1 files changed, 91 insertions, 0 deletions
diff --git a/vendor/rustix/src/fs/statx.rs b/vendor/rustix/src/fs/statx.rs
new file mode 100644
index 000000000..fa1d36779
--- /dev/null
+++ b/vendor/rustix/src/fs/statx.rs
@@ -0,0 +1,91 @@
+//! Linux `statx`.
+
+use crate::fd::{AsFd, BorrowedFd};
+use crate::ffi::CStr;
+use crate::fs::AtFlags;
+use crate::{imp, io, path};
+use core::sync::atomic::{AtomicU8, Ordering};
+
+pub use imp::fs::types::{Statx, StatxFlags, StatxTimestamp};
+
+/// `statx(dirfd, path, flags, mask, statxbuf)`
+///
+/// This function returns [`io::Errno::NOSYS`] if `statx` is not available on
+/// the platform, such as Linux before 4.11. This also includes older Docker
+/// versions where the actual syscall fails with different error codes; Rustix
+/// handles this and translates them into `NOSYS`.
+///
+/// # References
+///  - [Linux]
+///
+/// [Linux]: https://man7.org/linux/man-pages/man2/statx.2.html
+#[inline]
+pub fn statx<P: path::Arg, Fd: AsFd>(
+    dirfd: Fd,
+    path: P,
+    flags: AtFlags,
+    mask: StatxFlags,
+) -> io::Result<Statx> {
+    path.into_with_c_str(|path| _statx(dirfd.as_fd(), path, flags, mask))
+}
+
+// Linux kernel prior to 4.11 old versions of Docker don't support `statx`. We
+// store the availability in a global to avoid unnecessary syscalls.
+//
+// 0: Unknown
+// 1: Not available
+// 2: Available
+static STATX_STATE: AtomicU8 = AtomicU8::new(0);
+
+#[inline]
+fn _statx(
+    dirfd: BorrowedFd<'_>,
+    path: &CStr,
+    flags: AtFlags,
+    mask: StatxFlags,
+) -> io::Result<Statx> {
+    match STATX_STATE.load(Ordering::Relaxed) {
+        0 => statx_init(dirfd, path, flags, mask),
+        1 => Err(io::Errno::NOSYS),
+        _ => imp::fs::syscalls::statx(dirfd, path, flags, mask),
+    }
+}
+
+/// The first `statx` call. We don't know if `statx` is available yet.
+fn statx_init(
+    dirfd: BorrowedFd<'_>,
+    path: &CStr,
+    flags: AtFlags,
+    mask: StatxFlags,
+) -> io::Result<Statx> {
+    match imp::fs::syscalls::statx(dirfd, path, flags, mask) {
+        Err(io::Errno::NOSYS) => statx_error_nosys(),
+        Err(io::Errno::PERM) => statx_error_perm(),
+        result => {
+            STATX_STATE.store(2, Ordering::Relaxed);
+            result
+        }
+    }
+}
+
+/// The first `statx` call failed with `NOSYS` (or something we're treating
+/// like `NOSYS`).
+#[cold]
+fn statx_error_nosys() -> io::Result<Statx> {
+    STATX_STATE.store(1, Ordering::Relaxed);
+    Err(io::Errno::NOSYS)
+}
+
+/// The first `statx` call failed with `PERM`.
+#[cold]
+fn statx_error_perm() -> io::Result<Statx> {
+    // Some old versions of Docker have `statx` fail with `PERM` when it isn't
+    // recognized. Check whether `statx` really is available, and if so, fail
+    // with `PERM`, and if not, treat it like `NOSYS`.
+    if imp::fs::syscalls::is_statx_available() {
+        STATX_STATE.store(2, Ordering::Relaxed);
+        Err(io::Errno::PERM)
+    } else {
+        statx_error_nosys()
+    }
+}