lfs_core/
label.rs

1use {
2    super::*,
3    snafu::prelude::*,
4    std::fs,
5};
6
7/// the labelling of a file-system, that
8/// is the pair (label, fs)
9#[derive(Debug, Clone)]
10pub struct Labelling {
11    pub label: String,
12    pub fs_name: String,
13}
14
15pub fn get_label(
16    fs_name: &str,
17    labellings: Option<&[Labelling]>,
18) -> Option<String> {
19    labellings.as_ref().and_then(|labels| {
20        labels
21            .iter()
22            .find(|label| label.fs_name == fs_name)
23            .map(|label| label.label.clone())
24    })
25}
26
27/// try to read all mappings defined in /dev/disk/by-<by_kind>,
28/// where by_kind is one of "label", "uuid", "partuuid", "diskseq", etc.
29///
30/// An error can't be excluded as not all systems expose
31/// this information the way lfs-core reads it.
32pub fn read_by(by_kind: &str) -> Result<Vec<Labelling>, Error> {
33    let path = format!("/dev/disk/by-{by_kind}");
34    let entries = fs::read_dir(&path).context(CantReadDirSnafu { path })?;
35    let labels = entries
36        .filter_map(|entry| entry.ok())
37        .filter_map(|entry| {
38            let md = entry.metadata().ok()?;
39            let file_type = md.file_type();
40            if !file_type.is_symlink() {
41                return None;
42            }
43            let label = sys::decode_string(entry.file_name().to_string_lossy());
44            let linked_path = fs::read_link(entry.path())
45                .map(|path| path.to_string_lossy().to_string())
46                .ok()?;
47            let fs_name = format!("/dev/{}", linked_path.strip_prefix("../../")?,);
48            Some(Labelling { label, fs_name })
49        })
50        .collect();
51    Ok(labels)
52}
lfs_core/label.rs

lfs_core/
label.rs
