1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
//! Filesystem manipulation operations.
//!
//! To open a file ([`AsyncFd`]) use [`open_file`] or [`OpenOptions`].
use std::ffi::{CString, OsString};
use std::future::Future;
use std::marker::PhantomData;
use std::mem::zeroed;
use std::os::unix::ffi::OsStringExt;
use std::path::PathBuf;
use std::pin::Pin;
use std::task::{self, Poll};
use std::time::{Duration, SystemTime};
use std::{fmt, io, str};
use crate::extract::Extractor;
use crate::fd::{AsyncFd, Descriptor, File};
use crate::op::{op_future, poll_state, OpState};
use crate::{libc, Extract, SubmissionQueue};
/// Flags needed to fill [`Metadata`].
const METADATA_FLAGS: u32 = libc::STATX_TYPE
| libc::STATX_MODE
| libc::STATX_SIZE
| libc::STATX_BLOCKS
| libc::STATX_ATIME
| libc::STATX_MTIME
| libc::STATX_BTIME;
/// Options used to configure how a file ([`AsyncFd`]) is opened.
#[derive(Clone, Debug)]
#[must_use = "no file is opened until `a10::fs::OpenOptions::open` or `open_temp_file` is called"]
pub struct OpenOptions {
flags: libc::c_int,
mode: libc::mode_t,
}
impl OpenOptions {
/// Empty `OpenOptions`, has reading enabled by default.
pub const fn new() -> OpenOptions {
OpenOptions {
flags: libc::O_RDONLY, // NOTE: `O_RDONLY` is 0.
mode: 0o666, // Same as in std lib.
}
}
/// Enable read access.
///
/// Note that read access is already enabled by default, so this is only
/// useful if you called [`OpenOptions::write_only`] and want to enable read
/// access as well.
#[doc(alias = "O_RDONLY")]
#[doc(alias = "O_RDWR")]
pub const fn read(mut self) -> Self {
if (self.flags & libc::O_ACCMODE) == libc::O_WRONLY {
self.flags &= !libc::O_ACCMODE;
self.flags |= libc::O_RDWR;
} // Else we're already in read mode.
self
}
/// Enable write access.
#[doc(alias = "O_RDWR")]
pub const fn write(mut self) -> Self {
if (self.flags & libc::O_ACCMODE) == libc::O_RDONLY {
self.flags &= !libc::O_ACCMODE;
self.flags |= libc::O_RDWR;
} // Else we're already in write mode.
self
}
/// Only enable write access, disabling read access.
#[doc(alias = "O_WRONLY")]
pub const fn write_only(mut self) -> Self {
self.flags &= !libc::O_ACCMODE;
self.flags |= libc::O_WRONLY;
self
}
/// Set writing to append only mode.
///
/// # Notes
///
/// This requires [writing access] to be enabled.
///
/// [writing access]: OpenOptions::write
#[doc(alias = "O_APPEND")]
pub const fn append(mut self) -> Self {
self.flags |= libc::O_APPEND;
self
}
/// Truncate the file if it exists.
#[doc(alias = "O_TRUNC")]
pub const fn truncate(mut self) -> Self {
self.flags |= libc::O_TRUNC;
self
}
/// If the file doesn't exist create it.
pub const fn create(mut self) -> Self {
self.flags |= libc::O_CREAT;
self
}
/// Force a file to be created, failing if a file already exists.
///
/// This options implies [`OpenOptions::create`].
#[doc(alias = "O_EXCL")]
#[doc(alias = "O_CREAT")]
pub const fn create_new(mut self) -> Self {
self.flags |= libc::O_CREAT | libc::O_EXCL;
self
}
/// Write operations on the file will complete according to the requirements
/// of synchronized I/O *data* integrity completion.
///
/// By the time `write(2)` (and similar) return, the output data has been
/// transferred to the underlying hardware, along with any file metadata
/// that would be required to retrieve that data (i.e., as though each
/// `write(2)` was followed by a call to `fdatasync(2)`).
