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_impl.rs
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_impl.rs
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use std::{
ffi::OsStr,
fs::File,
io::{ErrorKind, Result},
path::Path,
};
#[cfg(windows)]
use fs_at::os::windows::{FileExt, OpenOptionsExt};
#[cfg(feature = "parallel")]
use rayon::prelude::*;
#[cfg(windows)]
use windows_sys::Win32::Storage::FileSystem::{DELETE, FILE_LIST_DIRECTORY, FILE_READ_ATTRIBUTES};
mod io;
mod path_components;
cfg_if::cfg_if! {
if #[cfg(windows)] {
mod win;
pub(crate) use win::WindowsIo as OsIo;
} else {
mod unix;
pub(crate) use unix::UnixIo as OsIo;
}
}
impl super::RemoveDir for std::fs::File {
fn remove_dir_contents(&mut self, debug_root: Option<&Path>) -> Result<()> {
// thunk over to the free version adding in the os-specific IO trait impl
let debug_root = match debug_root {
None => PathComponents::Path(Path::new("")),
Some(debug_root) => PathComponents::Path(debug_root),
};
_remove_dir_contents::<OsIo>(self, &debug_root)
}
}
/// Entry point for deprecated function
pub(crate) fn _ensure_empty_dir_path<I: io::Io, P: AsRef<Path>>(path: P) -> Result<()> {
// This is as TOCTOU safe as we can make it. Attacks via link replacements
// in interior components of the path is still possible. if the create
// succeeds, mission accomplished. if the create fails, open the dir
// (subject to races again), and then proceed to delete the contents via the
// descriptor.
match std::fs::create_dir(&path) {
Err(e) if e.kind() == ErrorKind::AlreadyExists => {
// Exists and is a dir. Open it
let mut existing_dir = I::open_dir(path.as_ref())?;
existing_dir.remove_dir_contents(Some(path.as_ref()))
}
otherwise => otherwise,
}
}
// Deprecated entry point
pub(crate) fn _remove_dir_contents_path<I: io::Io, P: AsRef<Path>>(path: P) -> Result<()> {
let mut d = I::open_dir(path.as_ref())?;
_remove_dir_contents::<I>(&mut d, &PathComponents::Path(path.as_ref()))
}
/// exterior lifetime interface to dir removal
fn _remove_dir_contents<I: io::Io>(d: &mut File, debug_root: &PathComponents<'_>) -> Result<()> {
let owned_handle = I::duplicate_fd(d)?;
remove_dir_contents_recursive::<I>(owned_handle, debug_root)?;
Ok(())
}
/// deprecated interface
pub(crate) fn remove_dir_all_path<I: io::Io, P: AsRef<Path>>(path: P) -> Result<()> {
let p = path.as_ref();
// Opportunity 1 for races
let d = I::open_dir(p)?;
let debug_root = PathComponents::Path(if p.has_root() { p } else { Path::new(".") });
remove_dir_contents_recursive::<OsIo>(d, &debug_root)?;
// Opportunity 2 for races
std::fs::remove_dir(&path)?;
#[cfg(feature = "log")]
log::trace!("removed {}", &debug_root);
Ok(())
}
use crate::RemoveDir;
use self::path_components::PathComponents;
// Core workhorse, heading towards this being able to be tasks.
#[allow(clippy::map_identity)]
fn remove_dir_contents_recursive<I: io::Io>(
mut d: File,
debug_root: &PathComponents<'_>,
) -> Result<File> {
#[cfg(feature = "log")]
log::trace!("scanning {}", &debug_root);
// We take a os level clone of the FD so that there are no lifetime
// concerns. It would *not* be ok to do readdir on one file twice
// concurrently because of shared kernel state.
let dirfd = I::duplicate_fd(&mut d)?;
cfg_if::cfg_if! {
if #[cfg(feature = "parallel")] {
let iter = fs_at::read_dir(&mut d)?;
let iter = iter.par_bridge();
} else {
let mut iter = fs_at::read_dir(&mut d)?;
}
}
iter.try_for_each(|dir_entry| -> Result<()> {
let dir_entry = dir_entry?;
let name = dir_entry.name();
if name == OsStr::new(".") || name == OsStr::new("..") {
return Ok(());
}
let dir_path = Path::new(name);
let dir_debug_root = PathComponents::Component(debug_root, dir_path);
#[cfg(windows)]
{
// On windows: open the file and then decide what to do with it.
let mut opts = fs_at::OpenOptions::default();
// Could possibly drop a syscall by dropping FILE_READ_ATTRIBUTES
// and trusting read_dir metadata more. OTOH that would introduce a
// race :/.
opts.desired_access(DELETE | FILE_LIST_DIRECTORY | FILE_READ_ATTRIBUTES);
let mut child_file = opts.open_path_at(&dirfd, name)?;
let metadata = child_file.metadata()?;
let is_dir = metadata.is_dir();
let is_symlink = metadata.is_symlink();
if is_dir && !is_symlink {
remove_dir_contents_recursive::<I>(
I::duplicate_fd(&mut child_file)?,
&dir_debug_root,
)?;
}
#[cfg(feature = "log")]
log::trace!("delete: {}", &dir_debug_root);
child_file.delete_by_handle().map_err(|(_f, e)| {
#[cfg(feature = "log")]
log::debug!("error removing {}", dir_debug_root);
e
})?;
}
#[cfg(not(windows))]
{
// Otherwise, open the path safely but normally, fstat to see if its
// a dir, then either unlink or recursively delete
let mut opts = fs_at::OpenOptions::default();
opts.read(true)
.write(fs_at::OpenOptionsWriteMode::Write)
.follow(false);
let child_result = opts.open_dir_at(&dirfd, name);
let is_dir = match child_result {
// We expect is_eloop to be the only error
Err(e) if !I::is_eloop(&e) => return Err(e),
Err(_) => false,
Ok(child_file) => {
let metadata = child_file.metadata()?;
let is_dir = metadata.is_dir();
if is_dir {
remove_dir_contents_recursive::<I>(child_file, &dir_debug_root)?;
#[cfg(feature = "log")]
log::trace!("rmdir: {}", &dir_debug_root);
let opts = fs_at::OpenOptions::default();
opts.rmdir_at(&dirfd, name).map_err(|e| {
#[cfg(feature = "log")]
log::debug!("error removing {}", dir_debug_root);
e
})?;
}
is_dir
}
};
if !is_dir {
#[cfg(feature = "log")]
log::trace!("unlink: {}", &dir_debug_root);
opts.unlink_at(&dirfd, name).map_err(|e| {
#[cfg(feature = "log")]
log::debug!("error removing {}", dir_debug_root);
e
})?;
}
}
#[cfg(feature = "log")]
log::trace!("removed {}", dir_debug_root);
Ok(())
})?;
#[cfg(feature = "log")]
log::trace!("scanned {}", &debug_root);
Ok(dirfd)
}