kargs: Handle addition/removal of kargs from kargs.d

Signed-off-by: Pragyan Poudyal <pragyanpoudyal41999@gmail.com>

Author: Johan-Liebert1

crates/lib/src/bootc_composefs/boot.rs

@@ -381,7 +381,7 @@ pub(crate) fn setup_composefs_bls_boot(
     repo: crate::store::ComposefsRepository,
     id: &Sha512HashValue,
     entry: &ComposefsBootEntry<Sha512HashValue>,
-    mounted_erofs: &Dir
+    mounted_erofs: &Dir,
 ) -> Result<String> {
     let id_hex = id.to_hex();
 
@@ -446,10 +446,16 @@ pub(crate) fn setup_composefs_bls_boot(
         }
     };
 
-    kargs_from_composefs_filesystem(mounted_erofs, &mut cmdline_refs)?;
-
     let is_upgrade = matches!(setup_type, BootSetupType::Upgrade(..));
 
+    let current_root = if is_upgrade {
+        Some(&Dir::open_ambient_dir("/", ambient_authority()).context("Opening root")?)
+    } else {
+        None
+    };
+
+    kargs_from_composefs_filesystem(mounted_erofs, current_root, &mut cmdline_refs)?;
+
     let (entry_paths, _tmpdir_guard) = match bootloader {
         Bootloader::Grub => {
             let root = Dir::open_ambient_dir(&root_path, ambient_authority())
@@ -1076,7 +1082,7 @@ pub(crate) fn setup_composefs_boot(
                 repo,
                 &id,
                 entry,
-                &mounted_fs
+                &mounted_fs,
             )?;
 
             boot_digest = Some(digest);

crates/lib/src/bootc_kargs.rs

@@ -45,13 +45,49 @@ impl Config {
     }
 }
 
+/// Compute the diff between existing and remote kargs
+/// Apply the diff to the new kargs
+fn compute_apply_kargs_diff(
+    existing_kargs: &Cmdline,
+    remote_kargs: &Cmdline,
+    new_kargs: &mut Cmdline,
+) {
+    // Calculate the diff between the existing and remote kargs
+    let added_kargs: Vec<_> = remote_kargs
+        .iter()
+        .filter(|item| !existing_kargs.iter().any(|existing| *item == existing))
+        .collect();
+    let removed_kargs: Vec<_> = existing_kargs
+        .iter()
+        .filter(|item| !remote_kargs.iter().any(|remote| *item == remote))
+        .collect();
+
+    tracing::debug!("kargs: added={:?} removed={:?}", added_kargs, removed_kargs);
+
+    // Apply the diff to the system kargs
+    for arg in &removed_kargs {
+        new_kargs.remove_exact(arg);
+    }
+    for arg in &added_kargs {
+        new_kargs.add(arg);
+    }
+}
+
 /// Looks for files in usr/lib/bootc/kargs.d and parses cmdline agruments
 pub(crate) fn kargs_from_composefs_filesystem(
     new_fs: &Dir,
-    cmdline: &mut Cmdline,
+    current_root: Option<&Dir>,
+    new_kargs: &mut Cmdline,
 ) -> Result<()> {
     let remote_kargs = get_kargs_in_root(new_fs, std::env::consts::ARCH)?;
-    cmdline.extend(&remote_kargs);
+
+    let existing_kargs = match current_root {
+        Some(root) => get_kargs_in_root(root, std::env::consts::ARCH)?,
+        None => Cmdline::new(),
+    };
+
+    compute_apply_kargs_diff(&existing_kargs, &remote_kargs, new_kargs);
+
     Ok(())
 }
 
@@ -185,29 +221,7 @@ pub(crate) fn get_kargs(
     // Fetch the kernel arguments from the new root
     let remote_kargs = get_kargs_from_ostree(repo, &fetched_tree, sys_arch)?;
 
-    // Calculate the diff between the existing and remote kargs
-    let added_kargs: Vec<_> = remote_kargs
-        .iter()
-        .filter(|item| !existing_kargs.iter().any(|existing| *item == existing))
-        .collect();
-    let removed_kargs: Vec<_> = existing_kargs
-        .iter()
-        .filter(|item| !remote_kargs.iter().any(|remote| *item == remote))
-        .collect();
-
-    tracing::debug!(
-        "kargs: added={:?} removed={:?}",
-        &added_kargs,
-        removed_kargs
-    );
-
-    // Apply the diff to the system kargs
-    for arg in &removed_kargs {
-        kargs.remove_exact(arg);
-    }
-    for arg in &added_kargs {
-        kargs.add(arg);
-    }
+    compute_apply_kargs_diff(&existing_kargs, &remote_kargs, &mut kargs);
 
     Ok(kargs)
 }