Files
asterinas/kernel/aster-nix/src/syscall/close.rs
2024-08-12 10:38:35 +08:00

31 lines
1.2 KiB
Rust

// SPDX-License-Identifier: MPL-2.0
use super::SyscallReturn;
use crate::{fs::file_table::FileDesc, prelude::*};
pub fn sys_close(fd: FileDesc, ctx: &Context) -> Result<SyscallReturn> {
debug!("fd = {}", fd);
let file = {
let mut file_table = ctx.process.file_table().lock();
let _ = file_table.get_file(fd)?;
file_table.close_file(fd).unwrap()
};
// Cleanup work needs to be done in the `Drop` impl.
//
// We don't mind the races between closing the file descriptor and using the file descriptor,
// because such races are explicitly allowed in the man pages. See the "Multithreaded processes
// and close()" section in <https://man7.org/linux/man-pages/man2/close.2.html>.
drop(file);
// Linux has error codes for the close() system call for diagnostic and remedial purposes, but
// only for a small subset of file systems such as NFS. We currently have no support for such
// file systems, so it's fine to just return zero.
//
// For details, see the discussion at <https://github.com/asterinas/asterinas/issues/506> and
// the "Dealing with error returns from close()" section at
// <https://man7.org/linux/man-pages/man2/close.2.html>.
Ok(SyscallReturn::Return(0))
}