Use less memory when decompressing images for install

1. Delete source image before decompressing temporary file
2. Decompress the images serially instead of spawning a thread for each
   one.

citadel-tool/src/boot/live.rs

@@ -20,7 +20,7 @@ pub fn live_rootfs() -> Result<()> {
 }
 
 pub fn live_setup() -> Result<()> {
-    decompress_images()?;
+    decompress_images(true)?;
     info!("Starting live setup");
     let live = Installer::new_livesetup();
     live.run()
@@ -131,14 +131,21 @@ fn find_rootfs_image() -> Result<ResourceImage> {
     bail!("unable to find rootfs resource image in {}", IMAGE_DIRECTORY)
 }
 
-fn decompress_images() -> Result<()> {
+fn decompress_images(sync: bool) -> Result<()> {
     info!("Decompressing images");
     let mut threads = Vec::new();
     util::read_directory("/run/citadel/images", |dent| {
         if dent.path().extension() == Some(OsStr::new("img")) {
             if let Ok(image) = ResourceImage::from_path(&dent.path()) {
                 if image.is_compressed() {
-                    threads.push(decompress_one_image(image));
+                    if sync {
+                        if let Err(err) = decompress_one_image_sync(image) {
+                            warn!("Error: {}", err);
+                        }
+
+                    } else {
+                        threads.push(decompress_one_image(image));
+                    }
                 }
             }
         }
@@ -146,22 +153,28 @@ fn decompress_images() -> Result<()> {
     })?;
 
     for t in threads {
-        t.join().unwrap()?;
+        if let Err(err) = t.join().unwrap() {
+            warn!("Error: {}", err);
+        }
     }
     info!("Finished decompressing images");
     Ok(())
-
 }
 
-fn decompress_one_image(image: ResourceImage) -> JoinHandle<Result<()>> {
-    thread::spawn(move || {
+fn decompress_one_image_sync(image: ResourceImage) -> Result<()> {
         let start = Instant::now();
         info!("Decompressing {}", image.path().display());
-        image.decompress()?;
+        image.decompress(true)
+            .map_err(|e| format_err!("Failed to decompress image file {}: {}", image.path().display(), e))?;
         cmd!("/usr/bin/du", "-h {}", image.path().display())?;
         info!("Decompress {:?} finished in {} seconds",
               image.path().file_name().unwrap(),
               start.elapsed().as_secs());
         Ok(())
+}
+
+fn decompress_one_image(image: ResourceImage) -> JoinHandle<Result<()>> {
+    thread::spawn(move || {
+        decompress_one_image_sync(image)
     })
 }

citadel-tool/src/boot/rootfs.rs

@@ -23,7 +23,7 @@ pub fn setup_rootfs_resource(rootfs: &ResourceImage) -> Result<()> {
 
 fn setup_resource_unverified(img: &ResourceImage) -> Result<()> {
     if img.is_compressed() {
-        img.decompress()?;
+        img.decompress(false)?;
     }
     let loopdev = LoopDevice::create(img.path(), Some(4096), true)?;
     info!("Loop device created: {}", loopdev);

citadel-tool/src/image/mod.rs

@@ -275,7 +275,7 @@ fn decompress(arg_matches: &ArgMatches) -> Result<()> {
     if !img.is_compressed() {
         info!("Image is not compressed, not decompressing.");
     } else {
-        img.decompress()?;
+        img.decompress(false)?;
     }
     Ok(())
 }

citadel-tool/src/update/mod.rs

@@ -122,7 +122,7 @@ fn install_image(path: &Path, flags: u32) -> Result<()> {
 // dmverity hash tree.
 fn prepare_image(image: &ResourceImage, flags: u32) -> Result<()> {
     if image.is_compressed() {
-        image.decompress()?;
+        image.decompress(false)?;
     }
 
     if flags & FLAG_SKIP_SHA == 0 {

libcitadel/src/exec.rs

@@ -54,7 +54,7 @@ impl Exec {
             .map_err(context!("failed to execute command {}", self.cmd_name))?;
 
         for line in BufReader::new(result.stderr.as_slice()).lines() {
-            verbose!("  {}", line.unwrap());
+            warn!("  {}", line.unwrap());
         }
         self.check_cmd_status(result.status)
     }

libcitadel/src/resource.rs

@@ -138,7 +138,7 @@ impl ResourceImage {
         self.header.has_flag(ImageHeader::FLAG_HASH_TREE)
     }
 
-    pub fn decompress(&self) -> Result<()> {
+    pub fn decompress(&self, early_remove: bool) -> Result<()> {
         if !self.is_compressed() {
             return Ok(())
         }
@@ -154,6 +154,10 @@ impl ResourceImage {
         io::copy(&mut reader, &mut out)
             .map_err(context!("error copying image file {:?} to temporary file", self.path()))?;
 
+        if early_remove {
+            util::remove_file(self.path())?;
+        }
+
         util::xz_decompress(xzfile)?;
         let tmpfile = self.path.with_extension("tmp");
         util::rename(&tmpfile, self.path())?;
@@ -218,7 +222,7 @@ impl ResourceImage {
             return Ok(())
         }
         if self.is_compressed() {
-            self.decompress()?;
+            self.decompress(false)?;
         }
         info!("Generating dm-verity hash tree for image {}", self.path.display());
         let verity = self.verity()?;
@@ -239,7 +243,7 @@ impl ResourceImage {
 
     pub fn generate_shasum(&self) -> Result<String> {
         if self.is_compressed() {
-            self.decompress()?;
+            self.decompress(false)?;
         }
         info!("Calculating sha256 of image");
         let output = util::exec_cmdline_pipe_input("sha256sum", "-", self.path(), util::FileRange::Range{offset: 4096, len: self.metainfo().nblocks() * 4096})
@@ -256,7 +260,7 @@ impl ResourceImage {
         info!("loop mounting image to {} (noverity)", self.mount_path().display());
 
         if self.is_compressed() {
-            self.decompress()?;
+            self.decompress(false)?;
         }
 
         let loopdev = LoopDevice::create(self.path(), Some(4096), true)?;