Perform mount using API (fix #10 fix #6)

Cargo.lock

@@ -4,6 +4,7 @@ version = "0.1.0"
 dependencies = [
  "failure 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "nix 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "simplelog 0.5.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "structopt 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "tempfile 3.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -148,6 +149,18 @@ dependencies = [
  "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "nix"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)",
+ "void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "num-integer"
 version = "0.1.39"
@@ -348,6 +361,11 @@ name = "vec_map"
 version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "which"
 version = "2.0.0"
@@ -394,6 +412,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
 "checksum libc 0.2.43 (registry+https://github.com/rust-lang/crates.io-index)" = "76e3a3ef172f1a0b9a9ff0dd1491ae5e6c948b94479a3021819ba7d860c8645d"
 "checksum log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "c84ec4b527950aa83a329754b01dbe3f58361d1c5efacd1f6d68c494d08a17c6"
+"checksum nix 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d37e713a259ff641624b6cb20e3b12b2952313ba36b6823c0f16e6cfd9e5de17"
 "checksum num-integer 0.1.39 (registry+https://github.com/rust-lang/crates.io-index)" = "e83d528d2677f0518c570baf2b7abdcf0cd2d248860b68507bdcb3e91d4c0cea"
 "checksum num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0b3a5d7cc97d6d30d8b9bc8fa19bf45349ffe46241e8816f50f62f6d6aaabee1"
 "checksum proc-macro2 0.4.20 (registry+https://github.com/rust-lang/crates.io-index)" = "3d7b7eaaa90b4a90a932a9ea6666c95a389e424eff347f0f793979289429feee"
@@ -419,6 +438,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "882386231c45df4700b275c7ff55b6f3698780a650026380e72dabe76fa46526"
 "checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
+"checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
 "checksum which 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "49c4f580e93079b70ac522e7bdebbe1568c8afa7d8d05ee534ee737ca37d2f51"
 "checksum winapi 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)" = "92c1eb33641e276cfa214a0522acad57be5c56b10cb348b3c5117db75f3ac4b0"
 "checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"

Cargo.toml

@@ -10,3 +10,4 @@ log = "0.4.6"
 structopt = "0.2.12"
 simplelog = "0.5.3"
 tempfile = "3.0.4"
+nix = "0.11.0"

src/main.rs

@@ -1,16 +1,19 @@
 #[macro_use]
 extern crate log;
 extern crate failure;
+extern crate nix;
 extern crate simplelog;
 extern crate structopt;
 extern crate tempfile;
 extern crate which;
 
 mod error;
+mod mountstack;
 mod tool;
 
 use error::*;
 use failure::{Fail, ResultExt};
+use mountstack::{Filesystem, MountStack};
 use simplelog::*;
 use std::fs;
 use std::path::PathBuf;
@@ -90,10 +93,9 @@ fn create(disk: PathBuf) -> Result<(), Error> {
     let pacstrap = Tool::find("pacstrap")?;
     let arch_chroot = Tool::find("arch-chroot")?;
     let genfstab = Tool::find("genfstab")?;
-    let mount = Tool::find("mount")?;
-    let umount = Tool::find("umount")?;
     let mkfat = Tool::find("mkfs.fat")?;
     let mkbtrfs = Tool::find("mkfs.btrfs")?;
+    let mut mount_stack = MountStack::new();
 
     if !(disk.starts_with("/dev/disk/by-id")
         && (disk
@@ -137,20 +139,24 @@ fn create(disk: PathBuf) -> Result<(), Error> {
         .run(ErrorKind::Creation)?;
 
     info!("Mounting filesystems to {}", mount_point.path().display());
-    mount
-        .execute()
-        .arg(format!("{}-part3", disk.display()))
-        .arg(mount_point.path())
-        .run(ErrorKind::Creation)?;
+    mount_stack
+        .mount(
+            &PathBuf::from(format!("{}-part3", disk.display())),
+            &mount_point.path(),
+            Filesystem::Btrfs,
+            Some("compress=zstd"),
+        ).context(ErrorKind::Creation)?;
 
     let boot_point = mount_point.path().join("boot");
     fs::create_dir(&boot_point).context(ErrorKind::Creation)?;
 
-    mount
-        .execute()
-        .arg(format!("{}-part2", disk.display()))
-        .arg(&boot_point)
-        .run(ErrorKind::Creation)?;
+    mount_stack
+        .mount(
+            &PathBuf::from(format!("{}-part2", disk.display())),
+            &boot_point,
+            Filesystem::Vfat,
+            None,
+        ).context(ErrorKind::Creation)?;
 
     info!("Bootstrapping system");
     pacstrap
@@ -199,12 +205,7 @@ fn create(disk: PathBuf) -> Result<(), Error> {
         .run(ErrorKind::Creation)?;
 
     info!("Unmounting filesystems");
-    umount
-        .execute()
-        .arg(boot_point)
-        .arg(mount_point.path())
-        .run(ErrorKind::Creation)?;
-
+    drop(mount_stack);
     sync.execute().run(ErrorKind::Creation)?;
 
     Ok(())

src/mountstack.rs

@@ -0,0 +1,60 @@
+use nix;
+use nix::mount::{mount, umount, MsFlags};
+use std::path::{Path, PathBuf};
+
+#[derive(Debug)]
+pub enum Filesystem {
+    Btrfs,
+    Vfat,
+}
+
+impl Filesystem {
+    fn to_type(self) -> &'static str {
+        match self {
+            Filesystem::Btrfs => "btrfs",
+            Filesystem::Vfat => "vfat",
+        }
+    }
+}
+
+pub struct MountStack {
+    targets: Vec<PathBuf>,
+}
+
+impl MountStack {
+    pub fn new() -> Self {
+        MountStack {
+            targets: Vec::new(),
+        }
+    }
+
+    #[must_use]
+    pub fn mount(
+        &mut self,
+        source: &Path,
+        target: &Path,
+        filesystem: Filesystem,
+        options: Option<&str>,
+    ) -> nix::Result<()> {
+        debug!("Mounting {:?} ({:?}) to {:?}", source, filesystem, target);
+        mount(
+            Some(source),
+            target,
+            Some(filesystem.to_type()),
+            MsFlags::empty(),
+            options,
+        )?;
+        self.targets.push(target.to_owned());
+        Ok(())
+    }
+}
+
+impl Drop for MountStack {
+    fn drop(&mut self) {
+        while let Some(target) = self.targets.pop() {
+            if !umount(&target).is_ok() {
+                warn!("Unable to mount {}", target.display());
+            };
+        }
+    }
+}