implement magic mount

userspace/ksud/Cargo.toml

@@ -39,7 +39,6 @@ sha256 = "1"
 sha1 = "0.10"
 tempfile = "3"
 chrono = "0.4"
-hole-punch = { git = "https://github.com/tiann/hole-punch" }
 regex-lite = "0.1"
 fs4 = "0.13"
 

userspace/ksud/src/cli.rs

@@ -161,17 +161,6 @@ enum Debug {
 
     Mount,
 
-    /// Copy sparse file
-    Xcp {
-        /// source file
-        src: String,
-        /// destination file
-        dst: String,
-        /// punch hole
-        #[arg(short, long, default_value = "false")]
-        punch_hole: bool,
-    },
-
     /// For testing
     Test,
 }
@@ -231,9 +220,6 @@ enum Module {
 
     /// list all modules
     List,
-
-    /// Shrink module image size
-    Shrink,
 }
 
 #[derive(clap::Subcommand, Debug)]
@@ -313,7 +299,6 @@ pub fn run() -> Result<()> {
                 Module::Disable { id } => module::disable_module(&id),
                 Module::Action { id } => module::run_action(&id),
                 Module::List => module::list_modules(),
-                Module::Shrink => module::shrink_ksu_images(),
             }
         }
         Commands::Install { magiskboot } => utils::install(magiskboot),
@@ -347,15 +332,7 @@ pub fn run() -> Result<()> {
                 Ok(())
             }
             Debug::Su { global_mnt } => crate::su::grant_root(global_mnt),
-            Debug::Mount => init_event::mount_modules_systemlessly(defs::MODULE_DIR),
+            Debug::Mount => init_event::mount_modules_systemlessly(),
-            Debug::Xcp {
-                src,
-                dst,
-                punch_hole,
-            } => {
-                utils::copy_sparse_file(src, dst, punch_hole)?;
-                Ok(())
-            }
             Debug::Test => assets::ensure_binaries(false),
         },
 

userspace/ksud/src/defs.rs

@@ -10,7 +10,7 @@ pub const PROFILE_SELINUX_DIR: &str = concatcp!(PROFILE_DIR, "selinux/");
 pub const PROFILE_TEMPLATE_DIR: &str = concatcp!(PROFILE_DIR, "templates/");
 
 pub const KSURC_PATH: &str = concatcp!(WORKING_DIR, ".ksurc");
-pub const KSU_OVERLAY_SOURCE: &str = "KSU";
+pub const KSU_MOUNT_SOURCE: &str = "KSU";
 pub const DAEMON_PATH: &str = concatcp!(ADB_DIR, "ksud");
 pub const MAGISKBOOT_PATH: &str = concatcp!(BINARY_DIR, "magiskboot");
 
@@ -18,15 +18,9 @@ pub const MAGISKBOOT_PATH: &str = concatcp!(BINARY_DIR, "magiskboot");
 pub const DAEMON_LINK_PATH: &str = concatcp!(BINARY_DIR, "ksud");
 
 pub const MODULE_DIR: &str = concatcp!(ADB_DIR, "modules/");
-pub const MODULE_IMG: &str = concatcp!(WORKING_DIR, "modules.img");
-pub const MODULE_UPDATE_IMG: &str = concatcp!(WORKING_DIR, "modules_update.img");
-
-pub const MODULE_UPDATE_TMP_IMG: &str = concatcp!(WORKING_DIR, "update_tmp.img");
 
 // warning: this directory should not change, or you need to change the code in module_installer.sh!!!
-pub const MODULE_UPDATE_TMP_DIR: &str = concatcp!(ADB_DIR, "modules_update/");
+pub const MODULE_UPDATE_DIR: &str = concatcp!(ADB_DIR, "modules_update/");
-
-pub const SYSTEM_RW_DIR: &str = concatcp!(MODULE_DIR, ".rw/");
 
 pub const TEMP_DIR: &str = "/debug_ramdisk";
 pub const MODULE_WEB_DIR: &str = "webroot";

userspace/ksud/src/init_event.rs

@@ -1,100 +1,11 @@
-use anyhow::{Context, Result, bail};
+use crate::module::{handle_updated_modules, prune_modules};
-use log::{info, warn};
-use std::{collections::HashMap, path::Path};
-
-use crate::module::prune_modules;
 use crate::{
-    assets, defs, ksucalls, mount, restorecon,
+    assets, defs, ksucalls, restorecon,
-    utils::{self, ensure_clean_dir},
+    utils::self,
 };
-
+use anyhow::{Context, Result};
-fn mount_partition(partition_name: &str, lowerdir: &Vec<String>) -> Result<()> {
+use log::{info, warn};
-    if lowerdir.is_empty() {
+use std::path::Path;
-        warn!("partition: {partition_name} lowerdir is empty");
-        return Ok(());
-    }
-
-    let partition = format!("/{partition_name}");
-
-    // if /partition is a symlink and linked to /system/partition, then we don't need to overlay it separately
-    if Path::new(&partition).read_link().is_ok() {
-        warn!("partition: {partition} is a symlink");
-        return Ok(());
-    }
-
-    let mut workdir = None;
-    let mut upperdir = None;
-    let system_rw_dir = Path::new(defs::SYSTEM_RW_DIR);
-    if system_rw_dir.exists() {
-        workdir = Some(system_rw_dir.join(partition_name).join("workdir"));
-        upperdir = Some(system_rw_dir.join(partition_name).join("upperdir"));
-    }
-
-    mount::mount_overlay(&partition, lowerdir, workdir, upperdir)
-}
-
-pub fn mount_modules_systemlessly(module_dir: &str) -> Result<()> {
-    // construct overlay mount params
-    let dir = std::fs::read_dir(module_dir);
-    let Ok(dir) = dir else {
-        bail!("open {} failed", defs::MODULE_DIR);
-    };
-
-    let mut system_lowerdir: Vec<String> = Vec::new();
-
-    let partition = vec!["vendor", "product", "system_ext", "odm", "oem"];
-    let mut partition_lowerdir: HashMap<String, Vec<String>> = HashMap::new();
-    for ele in &partition {
-        partition_lowerdir.insert((*ele).to_string(), Vec::new());
-    }
-
-    for entry in dir.flatten() {
-        let module = entry.path();
-        if !module.is_dir() {
-            continue;
-        }
-        let disabled = module.join(defs::DISABLE_FILE_NAME).exists();
-        if disabled {
-            info!("module: {} is disabled, ignore!", module.display());
-            continue;
-        }
-        let skip_mount = module.join(defs::SKIP_MOUNT_FILE_NAME).exists();
-        if skip_mount {
-            info!("module: {} skip_mount exist, skip!", module.display());
-            continue;
-        }
-
-        let module_system = Path::new(&module).join("system");
-        if module_system.is_dir() {
-            system_lowerdir.push(format!("{}", module_system.display()));
-        }
-
-        for part in &partition {
-            // if /partition is a mountpoint, we would move it to $MODPATH/$partition when install
-            // otherwise it must be a symlink and we don't need to overlay!
-            let part_path = Path::new(&module).join(part);
-            if part_path.is_dir() {
-                if let Some(v) = partition_lowerdir.get_mut(*part) {
-                    v.push(format!("{}", part_path.display()));
-                }
-            }
-        }
-    }
-
-    // mount /system first
-    if let Err(e) = mount_partition("system", &system_lowerdir) {
-        warn!("mount system failed: {:#}", e);
-    }
-
-    // mount other partitions
-    for (k, v) in partition_lowerdir {
-        if let Err(e) = mount_partition(&k, &v) {
-            warn!("mount {k} failed: {:#}", e);
-        }
-    }
-
-    Ok(())
-}
 
 pub fn on_post_data_fs() -> Result<()> {
     ksucalls::report_post_fs_data();
@@ -111,11 +22,9 @@ pub fn on_post_data_fs() -> Result<()> {
         return Ok(());
     }
 
-    let safe_mode = crate::utils::is_safe_mode();
+    let safe_mode = utils::is_safe_mode();
 
     if safe_mode {
-        // we should still mount modules.img to `/data/adb/modules` in safe mode
-        // becuase we may need to operate the module dir in safe mode
         warn!("safe mode, skip common post-fs-data.d scripts");
     } else {
         // Then exec common post-fs-data scripts
@@ -124,43 +33,8 @@ pub fn on_post_data_fs() -> Result<()> {
         }
     }
 