#[doc(alias = "O_DSYNC")]
pub const fn data_sync(mut self) -> Self {
self.flags |= libc::O_DSYNC;
self
}
/// Write operations on the file will complete according to the requirements
/// of synchronized I/O *file* integrity completion (by contrast with the
/// synchronized I/O data integrity completion provided by
/// [`OpenOptions::data_sync`].)
///
/// By the time `write(2)` (or similar) returns, the output data and
/// associated file metadata have been transferred to the underlying
/// hardware (i.e., as though each `write(2)` was followed by a call to
/// `fsync(2)`).
#[doc(alias = "O_SYNC")]
pub const fn sync(mut self) -> Self {
self.flags |= libc::O_SYNC;
self
}
/// Try to minimize cache effects of the I/O to and from this file.
///
/// File I/O is done directly to/from user-space buffers. This uses the
/// `O_DIRECT` flag which on its own makes an effort to transfer data
/// synchronously, but does not give the guarantees of the `O_SYNC` flag
/// ([`OpenOptions::sync`]) that data and necessary metadata are
/// transferred. To guarantee synchronous I/O, `O_SYNC` must be used in
/// addition to `O_DIRECT`.
#[doc(alias = "O_DIRECT")]
pub const fn direct(mut self) -> Self {
self.flags |= libc::O_DIRECT;
self
}
/// Sets the mode bits that a new file will be created with.
pub const fn mode(mut self, mode: libc::mode_t) -> Self {
self.mode = mode;
self
}
/// Create an unnamed temporary regular file. The `dir` argument specifies a
/// directory; an unnamed inode will be created in that directory's
/// filesystem. Anything written to the resulting file will be lost when the
/// last file descriptor is closed, unless the file is given a name.
///
/// [`OpenOptions::write`] must be set. The `linkat(2)` system call can be
/// used to make the temporary file permanent.
#[doc(alias = "O_TMPFILE")]
pub fn open_temp_file<D: Descriptor>(mut self, sq: SubmissionQueue, dir: PathBuf) -> Open<D> {
self.flags |= libc::O_TMPFILE;
self.open(sq, dir)
}
/// Open `path`.
#[doc(alias = "openat")]
pub fn open<D: Descriptor>(self, sq: SubmissionQueue, path: PathBuf) -> Open<D> {
Open {
path: Some(path_to_cstring(path)),
sq: Some(sq),
state: OpState::NotStarted((self.flags | D::cloexec_flag(), self.mode)),
kind: PhantomData,
}
}
}
/// Open a file in read-only mode.
pub fn open_file(sq: SubmissionQueue, path: PathBuf) -> Open<File> {
OpenOptions::new().read().open(sq, path)
}
/// [`Future`] to [`open`] an asynchronous file ([`AsyncFd`]).
///
/// [`open`]: OpenOptions::open
#[derive(Debug)]
#[must_use = "`Future`s do nothing unless polled"]
pub struct Open<D: Descriptor = File> {
/// Path used to open the file, need to stay in memory so the kernel can
/// access it safely.
// SAFETY: because this is not modified by the kernel it doesn't need an
// UnsafeCell. It is read-only (as the kernel also has read access).
path: Option<CString>,
sq: Option<SubmissionQueue>,
state: OpState<(libc::c_int, libc::mode_t)>,
kind: PhantomData<D>,
}
impl<D: Descriptor + Unpin> Future for Open<D> {
type Output = io::Result<AsyncFd<D>>;
fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<Self::Output> {
let op_index = poll_state!(
Open,
self.state,
self.sq.as_ref().unwrap(),
ctx,
|submission, (flags, mode)| unsafe {
// SAFETY: `path` is only removed after the state is set to `Done`.
let path = self.path.as_ref().unwrap();
submission.open_at(libc::AT_FDCWD, path.as_ptr(), flags, mode);
D::create_flags(submission);
}
);
match self.sq.as_ref().unwrap().poll_op(ctx, op_index) {
Poll::Ready(result) => {
self.state = OpState::Done;
match result {
Ok((_, fd)) => Poll::Ready(Ok(unsafe {
// SAFETY: the open operation ensures that `fd` is valid.
