Merge "Now for real unmount bind-mounts on top of /data" (ee08c978) · Commits · e / os / android_system_core

fs_mgr/fs_mgr.cpp

+35 −11

Original line number	Diff line number	Diff line
		@@ -34,6 +34,7 @@
		#include <time.h>
		#include <unistd.h>

		#include <chrono>
		#include <functional>
		#include <map>
		#include <memory>
		@@ -42,6 +43,7 @@
		#include <utility>
		#include <vector>

		#include <android-base/chrono_utils.h>
		#include <android-base/file.h>
		#include <android-base/properties.h>
		#include <android-base/stringprintf.h>
		@@ -94,6 +96,7 @@ using android::base::Basename;
		using android::base::GetBoolProperty;
		using android::base::Realpath;
		using android::base::StartsWith;
		using android::base::Timer;
		using android::base::unique_fd;
		using android::dm::DeviceMapper;
		using android::dm::DmDeviceState;
		@@ -1358,6 +1361,36 @@ int fs_mgr_umount_all(android::fs_mgr::Fstab* fstab) {
		return ret;
		}

		static bool fs_mgr_unmount_all_data_mounts(const std::string& block_device) {
		Timer t;
		// TODO(b/135984674): should be configured via a read-only property.
		std::chrono::milliseconds timeout = 5s;
		while (true) {
		bool umount_done = true;
		Fstab proc_mounts;
		if (!ReadFstabFromFile("/proc/mounts", &proc_mounts)) {
		LERROR << "Can't read /proc/mounts";
		return -1;
		}
		// Now proceed with other bind mounts on top of /data.
		for (const auto& entry : proc_mounts) {
		if (entry.blk_device == block_device) {
		if (umount2(entry.mount_point.c_str(), 0) != 0) {
		umount_done = false;
		}
		}
		}
		if (umount_done) {
		LINFO << "Unmounting /data took " << t;
		return true;
		}
		if (t.duration() > timeout) {
		return false;
		}
		std::this_thread::sleep_for(50ms);
		}
		}

		// TODO(b/143970043): return different error codes based on which step failed.
		int fs_mgr_remount_userdata_into_checkpointing(Fstab* fstab) {
		Fstab proc_mounts;
		@@ -1401,17 +1434,8 @@ int fs_mgr_remount_userdata_into_checkpointing(Fstab* fstab) {
		}
		} else {
		LINFO << "Unmounting /data before remounting into checkpointing mode";
		// First make sure that all the bind-mounts on top of /data are unmounted.
		for (const auto& entry : proc_mounts) {
		if (entry.blk_device == block_device && entry.mount_point != "/data") {
		LINFO << "Unmounting bind-mount " << entry.mount_point;
		if (umount2(entry.mount_point.c_str(), UMOUNT_NOFOLLOW) != 0) {
		PWARNING << "Failed to unmount " << entry.mount_point;
		}
		}
		}
		if (umount2("/data", UMOUNT_NOFOLLOW) != 0) {
		PERROR << "Failed to umount /data";
		if (!fs_mgr_unmount_all_data_mounts(block_device)) {
		LERROR << "Failed to umount /data";
		return -1;
		}
		DeviceMapper& dm = DeviceMapper::Instance();