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Refactor statvfs module
 * Use upstream libc FFI declarations and constants * Use more Rust-y interface of returning entire struct versus passing it as an argument to (f)statvfs. * Replace field accesses with accessor methods * Flatten vfs module into parent * Remove all non-libc-based interfaces for working with the statvfs struct
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‎CHANGELOG.md‎

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@@ -23,6 +23,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
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([#647](https://github.com/nix-rust/nix/pull/647))
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- Exposed `unistd::setresuid` and `unistd::setresgid` on FreeBSD and OpenBSD
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([#721](https://github.com/nix-rust/nix/pull/721))
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- Refactored the `statvfs` module removing extraneous API functions and the
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`statvfs::vfs` module. Additionally `(f)statvfs()` now return the struct
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directly. And the returned `Statvfs` struct now exposes its data through
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accessor methods. ([#729](https://github.com/nix-rust/nix/pull/729))
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# Fixed
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- Fix compilation and tests for OpenBSD targets

‎src/sys/statvfs.rs‎

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@@ -1,161 +1,142 @@
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//! FFI for statvfs functions
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//! Get filesystem statistics
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//!
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//! See the `vfs::Statvfs` struct for some rusty wrappers
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//! See [the man pages](http://pubs.opengroup.org/onlinepubs/9699919799/functions/fstatvfs.html)
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//! for more details.
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use std::mem;
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use std::os::unix::io::AsRawFd;
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use libc::{self, c_ulong};
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use {Errno, Result, NixPath};
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use std::os::unix::io::AsRawFd;
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pub mod vfs {
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//! Structs related to the `statvfs` and `fstatvfs` functions
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//!
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//! The `Statvfs` struct has some wrappers methods around the `statvfs` and
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//! `fstatvfs` calls.
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use libc::{c_ulong,c_int};
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use std::os::unix::io::AsRawFd;
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use {Result, NixPath};
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use super::{statvfs, fstatvfs};
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bitflags!(
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/// Mount Flags
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#[repr(C)]
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#[derive(Default)]
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pub struct FsFlags: c_ulong {
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/// Read Only
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const RDONLY = 1;
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/// Do not allow the set-uid bits to have an effect
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const NOSUID = 2;
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/// Do not interpret character or block-special devices
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const NODEV = 4;
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/// Do not allow execution of binaries on the filesystem
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const NOEXEC = 8;
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/// All IO should be done synchronously
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const SYNCHRONOUS = 16;
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/// Allow mandatory locks on the filesystem
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const MANDLOCK = 64;
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const WRITE = 128;
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const APPEND = 256;
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const IMMUTABLE = 512;
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/// Do not update access times on files
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const NOATIME = 1024;
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/// Do not update access times on files
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const NODIRATIME = 2048;
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/// Update access time relative to modify/change time
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const RELATIME = 4096;
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}
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);
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/// The posix statvfs struct
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///
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/// http://linux.die.net/man/2/statvfs
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bitflags!(
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/// File system mount Flags
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#[repr(C)]
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#[derive(Debug,Copy,Clone)]
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pub struct Statvfs {
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/// Filesystem block size. This is the value that will lead to
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/// most efficient use of the filesystem
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pub f_bsize: c_ulong,
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/// Fragment Size -- actual minimum unit of allocation on this
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/// filesystem
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pub f_frsize: c_ulong,
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/// Total number of blocks on the filesystem
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pub f_blocks: u64,
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/// Number of unused blocks on the filesystem, including those
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/// reserved for root
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pub f_bfree: u64,
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/// Number of blocks available to non-root users
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pub f_bavail: u64,