// SAFETY: unwrapped `sq` above already.
AsyncFd::from_raw(fd, self.sq.take().unwrap())
})),
Err(err) => Poll::Ready(Err(err)),
}
}
Poll::Pending => Poll::Pending,
}
}
}
impl<D: Descriptor> Extract for Open<D> {}
impl<D: Descriptor + Unpin> Future for Extractor<Open<D>> {
type Output = io::Result<(AsyncFd<D>, PathBuf)>;
fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<Self::Output> {
match Pin::new(&mut self.fut).poll(ctx) {
Poll::Ready(Ok(file)) => {
let path = path_from_cstring(self.fut.path.take().unwrap());
Poll::Ready(Ok((file, path)))
}
Poll::Ready(Err(err)) => Poll::Ready(Err(err)),
Poll::Pending => Poll::Pending,
}
}
}
impl<D: Descriptor> Drop for Open<D> {
fn drop(&mut self) {
if let Some(path) = self.path.take() {
match self.state {
OpState::Running(op_index) => {
// SAFETY: only when the `Future` completed is `self.sq`
// `None`, but in that case `self.path` would also be
// `None`.
let sq = self.sq.as_ref().unwrap();
let result = sq.cancel_op(op_index, path, |submission| unsafe {
submission.cancel_op(op_index);
// We'll get a canceled completion event if we succeeded, which
// is sufficient to cleanup the operation.
submission.no_completion_event();
});
if let Err(err) = result {
log::error!(
"dropped a10::Open before completion, attempt to cancel failed: {err}"
);
}
}
OpState::NotStarted(_) | OpState::Done => drop(path),
}
}
}
}
/// File(system) related system calls.
impl<D: Descriptor> AsyncFd<D> {
/// Sync all OS-internal metadata to disk.
///
/// # Notes
///
/// Any uncompleted writes may not be synced to disk.
#[doc(alias = "fsync")]
pub const fn sync_all<'fd>(&'fd self) -> SyncData<'fd, D> {
SyncData::new(self, 0)
}
/// This function is similar to [`sync_all`], except that it may not
/// synchronize file metadata to the filesystem.
///
/// This is intended for use cases that must synchronize content, but don’t
/// need the metadata on disk. The goal of this method is to reduce disk
/// operations.
///
/// [`sync_all`]: AsyncFd::sync_all
///
/// # Notes
///
/// Any uncompleted writes may not be synced to disk.
#[doc(alias = "fdatasync")]
pub const fn sync_data<'fd>(&'fd self) -> SyncData<'fd, D> {
SyncData::new(self, libc::IORING_FSYNC_DATASYNC)
}
/// Retrieve metadata about the file.
#[doc(alias = "statx")]
pub fn metadata<'fd>(&'fd self) -> Stat<'fd, D> {
let metadata = Box::new(Metadata {
// SAFETY: all zero values are valid representations.
inner: unsafe { zeroed() },
});
Stat::new(self, metadata, ())
}
/// Predeclare an access pattern for file data.
///
/// Announce an intention to access file data in a specific pattern in the
/// future, thus allowing the kernel to perform appropriate optimizations.
///
/// The advice applies to a (not necessarily existent) region starting at
/// offset and extending for len bytes (or until the end of the file if len
/// is 0). The advice is not binding; it merely constitutes an expectation
/// on behalf of the application.
#[doc(alias = "fadvise")]
#[doc(alias = "posix_fadvise")]
pub const fn advise<'fd>(
&'fd self,
offset: u64,
length: u32,
advice: libc::c_int,
) -> Advise<'fd, D> {
Advise::new(self, (offset, length, advice))
}
/// Manipulate file space.
