From 2599c9258e39d0c3d27232b8649f73e12df4246d Mon Sep 17 00:00:00 2001 From: Colin Walters Date: Fri, 22 Sep 2023 14:42:07 -0400 Subject: [PATCH 1/2] install: Trim bind/btrfs mount information This happens with btrfs subvolumes for the root; we'll need to handle that separately. Signed-off-by: Colin Walters --- lib/src/install.rs | 9 +++++++++ lib/src/mount.rs | 2 +- 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/lib/src/install.rs b/lib/src/install.rs index beeadb7c..185c7f63 100644 --- a/lib/src/install.rs +++ b/lib/src/install.rs @@ -967,6 +967,15 @@ pub(crate) async fn install_to_filesystem(opts: InstallToFilesystemOpts) -> Resu // for GRUB (BIOS) and in the future zipl (I think). let backing_device = { let mut dev = inspect.source; + // Hack: trim bind mount information from source + if dev.contains('[') { + dev = inspect + .sources + .into_iter() + .flatten() + .next() + .ok_or_else(|| anyhow!("Expected `sources` in findmnt output"))?; + } loop { tracing::debug!("Finding parents for {dev}"); let mut parents = crate::blockdev::find_parent_devices(&dev)?.into_iter(); diff --git a/lib/src/mount.rs b/lib/src/mount.rs index 0eac55ad..a2a780f3 100644 --- a/lib/src/mount.rs +++ b/lib/src/mount.rs @@ -25,7 +25,7 @@ pub(crate) struct Findmnt { pub(crate) fn inspect_filesystem(path: &Utf8Path) -> Result { tracing::debug!("Inspecting {path}"); let o = Command::new("findmnt") - .args(["-J", "--output-all", path.as_str()]) + .args(["-J", "-v", "--output-all", path.as_str()]) .output()?; let st = o.status; if !st.success() { From d9ca544d3ad180b4586171348d9b77513b61e13f Mon Sep 17 00:00:00 2001 From: Colin Walters Date: Sat, 16 Sep 2023 09:57:04 -0400 Subject: [PATCH 2/2] Support for `install-to-filesystem --replace=alongside` I was trying to be really ambitious in https://github.com/containers/bootc/pull/78 for the full "takeover" path. This is a *much* *much* simpler variant where we just: - Blow away and reinitialize the `/boot` and `/boot/efi` partitions - Write inside the existing filesystem, leaving the OS running Then when we reboot, we'll just need to clean up the old OS state (or optionally leave it). Signed-off-by: Colin Walters --- lib/src/bootloader.rs | 2 +- lib/src/install.rs | 126 +++++++++++++++++++++++++++--------- lib/src/install/baseline.rs | 3 +- lib/src/mount.rs | 2 + lib/src/utils.rs | 22 +++++++ 5 files changed, 122 insertions(+), 33 deletions(-) diff --git a/lib/src/bootloader.rs b/lib/src/bootloader.rs index 4c893d4d..b6f2520f 100644 --- a/lib/src/bootloader.rs +++ b/lib/src/bootloader.rs @@ -75,7 +75,7 @@ pub(crate) fn install_via_bootupd( let bootfs = &rootfs.join("boot"); let bootfs = Dir::open_ambient_dir(bootfs, cap_std::ambient_authority())?; - { + if super::install::ARCH_USES_EFI { let efidir = bootfs.open_dir("efi")?; install_grub2_efi(&efidir, &grub2_uuid_contents)?; } diff --git a/lib/src/install.rs b/lib/src/install.rs index 185c7f63..bfa1299e 100644 --- a/lib/src/install.rs +++ b/lib/src/install.rs @@ -21,6 +21,7 @@ use camino::Utf8PathBuf; use cap_std::fs::Dir; use cap_std_ext::cap_std; use cap_std_ext::prelude::CapStdExtDirExt; +use clap::ValueEnum; use rustix::fs::MetadataExt; use fn_error_context::context; @@ -44,6 +45,7 @@ const BOOT: &str = "boot"; const RUN_BOOTC: &str = "/run/bootc"; /// This is an ext4 special directory we need to ignore. const LOST_AND_FOUND: &str = "lost+found"; +pub(crate) const ARCH_USES_EFI: bool = cfg!(any(target_arch = "x86_64", target_arch = "aarch64")); /// Kernel argument used to specify we want the rootfs mounted read-write by default const RW_KARG: &str = "rw"; @@ -117,6 +119,28 @@ pub(crate) struct InstallOpts { pub(crate) config_opts: InstallConfigOpts, } +#[derive(ValueEnum, Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)] +#[serde(rename_all = "kebab-case")] +pub(crate) enum ReplaceMode { + /// Completely wipe the contents of the target filesystem. This cannot + /// be done if the target filesystem is the one the system is booted from. + Wipe, + /// This is a destructive operation in the sense that the bootloader state + /// will have its contents wiped and replaced. However, + /// the