-    let module_update_img = defs::MODULE_UPDATE_IMG;
-    let module_img = defs::MODULE_IMG;
-    let module_dir = defs::MODULE_DIR;
-    let module_update_flag = Path::new(defs::WORKING_DIR).join(defs::UPDATE_FILE_NAME);
-
-    // modules.img is the default image
-    let mut target_update_img = &module_img;
-
-    // we should clean the module mount point if it exists
-    ensure_clean_dir(module_dir)?;
-
     assets::ensure_binaries(true).with_context(|| "Failed to extract bin assets")?;
 
-    if Path::new(module_update_img).exists() {
-        if module_update_flag.exists() {
-            // if modules_update.img exists, and the the flag indicate this is an update
-            // this make sure that if the update failed, we will fallback to the old image
-            // if we boot succeed, we will rename the modules_update.img to modules.img #on_boot_complete
-            target_update_img = &module_update_img;
-            // And we should delete the flag immediately
-            std::fs::remove_file(module_update_flag)?;
-        } else {
-            // if modules_update.img exists, but the flag not exist, we should delete it
-            std::fs::remove_file(module_update_img)?;
-        }
-    }
-
-    if !Path::new(target_update_img).exists() {
-        return Ok(());
-    }
-
-    // we should always mount the module.img to module dir
-    // becuase we may need to operate the module dir in safe mode
-    info!("mount module image: {target_update_img} to {module_dir}");
-    mount::AutoMountExt4::try_new(target_update_img, module_dir, false)
-        .with_context(|| "mount module image failed".to_string())?;
-
     // tell kernel that we've mount the module, so that it can do some optimization
     ksucalls::report_module_mounted();
 
@@ -177,6 +51,10 @@ pub fn on_post_data_fs() -> Result<()> {
         warn!("prune modules failed: {}", e);
     }
 
+    if let Err(e) = handle_updated_modules() {
+        warn!("handle updated modules failed: {}", e);
+    }
+
     if let Err(e) = restorecon::restorecon() {
         warn!("restorecon failed: {}", e);
     }
@@ -190,11 +68,6 @@ pub fn on_post_data_fs() -> Result<()> {
         warn!("apply root profile sepolicy failed: {}", e);
     }
 
-    // mount temp dir
-    if let Err(e) = mount::mount_tmpfs(defs::TEMP_DIR) {
-        warn!("do temp dir mount failed: {}", e);
-    }
-
     // exec modules post-fs-data scripts
     // TODO: Add timeout
     if let Err(e) = crate::module::exec_stage_script("post-fs-data", true) {
@@ -206,15 +79,23 @@ pub fn on_post_data_fs() -> Result<()> {
         warn!("load system.prop failed: {}", e);
     }
 
-    // mount module systemlessly by overlay
+    // mount module systemlessly by magic mount
-    if let Err(e) = mount_modules_systemlessly(module_dir) {
+    if let Err(e) = mount_modules_systemlessly() {
         warn!("do systemless mount failed: {}", e);
     }
 
     run_stage("post-mount", true);
 
-    std::env::set_current_dir("/").with_context(|| "failed to chdir to /")?;
+    Ok(())
+}
 
+#[cfg(target_os = "android")]
+pub fn mount_modules_systemlessly() -> Result<()> {
+    crate::magic_mount::magic_mount()
+}
+
+#[cfg(not(target_os = "android"))]
+pub fn mount_modules_systemlessly() -> Result<()> {
     Ok(())
 }
 
@@ -249,17 +130,6 @@ pub fn on_services() -> Result<()> {
 pub fn on_boot_completed() -> Result<()> {
     ksucalls::report_boot_complete();
     info!("on_boot_completed triggered!");
-    let module_update_img = Path::new(defs::MODULE_UPDATE_IMG);
-    let module_img = Path::new(defs::MODULE_IMG);
-    if module_update_img.exists() {
-        // this is a update and we successfully booted
-        if std::fs::rename(module_update_img, module_img).is_err() {
-            warn!("Failed to rename images, copy it now.",);
-            utils::copy_sparse_file(module_update_img, module_img, false)
-                .with_context(|| "Failed to copy images")?;
-            std::fs::remove_file(module_update_img).with_context(|| "Failed to remove image!")?;
-        }
-    }
 
     run_stage("boot-completed", false);
 

userspace/ksud/src/installer.sh

@@ -85,7 +85,7 @@ setup_flashable() {
   $BOOTMODE && return
   if [ -z $OUTFD ] || readlink /proc/$$/fd/$OUTFD | grep -q /tmp; then
     # We will have to manually find out OUTFD
-    for FD in `ls /proc/$$/fd`; do
+    for FD in /proc/$$/fd/*; do
       if readlink /proc/$$/fd/$FD | grep -q pipe; then
         if ps | grep -v grep | grep -qE " 3 $FD |status_fd=$FD"; then
           OUTFD=$FD
@@ -302,18 +302,15 @@ is_legacy_script() {
 }
 
 handle_partition() {
-    # if /system/vendor is a symlink, we need to move it out of $MODPATH/system, otherwise it will be overlayed
+    PARTITION="$1"
-    # if /system/vendor is a normal directory, it is ok to overlay it and we don't need to overlay it separately.
+    if [ ! -e "$MODPATH/system/$PARTITION" ]; then
-    if [ ! -e $MODPATH/system/$1 ]; then
         # no partition found
         return;
     fi
 
-    if [ -L "/system/$1" ] && [ "$(readlink -f /system/$1)" = "/$1" ]; then
+    if [ -L "/system/$PARTITION" ] && [ "$(readlink -f "/system/$PARTITION")" = "/$PARTITION" ]; then
-        ui_print "- Handle partition /$1"
+        ui_print "- Handle partition /$PARTITION"
-        # we create a symlink if module want to access $MODPATH/system/$1
+        ln -sf "$MODPATH/$PARTITION" "$MODPATH/system/$PARTITION"
-        # but it doesn't always work(ie. write it in post-fs-data.sh would fail because it is readonly)
-        mv -f $MODPATH/system/$1 $MODPATH/$1 && ln -sf ../$1 $MODPATH/system/$1
     fi
 }
 