///
/// Manipulate the allocated disk space for the file referred for the byte
/// range starting at `offset` and continuing for `length` bytes.
#[doc(alias = "fallocate")]
#[doc(alias = "posix_fallocate")]
pub const fn allocate<'fd>(
&'fd self,
offset: u64,
length: u32,
mode: libc::c_int,
) -> Allocate<'fd, D> {
Allocate::new(self, (offset, length, mode))
}
}
// SyncData.
op_future! {
fn AsyncFd::sync_all -> (),
struct SyncData<'fd> {
// Doesn't need any fields.
},
setup_state: flags: u32,
setup: |submission, fd, (), flags| unsafe {
submission.fsync(fd.fd(), flags);
},
map_result: |n| Ok(debug_assert!(n == 0)),
}
// Metadata.
op_future! {
fn AsyncFd::metadata -> Box<Metadata>,
struct Stat<'fd> {
/// Buffer to write the statx data into.
metadata: Box<Metadata>,
},
setup_state: _unused: (),
setup: |submission, fd, (metadata,), ()| unsafe {
submission.statx_file(fd.fd(), &mut metadata.inner, METADATA_FLAGS);
},
map_result: |this, (metadata,), n| {
debug_assert!(n == 0);
debug_assert!(metadata.inner.stx_mask & METADATA_FLAGS == METADATA_FLAGS);
Ok(metadata)
},
}
// Advise.
op_future! {
fn AsyncFd::advise -> (),
struct Advise<'fd> {
// Doesn't need any fields.
},
setup_state: flags: (u64, u32, libc::c_int),
setup: |submission, fd, (), (offset, length, advise)| unsafe {
submission.fadvise(fd.fd(), offset, length, advise);
},
map_result: |this, (), res| {
debug_assert!(res == 0);
Ok(())
},
}
// Allocate.
op_future! {
fn AsyncFd::allocate -> (),
struct Allocate<'fd> {
// Doesn't need any fields.
},
setup_state: flags: (u64, u32, libc::c_int),
setup: |submission, fd, (), (offset, length, mode)| unsafe {
submission.fallocate(fd.fd(), offset, length, mode);
},
map_result: |this, (), res| {
debug_assert!(res == 0);
Ok(())
},
}
/// Metadata information about a file.
///
/// See [`AsyncFd::metadata`] and [`Stat`].
#[repr(transparent)]
pub struct Metadata {
inner: libc::statx,
}
impl Metadata {
/// Returns the file type for this metadata.
pub const fn file_type(&self) -> FileType {
FileType(self.inner.stx_mode)
}
/// Returns `true` if this represents a directory.
#[doc(alias = "S_IFDIR")]
pub const fn is_dir(&self) -> bool {
self.file_type().is_dir()
}
/// Returns `true` if this represents a file.
#[doc(alias = "S_IFREG")]
pub const fn is_file(&self) -> bool {
self.file_type().is_file()
}
/// Returns `true` if this represents a symbolic link.
#[doc(alias = "S_IFLNK")]
pub const fn is_symlink(&self) -> bool {
self.file_type().is_symlink()
}
/// Returns the size of the file, in bytes, this metadata is for.
#[allow(clippy::len_without_is_empty)] // Makes no sense.
pub const fn len(&self) -> u64 {
self.inner.stx_size
}
/// The "preferred" block size for efficient filesystem I/O.
pub const fn block_size(&self) -> u32 {
self.inner.stx_blksize
}
/// Returns the permissions of the file this metadata is for.
pub const fn permissions(&self) -> Permissions {
Permissions(self.inner.stx_mode)
}
/// Returns the time this file was last modified.
pub fn modified(&self) -> SystemTime {
timestamp(&self.inner.stx_mtime)
}
/// Returns the time this file was last accessed.