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/// Total number of inodes available on the filesystem
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pub f_files: u64,
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/// Number of inodes available on the filesystem
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pub f_ffree: u64,
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/// Number of inodes available to non-root users
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pub f_favail: u64,
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/// File System ID
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pub f_fsid: c_ulong,
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/// Mount Flags
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pub f_flag: FsFlags,
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/// Maximum filename length
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pub f_namemax: c_ulong,
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/// Reserved extra space, OS-dependent
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f_spare: [c_int; 6],
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}
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impl Statvfs {
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/// Create a new `Statvfs` object and fill it with information about
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/// the mount that contains `path`
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pub fn for_path<P: ?Sized + NixPath>(path: &P) -> Result<Statvfs> {
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let mut stat = Statvfs::default();
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let res = statvfs(path, &mut stat);
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res.map(|_| stat)
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}
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/// Replace information in this struct with information about `path`
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pub fn update_with_path<P: ?Sized + NixPath>(&mut self, path: &P) -> Result<()> {
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statvfs(path, self)
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}
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/// Create a new `Statvfs` object and fill it with information from fd
99-
pub fn for_fd<T: AsRawFd>(fd: &T) -> Result<Statvfs> {
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let mut stat = Statvfs::default();
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let res = fstatvfs(fd, &mut stat);
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res.map(|_| stat)
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}
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/// Replace information in this struct with information about `fd`
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pub fn update_with_fd<T: AsRawFd>(&mut self, fd: &T) -> Result<()> {
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fstatvfs(fd, self)
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}
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}
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impl Default for Statvfs {
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/// Create a statvfs object initialized to all zeros
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fn default() -> Self {
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Statvfs {
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f_bsize: 0,
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f_frsize: 0,
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f_blocks: 0,
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f_bfree: 0,
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f_bavail: 0,
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f_files: 0,
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f_ffree: 0,
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f_favail: 0,
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f_fsid: 0,
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f_flag: FsFlags::default(),
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f_namemax: 0,
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f_spare: [0, 0, 0, 0, 0, 0],
127-
}
128-
}
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#[derive(Default)]
16+
pub struct FsFlags: c_ulong {
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/// Read Only
18+
const RDONLY = libc::ST_RDONLY;
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/// Do not allow the set-uid bits to have an effect
20+
const NOSUID = libc::ST_NOSUID;
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/// Do not interpret character or block-special devices
22+
#[cfg(any(target_os = "android", target_os = "linux"))]
23+
const NODEV = libc::ST_NODEV;
24+
/// Do not allow execution of binaries on the filesystem
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#[cfg(any(target_os = "android", target_os = "linux"))]
26+
const NOEXEC = libc::ST_NOEXEC;
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/// All IO should be done synchronously
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#[cfg(any(target_os = "android", target_os = "linux"))]
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const SYNCHRONOUS = libc::ST_SYNCHRONOUS;
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/// Allow mandatory locks on the filesystem
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#[cfg(any(target_os = "android", target_os = "linux"))]
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const MANDLOCK = libc::ST_MANDLOCK;
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/// Write on file/directory/symlink
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#[cfg(any(target_os = "android", target_os = "linux"))]
35+
const WRITE = libc::ST_WRITE;
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/// Append-only file
37+
#[cfg(any(target_os = "android", target_os = "linux"))]
38+
const APPEND = libc::ST_APPEND;
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/// Immutable file
40+
#[cfg(any(target_os = "android", target_os = "linux"))]
41+
const IMMUTABLE = libc::ST_IMMUTABLE;
42+
/// Do not update access times on files
43+
#[cfg(any(target_os = "android", target_os = "linux"))]
44+
const NOATIME = libc::ST_NOATIME;
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/// Do not update access times on files
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#[cfg(any(target_os = "android", target_os = "linux"))]
47+
const NODIRATIME = libc::ST_NODIRATIME;
48+
/// Update access time relative to modify/change time
49+
#[cfg(any(target_os = "android", all(target_os = "linux", not(target_env = "musl"))))]
50+
const RELATIME = libc::ST_RELATIME;
51+
}
52+
);
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54+
/// Wrapper around the POSIX `statvfs` struct
55+
///
56+
/// For more information see the [`statvfs(3)` man pages](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_statvfs.h.html).
57+
// FIXME: Replace with repr(transparent)
58+
#[repr(C)]
59+
pub struct Statvfs(libc::statvfs);
60+
61+
impl Statvfs {
62+
/// get the file system block size
63+
pub fn block_size(&self) -> libc::c_ulong {
64+
self.0.f_bsize
12965
}
130-
}
13166

