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Diffstat (limited to 'vendor/rustix/src/fs/statx.rs')
| -rw-r--r-- | vendor/rustix/src/fs/statx.rs | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/vendor/rustix/src/fs/statx.rs b/vendor/rustix/src/fs/statx.rs new file mode 100644 index 00000000..f1d995ec --- /dev/null +++ b/vendor/rustix/src/fs/statx.rs @@ -0,0 +1,275 @@ +//! Linux `statx`. + +use crate::fd::AsFd; +use crate::fs::AtFlags; +use crate::{backend, io, path}; +use backend::c; +use bitflags::bitflags; + +#[cfg(feature = "linux_4_11")] +use backend::fs::syscalls::statx as _statx; +#[cfg(not(feature = "linux_4_11"))] +use compat::statx as _statx; + +/// `struct statx` for use with [`statx`]. +#[repr(C)] +#[derive(Debug, Copy, Clone)] +#[allow(missing_docs)] +#[non_exhaustive] +pub struct Statx { + pub stx_mask: u32, + pub stx_blksize: u32, + pub stx_attributes: StatxAttributes, + pub stx_nlink: u32, + pub stx_uid: u32, + pub stx_gid: u32, + pub stx_mode: u16, + pub(crate) __spare0: [u16; 1], + pub stx_ino: u64, + pub stx_size: u64, + pub stx_blocks: u64, + pub stx_attributes_mask: StatxAttributes, + pub stx_atime: StatxTimestamp, + pub stx_btime: StatxTimestamp, + pub stx_ctime: StatxTimestamp, + pub stx_mtime: StatxTimestamp, + pub stx_rdev_major: u32, + pub stx_rdev_minor: u32, + pub stx_dev_major: u32, + pub stx_dev_minor: u32, + pub stx_mnt_id: u64, + pub stx_dio_mem_align: u32, + pub stx_dio_offset_align: u32, + pub stx_subvol: u64, + pub stx_atomic_write_unit_min: u32, + pub stx_atomic_write_unit_max: u32, + pub stx_atomic_write_segments_max: u32, + pub(crate) __spare1: [u32; 1], + pub(crate) __spare3: [u64; 9], +} + +/// `struct statx_timestamp` for use with [`Statx`]. +#[repr(C)] +#[derive(Debug, Copy, Clone)] +#[non_exhaustive] +pub struct StatxTimestamp { + /// Seconds. + pub tv_sec: i64, + + /// Nanoseconds. Must be less than 1_000_000_000. + pub tv_nsec: u32, + + pub(crate) __reserved: i32, +} + +bitflags! { + /// `STATX_*` constants for use with [`statx`]. + /// + /// [`statx`]: crate::fs::statx + #[repr(transparent)] + #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)] + pub struct StatxFlags: u32 { + /// `STATX_TYPE` + const TYPE = c::STATX_TYPE; + + /// `STATX_MODE` + const MODE = c::STATX_MODE; + + /// `STATX_NLINK` + const NLINK = c::STATX_NLINK; + + /// `STATX_UID` + const UID = c::STATX_UID; + + /// `STATX_GID` + const GID = c::STATX_GID; + + /// `STATX_ATIME` + const ATIME = c::STATX_ATIME; + + /// `STATX_MTIME` + const MTIME = c::STATX_MTIME; + + /// `STATX_CTIME` + const CTIME = c::STATX_CTIME; + + /// `STATX_INO` + const INO = c::STATX_INO; + + /// `STATX_SIZE` + const SIZE = c::STATX_SIZE; + + /// `STATX_BLOCKS` + const BLOCKS = c::STATX_BLOCKS; + + /// `STATX_BASIC_STATS` + const BASIC_STATS = c::STATX_BASIC_STATS; + + /// `STATX_BTIME` + const BTIME = c::STATX_BTIME; + + /// `STATX_MNT_ID` (since Linux 5.8) + const MNT_ID = c::STATX_MNT_ID; + + /// `STATX_DIOALIGN` (since Linux 6.1) + const DIOALIGN = c::STATX_DIOALIGN; + + /// `STATX_ALL` + const ALL = c::STATX_ALL; + + /// <https://docs.rs/bitflags/*/bitflags/#externally-defined-flags> + const _ = !0; + } +} + +bitflags! { + /// `STATX_ATTR_*` flags for use with [`Statx`]. + #[repr(transparent)] + #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)] + pub