///
/// # Notes
///
/// It's possible to disable keeping track of this access time, which makes
/// this function return an invalid value.
pub fn accessed(&self) -> SystemTime {
timestamp(&self.inner.stx_atime)
}
/// Returns the time this file was created.
pub fn created(&self) -> SystemTime {
timestamp(&self.inner.stx_btime)
}
}
#[allow(clippy::cast_sign_loss)] // Checked.
fn timestamp(ts: &libc::statx_timestamp) -> SystemTime {
let dur = Duration::new(ts.tv_sec as u64, ts.tv_nsec);
if ts.tv_sec.is_negative() {
SystemTime::UNIX_EPOCH - dur
} else {
SystemTime::UNIX_EPOCH + dur
}
}
impl fmt::Debug for Metadata {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("Metadata")
.field("file_type", &self.file_type())
.field("len", &self.len())
.field("block_size", &self.block_size())
.field("permissions", &self.permissions())
.field("modified", &self.modified())
.field("accessed", &self.accessed())
.field("created", &self.created())
.finish()
}
}
/// A structure representing a type of file with accessors for each file type.
///
/// See [`Metadata`].
#[derive(Copy, Clone)]
pub struct FileType(u16);
impl FileType {
/// Returns `true` if this represents a directory.
#[doc(alias = "S_IFDIR")]
pub const fn is_dir(&self) -> bool {
(self.0 & libc::S_IFMT as u16) == libc::S_IFDIR as u16
}
/// Returns `true` if this represents a file.
#[doc(alias = "S_IFREG")]
pub const fn is_file(&self) -> bool {
(self.0 & libc::S_IFMT as u16) == libc::S_IFREG as u16
}
/// Returns `true` if this represents a symbolic link.
#[doc(alias = "S_IFLNK")]
pub const fn is_symlink(&self) -> bool {
(self.0 & libc::S_IFMT as u16) == libc::S_IFLNK as u16
}
/// Returns `true` if this represents a socket.
#[doc(alias = "S_IFSOCK")]
pub const fn is_socket(&self) -> bool {
(self.0 & libc::S_IFMT as u16) == libc::S_IFSOCK as u16
}
/// Returns `true` if this represents a block device.
#[doc(alias = "S_IFBLK")]
pub const fn is_block_device(&self) -> bool {
(self.0 & libc::S_IFMT as u16) == libc::S_IFBLK as u16
}
/// Returns `true` if this represents a character device.
#[doc(alias = "S_IFCHR")]
pub const fn is_character_device(&self) -> bool {
(self.0 & libc::S_IFMT as u16) == libc::S_IFCHR as u16
}
/// Returns `true` if this represents a named fifo pipe.
#[doc(alias = "S_IFIFO")]
pub const fn is_named_pipe(&self) -> bool {
(self.0 & libc::S_IFMT as u16) == libc::S_IFIFO as u16
}
}
impl fmt::Debug for FileType {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let ty = if f.alternate() {
if self.is_dir() {
"directory"
} else if self.is_file() {
"file"
} else if self.is_symlink() {
"symbolic link"
} else if self.is_socket() {
"socket"
} else if self.is_block_device() {
"block device"
} else if self.is_character_device() {
"character device"
} else if self.is_named_pipe() {
"named pipe"
} else {
"unknown"
}
} else if self.is_dir() {
"d"
} else if self.is_file() {
"-"
} else if self.is_symlink() {
"l"
} else if self.is_socket() {
"s"
} else if self.is_block_device() {
"b"
} else if self.is_character_device() {
"c"
} else if self.is_named_pipe() {
"p"
} else {
"?"
};
f.debug_tuple("FileType").field(&ty).finish()
}
}
/// Access permissions.
///
/// See [`Metadata`].
#[derive(Copy, Clone)]
pub struct Permissions(u16);
impl Permissions {
/// Return `true` if the owner has read permission.
