Move DeviceId to separate device-id crate

Cargo.lock

@@ -223,6 +223,7 @@ dependencies = [
  "controlled",
  "core2",
  "cpio-decoder",
+ "device-id",
  "getset",
  "hashbrown 0.14.5",
  "id-alloc",
@@ -665,6 +666,10 @@ dependencies = [
  "powerfmt",
 ]
 
+[[package]]
+name = "device-id"
+version = "0.1.0"
+
 [[package]]
 name = "either"
 version = "1.15.0"

Cargo.toml

@@ -33,6 +33,7 @@ members = [
     "kernel/libs/aster-rights-proc",
     "kernel/libs/aster-util",
     "kernel/libs/aster-bigtcp",
+    "kernel/libs/device-id",
     "kernel/libs/jhash",
     "kernel/libs/keyable-arc",
     "kernel/libs/logo-ascii-art",

Makefile

@@ -183,6 +183,7 @@ NON_OSDK_CRATES := \
 	kernel/libs/aster-rights-proc \
 	kernel/libs/atomic-integer-wrapper \
 	kernel/libs/cpio-decoder \
+	kernel/libs/device-id \
 	kernel/libs/int-to-c-enum \
 	kernel/libs/int-to-c-enum/derive \
 	kernel/libs/jhash \

kernel/Cargo.toml

@@ -32,6 +32,7 @@ aster-rights-proc = { path = "libs/aster-rights-proc" }
 aster-util = { path = "libs/aster-util" }
 aster-bigtcp = { path = "libs/aster-bigtcp" }
 atomic-integer-wrapper = { path = "libs/atomic-integer-wrapper" }
+device-id = { path = "libs/device-id" }
 id-alloc = { path = "../ostd/libs/id-alloc" }
 int-to-c-enum = { path = "libs/int-to-c-enum" }
 jhash = { path = "libs/jhash" }

kernel/libs/device-id/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "device-id"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[lints]
+workspace = true

kernel/libs/device-id/src/lib.rs

@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: MPL-2.0
+
+//! A module represents Linux kernel device IDs.
+//!
+//! In Linux, each device is identified by a **major** number and a **minor** number.
+//! These two numbers together form a unique identifier for the device, which is used
+//! in device files (e.g., `/dev/sda`, `/dev/null`) and system calls like `mknod`.
+//!
+//! For more information about device ID allocation and usage in Linux, see:
+//! <https://www.kernel.org/doc/Documentation/admin-guide/devices.txt>
+
+#![no_std]
+#![deny(unsafe_code)]
+
+/// A device ID, containing a major device number and a minor device number.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct DeviceId {
+    major: u32,
+    minor: u32,
+}
+
+impl DeviceId {
+    /// Creates a device ID from the major device number and the minor device number.
+    pub fn new(major: u32, minor: u32) -> Self {
+        Self { major, minor }
+    }
+
+    /// Returns the major device number.
+    pub fn major(&self) -> u32 {
+        self.major
+    }
+
+    /// Returns the minor device number.
+    pub fn minor(&self) -> u32 {
+        self.minor
+    }
+}
+
+impl DeviceId {
+    /// Creates a device ID from the encoded `u64` value.
+    ///
+    /// See [`as_encoded_u64`] for details about how to encode a device ID to a `u64` value.
+    ///
+    /// [`as_encoded_u64`]: Self::as_encoded_u64
+    pub fn from_encoded_u64(raw: u64) -> Self {
+        let major = ((raw >> 32) & 0xffff_f000 | (raw >> 8) & 0x0000_0fff) as u32;
+        let minor = ((raw >> 12) & 0xffff_ff00 | raw & 0x0000_00ff) as u32;
+        Self::new(major, minor)
+    }
+
+    /// Encodes the device ID as a `u64` value.
+    ///
+    /// The lower 32 bits use the same encoding strategy as Linux. See the Linux implementation at:
+    /// <https://github.com/torvalds/linux/blob/0ff41df1cb268fc69e703a08a57ee14ae967d0ca/include/linux/kdev_t.h#L39-L44>.
+    ///
+    /// If the major or minor device number is too large, the additional bits will be recorded
+    /// using the higher 32 bits. Note that as of 2025, the Linux kernel still has no support for
+    /// 64-bit device IDs:
+    /// <https://github.com/torvalds/linux/blob/0ff41df1cb268fc69e703a08a57ee14ae967d0ca/include/linux/types.h#L18>.
+    /// So this encoding follows the implementation in glibc:
+    /// <https://github.com/bminor/glibc/blob/632d895f3e5d98162f77b9c3c1da4ec19968b671/bits/sysmacros.h#L26-L34>.
+    pub fn as_encoded_u64(&self) -> u64 {
+        let major = self.major() as u64;
+        let minor = self.minor() as u64;
+        ((major & 0xffff_f000) << 32)
+            | ((major & 0x0000_0fff) << 8)
+            | ((minor & 0xffff_ff00) << 12)
+            | (minor & 0x0000_00ff)
+    }
+}

