Add FSCONFIG_CMD_CREATE_EXCL

Cargo.toml

@@ -36,7 +36,7 @@ once_cell = { version = "1.5.2", optional = true }
 # libc backend can be selected via adding `--cfg=rustix_use_libc` to
 # `RUSTFLAGS` or enabling the `use-libc` cargo feature.
 [target.'cfg(all(not(rustix_use_libc), not(miri), target_os = "linux", target_endian = "little", any(target_arch = "arm", all(target_arch = "aarch64", target_pointer_width = "64"), target_arch = "riscv64", all(rustix_use_experimental_asm, target_arch = "powerpc64"), all(rustix_use_experimental_asm, target_arch = "mips"), all(rustix_use_experimental_asm, target_arch = "mips32r6"), all(rustix_use_experimental_asm, target_arch = "mips64"), all(rustix_use_experimental_asm, target_arch = "mips64r6"), target_arch = "x86", all(target_arch = "x86_64", target_pointer_width = "64"))))'.dependencies]
-linux-raw-sys = { version = "0.4.14", default-features = false, features = ["general", "errno", "ioctl", "no_std", "elf"] }
+linux-raw-sys = { version = "0.6.5", default-features = false, features = ["general", "errno", "ioctl", "no_std", "elf"] }
 libc_errno = { package = "errno", version = "0.3.8", default-features = false, optional = true }
 libc = { version = "0.2.156", default-features = false, optional = true }
 

src/backend/libc/mount/syscalls.rs

@@ -270,3 +270,17 @@ pub(crate) fn fsconfig_reconfigure(fs_fd: BorrowedFd<'_>) -> io::Result<()> {
         ))
     }
 }
+
+#[cfg(linux_kernel)]
+#[cfg(feature = "mount")]
+pub(crate) fn fsconfig_create_excl(fs_fd: BorrowedFd<'_>) -> io::Result<()> {
+    unsafe {
+        ret(fsconfig(
+            borrowed_fd(fs_fd),
+            super::types::FsConfigCmd::CreateExclusive as _,
+            null(),
+            null(),
+            0,
+        ))
+    }
+}

src/backend/libc/mount/types.rs

@@ -145,6 +145,9 @@ pub(crate) enum FsConfigCmd {
 
     /// `FSCONFIG_CMD_RECONFIGURE`
     Reconfigure = 7,
+
+    /// `FSCONFIG_CMD_CREATE_EXCL`
+    CreateExclusive = 8,
 }
 
 #[cfg(feature = "mount")]

src/backend/linux_raw/mount/syscalls.rs

@@ -237,3 +237,18 @@ pub(crate) fn fsconfig_reconfigure(fs_fd: BorrowedFd<'_>) -> io::Result<()> {
         ))
     }
 }
+
+#[cfg(feature = "mount")]
+#[inline]
+pub(crate) fn fsconfig_create_excl(fs_fd: BorrowedFd<'_>) -> io::Result<()> {
+    unsafe {
+        ret(syscall_readonly!(
+            __NR_fsconfig,
+            fs_fd,
+            super::types::FsConfigCmd::CreateExclusive,
+            zero(),
+            zero(),
+            zero()
+        ))
+    }
+}

src/backend/linux_raw/mount/types.rs

@@ -143,6 +143,9 @@ pub(crate) enum FsConfigCmd {
 
     /// `FSCONFIG_CMD_RECONFIGURE`
     Reconfigure = linux_raw_sys::general::fsconfig_command::FSCONFIG_CMD_RECONFIGURE as u32,
+
+    /// `FSCONFIG_CMD_CREATE_EXCL`
+    CreateExclusive = linux_raw_sys::general::fsconfig_command::FSCONFIG_CMD_CREATE_EXCL as u32,
 }
 
 #[cfg(feature = "mount")]

src/mount/fsopen.rs

@@ -217,3 +217,15 @@ pub fn fsconfig_create(fs_fd: BorrowedFd<'_>) -> io::Result<()> {
 pub fn fsconfig_reconfigure(fs_fd: BorrowedFd<'_>) -> io::Result<()> {
     backend::mount::syscalls::fsconfig_reconfigure(fs_fd)
 }
+
+/// `fsconfig(fs_fd, FSCONFIG_CMD_CREATE_EXCL, key, NULL, 0)`
+///
+/// # References
+///  - [Unfinished draft]
+///
+/// [Unfinished draft]: https://github.com/sunfishcode/linux-mount-api-documentation/blob/main/fsconfig.md
+#[inline]
+#[doc(alias = "fsconfig")]
+pub fn fsconfig_create_exclusive(fs_fd: BorrowedFd<'_>) -> io::Result<()> {
+    backend::mount::syscalls::fsconfig_create_excl(fs_fd)
+}