#[doc(alias = "S_IRUSR")]
pub const fn owner_can_read(&self) -> bool {
self.0 & libc::S_IRUSR as u16 != 0
}
/// Return `true` if the owner has write permission.
#[doc(alias = "S_IWUSR")]
pub const fn owner_can_write(&self) -> bool {
self.0 & libc::S_IWUSR as u16 != 0
}
/// Return `true` if the owner has execute permission.
#[doc(alias = "S_IXUSR")]
pub const fn owner_can_execute(&self) -> bool {
self.0 & libc::S_IXUSR as u16 != 0
}
/// Return `true` if the group the file belongs to has read permission.
#[doc(alias = "S_IRGRP")]
pub const fn group_can_read(&self) -> bool {
self.0 & libc::S_IRGRP as u16 != 0
}
/// Return `true` if the group the file belongs to has write permission.
#[doc(alias = "S_IWGRP")]
pub const fn group_can_write(&self) -> bool {
self.0 & libc::S_IWGRP as u16 != 0
}
/// Return `true` if the group the file belongs to has execute permission.
#[doc(alias = "S_IXGRP")]
pub const fn group_can_execute(&self) -> bool {
self.0 & libc::S_IXGRP as u16 != 0
}
/// Return `true` if others have read permission.
#[doc(alias = "S_IROTH")]
pub const fn others_can_read(&self) -> bool {
self.0 & libc::S_IROTH as u16 != 0
}
/// Return `true` if others have write permission.
#[doc(alias = "S_IWOTH")]
pub const fn others_can_write(&self) -> bool {
self.0 & libc::S_IWOTH as u16 != 0
}
/// Return `true` if others have execute permission.
#[doc(alias = "S_IXOTH")]
pub const fn others_can_execute(&self) -> bool {
self.0 & libc::S_IXOTH as u16 != 0
}
}
impl fmt::Debug for Permissions {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
// Create the same format as `ls(1)` uses.
let mut buf = [b'-'; 9];
if self.owner_can_read() {
buf[0] = b'r';
}
if self.owner_can_write() {
buf[1] = b'w';
}
if self.owner_can_execute() {
buf[2] = b'x';
}
if self.group_can_read() {
buf[3] = b'r';
}
if self.group_can_write() {
buf[4] = b'w';
}
if self.group_can_execute() {
buf[5] = b'x';
}
if self.others_can_read() {
buf[6] = b'r';
}
if self.others_can_write() {
buf[7] = b'w';
}
if self.others_can_execute() {
buf[8] = b'x';
}
let permissions = str::from_utf8(&buf).unwrap();
f.debug_tuple("Permissions").field(&permissions).finish()
}
}
/// Creates a new, empty directory.
pub fn create_dir(sq: SubmissionQueue, path: PathBuf) -> CreateDir {
CreateDir {
sq,
path: Some(path_to_cstring(path)),
state: OpState::NotStarted(()),
}
}
/// [`Future`] to [create a directory].
///
/// [create a directory]: create_dir
#[derive(Debug)]
#[must_use = "`Future`s do nothing unless polled"]
pub struct CreateDir {
sq: SubmissionQueue,
/// Path used to create the directory, need to stay in memory so the kernel
/// can access it safely.
// SAFETY: because this is not modified by the kernel it doesn't need an
// UnsafeCell. It is read-only (as the kernel also has read access).
path: Option<CString>,
state: OpState<()>,
}
impl Future for CreateDir {
type Output = io::Result<()>;
fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<Self::Output> {
#[rustfmt::skip]
let op_index = poll_state!(CreateDir, self.state, self.sq, ctx, |submission, ()| unsafe {
// SAFETY: `path` is only removed after the state is set to `Done`.
let path = self.path.as_ref().unwrap();
let mode = 0o777; // Same as used by the standard library.