kernel/src/device/full.rs

@@ -1,9 +1,11 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use crate::{
     events::IoEvents,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         inode_handle::FileIo,
         utils::StatusFlags,
     },

kernel/src/device/mod.rs

@@ -14,13 +14,14 @@ pub mod tdxguest;
 
 use alloc::format;
 
+use device_id::DeviceId;
 pub use pty::{new_pty_pair, PtyMaster, PtySlave};
 pub use random::Random;
 pub use urandom::Urandom;
 
 use crate::{
     fs::{
-        device::{add_node, Device, DeviceId},
+        device::{add_node, Device},
         fs_resolver::FsPath,
         path::PerMountFlags,
         ramfs::RamFs,

kernel/src/device/null.rs

@@ -1,9 +1,11 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use crate::{
     events::IoEvents,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         inode_handle::FileIo,
         utils::StatusFlags,
     },

kernel/src/device/random.rs

@@ -1,10 +1,12 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use super::Urandom;
 use crate::{
     events::IoEvents,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         inode_handle::FileIo,
         utils::StatusFlags,
     },

kernel/src/device/tdxguest/mod.rs

@@ -4,6 +4,7 @@ use core::{mem::size_of, time::Duration};
 
 use align_ext::AlignExt;
 use aster_util::{field_ptr, safe_ptr::SafePtr};
+use device_id::DeviceId;
 use ostd::{
     mm::{DmaCoherent, FrameAllocOptions, HasPaddr, HasSize, VmIo, PAGE_SIZE},
     sync::WaitQueue,
@@ -17,7 +18,7 @@ use tdx_guest::{
 use crate::{
     events::IoEvents,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         inode_handle::FileIo,
         utils::{IoctlCmd, StatusFlags},
     },

kernel/src/device/tty/device.rs

@@ -1,9 +1,11 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use crate::{
     events::IoEvents,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         inode_handle::FileIo,
         utils::StatusFlags,
     },

kernel/src/device/tty/mod.rs

@@ -5,6 +5,7 @@ use aster_console::{
     mode::{ConsoleMode, KeyboardMode},
     AnyConsoleDevice,
 };
+use device_id::DeviceId;
 use ostd::sync::LocalIrqDisabled;
 
 use self::{line_discipline::LineDiscipline, termio::CFontOp};
@@ -12,7 +13,7 @@ use crate::{
     current_userspace,
     events::IoEvents,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         inode_handle::FileIo,
         utils::{IoctlCmd, StatusFlags},
     },

kernel/src/device/urandom.rs

@@ -1,9 +1,11 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use crate::{
     events::IoEvents,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         inode_handle::FileIo,
         utils::StatusFlags,
     },

kernel/src/device/zero.rs

@@ -1,9 +1,11 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use crate::{
     events::IoEvents,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         inode_handle::FileIo,
         utils::StatusFlags,
     },

kernel/src/fs/device.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use super::inode_handle::FileIo;
 use crate::{
     fs::{
@@ -43,63 +45,6 @@ pub enum DeviceType {
     Misc,
 }
 
