Makes the whole routine a lot more robust by parsing the JSON output of
`lsblk` instead of the human-readable output from `btrfs filesystem
show`.
The labels of Btrfs filesystems are pretty much arbitrary labels, e.g.
the following is a valid filesystem and thus output from `btrfs
filesystem show`:
Label: 'uuid: 70361d98-7492-45d4-a0e4-bf8fee9203a3' uuid:
ab158685-c0b7-4540-a739-72c43a773282
Total devices 1 FS bytes used 144.00KiB
devid 1 size 8.00GiB used 536.00MiB path /dev/sda
.. which would break the current parsing code.
Also drops the usage of a regex, thus being able to eliminate the whole
regex machinery from the final binary. This reduces (stripped) binary
size significantly, from 2.4 MiB to ~727 KiB, a ~70%(!) decrease.
text data bss dec hex filename
2213016 261208 408 2474632 25c288 proxmox-chroot-old
702481 27776 360 730617 b25f9 proxmox-chroot-new
No functional changes.
Signed-off-by: Christoph Heiss <c.he...@proxmox.com>
---
proxmox-chroot/Cargo.toml | 2 +-
proxmox-chroot/src/main.rs | 48 +++++++++++++++++++++++++++-----------
2 files changed, 35 insertions(+), 15 deletions(-)
diff --git a/proxmox-chroot/Cargo.toml b/proxmox-chroot/Cargo.toml
index c043938..a6a705d 100644
--- a/proxmox-chroot/Cargo.toml
+++ b/proxmox-chroot/Cargo.toml
@@ -9,6 +9,6 @@ homepage = "https://www.proxmox.com";
[dependencies]
anyhow.workspace = true
-regex.workspace = true
proxmox-installer-common = { workspace = true, features = [ "cli" ] }
+serde = { workspace = true, features = [ "derive" ] }
serde_json.workspace = true
diff --git a/proxmox-chroot/src/main.rs b/proxmox-chroot/src/main.rs
index 037f079..2cff630 100644
--- a/proxmox-chroot/src/main.rs
+++ b/proxmox-chroot/src/main.rs
@@ -18,7 +18,7 @@ use proxmox_installer_common::{
options::FsType,
setup::{InstallConfig, SetupInfo},
};
-use regex::Regex;
+use serde::Deserialize;
const ANSWER_MP: &str = "answer";
static BINDMOUNTS: [&str; 4] = ["dev", "proc", "run", "sys"];
@@ -355,29 +355,49 @@ fn mount_btrfs(btrfs_uuid: Option<String>) -> Result<()> {
Ok(())
}
+/// Searches for all Btrfs filesystems present on the system.
+///
+/// # Returns
+///
+/// The UUID of that filesystem, if a single Btrfs filesystem is found.
+/// If multiple are found, returns a (human-readable) error with all possible
+/// filesystem UUIDs.
fn get_btrfs_uuid() -> Result<String> {
- let output = Command::new("btrfs")
- .arg("filesystem")
- .arg("show")
+ let output = Command::new("lsblk")
+ .args(["--json", "--fs", "--list", "--output", "fstype,uuid"])
.output()?;
+
if !output.status.success() {
bail!(
"Error checking for BTRFS file systems: {}",
String::from_utf8(output.stderr)?
);
}
- let out = String::from_utf8(output.stdout)?;
- let mut uuids = Vec::new();
- let re_uuid =
- Regex::new(r"uuid:
([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})$")?;
- for line in out.lines() {
- if let Some(cap) = re_uuid.captures(line) {
- if let Some(uuid) = cap.get(1) {
- uuids.push(uuid.as_str());
- }
- }
+ #[derive(Deserialize)]
+ struct Entry {
+ fstype: Option<String>,
+ uuid: Option<String>,
}
+
+ #[derive(Deserialize)]
+ struct LsblkOutput {
+ blockdevices: Vec<Entry>,
+ }
+
+ let out: LsblkOutput = serde_json::from_slice(&output.stdout)?;
+ let uuids = out
+ .blockdevices
+ .iter()
+ .filter_map(|entry| match entry {
+ Entry {
+ fstype: Some(fstype),
+ uuid: Some(uuid),
+ } if fstype == "btrfs" => Some(uuid),
+ _ => None,
+ })
+ .collect::<Vec<&String>>();
+
match uuids.len() {
0 => bail!("Could not find any BTRFS UUID"),
i if i > 1 => {
--
2.49.0
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