userspace/ksud/src/magic_mount.rs

@@ -0,0 +1,349 @@
+use crate::defs::{KSU_MOUNT_SOURCE, MODULE_DIR, SKIP_MOUNT_FILE_NAME, TEMP_DIR};
+use crate::magic_mount::NodeFileType::{Directory, RegularFile, Symlink};
+use crate::restorecon::{lgetfilecon, lsetfilecon};
+use anyhow::{bail, Context, Result};
+use rustix::fs::{
+    bind_mount, chmod, chown, mount, move_mount, unmount, Gid, MetadataExt, Mode, MountFlags,
+    MountPropagationFlags, Uid, UnmountFlags,
+};
+use rustix::mount::mount_change;
+use rustix::path::Arg;
+use std::cmp::PartialEq;
+use std::collections::hash_map::Entry;
+use std::collections::HashMap;
+use std::fs;
+use std::fs::{create_dir, create_dir_all, read_dir, DirEntry, FileType};
+use std::os::unix::fs::symlink;
+use std::path::{Path, PathBuf};
+
+#[derive(PartialEq, Eq, Hash, Clone, Debug)]
+enum NodeFileType {
+    RegularFile,
+    Directory,
+    Symlink,
+}
+
+impl NodeFileType {
+    fn from_file_type(file_type: FileType) -> Option<Self> {
+        if file_type.is_file() {
+            Some(RegularFile)
+        } else if file_type.is_dir() {
+            Some(Directory)
+        } else if file_type.is_symlink() {
+            Some(Symlink)
+        } else {
+            None
+        }
+    }
+}
+
+struct Node {
+    name: String,
+    file_type: NodeFileType,
+    children: HashMap<String, Node>,
+    // the module that owned this node
+    module_path: Option<PathBuf>,
+    replace: bool,
+}
+
+impl Node {
+    fn collect_module_files<T: AsRef<Path>>(&mut self, module_dir: T) -> Result<bool> {
+        let dir = module_dir.as_ref();
+        let mut has_file = false;
+        for entry in dir.read_dir()?.flatten() {
+            let name = entry.file_name().to_string_lossy().to_string();
+            if name == ".replace" {
+                has_file = true;
+                self.replace = true;
+                continue;
+            }
+
+            let file_type = entry.file_type()?;
+
+            let node = match self.children.entry(name.clone()) {
+                Entry::Occupied(o) => Some(o.into_mut()),
+                Entry::Vacant(v) => {
+                    Self::new_module(&name, file_type, dir.join(&name)).map(|it| v.insert(it))
+                }
+            };
+
+            if let Some(node) = node {
+                has_file |= if let Directory = node.file_type {
+                    node.collect_module_files(&dir.join(&node.name))?
+                } else {
+                    true
+                }
+            }
+        }
+
+        Ok(has_file)
+    }
+
+    fn new_root<T: ToString>(name: T) -> Self {
+        Node {
+            name: name.to_string(),
+            file_type: Directory,
+            children: Default::default(),
+            module_path: None,
+            replace: false,
+        }
+    }
+
+    fn new_module<T: ToString, P: AsRef<Path>>(
+        name: T,
+        file_type: FileType,
+        module_path: P,
+    ) -> Option<Self> {
+        let file_type = NodeFileType::from_file_type(file_type)?;
+
+        Some(Node {
+            name: name.to_string(),
+            file_type,
+            children: Default::default(),
+            module_path: Some(PathBuf::from(module_path.as_ref())),
+            replace: false,
+        })
+    }
+}
+
+fn collect_module_files() -> Result<Option<Node>> {
+    let mut root = Node::new_root("");
+    let mut system = Node::new_root("system");
+    let module_root = Path::new(MODULE_DIR);
+    let mut has_file = false;
+    for entry in module_root.read_dir()?.flatten() {
+        if !entry.file_type()?.is_dir() {
+            continue;
+        }
+
+        if entry.path().join("disable").exists() || entry.path().join(SKIP_MOUNT_FILE_NAME).exists() {
+            continue;
+        }
+
+        let mod_system = entry.path().join("system");
+        if !mod_system.is_dir() {
+            continue;
+        }
+
+        log::debug!("collecting {}", entry.path().display());
+
+        has_file |= system.collect_module_files(&mod_system)?;
+    }
+
+    if has_file {
+        for partition in vec!["vendor", "system_ext", "product", "odm"] {
+            let path_of_root = Path::new("/").join(partition);
+            let path_of_system = Path::new("/system").join(partition);
+            if path_of_root.is_dir() && path_of_system.is_symlink() {
+                let name = partition.to_string();
+                if let Some(node) = system.children.remove(&name) {
+                    root.children.insert(name, node);
+                }
+            }
+        }
+        root.children.insert("system".to_string(), system);
+        Ok(Some(root))
+    } else {
+        Ok(None)
+    }
+}
+
+fn clone_symlink<Src: AsRef<Path>, Dst: AsRef<Path>>(src: Src, dst: Dst) -> Result<()> {
+    symlink(src.as_ref(), dst.as_ref())?;
+    lsetfilecon(dst.as_ref(), lgetfilecon(src.as_ref())?.as_str())?;
+    Ok(())
+}
+
+fn mount_mirror<P: AsRef<Path>, WP: AsRef<Path>>(
+    path: P,
+    work_dir_path: WP,
+    entry: &DirEntry,
+) -> Result<()> {
+    let path = path.as_ref().join(entry.file_name());
+    let work_dir_path = work_dir_path.as_ref().join(entry.file_name());
+    let file_type = entry.file_type()?;
+
+    if file_type.is_file() {
+        log::debug!(
+            "mount mirror file {} -> {}",
+            path.display(),
+            work_dir_path.display()
+        );
+        fs::File::create(&work_dir_path)?;
+        bind_mount(&path, &work_dir_path)?;
+    } else if file_type.is_dir() {
+        log::debug!(
+            "mount mirror dir {} -> {}",
+            path.display(),
+            work_dir_path.display()
+        );
+        create_dir(&work_dir_path)?;
+        let metadata = entry.metadata()?;
+        chmod(&work_dir_path, Mode::from_raw_mode(metadata.mode()))?;
+        unsafe {
+            chown(
+                &work_dir_path,
+                Some(Uid::from_raw(metadata.uid())),
+                Some(Gid::from_raw(metadata.gid())),
+            )?;
+        }
+        lsetfilecon(&work_dir_path, lgetfilecon(&path)?.as_str())?;
+        for entry in read_dir(&path)?.flatten() {
+            mount_mirror(&path, &work_dir_path, &entry)?;
+        }
+    } else if file_type.is_symlink() {
+        log::debug!(
+            "create mirror symlink {} -> {}",
+            path.display(),
+            work_dir_path.display()
+        );
+        clone_symlink(&path, &work_dir_path)?;
+    }
+
+    Ok(())
+}
+
+fn do_magic_mount<P: AsRef<Path>, WP: AsRef<Path>>(
+    path: P,
+    work_dir_path: WP,
+    current: Node,
+    has_tmpfs: bool,
+) -> Result<()> {
+    let mut current = current;
+    let path = path.as_ref().join(&current.name);
+    let work_dir_path = work_dir_path.as_ref().join(&current.name);
+    match current.file_type {
+        RegularFile => {
+            if has_tmpfs {
+                fs::File::create(&work_dir_path)?;
+            }
+            if let Some(module_path) = &current.module_path {
+                log::debug!(
+                    "mount module file {} -> {}",
+                    module_path.display(),
+                    work_dir_path.display()
+                );
+                bind_mount(module_path, &work_dir_path)?;
+            } else {
+                bail!("cannot mount root file {}!", path.display());
+            }
+        }
+        Symlink => {
+            if let Some(module_path) = &current.module_path {
+                log::debug!(
+                    "create module symlink {} -> {}",
+                    module_path.display(),
+                    work_dir_path.display()
+                );
+                clone_symlink(module_path, &work_dir_path)?;
+            } else {
+                bail!("cannot mount root symlink {}!", path.display());
+            }
+        }
+        Directory => {
+            let mut create_tmpfs = false;
+            if !has_tmpfs {
+                for (name, node) in &current.children {
+                    let real_path = path.join(name);
+                    let need = if node.file_type == Symlink || !real_path.exists() {
+                        true
+                    } else {
+                        let file_type = real_path.metadata()?.file_type();
+                        let file_type =
+                            NodeFileType::from_file_type(file_type).unwrap_or(RegularFile);
+                        file_type != node.file_type || file_type == Symlink
+                    };
+                    if need {
+                        create_tmpfs = need;
+                        break;
+                    }
+                }
+            }
+
+            let has_tmpfs = has_tmpfs || create_tmpfs;
+
+            if has_tmpfs {
+                log::debug!(
+                    "creating tmpfs skeleton for {} at {}",
+                    path.display(),
+                    work_dir_path.display()
+                );
+                create_dir_all(&work_dir_path)?;
+                let (metadata, path) = if path.exists() {
+                    (path.metadata()?, &path)
+                } else if let Some(module_path) = &current.module_path {
+                    (module_path.metadata()?, module_path)
+                } else {
+                    bail!("cannot mount root dir {}!", path.display());
+                };
+                chmod(&work_dir_path, Mode::from_raw_mode(metadata.mode()))?;
+                unsafe {
+                    chown(
+                        &work_dir_path,
+                        Some(Uid::from_raw(metadata.uid())),
+                        Some(Gid::from_raw(metadata.gid())),
+                    )?;
+                }
+                lsetfilecon(&work_dir_path, lgetfilecon(&path)?.as_str())?;
+            }
+
+            if create_tmpfs {
+                log::debug!(
+                    "creating tmpfs for {} at {}",
+                    path.display(),
+                    work_dir_path.display()
+                );
+                bind_mount(&work_dir_path, &work_dir_path)?;
+            }
+
+            if path.exists() && !current.replace {
+                for entry in path.read_dir()?.flatten() {
+                    let name = entry.file_name().to_string_lossy().to_string();
+                    if let Some(node) = current.children.remove(&name) {
+                        do_magic_mount(&path, &work_dir_path, node, has_tmpfs)?;
+                    } else if has_tmpfs {
+                        mount_mirror(&path, &work_dir_path, &entry)?;
+                    }
+                }
+            }
+
+            if current.replace && current.module_path.is_none() {
+                bail!(
+                    "dir {} is declared as replaced but it is root!",
+                    path.display()
+                );
+            }
+
+            for node in current.children.into_values() {
+                do_magic_mount(&path, &work_dir_path, node, has_tmpfs)?;
+            }
+
+            if create_tmpfs {
+                log::debug!(
+                    "moving tmpfs {} -> {}",
+                    work_dir_path.display(),
+                    path.display()
+                );
+                move_mount(&work_dir_path, &path)?;
+            }
+        }
+    }
+
+    Ok(())
+}
+
+pub fn magic_mount() -> Result<()> {
+    if let Some(root) = collect_module_files()? {
+        let tmp_dir = PathBuf::from(TEMP_DIR);
+        mount(KSU_MOUNT_SOURCE, &tmp_dir, "tmpfs", MountFlags::empty(), "").context("mount tmp")?;
+        mount_change(&tmp_dir, MountPropagationFlags::PRIVATE).context("make tmp private")?;
+        let result = do_magic_mount("/", &tmp_dir, root, false);
+        if let Err(e) = unmount(&tmp_dir, UnmountFlags::DETACH) {
+            log::error!("failed to unmount tmp {}", e);
+        }
+        result
+    } else {
+        log::info!("no modules to mount, skipping!");
+        Ok(())
+    }
+}

