Introduce post-mount stage scripts

Same as post-fs-data mode, only difference is that scripts run
after magic mount completes. This provides a stage where scripts
can be instantly executed after module mount is ready to keep a
clean memory map/mount namespace for new exec.

docs/details.md

@@ -51,6 +51,9 @@ SECURE_DIR=/data/adb
 # Folder storing general post-fs-data scripts
 $SECURE_DIR/post-fs-data.d
 
+# Folder storing general post-mount scripts
+$SECURE_DIR/post-mount.d
+
 # Folder storing general late_start service scripts
 $SECURE_DIR/service.d
 
@@ -89,6 +92,10 @@ DATABIN=$SECURE_DIR/magisk
 
 This triggers on `post-fs-data` when `/data` is decrypted and mounted. The daemon `magiskd` will be launched, post-fs-data scripts are executed, and module files are magic mounted.
 
+### post-mount
+
+This triggers on `post-fs-data` but instantly after magic mount completes. In this mode, post-mount scripts are executed.
+
 ### late_start
 
 Later in the booting process, the class `late_start` will be triggered, and Magisk "service" mode will be started. In this mode, service scripts are executed.

docs/guides.md

@@ -51,7 +51,8 @@ A Magisk module is a folder placed in `/data/adb/modules` with the structure bel
 │   │
 │   │      *** Optional Files ***
 │   │
-│   ├── post-fs-data.sh     <--- This script will be executed in post-fs-data
+│   ├── post-fs-data.sh     <--- This script will be executed in post-fs-data and before magic mount is done
+│   ├── post-mount.sh       <--- This script will be executed in post-fs-data and after magic mount is done
 │   ├── service.sh          <--- This script will be executed in late_start service
 |   ├── uninstall.sh        <--- This script will be executed when Magisk removes your module
 |   ├── action.sh           <--- This script will be executed when user click the action button in Magisk app
@@ -111,7 +112,7 @@ Update JSON format:
 
 #### Shell scripts (`*.sh`)
 
-Please read the [Boot Scripts](#boot-scripts) section to understand the difference between `post-fs-data.sh` and `service.sh`. For most module developers, `service.sh` should be good enough if you just need to run a boot script. If you need to wait for boot completed, you can use `resetprop -w sys.boot_completed 0`.
+Please read the [Boot Scripts](#boot-scripts) section to understand the difference between `post-fs-data.sh`, `post-mount.sh` and `service.sh`. For most module developers, `service.sh` should be good enough if you just need to run a boot script. If you need to wait for boot completed, you can use `resetprop -w sys.boot_completed 0`.
 
 In all scripts of your module, please use `MODDIR=${0%/*}` to get your module's base directory path; do **NOT** hardcode your module path in scripts.
 If Zygisk is enabled, the environment variable `ZYGISK_ENABLED` will be set to `1`.
@@ -242,29 +243,32 @@ The list above will result in the following dummy devices being created: `$MODPA
 
 ## Boot Scripts
 
-In Magisk, you can run boot scripts in 2 different modes: **post-fs-data** and **late_start service** mode.
+In Magisk, you can run boot scripts in 3 different modes: **post-fs-data**, **post-mount** and **late_start service** mode.
 
 - post-fs-data mode
   - This stage is BLOCKING. The boot process is paused before execution is done, or 40 seconds have passed.
   - Scripts run before any modules are mounted. This allows a module developer to dynamically adjust their modules before it gets mounted.
   - This stage happens before Zygote is started, which pretty much means everything in Android
   - **WARNING:** using `setprop` will deadlock the boot process! Please use `resetprop -n <prop_name> <prop_value>` instead.
   - **Only run scripts in this mode if necessary.**
+- post-mount mode
+  - Same as post-fs-data mode, only difference is that scripts run after every module is mounted.
+  - **This is the recommended stage to run app_process.**
 - late_start service mode
   - This stage is NON-BLOCKING. Your script runs in parallel with the rest of the booting process.
   - **This is the recommended stage to run most scripts.**
 
 In Magisk, there are also 2 kinds of scripts: **general scripts** and **module scripts**.
 