submission.mkdirat(libc::AT_FDCWD, path.as_ptr(), mode);
});
match self.sq.poll_op(ctx, op_index) {
Poll::Ready(result) => {
self.state = OpState::Done;
match result {
Ok((_, res)) => Poll::Ready(Ok(debug_assert!(res == 0))),
Err(err) => Poll::Ready(Err(err)),
}
}
Poll::Pending => Poll::Pending,
}
}
}
impl Extract for CreateDir {}
impl Future for Extractor<CreateDir> {
type Output = io::Result<PathBuf>;
fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<Self::Output> {
match Pin::new(&mut self.fut).poll(ctx) {
Poll::Ready(Ok(())) => {
let path = path_from_cstring(self.fut.path.take().unwrap());
Poll::Ready(Ok(path))
}
Poll::Ready(Err(err)) => Poll::Ready(Err(err)),
Poll::Pending => Poll::Pending,
}
}
}
impl Drop for CreateDir {
fn drop(&mut self) {
if let Some(path) = self.path.take() {
match self.state {
OpState::Running(op_index) => {
let result = self.sq.cancel_op(op_index, path, |submission| unsafe {
submission.cancel_op(op_index);
// We'll get a canceled completion event if we succeeded, which
// is sufficient to cleanup the operation.
submission.no_completion_event();
});
if let Err(err) = result {
log::error!("dropped a10::CreateDir before completion, attempt to cancel failed: {err}");
}
}
OpState::NotStarted(()) | OpState::Done => drop(path),
}
}
}
}
/// Rename a file or directory to a new name.
pub fn rename(sq: SubmissionQueue, from: PathBuf, to: PathBuf) -> Rename {
Rename {
sq,
from: Some(path_to_cstring(from)),
to: Some(path_to_cstring(to)),
state: OpState::NotStarted(()),
}
}
/// [`Future`] to [`rename`] a file.
#[derive(Debug)]
#[must_use = "`Future`s do nothing unless polled"]
pub struct Rename {
sq: SubmissionQueue,
/// Paths used to rename the file, need to stay in memory so the kernel can
/// access it safely.
// SAFETY: because this is not modified by the kernel it doesn't need an
// UnsafeCell. It is read-only (as the kernel also has read access).
from: Option<CString>,
to: Option<CString>,
state: OpState<()>,
}
impl Future for Rename {
type Output = io::Result<()>;
fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<Self::Output> {
let op_index = poll_state!(Rename, self.state, self.sq, ctx, |submission, ()| unsafe {
// SAFETY: `from` and `to` are only removed after the state is set to `Done`.
let from = self.from.as_ref().unwrap();
let to = self.to.as_ref().unwrap();
submission.rename(
libc::AT_FDCWD,
from.as_ptr(),
libc::AT_FDCWD,
to.as_ptr(),
0,
);
});
match self.sq.poll_op(ctx, op_index) {
Poll::Ready(result) => {
self.state = OpState::Done;
match result {
Ok((_, res)) => Poll::Ready(Ok(debug_assert!(res == 0))),
Err(err) => Poll::Ready(Err(err)),
}
}
Poll::Pending => Poll::Pending,
}
}
}
impl Extract for Rename {}
impl Future for Extractor<Rename> {
type Output = io::Result<(PathBuf, PathBuf)>;
fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<Self::Output> {
match Pin::new(&mut self.fut).poll(ctx) {
Poll::Ready(Ok(())) => {
let from = path_from_cstring(self.fut.from.take().unwrap());
let to = path_from_cstring(self.fut.to.take().unwrap());
Poll::Ready(Ok((from, to)))
}
Poll::Ready(Err(err)) => Poll::Ready(Err(err)),
Poll::Pending => Poll::Pending,
}
}
}
impl Drop for Rename {
fn drop(&mut self) {
if let Some(from) = self.from.take() {
// SAFETY: if `from` is `Some`, so is `to` as we extract both or
// neither.
let to = self.to.take().unwrap();
match self.state {
OpState::Running(op_index) => {
let result = self
.sq
.cancel_op(op_index, (from, to), |submission| unsafe {
submission.cancel_op(op_index);
// We'll get a canceled completion event if we succeeded, which
// is sufficient to cleanup the operation.
submission.no_completion_event();
});
if let Err(err) = result {
log::error!("dropped a10::CreateDir before completion, attempt to cancel failed: {err}");
}
}
OpState::NotStarted(()) | OpState::Done => {
drop(from);
drop(to);
}
}
}
}
}
/// Remove a file.