userspace/ksud/src/main.rs

@@ -6,8 +6,9 @@ mod debug;
 mod defs;
 mod init_event;
 mod ksucalls;
+#[cfg(target_os = "android")]
+mod magic_mount;
 mod module;
-mod mount;
 mod profile;
 mod restorecon;
 mod sepolicy;

userspace/ksud/src/module.rs

@@ -1,9 +1,9 @@
 #[allow(clippy::wildcard_imports)]
 use crate::utils::*;
 use crate::{
-    assets, defs, ksucalls, mount,
+    assets, defs, ksucalls,
     restorecon::{restore_syscon, setsyscon},
-    sepolicy, utils,
+    sepolicy,
 };
 
 use anyhow::{Context, Result, anyhow, bail, ensure};
@@ -12,20 +12,21 @@ use is_executable::is_executable;
 use java_properties::PropertiesIter;
 use log::{info, warn};
 
-use std::fs::OpenOptions;
+use std::fs::{copy, rename};
 use std::{
     collections::HashMap,
     env::var as env_var,
     fs::{File, Permissions, remove_dir_all, remove_file, set_permissions},
     io::Cursor,
     path::{Path, PathBuf},
-    process::{Command, Stdio},
+    process::{Command},
     str::FromStr,
 };
 use zip_extensions::zip_extract_file_to_memory;
 
+use crate::defs::{MODULE_DIR, MODULE_UPDATE_DIR, UPDATE_FILE_NAME};
 #[cfg(unix)]
-use std::os::unix::{fs::MetadataExt, prelude::PermissionsExt, process::CommandExt};
+use std::os::unix::{prelude::PermissionsExt, process::CommandExt};
 
 const INSTALLER_CONTENT: &str = include_str!("./installer.sh");
 const INSTALL_MODULE_SCRIPT: &str = concatcp!(
@@ -75,24 +76,34 @@ fn ensure_boot_completed() -> Result<()> {
     Ok(())
 }
 
-fn mark_update() -> Result<()> {
+fn mark_module_state(module: &str, flag_file: &str, create: bool) -> Result<()> {
-    ensure_file_exists(concatcp!(defs::WORKING_DIR, defs::UPDATE_FILE_NAME))
+    let module_state_file = Path::new(MODULE_DIR).join(module).join(flag_file);
-}
+    if create {
-
-fn mark_module_state(module: &str, flag_file: &str, create_or_delete: bool) -> Result<()> {
-    let module_state_file = Path::new(defs::MODULE_DIR).join(module).join(flag_file);
-    if create_or_delete {
         ensure_file_exists(module_state_file)
     } else {
         if module_state_file.exists() {
-            std::fs::remove_file(module_state_file)?;
+            remove_file(module_state_file)?;
         }
         Ok(())
     }
 }
 
-fn foreach_module(active_only: bool, mut f: impl FnMut(&Path) -> Result<()>) -> Result<()> {
+#[derive(PartialEq, Eq)]
-    let modules_dir = Path::new(defs::MODULE_DIR);
+enum ModuleType {
+    All,
+    Active,
+    Updated,
+}
+
+fn foreach_module(module_type: ModuleType, mut f: impl FnMut(&Path) -> Result<()>) -> Result<()> {
+    let modules_dir = Path::new(match module_type {
+        ModuleType::Updated => MODULE_UPDATE_DIR,
+        _ => defs::MODULE_DIR,
+    });
+    if !modules_dir.is_dir() {
+        warn!("{} is not a directory, skip", modules_dir.display());
+        return Ok(());
+    }
     let dir = std::fs::read_dir(modules_dir)?;
     for entry in dir.flatten() {
         let path = entry.path();
@@ -101,11 +112,11 @@ fn foreach_module(active_only: bool, mut f: impl FnMut(&Path) -> Result<()>) ->
             continue;
         }
 
-        if active_only && path.join(defs::DISABLE_FILE_NAME).exists() {
+        if module_type == ModuleType::Active && path.join(defs::DISABLE_FILE_NAME).exists() {
             info!("{} is disabled, skip", path.display());
             continue;
         }
-        if active_only && path.join(defs::REMOVE_FILE_NAME).exists() {
+        if module_type == ModuleType::Active && path.join(defs::REMOVE_FILE_NAME).exists() {
             warn!("{} is removed, skip", path.display());
             continue;
         }
@@ -117,27 +128,7 @@ fn foreach_module(active_only: bool, mut f: impl FnMut(&Path) -> Result<()>) ->
 }
 
 fn foreach_active_module(f: impl FnMut(&Path) -> Result<()>) -> Result<()> {
-    foreach_module(true, f)
+    foreach_module(ModuleType::Active, f)
-}
-
-fn check_image(img: &str) -> Result<()> {
-    let result = Command::new("e2fsck")
-        .args(["-yf", img])
-        .stdout(Stdio::piped())
-        .status()
-        .with_context(|| format!("Failed to exec e2fsck {img}"))?;
-    let code = result.code();
-    // 0 or 1 is ok
-    // 0: no error
-    // 1: file system errors corrected
-    // https://man7.org/linux/man-pages/man8/e2fsck.8.html
-    // ensure!(
-    //     code == Some(0) || code == Some(1),
-    //     "Failed to check image, e2fsck exit code: {}",
-    //     code.unwrap_or(-1)
-    // );
-    info!("e2fsck exit code: {}", code.unwrap_or(-1));
-    Ok(())
 }
 
 pub fn load_sepolicy_rule() -> Result<()> {
@@ -256,13 +247,8 @@ pub fn load_system_prop() -> Result<()> {
 }
 
 pub fn prune_modules() -> Result<()> {
-    foreach_module(false, |module| {
+    foreach_module(ModuleType::All, |module| {
-        remove_file(module.join(defs::UPDATE_FILE_NAME)).ok();
+        if module.join(defs::REMOVE_FILE_NAME).exists() {
-
-        if !module.join(defs::REMOVE_FILE_NAME).exists() {
-            return Ok(());
-        }
-
             info!("remove module: {}", module.display());
 
             let uninstaller = module.join("uninstall.sh");
@@ -275,48 +261,40 @@ pub fn prune_modules() -> Result<()> {
             if let Err(e) = remove_dir_all(module) {
                 warn!("Failed to remove {}: {}", module.display(), e);
             }
-
+        } else {
+            remove_file(module.join(defs::UPDATE_FILE_NAME)).ok();
+        }
         Ok(())
     })?;
 
-    // collect remaining modules, if none, remove img
+    Ok(())
-    let remaining_modules: Vec<_> = std::fs::read_dir(defs::MODULE_DIR)?
+}
-        .filter_map(|entry| entry.ok())
-        .filter(|entry| entry.path().join("module.prop").exists())
-        .collect();
 
-    if remaining_modules.is_empty() {
+pub fn handle_updated_modules() -> Result<()> {
-        info!("no remaining modules, deleting image files.");
+    let modules_root = Path::new(MODULE_DIR);
-        std::fs::remove_file(defs::MODULE_IMG).ok();
+    foreach_module(ModuleType::Updated, |module| {
-        std::fs::remove_file(defs::MODULE_UPDATE_IMG).ok();
+        if !module.is_dir() {
+            return Ok(());
         }
 
+        if let Some(name) = module.file_name() {
+            let old_dir = modules_root.join(name);
+            if old_dir.exists() {
+                if let Err(e) = remove_dir_all(&old_dir) {
+                    log::error!("Failed to remove old {}: {}", old_dir.display(), e);
+                }
+            }
+            if let Err(e) = rename(&module, &old_dir) {
+                log::error!("Failed to move new module {}: {}", module.display(), e);
+            }
+        }
+        Ok(())
+    })?;
     Ok(())
 }
 