-/// A device ID, containing a major device number and a minor device number.
-#[derive(Clone, Copy, Debug)]
-pub struct DeviceId {
-    major: u32,
-    minor: u32,
-}
-
-impl DeviceId {
-    /// Creates a device ID from the major device number and the minor device number.
-    pub fn new(major: u32, minor: u32) -> Self {
-        Self { major, minor }
-    }
-
-    /// Returns the major device number.
-    pub fn major(&self) -> u32 {
-        self.major
-    }
-
-    /// Returns the minor device number.
-    pub fn minor(&self) -> u32 {
-        self.minor
-    }
-}
-
-impl DeviceId {
-    /// Creates a device ID from the encoded `u64` value.
-    ///
-    /// See [`as_encoded_u64`] for details about how to encode a device ID to a `u64` value.
-    ///
-    /// [`as_encoded_u64`]: Self::as_encoded_u64
-    pub fn from_encoded_u64(raw: u64) -> Self {
-        let major = ((raw >> 32) & 0xffff_f000 | (raw >> 8) & 0x0000_0fff) as u32;
-        let minor = ((raw >> 12) & 0xffff_ff00 | raw & 0x0000_00ff) as u32;
-        Self::new(major, minor)
-    }
-
-    /// Encodes the device ID as a `u64` value.
-    ///
-    /// The lower 32 bits use the same encoding strategy as Linux. See the Linux implementation at:
-    /// <https://github.com/torvalds/linux/blob/0ff41df1cb268fc69e703a08a57ee14ae967d0ca/include/linux/kdev_t.h#L39-L44>.
-    ///
-    /// If the major or minor device number is too large, the additional bits will be recorded
-    /// using the higher 32 bits. Note that as of 2025, the Linux kernel still has no support for
-    /// 64-bit device IDs:
-    /// <https://github.com/torvalds/linux/blob/0ff41df1cb268fc69e703a08a57ee14ae967d0ca/include/linux/types.h#L18>.
-    /// So this encoding follows the implementation in glibc:
-    /// <https://github.com/bminor/glibc/blob/632d895f3e5d98162f77b9c3c1da4ec19968b671/bits/sysmacros.h#L26-L34>.
-    pub fn as_encoded_u64(&self) -> u64 {
-        let major = self.major() as u64;
-        let minor = self.minor() as u64;
-        ((major & 0xffff_f000) << 32)
-            | ((major & 0x0000_0fff) << 8)
-            | ((minor & 0xffff_ff00) << 12)
-            | (minor & 0x0000_00ff)
-    }
-}
-
 /// Adds a device node in `/dev`.
 ///
 /// If the parent path does not exist, it will be created as a directory.

kernel/src/fs/devpts/mod.rs

@@ -13,7 +13,7 @@ use super::utils::MknodType;
 use crate::{
     device::PtyMaster,
     fs::{
-        device::{Device, DeviceId, DeviceType},
+        device::{Device, DeviceType},
         registry::{FsProperties, FsType},
         utils::{
             mkmod, DirEntryVecExt, DirentVisitor, FileSystem, FsFlags, Inode, InodeMode, InodeType,

kernel/src/fs/devpts/ptmx.rs

@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use super::*;
 use crate::{
     events::IoEvents,

kernel/src/syscall/mknod.rs

@@ -1,10 +1,11 @@
 // SPDX-License-Identifier: MPL-2.0
 
+use device_id::DeviceId;
+
 use super::SyscallReturn;
 use crate::{
     device::get_device,
     fs::{
-        device::DeviceId,
         file_table::FileDesc,
         fs_resolver::{FsPath, AT_FDCWD},
         utils::{InodeMode, InodeType, MknodType},

kernel/src/syscall/statx.rs

@@ -2,9 +2,11 @@
 
 use core::time::Duration;
 
+use device_id::DeviceId;
+
 use super::SyscallReturn;
 use crate::{
-    fs::{device::DeviceId, file_table::FileDesc, fs_resolver::FsPath, utils::Metadata},
+    fs::{file_table::FileDesc, fs_resolver::FsPath, utils::Metadata},
     prelude::*,
     syscall::constants::MAX_FILENAME_LEN,
 };