Add ro.boot.fstab_suffix and modify mount_all to use it

Currently the ReadDefaultFstab function, which calls GetFstabPath,
makes some assumptions about what the fstab will be called and where
it is located. This is being used by vold to set up userdata encryption
and for gsid, and is even used in the default boot control HAL, so it
has become quite baked.

The original way for a board to specify things to mount was to use the
"mount_all /path/to/fstab" command in init.rc. However, due to the
above functionality, the path after mount_all is no longer very useful,
as it cannot differ from the inferred path, or userdata encryption and
other features will be broken.

On Cuttlefish, we have an interest in being able to test alternative
userdata configurations (ext4 vs f2fs, encryption on/off, etc.) and
currently the only way to achieve this is to either a) modify the
ro.hardware or ro.hardware.platform properties, which breaks a bunch
of things like default HAL filenames, or regenerate our odm.img or
vendor.img filesystems. We can't simply install another fstab and
point to it with "mount_all".

This change allows the fstab path to be omitted from "mount_all", and
adds another property which overrides the existing checks for
fstab.${ro.hardware} and fstab.${ro.hardware.platform}. Specifying
${ro.boot.fstab_suffix} will cause fstab.${ro.boot.fstab_suffix}
to be checked first.

Bug: 142424832
Test: booted cuttlefish with 'mount_all ${ro.hardware} --late'
Test: booted cuttlefish with 'mount_all --late'
Test: booted cuttlefish with 'mount_all --late' and fstab_suffix=f2fs
Test: partially booted cuttlefish with 'mount_all ${ro.hardware}'
Test: partially booted cuttlefish with 'mount_all'
Change-Id: I3e10f66aecfcd48bdb9ebf1d304b7aae745cbd3c

1 files changed, 41 insertions, 36 deletions

diff --git a/init/builtins.cpp b/init/builtins.cpp
index 149a766b3..e918e12ae 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -518,21 +518,21 @@ static Result<void> do_mount(const BuiltinArguments& args) {
 
 /* Imports .rc files from the specified paths. Default ones are applied if none is given.
  *
- * start_index: index of the first path in the args list
+ * rc_paths: list of paths to rc files to import
  */
-static void import_late(const std::vector<std::string>& args, size_t start_index, size_t end_index) {
+static void import_late(const std::vector<std::string>& rc_paths) {
     auto& action_manager = ActionManager::GetInstance();
     auto& service_list = ServiceList::GetInstance();
     Parser parser = CreateParser(action_manager, service_list);
-    if (end_index <= start_index) {
+    if (rc_paths.empty()) {
         // Fallbacks for partitions on which early mount isn't enabled.
         for (const auto& path : late_import_paths) {
             parser.ParseConfig(path);
         }
         late_import_paths.clear();
     } else {
-        for (size_t i = start_index; i < end_index; ++i) {
-            parser.ParseConfig(args[i]);
+        for (const auto& rc_path : rc_paths) {
+            parser.ParseConfig(rc_path);
         }
     }
 
@@ -633,48 +633,44 @@ static Result<void> queue_fs_event(int code, bool userdata_remount) {
 
 static int initial_mount_fstab_return_code = -1;
 
-/* mount_all <fstab> [ <path> ]* [--<options>]*
+/* <= Q: mount_all <fstab> [ <path> ]* [--<options>]*
+ * >= R: mount_all [ <fstab> ] [--<options>]*
  *
  * This function might request a reboot, in which case it will
  * not return.
  */
 static Result<void> do_mount_all(const BuiltinArguments& args) {
-    std::size_t na = 0;
-    bool import_rc = true;
-    bool queue_event = true;
-    int mount_mode = MOUNT_MODE_DEFAULT;
-    const auto& fstab_file = args[1];
-    std::size_t path_arg_end = args.size();
-    const char* prop_post_fix = "default";
+    auto mount_all = ParseMountAll(args.args);
+    if (!mount_all.ok()) return mount_all.error();
 