struct StatxAttributes: u64 { + /// `STATX_ATTR_COMPRESSED` + const COMPRESSED = c::STATX_ATTR_COMPRESSED as u64; + + /// `STATX_ATTR_IMMUTABLE` + const IMMUTABLE = c::STATX_ATTR_IMMUTABLE as u64; + + /// `STATX_ATTR_APPEND` + const APPEND = c::STATX_ATTR_APPEND as u64; + + /// `STATX_ATTR_NODUMP` + const NODUMP = c::STATX_ATTR_NODUMP as u64; + + /// `STATX_ATTR_ENCRYPTED` + const ENCRYPTED = c::STATX_ATTR_ENCRYPTED as u64; + + /// `STATX_ATTR_AUTOMOUNT` + const AUTOMOUNT = c::STATX_ATTR_AUTOMOUNT as u64; + + /// `STATX_ATTR_MOUNT_ROOT` + const MOUNT_ROOT = c::STATX_ATTR_MOUNT_ROOT as u64; + + /// `STATX_ATTR_VERITY` + const VERITY = c::STATX_ATTR_VERITY as u64; + + /// `STATX_ATTR_DAX` + const DAX = c::STATX_ATTR_DAX as u64; + + /// <https://docs.rs/bitflags/*/bitflags/#externally-defined-flags> + const _ = !0; + } +} + +/// `statx(dirfd, path, flags, mask, statxbuf)`—Extended `stat`. +/// +/// 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] +/// +/// # Examples +/// +/// ``` +/// # use std::path::Path; +/// # use std::io; +/// # use rustix::fs::{AtFlags, StatxFlags}; +/// # use rustix::fd::BorrowedFd; +/// /// Try to determine if the provided path is a mount root. Will return +/// /// `Ok(None)` if the kernel is not new enough to support `statx` or +/// /// [`StatxAttributes::MOUNT_ROOT`]. +/// fn is_mountpoint(root: BorrowedFd<'_>, path: &Path) -> io::Result<Option<bool>> { +/// use rustix::fs::{AtFlags, StatxAttributes, StatxFlags}; +/// +/// match rustix::fs::statx( +/// root, +/// path, +/// AtFlags::NO_AUTOMOUNT | AtFlags::SYMLINK_NOFOLLOW, +/// StatxFlags::empty(), +/// ) { +/// Ok(r) => { +/// let present = r.stx_attributes_mask.contains(StatxAttributes::MOUNT_ROOT); +/// Ok(present.then(|| r.stx_attributes.contains(StatxAttributes::MOUNT_ROOT))) +/// } +/// Err(rustix::io::Errno::NOSYS) => Ok(None), +/// Err(e) => Err(e.into()), +/// } +/// } +/// ``` +/// +/// [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)) +} + +#[cfg(not(feature = "linux_4_11"))] +mod compat { + use crate::fd::BorrowedFd; + use crate::ffi::CStr; + use crate::fs::{AtFlags, Statx, StatxFlags}; + use crate::{backend, io}; + use core::sync::atomic::{AtomicU8, Ordering}; + + // Linux kernel prior to 4.11 and 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] + pub 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), + _ => backend::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 backend::fs::syscalls::statx(dirfd, path, flags, mask) { + Err(err) => statx_error(err), + result => { + STATX_STATE.store(2, Ordering::Relaxed); + result + } + } + } + + /// The first `statx` call failed. We can get a variety of error codes + /// from seccomp configs or faulty FUSE drivers, so we don't trust + /// `ENOSYS` or `EPERM` to tell us whether statx is available. + #[cold] + fn statx_error(err: io::Errno) -> io::Result<Statx> { + if backend::fs::syscalls::is_statx_available() { + // Statx is available. Record this, and fail with the error + // code of the initial `statx` call. + STATX_STATE.store(2, Ordering::Relaxed); + Err(err) + } else { + // Statx is not available. Record this, and fail with `NOSYS`. + STATX_STATE.store(1, Ordering::Relaxed); + Err(io::Errno::NOSYS) + } + } +} |