1 //! # libmount
2 //!
3 //! [Documentation](https://docs.rs/libmount) |
4 //! [Github](https://github.com/tailhook/libmount) |
5 //! [Crate](https://crates.io/crates/libmount)
6 //!
7 //! This library has two major goals:
8 //!
9 //! 1. Add type-safe interface for mount() system call
10 //! 2. Add very good explanation of what's wrong when the call fails
11 //!
12 //! So we have two error types:
13 //!
14 //! 1. `OSError` holds mount info and errno
15 //! 2. `Error` is returned by `OSError::explain()`
16 //!
17 //! The first one is returned by `bare_mount()` the second by `mount()`, and
18 //! using latter is preffered for most situations. Unless performance is
19 //! too critical (i.e. you are doing thousands of *failing* mounts per second).
20 //! On the success path there is no overhead.
21 //!
22 #![warn(missing_debug_implementations)]
23 #![warn(missing_docs)]
24 
25 extern crate libc;
26 extern crate nix;
27 #[macro_use] extern crate quick_error;
28 
29 mod util;
30 mod error;
31 mod explain;
32 mod bind;
33 mod overlay;
34 mod tmpfs;
35 mod modify;
36 mod remount;
37 pub mod mountinfo;
38 
39 use std::io;
40 
41 use explain::Explainable;
42 use remount::RemountError;
43 pub use bind::BindMount;
44 pub use overlay::Overlay;
45 pub use tmpfs::Tmpfs;
46 pub use modify::Move;
47 pub use remount::Remount;
48 
49 quick_error! {
50     #[derive(Debug)]
51     enum MountError {
52         Io(err: io::Error) {
53             cause(err)
54             from()
55         }
56         Remount(err: RemountError) {
57             cause(err)
58             from()
59         }
60     }
61 }
62 
63 /// The raw os error
64 ///
65 /// This is a wrapper around `io::Error` providing `explain()` method
66 ///
67 /// Note: you need to explain as fast as possible, because during explain
68 /// library makes some probes for different things in filesystem, and if
69 /// anything changes it may give incorrect results.
70 ///
71 /// You should always `explain()` the errors, unless you are trying lots of
72 /// mounts for bruteforcing or other similar thing and you are concerned of
73 /// performance. Usually library does `stat()` and similar things which are
74 /// much faster than mount anyway. Also explaining is zero-cost in the success
75 /// path.
76 ///
77 #[derive(Debug)]
78 pub struct OSError(MountError, Box<Explainable>);
79 
80 impl OSError {
from_remount(err: RemountError, explain: Box<Explainable>) -> OSError81     fn from_remount(err: RemountError, explain: Box<Explainable>) -> OSError {
82         OSError(MountError::Remount(err), explain)
83     }
84 
from_nix(err: nix::Error, explain: Box<Explainable>) -> OSError85     fn from_nix(err: nix::Error, explain: Box<Explainable>) -> OSError {
86         OSError(
87             MountError::Io(
88                 err.as_errno().map_or_else(|| io::Error::new(io::ErrorKind::Other, err), io::Error::from),
89             ),
90             explain,
91         )
92     }
93 }
94 
95 /// The error holder which contains as much information about why failure
96 /// happens as the library implementors could gain
97 ///
98 /// This type only provides `Display` for now, but some programmatic interface
99 /// is expected in future.
100 #[derive(Debug)]
101 pub struct Error(Box<Explainable>, io::Error, String);
102