Merge "Switch sdcardfs over to bind mounts." (94b9e4df) · Commits · e / os / android_system_core

sdcard/sdcard.cpp

+25 −5

Original line number	Diff line number	Diff line
		@@ -331,6 +331,27 @@ static bool sdcardfs_setup(const std::string& source_path, const std::string& de
		return true;
		}

		static bool sdcardfs_setup_bind_remount(const std::string& source_path, const std::string& dest_path,
		gid_t gid, mode_t mask) {
		std::string opts = android::base::StringPrintf("mask=%d,gid=%d", mask, gid);

		if (mount(source_path.c_str(), dest_path.c_str(), nullptr,
		MS_BIND, nullptr) != 0) {
		PLOG(ERROR) << "failed to bind mount sdcardfs filesystem";
		return false;
		}

		if (mount(source_path.c_str(), dest_path.c_str(), "none",
		MS_REMOUNT \| MS_NOSUID \| MS_NODEV \| MS_NOEXEC \| MS_NOATIME, opts.c_str()) != 0) {
		PLOG(ERROR) << "failed to mount sdcardfs filesystem";
		if (umount2(dest_path.c_str(), MNT_DETACH))
		PLOG(WARNING) << "Failed to unmount bind";
		return false;
		}

		return true;
		}

		static void run_sdcardfs(const std::string& source_path, const std::string& label, uid_t uid,
		gid_t gid, userid_t userid, bool multi_user, bool full_write) {
		std::string dest_path_default = "/mnt/runtime/default/" + label;
		@@ -343,9 +364,8 @@ static void run_sdcardfs(const std::string& source_path, const std::string& labe
		// permissions are completely masked off.
		if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
		AID_SDCARD_RW, 0006)
		\|\| !sdcardfs_setup(source_path, dest_path_read, uid, gid, multi_user, userid,
		AID_EVERYBODY, 0027)
		\|\| !sdcardfs_setup(source_path, dest_path_write, uid, gid, multi_user, userid,
		\|\| !sdcardfs_setup_bind_remount(dest_path_default, dest_path_read, AID_EVERYBODY, 0027)
		\|\| !sdcardfs_setup_bind_remount(dest_path_default, dest_path_write,
		AID_EVERYBODY, full_write ? 0007 : 0027)) {
		LOG(FATAL) << "failed to sdcardfs_setup";
		}
		@@ -355,9 +375,9 @@ static void run_sdcardfs(const std::string& source_path, const std::string& labe
		// deep inside attr_from_stat().
		if (!sdcardfs_setup(source_path, dest_path_default, uid, gid, multi_user, userid,
		AID_SDCARD_RW, 0006)
		\|\| !sdcardfs_setup(source_path, dest_path_read, uid, gid, multi_user, userid,
		\|\| !sdcardfs_setup_bind_remount(dest_path_default, dest_path_read,
		AID_EVERYBODY, full_write ? 0027 : 0022)
		\|\| !sdcardfs_setup(source_path, dest_path_write, uid, gid, multi_user, userid,
		\|\| !sdcardfs_setup_bind_remount(dest_path_default, dest_path_write,
		AID_EVERYBODY, full_write ? 0007 : 0022)) {
		LOG(FATAL) << "failed to sdcardfs_setup";
		}