132-
mod ffi {
133-
use libc::{c_char, c_int};
134-
use sys::statvfs::vfs;
67+
/// Get the fundamental file system block size
68+
pub fn fragment_size(&self) -> libc::c_ulong {
69+
self.0.f_frsize
70+
}
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136-
extern {
137-
pub fn statvfs(path: * const c_char, buf: *mut vfs::Statvfs) -> c_int;
138-
pub fn fstatvfs(fd: c_int, buf: *mut vfs::Statvfs) -> c_int;
72+
/// Get the number of blocks.
73+
///
74+
/// Units are in units of `fragment_size()`
75+
pub fn blocks(&self) -> libc::fsblkcnt_t {
76+
self.0.f_blocks
77+
}
78+
79+
/// Get the number of free blocks in the file system
80+
pub fn blocks_free(&self) -> libc::fsblkcnt_t {
81+
self.0.f_bfree
13982
}
83+
84+
/// Get the number of free blocks for unprivileged users
85+
pub fn blocks_available(&self) -> libc::fsblkcnt_t {
86+
self.0.f_bavail
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}
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/// Get the total number of file inodes
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pub fn files(&self) -> libc::fsfilcnt_t {
91+
self.0.f_files
92+
}
93+
94+
/// Get the number of free file inodes
95+
pub fn files_free(&self) -> libc::fsfilcnt_t {
96+
self.0.f_ffree
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}
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99+
/// Get the number of free file inodes for unprivileged users
100+
pub fn files_available(&self) -> libc::fsfilcnt_t {
101+
self.0.f_favail
102+
}
103+
104+
/// Get the file system id
105+
pub fn filesystem_id(&self) -> c_ulong {
106+
self.0.f_fsid
107+
}
108+
109+
/// Get the mount flags
110+
pub fn flags(&self) -> FsFlags {
111+
FsFlags::from_bits_truncate(self.0.f_flag)
112+
}
113+
114+
/// Get the maximum filename length
115+
pub fn name_max(&self) -> libc::c_ulong {
116+
self.0.f_namemax
117+
}
118+
140119
}
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142-
/// Fill an existing `Statvfs` object with information about the `path`
143-
pub fn statvfs<P: ?Sized + NixPath>(path: &P, stat: &mut vfs::Statvfs) -> Result<()> {
121+
/// Return a `Statvfs` object with information about the `path`
122+
pub fn statvfs<P: ?Sized + NixPath>(path: &P) -> Result<Statvfs> {
144123
unsafe {
145124
Errno::clear();
125+
let mut stat: Statvfs = mem::uninitialized();
146126
let res = try!(
147-
path.with_nix_path(|path| ffi::statvfs(path.as_ptr(), stat))
127+
path.with_nix_path(|path| libc::statvfs(path.as_ptr(), &mut stat.0))
148128
);
149129

150-
Errno::result(res).map(drop)
130+
Errno::result(res).map(|_| stat)
151131
}
152132
}
153133

154-
/// Fill an existing `Statvfs` object with information about `fd`
155-
pub fn fstatvfs<T: AsRawFd>(fd: &T, stat: &mut vfs::Statvfs) -> Result<()> {
134+
/// Return a `Statvfs` object with information about `fd`
135+
pub fn fstatvfs<T: AsRawFd>(fd: &T) -> Result<Statvfs> {
156136
unsafe {
157137
Errno::clear();
158-
Errno::result(ffi::fstatvfs(fd.as_raw_fd(), stat)).map(drop)
138+
let mut stat: Statvfs = mem::uninitialized();
139+
Errno::result(libc::fstatvfs(fd.as_raw_fd(), &mut stat.0)).map(|_| stat)
159140
}
160141
}
161142

@@ -166,14 +147,12 @@ mod test {
166147

167148
#[test]
168149
fn statvfs_call() {
169-
let mut stat = vfs::Statvfs::default();
170-
statvfs("/".as_bytes(), &mut stat).unwrap()
150+
statvfs("/".as_bytes()).unwrap();
171151
}
172152

173153
#[test]
174154
fn fstatvfs_call() {
175-
let mut stat = vfs::Statvfs::default();
176155
let root = File::open("/").unwrap();
177-
fstatvfs(&root, &mut stat).unwrap()
156+
fstatvfs(&root).unwrap();
178157
}
179158
}

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