efi: Handle compatibility for systems with no usr/lib/efi

In #995 changes were made to move
files from `usr/lib/ostree-boot/EFI` to `usr/lib/efi` which caused issues
with older bootupd failing to understand the new layout created by newer
version of bootupd.

To make the change backwards compatible, we now check for the existence
of `usr/lib/efi`, and only use the new layout if we find it. Else,
default back to the older layout at `usr/lib/bootupd`

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

Author: Johan-Liebert1

src/efi.rs

@@ -568,50 +568,44 @@ impl Component for Efi {
     }
 
     fn generate_update_metadata(&self, sysroot: &str) -> Result<Option<ContentMetadata>> {
-        let sysroot_path = Path::new(sysroot);
+        let sysroot_path = Utf8Path::new(sysroot);
         let sysroot_dir = Dir::open_ambient_dir(sysroot_path, cap_std::ambient_authority())?;
 
-        if let Some(ostreeboot) = sysroot_dir
+        let ostreeboot = sysroot_dir
             .open_dir_optional(ostreeutil::BOOT_PREFIX)
-            .context("Opening usr/lib/ostree-boot")?
-        {
-            let cruft = ["loader", "grub2"];
-            for p in cruft.iter() {
-                ostreeboot.remove_all_optional(p)?;
-            }
-            // Transfer ostree-boot EFI files to usr/lib/efi
-            transfer_ostree_boot_to_usr(sysroot_path)?;
+            .context("Opening usr/lib/ostree-boot")?;
+
+        // Newer images >= F44 have boot entries in /usr/lib/efi, but older images
+        // have them in /usr/lib/ostree-boot, which we move to /usr/lib/bootupd/updates/EFI
+        let metadata = match ostreeboot {
+            Some(ostreeboot) => {
+                let cruft = ["loader", "grub2"];
+                for p in cruft.iter() {
+                    ostreeboot.remove_all_optional(p)?;
+                }
 
-            // Remove usr/lib/ostree-boot/efi/EFI dir (after transfer) or if it is empty
-            ostreeboot.remove_all_optional("efi/EFI")?;
-        }
+                let meta = if sysroot_path.join(EFILIB).exists() {
+                    // Transfer usr/lib/ostree-boot/EFI files to usr/lib/efi
+                    transfer_ostree_boot_to_usr(sysroot_path)?;
+                    generate_meta_from_usr_efi(sysroot_path)?
+                } else {
+                    // Transfer usr/lib/ostree-boot/EFI files to usr/lib/bootupd/updates/EFI
+                    transfer_ostree_boot_to_bootupd_updates(sysroot_path, self)?
+                };
 
-        if let Some(efi_components) =
-            get_efi_component_from_usr(Utf8Path::from_path(sysroot_path).unwrap(), EFILIB)?
-        {
-            let mut packages = Vec::new();
-            let mut modules_vec: Vec<Module> = vec![];
-            for efi in efi_components {
-                packages.push(format!("{}-{}", efi.name, efi.version));
-                modules_vec.push(Module {
-                    name: efi.name,
-                    rpm_evr: efi.version,
-                });
+                // Remove usr/lib/ostree-boot/efi/EFI dir (after transfer) or if it is empty
+                ostreeboot.remove_all_optional("efi/EFI")?;
+
+                meta
             }
-            modules_vec.sort_unstable();
-
-            // change to now to workaround https://github.com/coreos/bootupd/issues/933
-            let timestamp = std::time::SystemTime::now();
-            let meta = ContentMetadata {
-                timestamp: chrono::DateTime::<Utc>::from(timestamp),
-                version: packages.join(","),
-                versions: Some(modules_vec),
-            };
-            write_update_metadata(sysroot, self, &meta)?;
-            Ok(Some(meta))
-        } else {
-            anyhow::bail!("Failed to find EFI components");
-        }
+
+            // If /usr/lib/ostree-boot doesn't exist, assume /usr/lib/efi will
+            None => generate_meta_from_usr_efi(sysroot_path)?,
+        };
+
+        write_update_metadata(sysroot_path.as_str(), self, &metadata)?;
+
+        Ok(Some(metadata))
     }
 
     fn query_update(&self, sysroot: &openat::Dir) -> Result<Option<ContentMetadata>> {
@@ -801,6 +795,34 @@ fn find_file_recursive<P: AsRef<Path>>(dir: P, target_file: &str) -> Result<Vec<
     Ok(result)
 }
 