#[doc(alias = "unlink")]
#[doc(alias = "unlinkat")]
pub fn remove_file(sq: SubmissionQueue, path: PathBuf) -> Delete {
Delete {
sq,
path: Some(path_to_cstring(path)),
state: OpState::NotStarted(0),
}
}
/// Remove a directory.
#[doc(alias = "rmdir")]
#[doc(alias = "unlinkat")]
pub fn remove_dir(sq: SubmissionQueue, path: PathBuf) -> Delete {
Delete {
sq,
path: Some(path_to_cstring(path)),
state: OpState::NotStarted(libc::AT_REMOVEDIR),
}
}
/// [`Future`] to remove a [file] or [directory].
///
/// [file]: remove_file
/// [directory]: remove_dir
#[derive(Debug)]
#[must_use = "`Future`s do nothing unless polled"]
pub struct Delete {
sq: SubmissionQueue,
/// Paths used to rename the file, need to stay in memory so the kernel can
/// access it safely.
// SAFETY: because this is not modified by the kernel it doesn't need an
// UnsafeCell. It is read-only (as the kernel also has read access).
path: Option<CString>,
state: OpState<libc::c_int>,
}
impl Future for Delete {
type Output = io::Result<()>;
fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<Self::Output> {
#[rustfmt::skip]
let op_index = poll_state!(Delete, self.state, self.sq, ctx, |submission, flags| unsafe {
// SAFETY: `path` is only removed after the state is set to `Done`.
let path = self.path.as_ref().unwrap();
submission.unlinkat(libc::AT_FDCWD, path.as_ptr(), flags);
});
match self.sq.poll_op(ctx, op_index) {
Poll::Ready(result) => {
self.state = OpState::Done;
match result {
Ok((_, res)) => Poll::Ready(Ok(debug_assert!(res == 0))),
Err(err) => Poll::Ready(Err(err)),
}
}
Poll::Pending => Poll::Pending,
}
}
}
impl Extract for Delete {}
impl Future for Extractor<Delete> {
type Output = io::Result<PathBuf>;
fn poll(mut self: Pin<&mut Self>, ctx: &mut task::Context<'_>) -> Poll<Self::Output> {
match Pin::new(&mut self.fut).poll(ctx) {
Poll::Ready(Ok(())) => {
let path = path_from_cstring(self.fut.path.take().unwrap());
Poll::Ready(Ok(path))
}
Poll::Ready(Err(err)) => Poll::Ready(Err(err)),
Poll::Pending => Poll::Pending,
}
}
}
impl Drop for Delete {
fn drop(&mut self) {
if let Some(path) = self.path.take() {
match self.state {
OpState::Running(op_index) => {
let result = self.sq.cancel_op(op_index, path, |submission| unsafe {
submission.cancel_op(op_index);
// We'll get a canceled completion event if we succeeded, which
// is sufficient to cleanup the operation.
submission.no_completion_event();
});
if let Err(err) = result {
log::error!("dropped a10::CreateDir before completion, attempt to cancel failed: {err}");
}
}
OpState::NotStarted(_) | OpState::Done => drop(path),
}
}
}
}
fn path_to_cstring(path: PathBuf) -> CString {
unsafe { CString::from_vec_unchecked(path.into_os_string().into_vec()) }
}
fn path_from_cstring(path: CString) -> PathBuf {
OsString::from_vec(path.into_bytes()).into()
}