-fn create_module_image(image: &str, image_size: u64) -> Result<()> {
+pub fn install_module(zip: &str) -> Result<()> {
-    File::create(image)
+    fn inner(zip: &str) -> Result<()> {
-        .context("Failed to create ext4 image file")?
-        .set_len(image_size)
-        .context("Failed to truncate ext4 image")?;
-
-    // format the img to ext4 filesystem
-    let result = Command::new("mkfs.ext4")
-        .arg("-O")
-        .arg("^has_journal")
-        .arg(image)
-        .stdout(Stdio::piped())
-        .output()?;
-    ensure!(
-        result.status.success(),
-        "Failed to format ext4 image: {}",
-        String::from_utf8(result.stderr).unwrap()
-    );
-    check_image(image)?;
-    Ok(())
-}
-
-fn _install_module(zip: &str) -> Result<()> {
         ensure_boot_completed()?;
 
         // print banner
@@ -324,11 +302,11 @@ fn _install_module(zip: &str) -> Result<()> {
 
         assets::ensure_binaries(false).with_context(|| "Failed to extract assets")?;
 
-    // first check if workding dir is usable
+        // first check if working dir is usable
         ensure_dir_exists(defs::WORKING_DIR).with_context(|| "Failed to create working dir")?;
         ensure_dir_exists(defs::BINARY_DIR).with_context(|| "Failed to create bin dir")?;
 
-    // read the module_id from zip, if faild if will return early.
+        // read the module_id from zip, if failed it will return early.
         let mut buffer: Vec<u8> = Vec::new();
         let entry_path = PathBuf::from_str("module.prop")?;
         let zip_path = PathBuf::from_str(zip)?;
@@ -348,20 +326,6 @@ fn _install_module(zip: &str) -> Result<()> {
         };
         let module_id = module_id.trim();
 
-    let modules_img = Path::new(defs::MODULE_IMG);
-    let modules_update_img = Path::new(defs::MODULE_UPDATE_IMG);
-    let module_update_tmp_dir = defs::MODULE_UPDATE_TMP_DIR;
-
-    let modules_img_exist = modules_img.exists();
-    let modules_update_img_exist = modules_update_img.exists();
-
-    // prepare the tmp module img
-    let tmp_module_img = defs::MODULE_UPDATE_TMP_IMG;
-    let tmp_module_path = Path::new(tmp_module_img);
-    if tmp_module_path.exists() {
-        std::fs::remove_file(tmp_module_path)?;
-    }
-
         let zip_uncompressed_size = get_zip_uncompressed_size(zip)?;
 
         info!(
@@ -369,92 +333,28 @@ fn _install_module(zip: &str) -> Result<()> {
             humansize::format_size(zip_uncompressed_size, humansize::DECIMAL)
         );
 
-    println!("- Preparing image");
+        println!("- Preparing Zip");
         println!(
             "- Module size: {}",
             humansize::format_size(zip_uncompressed_size, humansize::DECIMAL)
         );
 
-    let data_vfs = fs4::statvfs("/data").with_context(|| "Failed to stat /data".to_string())?;
-    let sparse_image_size = data_vfs.total_space();
-    if !modules_img_exist && !modules_update_img_exist {
-        // if no modules and modules_update, it is brand new installation, we should create a new img
-        // create a tmp module img and mount it to modules_update
-        info!("Creating brand new module image");
-        create_module_image(tmp_module_img, sparse_image_size)?;
-    } else if modules_update_img_exist {
-        // modules_update.img exists, we should use it as tmp img
-        info!("Using existing modules_update.img as tmp image");
-        utils::copy_sparse_file(modules_update_img, tmp_module_img, true).with_context(|| {
-            format!(
-                "Failed to copy {} to {}",
-                modules_update_img.display(),
-                tmp_module_img
-            )
-        })?;
-    } else {
-        // modules.img exists, we should use it as tmp img
-        info!("Using existing modules.img as tmp image");
-
-        #[cfg(unix)]
-        let blksize = std::fs::metadata(defs::MODULE_DIR)?.blksize();
-        #[cfg(not(unix))]
-        let blksize = 0;
-        // legacy image, it's block size is 1024 with unlimited journal size
-        if blksize == 1024 {
-            println!("- Legacy image, migrating to new format, please be patient...");
-            create_module_image(tmp_module_img, sparse_image_size)?;
-            let _dontdrop =
-                mount::AutoMountExt4::try_new(tmp_module_img, module_update_tmp_dir, true)
-                    .with_context(|| format!("Failed to mount {tmp_module_img}"))?;
-            utils::copy_module_files(defs::MODULE_DIR, module_update_tmp_dir)
-                .with_context(|| "Failed to migrate module files".to_string())?;
-        } else {
-            utils::copy_sparse_file(modules_img, tmp_module_img, true)
-                .with_context(|| "Failed to copy module image".to_string())?;
-
-            if std::fs::metadata(tmp_module_img)?.len() < sparse_image_size {
-                // truncate the file to new size
-                OpenOptions::new()
-                    .write(true)
-                    .open(tmp_module_img)
-                    .context("Failed to open ext4 image")?
-                    .set_len(sparse_image_size)
-                    .context("Failed to truncate ext4 image")?;
-
-                // resize the image to new size
-                check_image(tmp_module_img)?;
-                Command::new("resize2fs")
-                    .arg(tmp_module_img)
-                    .stdout(Stdio::piped())
-                    .status()?;
-            }
-        }
-    }
-
         // ensure modules_update exists
-    ensure_dir_exists(module_update_tmp_dir)?;
+        ensure_dir_exists(MODULE_UPDATE_DIR)?;
+        setsyscon(MODULE_UPDATE_DIR)?;
 
-    // mount the modules_update.img to mountpoint
+        let update_module_dir = Path::new(MODULE_UPDATE_DIR).join(module_id);
-    println!("- Mounting image");
+        ensure_clean_dir(&update_module_dir)?;
-
+        info!("module dir: {}", update_module_dir.display());
-    let _dontdrop = mount::AutoMountExt4::try_new(tmp_module_img, module_update_tmp_dir, true)?;
-
-    info!("mounted {} to {}", tmp_module_img, module_update_tmp_dir);
-
-    setsyscon(module_update_tmp_dir)?;
-
-    let module_dir = format!("{module_update_tmp_dir}/{module_id}");
-    ensure_clean_dir(&module_dir)?;
-    info!("module dir: {}", module_dir);
 
+        let do_install = || -> Result<()> {
             // unzip the image and move it to modules_update/<id> dir
             let file = File::open(zip)?;
             let mut archive = zip::ZipArchive::new(file)?;
-    archive.extract(&module_dir)?;
+            archive.extract(&update_module_dir)?;
 
             // set permission and selinux context for $MOD/system
-    let module_system_dir = PathBuf::from(module_dir).join("system");
+            let module_system_dir = update_module_dir.join("system");
             if module_system_dir.exists() {
                 #[cfg(unix)]
                 set_permissions(&module_system_dir, Permissions::from_mode(0o755))?;
@@ -463,124 +363,33 @@ fn _install_module(zip: &str) -> Result<()> {
 
             exec_install_script(zip)?;
 
-    info!("rename {tmp_module_img} to {}", defs::MODULE_UPDATE_IMG);
+            let module_dir = Path::new(MODULE_DIR).join(module_id);
-    // all done, rename the tmp image to modules_update.img
+            ensure_dir_exists(&module_dir)?;
-    if std::fs::rename(tmp_module_img, defs::MODULE_UPDATE_IMG).is_err() {
+            copy(
-        warn!("Rename image failed, try copy it.");
+                update_module_dir.join("module.prop"),
-        utils::copy_sparse_file(tmp_module_img, defs::MODULE_UPDATE_IMG, true)
+                module_dir.join("module.prop"),
-            .with_context(|| "Failed to copy image.".to_string())?;
+            )?;
-        let _ = std::fs::remove_file(tmp_module_img);
+            ensure_file_exists(module_dir.join(UPDATE_FILE_NAME))?;
-    }
-
-    mark_update()?;
 
             info!("Module install successfully!");
 