-    for (na = args.size() - 1; na > 1; --na) {
-        if (args[na] == "--early") {
-            path_arg_end = na;
-            queue_event = false;
-            mount_mode = MOUNT_MODE_EARLY;
-            prop_post_fix = "early";
-        } else if (args[na] == "--late") {
-            path_arg_end = na;
-            import_rc = false;
-            mount_mode = MOUNT_MODE_LATE;
-            prop_post_fix = "late";
-        }
+    const char* prop_post_fix = "default";
+    bool queue_event = true;
+    if (mount_all->mode == MOUNT_MODE_EARLY) {
+        prop_post_fix = "early";
+        queue_event = false;
+    } else if (mount_all->mode == MOUNT_MODE_LATE) {
+        prop_post_fix = "late";
     }
 
     std::string prop_name = "ro.boottime.init.mount_all."s + prop_post_fix;
     android::base::Timer t;
 
     Fstab fstab;
-    if (!ReadFstabFromFile(fstab_file, &fstab)) {
-        return Error() << "Could not read fstab";
+    if (mount_all->fstab_path.empty()) {
+        if (!ReadDefaultFstab(&fstab)) {
+            return Error() << "Could not read default fstab";
+        }
+    } else {
+        if (!ReadFstabFromFile(mount_all->fstab_path, &fstab)) {
+            return Error() << "Could not read fstab";
+        }
     }
 
-    auto mount_fstab_return_code = fs_mgr_mount_all(&fstab, mount_mode);
+    auto mount_fstab_return_code = fs_mgr_mount_all(&fstab, mount_all->mode);
     SetProperty(prop_name, std::to_string(t.duration().count()));
 
-    if (import_rc && SelinuxGetVendorAndroidVersion() <= __ANDROID_API_Q__) {
-        /* Paths of .rc files are specified at the 2nd argument and beyond */
-        import_late(args.args, 2, path_arg_end);
+    if (mount_all->import_rc) {
+        import_late(mount_all->rc_paths);
     }
 
     if (queue_event) {
@@ -690,11 +686,20 @@ static Result<void> do_mount_all(const BuiltinArguments& args) {
     return {};
 }
 
-/* umount_all <fstab> */
+/* umount_all [ <fstab> ] */
 static Result<void> do_umount_all(const BuiltinArguments& args) {
+    auto umount_all = ParseUmountAll(args.args);
+    if (!umount_all.ok()) return umount_all.error();
+
     Fstab fstab;
-    if (!ReadFstabFromFile(args[1], &fstab)) {
-        return Error() << "Could not read fstab";
+    if (umount_all->empty()) {
+        if (!ReadDefaultFstab(&fstab)) {
+            return Error() << "Could not read default fstab";
+        }
+    } else {
+        if (!ReadFstabFromFile(*umount_all, &fstab)) {
+            return Error() << "Could not read fstab";
+        }
     }
 
     if (auto result = fs_mgr_umount_all(&fstab); result != 0) {
@@ -1349,11 +1354,11 @@ const BuiltinFunctionMap& GetBuiltinFunctionMap() {
         // mount_all is currently too complex to run in vendor_init as it queues action triggers,
         // imports rc scripts, etc.  It should be simplified and run in vendor_init context.
         // mount and umount are run in the same context as mount_all for symmetry.
-        {"mount_all",               {1,     kMax, {false,  do_mount_all}}},
+        {"mount_all",               {0,     kMax, {false,  do_mount_all}}},
         {"mount",                   {3,     kMax, {false,  do_mount}}},
         {"perform_apex_config",     {0,     0,    {false,  do_perform_apex_config}}},
         {"umount",                  {1,     1,    {false,  do_umount}}},
-        {"umount_all",              {1,     1,    {false,  do_umount_all}}},
+        {"umount_all",              {0,     1,    {false,  do_umount_all}}},
         {"update_linker_config",    {0,     0,    {false,  do_update_linker_config}}},
         {"readahead",               {1,     2,    {true,   do_readahead}}},
         {"remount_userdata",        {0,     0,    {false,  do_remount_userdata}}},