Merge pull request #191 from jlebon/pr/osmet-prep

blockdev: preparatory patches for osmet

src/blockdev.rs

@@ -13,8 +13,7 @@
 // limitations under the License.
 
 use error_chain::bail;
-use nix::errno::Errno;
-use nix::{self, ioctl_none, ioctl_read_bad, mount, request_code_none};
+use nix::{errno::Errno, mount};
 use regex::Regex;
 use std::collections::HashMap;
 use std::convert::TryInto;
@@ -30,28 +29,36 @@ use tempfile;
 
 use crate::errors::*;
 
-pub fn mount_boot(device: &str) -> Result<Mount> {
+pub fn mount_partition_by_label(device: &str, label: &str, flags: mount::MsFlags) -> Result<Mount> {
     // get partition list
     let partitions = get_partitions(device)?;
     if partitions.is_empty() {
         bail!("couldn't find any partitions on {}", device);
     }
 
-    // find the boot partition
-    let boot_partitions = partitions
+    // find the partition with the matching label
+    let matching_partitions = partitions
         .iter()
-        .filter(|d| d.label.as_ref().unwrap_or(&"".to_string()) == "boot")
+        .filter(|d| d.label.as_ref().unwrap_or(&"".to_string()) == label)
         .collect::<Vec<&BlkDev>>();
-    let dev = match boot_partitions.len() {
-        0 => bail!("couldn't find boot device for {}", device),
-        1 => boot_partitions[0],
-        _ => bail!("found multiple devices on {} with label \"boot\"", device),
+    let dev = match matching_partitions.len() {
+        0 => bail!("couldn't find {} device for {}", label, device),
+        1 => matching_partitions[0],
+        _ => bail!(
+            "found multiple devices on {} with label \"{}\"",
+            device,
+            label
+        ),
     };
 
     // mount it
     match &dev.fstype {
-        Some(fstype) => Mount::try_mount(&dev.path, &fstype),
-        None => Err(format!("couldn't get filesystem type of boot device for {}", device).into()),
+        Some(fstype) => Mount::try_mount(&dev.path, &fstype, flags),
+        None => Err(format!(
+            "couldn't get filesystem type of {} device for {}",
+            label, device
+        )
+        .into()),
     }
 }
 
@@ -126,7 +133,7 @@ pub struct Mount {
 }
 
 impl Mount {
-    fn try_mount(device: &str, fstype: &str) -> Result<Mount> {
+    fn try_mount(device: &str, fstype: &str, flags: mount::MsFlags) -> Result<Mount> {
         let tempdir = tempfile::Builder::new()
             .prefix("coreos-installer-")
             .tempdir()
@@ -135,14 +142,8 @@ impl Mount {
         // the partition contents if umount failed
         let mountpoint = tempdir.into_path();
 
-        mount::mount::<str, Path, str, str>(
-            Some(device),
-            &mountpoint,
-            Some(fstype),
-            mount::MsFlags::empty(),
-            None,
-        )
-        .chain_err(|| format!("mounting device {} on {}", device, mountpoint.display()))?;
+        mount::mount::<str, Path, str, str>(Some(device), &mountpoint, Some(fstype), flags, None)
+            .chain_err(|| format!("mounting device {} on {}", device, mountpoint.display()))?;
 
         Ok(Mount {
             device: device.to_string(),
@@ -184,7 +185,7 @@ pub fn reread_partition_table(file: &mut File) -> Result<()> {
     // Reread sometimes fails inexplicably.  Retry several times before
     // giving up.
     for retries in (0..20).rev() {
-        let result = unsafe { blkrrpart(fd) };
+        let result = unsafe { ioctl::blkrrpart(fd) };
         match result {
             Ok(_) => break,
             Err(err) => {
@@ -209,10 +210,10 @@ pub fn reread_partition_table(file: &mut File) -> Result<()> {
 }
 
 /// Get the logical sector size of a block device.
-pub fn get_sector_size(file: &mut File) -> Result<NonZeroU32> {
+pub fn get_sector_size(file: &File) -> Result<NonZeroU32> {
     let fd = file.as_raw_fd();
     let mut size: c_int = 0;
-    match unsafe { blksszget(fd, &mut size) } {
+    match unsafe { ioctl::blksszget(fd, &mut size) } {
         Ok(_) => {
             let size_u32: u32 = size
                 .try_into()
@@ -224,8 +225,13 @@ pub fn get_sector_size(file: &mut File) -> Result<NonZeroU32> {
 }
 
 // create unsafe ioctl wrappers
-ioctl_none!(blkrrpart, 0x12, 95);
-ioctl_read_bad!(blksszget, request_code_none!(0x12, 104), c_int);
+#[allow(clippy::missing_safety_doc)]
+mod ioctl {
+    use super::c_int;
+    use nix::{ioctl_none, ioctl_read_bad, request_code_none};
+    ioctl_none!(blkrrpart, 0x12, 95);
+    ioctl_read_bad!(blksszget, request_code_none!(0x12, 104), c_int);
+}
 
 pub fn udev_settle() -> Result<()> {
     // "udevadm settle" silently no-ops if the udev socket is missing, and

src/install.rs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 use error_chain::{bail, ChainedError};
+use nix::mount;
 use std::fs::{create_dir_all, read_dir, File, OpenOptions};
 use std::io::{copy, Read, Seek, SeekFrom, Write};
 use std::os::unix::fs::FileTypeExt;
@@ -111,7 +112,7 @@ fn write_disk(
 
     // postprocess
     if ignition.is_some() || config.firstboot_kargs.is_some() || config.platform.is_some() {
-        let mount = mount_boot(&config.device)?;
+        let mount = mount_partition_by_label(&config.device, "boot", mount::MsFlags::empty())?;
         if let Some(ignition) = ignition {
             write_ignition(mount.mountpoint(), ignition)?;
         }