             Ok(())
-}
+        };
-
+        let result = do_install();
-pub fn install_module(zip: &str) -> Result<()> {
+        if result.is_err() {
-    let result = _install_module(zip);
+            remove_dir_all(&update_module_dir).ok();
+        }
+        result
+    }
+    let result = inner(zip);
     if let Err(ref e) = result {
-        // error happened, do some cleanup!
-        let _ = std::fs::remove_file(defs::MODULE_UPDATE_TMP_IMG);
-        let _ = mount::umount_dir(defs::MODULE_UPDATE_TMP_DIR);
         println!("- Error: {e}");
     }
     result
 }
 
-fn update_module<F>(update_dir: &str, id: &str, func: F) -> Result<()>
-where
-    F: Fn(&str, &str) -> Result<()>,
-{
-    ensure_boot_completed()?;
-
-    let modules_img = Path::new(defs::MODULE_IMG);
-    let modules_update_img = Path::new(defs::MODULE_UPDATE_IMG);
-    let modules_update_tmp_img = Path::new(defs::MODULE_UPDATE_TMP_IMG);
-    if !modules_update_img.exists() && !modules_img.exists() {
-        bail!("Please install module first!");
-    } else if modules_update_img.exists() {
-        info!(
-            "copy {} to {}",
-            modules_update_img.display(),
-            modules_update_tmp_img.display()
-        );
-        utils::copy_sparse_file(modules_update_img, modules_update_tmp_img, true)?;
-    } else {
-        info!(
-            "copy {} to {}",
-            modules_img.display(),
-            modules_update_tmp_img.display()
-        );
-        utils::copy_sparse_file(modules_img, modules_update_tmp_img, true)?;
-    }
-
-    // ensure modules_update dir exist
-    ensure_clean_dir(update_dir)?;
-
-    // mount the modules_update img
-    let _dontdrop = mount::AutoMountExt4::try_new(defs::MODULE_UPDATE_TMP_IMG, update_dir, true)?;
-
-    // call the operation func
-    let result = func(id, update_dir);
-
-    if let Err(e) = std::fs::rename(modules_update_tmp_img, defs::MODULE_UPDATE_IMG) {
-        warn!("Rename image failed: {e}, try copy it.");
-        utils::copy_sparse_file(modules_update_tmp_img, defs::MODULE_UPDATE_IMG, true)
-            .with_context(|| "Failed to copy image.".to_string())?;
-        let _ = std::fs::remove_file(modules_update_tmp_img);
-    }
-
-    mark_update()?;
-
-    result
-}
-
 pub fn uninstall_module(id: &str) -> Result<()> {
-    update_module(defs::MODULE_UPDATE_TMP_DIR, id, |mid, update_dir| {
+    mark_module_state(id, defs::REMOVE_FILE_NAME, true)
-        let dir = Path::new(update_dir);
-        ensure!(dir.exists(), "No module installed");
-
-        // iterate the modules_update dir, find the module to be removed
-        let dir = std::fs::read_dir(dir)?;
-        for entry in dir.flatten() {
-            let path = entry.path();
-            let module_prop = path.join("module.prop");
-            if !module_prop.exists() {
-                continue;
-            }
-            let content = std::fs::read(module_prop)?;
-            let mut module_id: String = String::new();
-            PropertiesIter::new_with_encoding(Cursor::new(content), encoding_rs::UTF_8).read_into(
-                |k, v| {
-                    if k.eq("id") {
-                        module_id = v;
-                    }
-                },
-            )?;
-            if module_id.eq(mid) {
-                let remove_file = path.join(defs::REMOVE_FILE_NAME);
-                File::create(remove_file).with_context(|| "Failed to create remove file.")?;
-                break;
-            }
-        }
-
-        // santity check
-        let target_module_path = format!("{update_dir}/{mid}");
-        let target_module = Path::new(&target_module_path);
-        if target_module.exists() {
-            let remove_file = target_module.join(defs::REMOVE_FILE_NAME);
-            if !remove_file.exists() {
-                File::create(remove_file).with_context(|| "Failed to create remove file.")?;
-            }
-        }
-
-        let _ = mark_module_state(id, defs::REMOVE_FILE_NAME, true);
-
-        Ok(())
-    })
 }
 
 pub fn run_action(id: &str) -> Result<()> {
@@ -588,37 +397,12 @@ pub fn run_action(id: &str) -> Result<()> {
     exec_script(&action_script_path, true)
 }
 
-fn _enable_module(module_dir: &str, mid: &str, enable: bool) -> Result<()> {
-    let src_module_path = format!("{module_dir}/{mid}");
-    let src_module = Path::new(&src_module_path);
-    ensure!(src_module.exists(), "module: {} not found!", mid);
-
-    let disable_path = src_module.join(defs::DISABLE_FILE_NAME);
-    if enable {
-        if disable_path.exists() {
-            std::fs::remove_file(&disable_path).with_context(|| {
-                format!("Failed to remove disable file: {}", &disable_path.display())
-            })?;
-        }
-    } else {
-        ensure_file_exists(disable_path)?;
-    }
-
-    let _ = mark_module_state(mid, defs::DISABLE_FILE_NAME, !enable);
-
-    Ok(())
-}
-
 pub fn enable_module(id: &str) -> Result<()> {
-    update_module(defs::MODULE_UPDATE_TMP_DIR, id, |mid, update_dir| {
+    mark_module_state(id, defs::DISABLE_FILE_NAME, true)
-        _enable_module(update_dir, mid, true)
-    })
 }
 
 pub fn disable_module(id: &str) -> Result<()> {
-    update_module(defs::MODULE_UPDATE_TMP_DIR, id, |mid, update_dir| {
+    mark_module_state(id, defs::DISABLE_FILE_NAME, false)
-        _enable_module(update_dir, mid, false)
-    })
 }
 
 pub fn disable_all_modules() -> Result<()> {
@@ -630,8 +414,7 @@ pub fn uninstall_all_modules() -> Result<()> {
 }
 
 fn mark_all_modules(flag_file: &str) -> Result<()> {
-    // we assume the module dir is already mounted
+    let dir = std::fs::read_dir(MODULE_DIR)?;
-    let dir = std::fs::read_dir(defs::MODULE_DIR)?;
     for entry in dir.flatten() {
         let path = entry.path();
         let flag = path.join(flag_file);
@@ -712,21 +495,3 @@ pub fn list_modules() -> Result<()> {
     println!("{}", serde_json::to_string_pretty(&modules)?);
     Ok(())
 }
-
-pub fn shrink_image(img: &str) -> Result<()> {
-    check_image(img)?;
-    Command::new("resize2fs")
-        .arg("-M")
-        .arg(img)
-        .stdout(Stdio::piped())
-        .status()?;
-    Ok(())
-}
-
-pub fn shrink_ksu_images() -> Result<()> {
-    shrink_image(defs::MODULE_IMG)?;
-    if Path::new(defs::MODULE_UPDATE_IMG).exists() {
-        shrink_image(defs::MODULE_UPDATE_IMG)?;
-    }
-    Ok(())
-}