+#[context("Generating metadata from usr/lib/efi")]
+fn generate_meta_from_usr_efi(sysroot_path: &Utf8Path) -> Result<ContentMetadata> {
+    let Some(efi_components) = get_efi_component_from_usr(sysroot_path, EFILIB)? else {
+        anyhow::bail!("Failed to find EFI components");
+    };
+
+    let mut packages = Vec::new();
+    let mut modules_vec: Vec<Module> = vec![];
+    for efi in efi_components {
+        packages.push(format!("{}-{}", efi.name, efi.version));
+        modules_vec.push(Module {
+            name: efi.name,
+            rpm_evr: efi.version,
+        });
+    }
+    modules_vec.sort_unstable();
+
+    // change to now to workaround https://github.com/coreos/bootupd/issues/933
+    let timestamp = std::time::SystemTime::now();
+    let meta = ContentMetadata {
+        timestamp: chrono::DateTime::<Utc>::from(timestamp),
+        version: packages.join(","),
+        versions: Some(modules_vec),
+    };
+
+    Ok(meta)
+}
+
 #[derive(Debug, PartialEq, Eq)]
 pub struct EFIComponent {
     pub name: String,
@@ -851,9 +873,48 @@ fn get_efi_component_from_usr<'a>(
     Ok(Some(components))
 }
 
+/// Copies usr/lib/ostree-boot/EFI to usr/lib/bootupd/updates
+fn transfer_ostree_boot_to_bootupd_updates(
+    sysroot: &Utf8Path,
+    component: &Efi,
+) -> Result<ContentMetadata> {
+    let ostreebootdir = sysroot.join(ostreeutil::BOOT_PREFIX);
+
+    // move EFI files to updates dir from /usr/lib/ostree-boot
+    if !ostreebootdir.exists() {
+        anyhow::bail!("Failed to find {ostreebootdir}");
+    }
+
+    let efisrc = ostreebootdir.join("efi/EFI");
+    if !efisrc.exists() {
+        bail!("Failed to find {:?}", &efisrc);
+    }
+
+    let dest_efidir = component_updatedir(sysroot.as_str(), component);
+    let dest_efidir = Utf8PathBuf::from_path_buf(dest_efidir).expect("Path is invalid UTF-8");
+
+    // Fork off mv() because on overlayfs one can't rename() a lower level
+    // directory today, and this will handle the copy fallback.
+    Command::new("mv")
+        .args([&efisrc, &dest_efidir])
+        .run_capture_stderr()?;
+
+    let efidir = openat::Dir::open(dest_efidir.as_std_path())
+        .with_context(|| format!("Opening {}", dest_efidir))?;
+
+    let files = crate::util::filenames(&efidir)?.into_iter().map(|mut f| {
+        f.insert_str(0, "/boot/efi/EFI");
+        f
+    });
+
+    let files = files.collect::<Vec<_>>();
+
+    query_files(sysroot.as_str(), files)
+}
+
 /// Copy files from usr/lib/ostree-boot/efi/EFI to /usr/lib/efi/<component>/<evr>/
-fn transfer_ostree_boot_to_usr(sysroot: &Path) -> Result<()> {
-    let ostreeboot_efi = Path::new(ostreeutil::BOOT_PREFIX).join("efi");
+fn transfer_ostree_boot_to_usr(sysroot: &Utf8Path) -> Result<()> {
+    let ostreeboot_efi = Utf8Path::new(ostreeutil::BOOT_PREFIX).join("efi");
     let ostreeboot_efi_path = sysroot.join(&ostreeboot_efi);
 
     let efi = ostreeboot_efi_path.join("EFI");
@@ -873,7 +934,7 @@ fn transfer_ostree_boot_to_usr(sysroot: &Path) -> Result<()> {
 
             // Run `rpm -qf <filepath>`
             let pkg = crate::packagesystem::query_file(
-                sysroot.to_str().unwrap(),
+                sysroot.as_str(),
                 boot_filepath.to_str().unwrap(),
             )?;
 
@@ -882,15 +943,15 @@ fn transfer_ostree_boot_to_usr(sysroot: &Path) -> Result<()> {
             // get path usr/lib/efi/<component>/<evr>
             let efilib_path = Path::new(EFILIB).join(component).join(evr);
 
-            let sysroot_dir = openat::Dir::open(sysroot)?;
+            let sysroot_dir = openat::Dir::open(sysroot.as_str())?;
             // Ensure dest parent directory exists
             if let Some(parent) = efilib_path.join(filepath).parent() {
                 sysroot_dir.ensure_dir_all(parent, 0o755)?;
             }
 
             // Source dir is usr/lib/ostree-boot/efi
             let src = sysroot_dir
-                .sub_dir(&ostreeboot_efi)
+                .sub_dir(ostreeboot_efi.as_str())
                 .context("Opening ostree-boot dir")?;
             // Dest dir is usr/lib/efi/<component>/<evr>
             let dest = sysroot_dir