmlinux | grep ' _R'.*FileDescriptorReservation | rustfilt
> > ... T <kernel::fs::file::FileDescriptorReservation>::fd_install
> > ... T <kernel::fs::file::FileDescriptorReservation>::get_unused_fd_flags
> > ... T <kernel::fs::file::FileDescriptorReservation as core::ops::drop::Drop>::drop
> > 
> > These Rust symbols are trivial wrappers around the C functions
> > fd_install, put_unused_fd and put_task_struct. It
> > doesn't make sense to go through a trivial wrapper for these
> > functions, so mark them inline.
> > 
> > Link: https://github.com/Rust-for-Linux/linux/issues/1145
> > Suggested-by: Alice Ryhl <aliceryhl@google.com>
> > Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> > Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> > Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
> 
> Reviewed-by: Alice Ryhl <aliceryhl@google.com>

I mentioned various times that anything fs related goes through the VFS
tree, I hope that we're all still aware of this agreement.

Re: [PATCH v2] rust: file: optimize rust symbol generation for FileDescriptorReservation

[Christian Brauner]

On Mon, 17 Mar 2025 10:37:02 +0800, Kunwu Chan wrote:
> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> with ARCH=arm64, the following symbols are generated:
> 
> $ nm vmlinux | grep ' _R'.*FileDescriptorReservation | rustfilt
> ... T <kernel::fs::file::FileDescriptorReservation>::fd_install
> ... T <kernel::fs::file::FileDescriptorReservation>::get_unused_fd_flags
> ... T <kernel::fs::file::FileDescriptorReservation as core::ops::drop::Drop>::drop
> 
> [...]

Applied to the vfs-6.15.rust branch of the vfs/vfs.git tree.
Patches in the vfs-6.15.rust branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-6.15.rust

[1/1] rust: file: optimize rust symbol generation for FileDescriptorReservation
      https://git.kernel.org/vfs/vfs/c/e27b0e3c54f0

Re: [PATCH v2] rust: file: optimize rust symbol generation for FileDescriptorReservation

[Benno Lossin]

On Mon Mar 17, 2025 at 3:37 AM CET, Kunwu Chan wrote:
> From: Kunwu Chan <kunwu.chan@hotmail.com>
>
> When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
> with ARCH=arm64, the following symbols are generated:
>
> $ nm vmlinux | grep ' _R'.*FileDescriptorReservation | rustfilt
> ... T <kernel::fs::file::FileDescriptorReservation>::fd_install
> ... T <kernel::fs::file::FileDescriptorReservation>::get_unused_fd_flags
> ... T <kernel::fs::file::FileDescriptorReservation as core::ops::drop::Drop>::drop
>
> These Rust symbols are trivial wrappers around the C functions
> fd_install, put_unused_fd and put_task_struct. It
> doesn't make sense to go through a trivial wrapper for these
> functions, so mark them inline.
>
> Link: https://github.com/Rust-for-Linux/linux/issues/1145
> Suggested-by: Alice Ryhl <aliceryhl@google.com>
> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>

Reviewed-by: Benno Lossin <benno.lossin@proton.me>

---
Cheers,
Benno


> ---
> Changes in v2:
>  - Add link and Suggested-by
>  - Mark 'reserved_fd' as inline
>  - Reword commit msg
> ---
>  rust/kernel/fs/file.rs | 4 ++++
>  1 file changed, 4 insertions(+)