userspace/ksud/src/mount.rs

@@ -1,306 +0,0 @@
-use anyhow::{Ok, Result, anyhow, bail};
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-use anyhow::Context;
-#[cfg(any(target_os = "linux", target_os = "android"))]
-use rustix::{fd::AsFd, fs::CWD, mount::*};
-
-use crate::defs::KSU_OVERLAY_SOURCE;
-use log::{info, warn};
-#[cfg(any(target_os = "linux", target_os = "android"))]
-use procfs::process::Process;
-use std::path::Path;
-use std::path::PathBuf;
-
-pub struct AutoMountExt4 {
-    target: String,
-    auto_umount: bool,
-}
-
-impl AutoMountExt4 {
-    #[cfg(any(target_os = "linux", target_os = "android"))]
-    pub fn try_new(source: &str, target: &str, auto_umount: bool) -> Result<Self> {
-        mount_ext4(source, target)?;
-        Ok(Self {
-            target: target.to_string(),
-            auto_umount,
-        })
-    }
-
-    #[cfg(not(any(target_os = "linux", target_os = "android")))]
-    pub fn try_new(_src: &str, _mnt: &str, _auto_umount: bool) -> Result<Self> {
-        unimplemented!()
-    }
-
-    #[cfg(any(target_os = "linux", target_os = "android"))]
-    pub fn umount(&self) -> Result<()> {
-        unmount(self.target.as_str(), UnmountFlags::DETACH)?;
-        Ok(())
-    }
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-impl Drop for AutoMountExt4 {
-    fn drop(&mut self) {
-        log::info!(
-            "AutoMountExt4 drop: {}, auto_umount: {}",
-            self.target,
-            self.auto_umount
-        );
-        if self.auto_umount {
-            let _ = self.umount();
-        }
-    }
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn mount_ext4(source: impl AsRef<Path>, target: impl AsRef<Path>) -> Result<()> {
-    let new_loopback = loopdev::LoopControl::open()?
-        .next_free()
-        .with_context(|| "Failed to alloc loop")?;
-    new_loopback
-        .with()
-        .attach(source)
-        .with_context(|| "Failed to attach loop")?;
-    let lo = new_loopback.path().ok_or(anyhow!("no loop"))?;
-    let fs = fsopen("ext4", FsOpenFlags::FSOPEN_CLOEXEC)?;
-    let fs = fs.as_fd();
-    fsconfig_set_string(fs, "source", lo)?;
-    fsconfig_create(fs)?;
-    let mount = fsmount(fs, FsMountFlags::FSMOUNT_CLOEXEC, MountAttrFlags::empty())?;
-    move_mount(
-        mount.as_fd(),
-        "",
-        CWD,
-        target.as_ref(),
-        MoveMountFlags::MOVE_MOUNT_F_EMPTY_PATH,
-    )?;
-    Ok(())
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn umount_dir(src: impl AsRef<Path>) -> Result<()> {
-    unmount(src.as_ref(), UnmountFlags::empty())
-        .with_context(|| format!("Failed to umount {}", src.as_ref().display()))?;
-    Ok(())
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn mount_overlayfs(
-    lower_dirs: &[String],
-    lowest: &str,
-    upperdir: Option<PathBuf>,
-    workdir: Option<PathBuf>,
-    dest: impl AsRef<Path>,
-) -> Result<()> {
-    let lowerdir_config = lower_dirs
-        .iter()
-        .map(|s| s.as_ref())
-        .chain(std::iter::once(lowest))
-        .collect::<Vec<_>>()
-        .join(":");
-    info!(
-        "mount overlayfs on {:?}, lowerdir={}, upperdir={:?}, workdir={:?}",
-        dest.as_ref(),
-        lowerdir_config,
-        upperdir,
-        workdir
-    );
-
-    let upperdir = upperdir
-        .filter(|up| up.exists())
-        .map(|e| e.display().to_string());
-    let workdir = workdir
-        .filter(|wd| wd.exists())
-        .map(|e| e.display().to_string());
-
-    let result = (|| {
-        let fs = fsopen("overlay", FsOpenFlags::FSOPEN_CLOEXEC)?;
-        let fs = fs.as_fd();
-        fsconfig_set_string(fs, "lowerdir", &lowerdir_config)?;
-        if let (Some(upperdir), Some(workdir)) = (&upperdir, &workdir) {
-            fsconfig_set_string(fs, "upperdir", upperdir)?;
-            fsconfig_set_string(fs, "workdir", workdir)?;
-        }
-        fsconfig_set_string(fs, "source", KSU_OVERLAY_SOURCE)?;
-        fsconfig_create(fs)?;
-        let mount = fsmount(fs, FsMountFlags::FSMOUNT_CLOEXEC, MountAttrFlags::empty())?;
-        move_mount(
-            mount.as_fd(),
-            "",
-            CWD,
-            dest.as_ref(),
-            MoveMountFlags::MOVE_MOUNT_F_EMPTY_PATH,
-        )
-    })();
-
-    if let Err(e) = result {
-        warn!("fsopen mount failed: {:#}, fallback to mount", e);
-        let mut data = format!("lowerdir={lowerdir_config}");
-        if let (Some(upperdir), Some(workdir)) = (upperdir, workdir) {
-            data = format!("{data},upperdir={upperdir},workdir={workdir}");
-        }
-        mount(
-            KSU_OVERLAY_SOURCE,
-            dest.as_ref(),
-            "overlay",
-            MountFlags::empty(),
-            data,
-        )?;
-    }
-    Ok(())
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn mount_tmpfs(dest: impl AsRef<Path>) -> Result<()> {
-    info!("mount tmpfs on {}", dest.as_ref().display());
-    let fs = fsopen("tmpfs", FsOpenFlags::FSOPEN_CLOEXEC)?;
-    let fs = fs.as_fd();
-    fsconfig_set_string(fs, "source", KSU_OVERLAY_SOURCE)?;
-    fsconfig_create(fs)?;
-    let mount = fsmount(fs, FsMountFlags::FSMOUNT_CLOEXEC, MountAttrFlags::empty())?;
-    move_mount(
-        mount.as_fd(),
-        "",
-        CWD,
-        dest.as_ref(),
-        MoveMountFlags::MOVE_MOUNT_F_EMPTY_PATH,
-    )?;
-    Ok(())
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn bind_mount(from: impl AsRef<Path>, to: impl AsRef<Path>) -> Result<()> {
-    info!(
-        "bind mount {} -> {}",
-        from.as_ref().display(),
-        to.as_ref().display()
-    );
-    let tree = open_tree(
-        CWD,
-        from.as_ref(),
-        OpenTreeFlags::OPEN_TREE_CLOEXEC
-            | OpenTreeFlags::OPEN_TREE_CLONE
-            | OpenTreeFlags::AT_RECURSIVE,
-    )?;
-    move_mount(
-        tree.as_fd(),
-        "",
-        CWD,
-        to.as_ref(),
-        MoveMountFlags::MOVE_MOUNT_F_EMPTY_PATH,
-    )?;
-    Ok(())
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-fn mount_overlay_child(
-    mount_point: &str,
-    relative: &String,
-    module_roots: &Vec<String>,
-    stock_root: &String,
-) -> Result<()> {
-    if !module_roots
-        .iter()
-        .any(|lower| Path::new(&format!("{lower}{relative}")).exists())
-    {
-        return bind_mount(stock_root, mount_point);
-    }
-    if !Path::new(&stock_root).is_dir() {
-        return Ok(());
-    }
-    let mut lower_dirs: Vec<String> = vec![];
-    for lower in module_roots {
-        let lower_dir = format!("{lower}{relative}");
-        let path = Path::new(&lower_dir);
-        if path.is_dir() {
-            lower_dirs.push(lower_dir);
-        } else if path.exists() {
-            // stock root has been blocked by this file
-            return Ok(());
-        }
-    }
-    if lower_dirs.is_empty() {
-        return Ok(());
-    }
-    // merge modules and stock
-    if let Err(e) = mount_overlayfs(&lower_dirs, stock_root, None, None, mount_point) {
-        warn!("failed: {:#}, fallback to bind mount", e);
-        bind_mount(stock_root, mount_point)?;
-    }
-    Ok(())
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn mount_overlay(
-    root: &String,
-    module_roots: &Vec<String>,
-    workdir: Option<PathBuf>,
-    upperdir: Option<PathBuf>,
-) -> Result<()> {
-    info!("mount overlay for {}", root);
-    std::env::set_current_dir(root).with_context(|| format!("failed to chdir to {root}"))?;
-    let stock_root = ".";
-
-    // collect child mounts before mounting the root
-    let mounts = Process::myself()?
-        .mountinfo()
-        .with_context(|| "get mountinfo")?;
-    let mut mount_seq = mounts
-        .0
-        .iter()
-        .filter(|m| {
-            m.mount_point.starts_with(root) && !Path::new(&root).starts_with(&m.mount_point)
-        })
-        .map(|m| m.mount_point.to_str())
-        .collect::<Vec<_>>();
-    mount_seq.sort();
-    mount_seq.dedup();
-
-    mount_overlayfs(module_roots, root, upperdir, workdir, root)
-        .with_context(|| "mount overlayfs for root failed")?;
-    for mount_point in mount_seq.iter() {
-        let Some(mount_point) = mount_point else {
-            continue;
-        };
-        let relative = mount_point.replacen(root, "", 1);
-        let stock_root: String = format!("{stock_root}{relative}");
-        if !Path::new(&stock_root).exists() {
-            continue;
-        }
-        if let Err(e) = mount_overlay_child(mount_point, &relative, module_roots, &stock_root) {
-            warn!(
-                "failed to mount overlay for child {}: {:#}, revert",
-                mount_point, e
-            );
-            umount_dir(root).with_context(|| format!("failed to revert {root}"))?;
-            bail!(e);
-        }
-    }
-    Ok(())
-}
-
-#[cfg(not(any(target_os = "linux", target_os = "android")))]
-pub fn mount_ext4(_src: &str, _target: &str, _autodrop: bool) -> Result<()> {
-    unimplemented!()
-}
-
-#[cfg(not(any(target_os = "linux", target_os = "android")))]
-pub fn umount_dir(_src: &str) -> Result<()> {
-    unimplemented!()
-}
-
-#[cfg(not(any(target_os = "linux", target_os = "android")))]
-pub fn mount_overlay(
-    _root: &String,
-    _module_roots: &Vec<String>,
-    _workdir: Option<PathBuf>,
-    _upperdir: Option<PathBuf>,
-) -> Result<()> {
-    unimplemented!()
-}
-
-#[cfg(not(any(target_os = "linux", target_os = "android")))]
-pub fn mount_tmpfs(_dest: impl AsRef<Path>) -> Result<()> {
-    unimplemented!()
-}

userspace/ksud/src/utils.rs

@@ -15,10 +15,6 @@ use std::fs::{Permissions, set_permissions};
 #[cfg(unix)]
 use std::os::unix::prelude::PermissionsExt;
 