running system (and all files) will remain in place until reboot. + /// + /// As a corollary to this, you will also need to remove all the old operating + /// system binaries after the reboot into the target system; this can be done + /// with code in the new target system, or manually. + Alongside, +} + +impl std::fmt::Display for ReplaceMode { + fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + self.to_possible_value().unwrap().get_name().fmt(f) + } +} + /// Options for installing to a filesystem #[derive(Debug, Clone, clap::Args)] pub(crate) struct InstallTargetFilesystemOpts { @@ -141,9 +165,10 @@ pub(crate) struct InstallTargetFilesystemOpts { #[clap(long)] pub(crate) boot_mount_spec: Option, - /// Automatically wipe existing data on the filesystems. + /// Initialize the system in-place; at the moment, only one mode for this is implemented. + /// In the future, it may also be supported to set up an explicit "dual boot" system. #[clap(long)] - pub(crate) wipe: bool, + pub(crate) replace: Option, } /// Perform an installation to a mounted filesystem. @@ -592,6 +617,8 @@ pub(crate) struct RootSetup { device: Utf8PathBuf, rootfs: Utf8PathBuf, rootfs_fd: Dir, + /// If true, do not try to remount the root read-only and flush the journal, etc. + skip_finalize: bool, boot: MountSpec, kargs: Vec, } @@ -826,9 +853,11 @@ async fn install_to_filesystem_impl(state: &State, rootfs: &mut RootSetup) -> Re .run()?; // Finalize mounted filesystems - let bootfs = rootfs.rootfs.join("boot"); - for fs in [bootfs.as_path(), rootfs.rootfs.as_path()] { - finalize_filesystem(fs)?; + if !rootfs.skip_finalize { + let bootfs = rootfs.rootfs.join("boot"); + for fs in [bootfs.as_path(), rootfs.rootfs.as_path()] { + finalize_filesystem(fs)?; + } } Ok(()) @@ -900,6 +929,36 @@ fn require_empty_rootdir(rootfs_fd: &Dir) -> Result<()> { Ok(()) } +/// Remove all entries in a directory, but do not traverse across distinct devices. +#[context("Removing entries (noxdev")] +fn remove_all_in_dir_no_xdev(d: &Dir) -> Result<()> { + let parent_dev = d.dir_metadata()?.dev(); + for entry in d.entries()? { + let entry = entry?; + let entry_dev = entry.metadata()?.dev(); + if entry_dev == parent_dev { + d.remove_all_optional(entry.file_name())?; + } + } + anyhow::Ok(()) +} + +#[context("Removing boot directory content")] +fn clean_boot_directories(rootfs: &Dir) -> Result<()> { + let bootdir = rootfs.open_dir(BOOT).context("Opening /boot")?; + // This should not remove /boot/efi note. + remove_all_in_dir_no_xdev(&bootdir)?; + if ARCH_USES_EFI { + if let Some(efidir) = bootdir + .open_dir_optional(crate::bootloader::EFI_DIR) + .context("Opening /boot/efi")? + { + remove_all_in_dir_no_xdev(&efidir)?; + } + } + Ok(()) +} + /// Implementation of the `bootc install-to-filsystem` CLI command. pub(crate) async fn install_to_filesystem(opts: InstallToFilesystemOpts) -> Result<()> { // Gather global state, destructuring the provided options @@ -909,19 +968,21 @@ pub(crate) async fn install_to_filesystem(opts: InstallToFilesystemOpts) -> Resu let root_path = &fsopts.root_path; let rootfs_fd = Dir::open_ambient_dir(root_path, cap_std::ambient_authority()) .with_context(|| format!("Opening target root directory {root_path}"))?; - if fsopts.wipe { - let rootfs_fd = rootfs_fd.try_clone()?; - println!("Wiping contents of root"); - tokio::task::spawn_blocking(move || { - for e in rootfs_fd.entries()? { - let e = e?; - rootfs_fd.remove_all_optional(e.file_name())?; - } - anyhow::Ok(()) - }) - .await??; - } else { - require_empty_rootdir(&rootfs_fd)?; + match fsopts.replace { + Some(ReplaceMode::Wipe) => { + let rootfs_fd = rootfs_fd.try_clone()?; + println!("Wiping contents of root"); + tokio::task::spawn_blocking(move || { + for e in rootfs_fd.entries()? { + let e = e?; + rootfs_fd.remove_all_optional(e.file_name())?; + } + anyhow::Ok(()) + }) + .await??; + } + Some(ReplaceMode::Alongside) => clean_boot_directories(&rootfs_fd)?, + None => require_empty_rootdir(&rootfs_fd)?, } // Gather data about the root filesystem @@ -929,15 +990,22 @@ pub(crate) async fn install_to_filesystem(opts: InstallToFilesystemOpts) -> Resu // We support overriding the mount specification for root (i.e. LABEL vs UUID versus // raw paths). - let root_mount_spec = if let Some(s) = fsopts.root_mount_spec { - s + let (root_mount_spec, root_extra) = if let Some(s) = fsopts.root_mount_spec { + (s, None) } else { let mut uuid = inspect .uuid .ok_or_else(|| anyhow!