Merge "init: mount_handler: system-as-root (legacy)" (a896e2ae) · Commits · e / os / android_system_core

init/mount_handler.cpp

+29 −15

Original line number	Diff line number	Diff line
		@@ -27,6 +27,7 @@
		#include <algorithm>
		#include <string>
		#include <utility>
		#include <vector>

		#include <android-base/file.h>
		#include <android-base/logging.h>
		@@ -34,6 +35,7 @@
		#include <android-base/strings.h>
		#include <fs_mgr.h>
		#include <fstab/fstab.h>
		#include <libdm/dm.h>

		#include "epoll.h"
		#include "property_service.h"
		@@ -47,8 +49,13 @@ MountHandlerEntry ParseMount(const std::string& line) {
		auto fields = android::base::Split(line, " ");
		while (fields.size() < 3) fields.emplace_back("");
		if (fields[0] == "/dev/root") {
		if (android::fs_mgr::Fstab fstab; android::fs_mgr::ReadDefaultFstab(&fstab)) {
		if (auto entry = GetEntryForMountPoint(&fstab, "/")) {
		auto& dm = dm::DeviceMapper::Instance();
		std::string path;
		if (dm.GetDmDevicePathByName("system", &path) \|\| dm.GetDmDevicePathByName("vroot", &path)) {
		fields[0] = path;
		} else if (android::fs_mgr::Fstab fstab; android::fs_mgr::ReadDefaultFstab(&fstab)) {
		auto entry = GetEntryForMountPoint(&fstab, "/");
		if (entry \|\| (entry = GetEntryForMountPoint(&fstab, "/system"))) {
		fields[0] = entry->blk_device;
		}
		}
		@@ -77,14 +84,19 @@ void SetMountProperty(const MountHandlerEntry& entry, bool add) {
		struct stat sb;
		if (stat(queue.c_str(), &sb) \|\| !S_ISDIR(sb.st_mode)) value = "";
		if (stat(entry.mount_point.c_str(), &sb) \|\| !S_ISDIR(sb.st_mode)) value = "";
		// Skip the noise associated with APEX until there is a need
		// Clear the noise associated with loopback and APEX.
		if (android::base::StartsWith(value, "loop")) value = "";
		if (android::base::StartsWith(entry.mount_point, "/apex/")) value = "";
		}
		std::string property =
		"dev.mnt.blk" + ((entry.mount_point == "/") ? "/root" : entry.mount_point);
		std::replace(property.begin(), property.end(), '/', '.');
		if (value.empty() && android::base::GetProperty(property, "").empty()) return;
		property_set(property, value);
		auto mount_prop = entry.mount_point;
		if (mount_prop == "/") mount_prop = "/root";
		std::replace(mount_prop.begin(), mount_prop.end(), '/', '.');
		mount_prop = "dev.mnt.blk" + mount_prop;
		// Set property even if its value does not change to trigger 'on property:'
		// handling, except for clearing non-existent or already clear property.
		// Goal is reduction of empty properties and associated triggers.
		if (value.empty() && android::base::GetProperty(mount_prop, "").empty()) return;
		property_set(mount_prop, value);
		}

		} // namespace
		@@ -114,25 +126,27 @@ MountHandler::~MountHandler() {

		void MountHandler::MountHandlerFunction() {
		rewind(fp_.get());
		std::vector<MountHandlerEntry> touched;
		auto untouched = mounts_;
		char* buf = nullptr;
		size_t len = 0;
		auto untouched = mounts_;
		while (getline(&buf, &len, fp_.get()) != -1) {
		auto entry = ParseMount(std::string(buf, len));
		auto entry = ParseMount(std::string(buf));
		auto match = untouched.find(entry);
		if (match == untouched.end()) {
		SetMountProperty(entry, true);
		mounts_.emplace(std::move(entry));
		touched.emplace_back(std::move(entry));
		} else {
		untouched.erase(match);
		}
		}
		free(buf);
		for (auto entry : untouched) {
		auto match = mounts_.find(entry);
		if (match == mounts_.end()) continue;
		mounts_.erase(match);
		SetMountProperty(entry, false);
		mounts_.erase(entry);
		}
		for (auto entry : touched) {
		SetMountProperty(entry, true);
		mounts_.emplace(std::move(entry));
		}
		}