 - General Scripts
-  - Placed in `/data/adb/post-fs-data.d` or `/data/adb/service.d`
+  - Placed in `/data/adb/post-fs-data.d`, `/data/adb/post-mount.d` or `/data/adb/service.d`
   - Only executed if the script is set as executable (`chmod +x script.sh`)
-  - Scripts in `post-fs-data.d` runs in post-fs-data mode, and scripts in `service.d` runs in late_start service mode.
+  - Scripts in `post-fs-data.d` runs in post-fs-data mode, scripts in `/data/adb/post-mount.d` runs in post-mount mode and scripts in `service.d` runs in late_start service mode.
   - Modules should **NOT** add general scripts during installation
 - Module Scripts
   - Placed in the module's own folder
   - Only executed if the module is enabled
-  - `post-fs-data.sh` runs in post-fs-data mode, and `service.sh` runs in late_start service mode.
+  - `post-fs-data.sh` and `post-mount.sh` runs in post-fs-data mode, and `service.sh` runs in late_start service mode.
 
 All boot scripts will run in Magisk's BusyBox `ash` shell with "Standalone Mode" enabled.
 

native/src/core/bootstages.cpp

@@ -41,6 +41,7 @@ static bool magisk_env() {
     xmkdir(DATABIN, 0755);
     xmkdir(MODULEROOT, 0755);
     xmkdir(SECURE_DIR "/post-fs-data.d", 0755);
+    xmkdir(SECURE_DIR "/post-mount.d", 0755);
     xmkdir(SECURE_DIR "/service.d", 0755);
     restorecon();
 
@@ -180,6 +181,10 @@ bool MagiskD::post_fs_data() const noexcept {
     setup_mounts();
     handle_modules();
     load_modules();
+
+    LOGI("** post-mount mode running\n");
+    exec_common_scripts("post-mount");
+    exec_module_scripts("post-mount");
     return false;
 }
 

native/src/core/scripting.cpp

@@ -63,7 +63,7 @@ if (pfs) { \
     if (timer_pid < 0) \
         continue; \
     if (int pid = waitpid(-1, nullptr, 0); pid == timer_pid) { \
-        LOGW("* post-fs-data scripts blocking phase timeout\n"); \
+        LOGW("* post-fs-data or post-mount scripts blocking phase timeout\n"); \
         timer_pid = -1; \
     } \
 }
@@ -82,6 +82,7 @@ void exec_common_scripts(const char *stage) {
     auto dir = xopen_dir(path);
     if (!dir) return;
 
+    // No need to check post-mount becasue it is not a separate stage
     bool pfs = stage == "post-fs-data"sv;
     int timer_pid = -1;
     if (pfs) {
@@ -122,7 +123,7 @@ void exec_module_scripts(const char *stage, const vector<string_view> &modules)
     if (modules.empty())
         return;
 
-    bool pfs = stage == "post-fs-data"sv;
+    bool pfs = stage == "post-fs-data"sv || stage == "post-mount"sv;
     if (pfs) {
         timespec now{};
         clock_gettime(CLOCK_MONOTONIC, &now);

scripts/avd_magisk.sh

@@ -125,6 +125,7 @@ mkdir -p $MAGISKBIN 2>/dev/null
 unzip -oj magisk.apk 'assets/*.sh' -d $MAGISKBIN
 mkdir /data/adb/modules 2>/dev/null
 mkdir /data/adb/post-fs-data.d 2>/dev/null
+mkdir /data/adb/post-mount.d 2>/dev/null
 mkdir /data/adb/service.d 2>/dev/null
 
 for file in magisk magisk32 magiskpolicy stub.apk; do

scripts/uninstaller.sh

@@ -150,7 +150,7 @@ ui_print "- Removing Magisk files"
 rm -rf \
 /cache/*magisk* /cache/unblock /data/*magisk* /data/cache/*magisk* /data/property/*magisk* \
 /data/Magisk.apk /data/busybox /data/custom_ramdisk_patch.sh /data/adb/*magisk* \
-/data/adb/post-fs-data.d /data/adb/service.d /data/adb/modules* \
+/data/adb/post-fs-data.d /data/adb/post-mount.d /data/adb/service.d /data/adb/modules* \
 /data/unencrypted/magisk /metadata/magisk /metadata/watchdog/magisk /persist/magisk /mnt/vendor/persist/magisk
 
 ADDOND=/system/addon.d/99-magisk.sh