-use hole_punch::*;
-use std::io::{Read, Seek, SeekFrom};
-
-use jwalk::WalkDir;
 use std::path::PathBuf;
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
@@ -39,7 +35,7 @@ pub fn ensure_clean_dir(dir: impl AsRef<Path>) -> Result<()> {
 
 pub fn ensure_file_exists<T: AsRef<Path>>(file: T) -> Result<()> {
     match File::options().write(true).create_new(true).open(&file) {
-        std::result::Result::Ok(_) => Ok(()),
+        Result::Ok(_) => Ok(()),
         Err(err) => {
             if err.kind() == AlreadyExists && file.as_ref().is_file() {
                 Ok(())
@@ -218,9 +214,7 @@ pub fn uninstall(magiskboot_path: Option<PathBuf>) -> Result<()> {
     println!("- Removing directories..");
     std::fs::remove_dir_all(defs::WORKING_DIR).ok();
     std::fs::remove_file(defs::DAEMON_PATH).ok();
-    crate::mount::umount_dir(defs::MODULE_DIR).ok();
     std::fs::remove_dir_all(defs::MODULE_DIR).ok();
-    std::fs::remove_dir_all(defs::MODULE_UPDATE_TMP_DIR).ok();
     println!("- Restore boot image..");
     boot_patch::restore(None, magiskboot_path, true)?;
     println!("- Uninstall KernelSU manager..");
@@ -232,153 +226,3 @@ pub fn uninstall(magiskboot_path: Option<PathBuf>) -> Result<()> {
     Command::new("reboot").spawn()?;
     Ok(())
 }
-
-// TODO: use libxcp to improve the speed if cross's MSRV is 1.70
-pub fn copy_sparse_file<P: AsRef<Path>, Q: AsRef<Path>>(
-    src: P,
-    dst: Q,
-    punch_hole: bool,
-) -> Result<()> {
-    let mut src_file = File::open(src.as_ref())?;
-    let mut dst_file = OpenOptions::new()
-        .write(true)
-        .create(true)
-        .truncate(true)
-        .open(dst.as_ref())?;
-
-    dst_file.set_len(src_file.metadata()?.len())?;
-
-    let segments = src_file.scan_chunks()?;
-    for segment in segments {
-        if let SegmentType::Data = segment.segment_type {
-            let start = segment.start;
-            let end = segment.end + 1;
-
-            src_file.seek(SeekFrom::Start(start))?;
-            dst_file.seek(SeekFrom::Start(start))?;
-
-            let mut buffer = [0; 4096];
-            let mut total_bytes_copied = 0;
-
-            while total_bytes_copied < end - start {
-                let bytes_to_read =
-                    std::cmp::min(buffer.len() as u64, end - start - total_bytes_copied);
-                let bytes_read = src_file.read(&mut buffer[..bytes_to_read as usize])?;
-
-                if bytes_read == 0 {
-                    break;
-                }
-
-                if punch_hole && buffer[..bytes_read].iter().all(|&x| x == 0) {
-                    // all zero, don't copy it at all!
-                    dst_file.seek(SeekFrom::Current(bytes_read as i64))?;
-                    total_bytes_copied += bytes_read as u64;
-                    continue;
-                }
-                dst_file.write_all(&buffer[..bytes_read])?;
-                total_bytes_copied += bytes_read as u64;
-            }
-        }
-    }
-
-    Ok(())
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-fn copy_xattrs(src_path: impl AsRef<Path>, dest_path: impl AsRef<Path>) -> Result<()> {
-    use rustix::path::Arg;
-    let std::result::Result::Ok(xattrs) = extattr::llistxattr(src_path.as_ref()) else {
-        return Ok(());
-    };
-    for xattr in xattrs {
-        let std::result::Result::Ok(value) = extattr::lgetxattr(src_path.as_ref(), &xattr) else {
-            continue;
-        };
-        log::info!(
-            "Set {:?} xattr {} = {}",
-            dest_path.as_ref(),
-            xattr.to_string_lossy(),
-            value.to_string_lossy(),
-        );
-        if let Err(e) =
-            extattr::lsetxattr(dest_path.as_ref(), &xattr, &value, extattr::Flags::empty())
-        {
-            log::warn!("Failed to set xattr: {}", e);
-        }
-    }
-    Ok(())
-}
-
-#[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn copy_module_files(source: impl AsRef<Path>, destination: impl AsRef<Path>) -> Result<()> {
-    use rustix::fs::FileTypeExt;
-    use rustix::fs::MetadataExt;
-
-    for entry in WalkDir::new(source.as_ref()).into_iter() {
-        let entry = entry.context("Failed to access entry")?;
-        let source_path = entry.path();
-        let relative_path = source_path
-            .strip_prefix(source.as_ref())
-            .context("Failed to generate relative path")?;
-        let dest_path = destination.as_ref().join(relative_path);
-
-        if let Some(parent) = dest_path.parent() {
-            std::fs::create_dir_all(parent).context("Failed to create directory")?;
-        }
-
-        if entry.file_type().is_file() {
-            std::fs::copy(&source_path, &dest_path).with_context(|| {
-                format!("Failed to copy file from {source_path:?} to {dest_path:?}",)
-            })?;
-            copy_xattrs(&source_path, &dest_path)?;
-        } else if entry.file_type().is_symlink() {
-            if dest_path.exists() {
-                std::fs::remove_file(&dest_path).context("Failed to remove file")?;
-            }
-            let target = std::fs::read_link(entry.path()).context("Failed to read symlink")?;
-            log::info!("Symlink: {:?} -> {:?}", dest_path, target);
-            std::os::unix::fs::symlink(target, &dest_path).context("Failed to create symlink")?;
-            copy_xattrs(&source_path, &dest_path)?;
-        } else if entry.file_type().is_dir() {
-            create_dir_all(&dest_path)?;
-            let metadata = std::fs::metadata(&source_path).context("Failed to read metadata")?;
-            std::fs::set_permissions(&dest_path, metadata.permissions())
-                .with_context(|| format!("Failed to set permissions for {dest_path:?}"))?;
-            copy_xattrs(&source_path, &dest_path)?;
-        } else if entry.file_type().is_char_device() {
-            if dest_path.exists() {
-                std::fs::remove_file(&dest_path).context("Failed to remove file")?;
-            }
-            let metadata = std::fs::metadata(&source_path).context("Failed to read metadata")?;
-            let mode = metadata.permissions().mode();
-            let dev = metadata.rdev();
-            if dev == 0 {
-                log::info!(
-                    "Found a char device with major 0: {}",
-                    entry.path().display()
-                );
-                rustix::fs::mknodat(
-                    rustix::fs::CWD,
-                    &dest_path,
-                    rustix::fs::FileType::CharacterDevice,
-                    mode.into(),
-                    dev,
-                )
-                .with_context(|| format!("Failed to create device file at {dest_path:?}"))?;
-                copy_xattrs(&source_path, &dest_path)?;
-            }
-        } else {
-            log::info!(
-                "Unknown file type: {:?}, {:?},",
-                entry.file_type(),
-                entry.path(),
-            );
-        }
-    }
-    Ok(())
-}
-
-#[cfg(not(any(target_os = "linux", target_os = "android")))]
-pub fn copy_module_files(_source: impl AsRef<Path>, _destination: impl AsRef<Path>) -> Result<()> {
-    unimplemented!()
-}