("No filesystem uuid found in target root"))?; uuid.insert_str(0, "UUID="); tracing::debug!("root {uuid}"); - uuid + let opts = match inspect.fstype.as_str() { + "btrfs" => { + let subvol = crate::utils::find_mount_option(&inspect.options, "subvol"); + subvol.map(|vol| format!("rootflags=subvol={vol}")) + } + _ => None, + }; + (uuid, opts) }; tracing::debug!("Root mount spec: {root_mount_spec}"); @@ -967,15 +1035,6 @@ pub(crate) async fn install_to_filesystem(opts: InstallToFilesystemOpts) -> Resu // for GRUB (BIOS) and in the future zipl (I think). let backing_device = { let mut dev = inspect.source; - // Hack: trim bind mount information from source - if dev.contains('[') { - dev = inspect - .sources - .into_iter() - .flatten() - .next() - .ok_or_else(|| anyhow!("Expected `sources` in findmnt output"))?; - } loop { tracing::debug!("Finding parents for {dev}"); let mut parents = crate::blockdev::find_parent_devices(&dev)?.into_iter(); @@ -1004,7 +1063,11 @@ pub(crate) async fn install_to_filesystem(opts: InstallToFilesystemOpts) -> Resu // By default, we inject a boot= karg because things like FIPS compliance currently // require checking in the initramfs. let bootarg = format!("boot={}", &boot.source); - let kargs = vec![rootarg, RW_KARG.to_string(), bootarg]; + let kargs = [rootarg] + .into_iter() + .chain(root_extra) + .chain([RW_KARG.to_string(), bootarg]) + .collect::>(); let mut rootfs = RootSetup { luks_device: None, @@ -1013,6 +1076,7 @@ pub(crate) async fn install_to_filesystem(opts: InstallToFilesystemOpts) -> Resu rootfs_fd, boot, kargs, + skip_finalize: matches!(fsopts.replace, Some(ReplaceMode::Alongside)), }; install_to_filesystem_impl(&state, &mut rootfs).await?; diff --git a/lib/src/install/baseline.rs b/lib/src/install/baseline.rs index 9dd9be02..433447a5 100644 --- a/lib/src/install/baseline.rs +++ b/lib/src/install/baseline.rs @@ -233,7 +233,7 @@ pub(crate) fn install_create_rootfs( anyhow::bail!("Unsupported architecture: {}", std::env::consts::ARCH); } - let espdev = if cfg!(any(target_arch = "x86_64", target_arch = "aarch64")) { + let espdev = if super::ARCH_USES_EFI { sgdisk_partition( &mut sgdisk.cmd, EFIPN, @@ -370,5 +370,6 @@ pub(crate) fn install_create_rootfs( rootfs_fd, boot, kargs, + skip_finalize: false, }) } diff --git a/lib/src/mount.rs b/lib/src/mount.rs index a2a780f3..42d2c392 100644 --- a/lib/src/mount.rs +++ b/lib/src/mount.rs @@ -13,6 +13,8 @@ use crate::task::Task; #[serde(rename_all = "kebab-case")] pub(crate) struct Filesystem { pub(crate) source: String, + pub(crate) fstype: String, + pub(crate) options: String, pub(crate) uuid: Option, } diff --git a/lib/src/utils.rs b/lib/src/utils.rs index bed352d3..51a73c41 100644 --- a/lib/src/utils.rs +++ b/lib/src/utils.rs @@ -18,6 +18,20 @@ pub(crate) fn origin_has_rpmostree_stuff(kf: &glib::KeyFile) -> bool { false } +/// Given an mount option string list like foo,bar=baz,something=else,ro parse it and find +/// the first entry like $optname= +/// This will not match a bare `optname` without an equals. +pub(crate) fn find_mount_option<'a>( + option_string_list: &'a str, + optname: &'_ str, +) -> Option<&'a str> { + option_string_list + .split(',') + .filter_map(|k| k.split_once('=')) + .filter_map(|(k, v)| (k == optname).then_some(v)) + .next() +} + /// Run a command in the host mount namespace #[allow(dead_code)] pub(crate) fn run_in_host_mountns(cmd: &str) -> Command { @@ -71,3 +85,11 @@ fn test_digested_pullspec() { format!("quay.io/example/foo@{digest}") ); } + +#[test] +fn test_find_mount_option() { + const V1: &str = "rw,relatime,compress=foo,subvol=blah,fast"; + assert_eq!(find_mount_option(V1, "subvol").unwrap(), "blah"); + assert_eq!(find_mount_option(V1, "rw"), None); + assert_eq!(find_mount_option(V1, "somethingelse"), None); +}