get_mounted_entry_for_userdata: Realpath block devices from fstabs am: 7facdac6af am: a910b8b83f (6728c7f0) · Commits · e / os / android_system_core

fs_mgr/fs_mgr.cpp

+24 −18

Original line number	Diff line number	Diff line
		@@ -97,7 +97,6 @@
		using android::base::Basename;
		using android::base::GetBoolProperty;
		using android::base::GetUintProperty;
		using android::base::Readlink;
		using android::base::Realpath;
		using android::base::SetProperty;
		using android::base::StartsWith;
		@@ -1573,8 +1572,8 @@ static std::chrono::milliseconds GetMillisProperty(const std::string& name,
		return std::chrono::milliseconds(std::move(value));
		}

		static bool fs_mgr_unmount_all_data_mounts(const std::string& block_device) {
		LINFO << __FUNCTION__ << "(): about to umount everything on top of " << block_device;
		static bool fs_mgr_unmount_all_data_mounts(const std::string& data_block_device) {
		LINFO << __FUNCTION__ << "(): about to umount everything on top of " << data_block_device;
		Timer t;
		auto timeout = GetMillisProperty("init.userspace_reboot.userdata_remount.timeoutmillis", 5s);
		while (true) {
		@@ -1586,7 +1585,13 @@ static bool fs_mgr_unmount_all_data_mounts(const std::string& block_device) {
		}
		// Now proceed with other bind mounts on top of /data.
		for (const auto& entry : proc_mounts) {
		if (entry.blk_device == block_device) {
		std::string block_device;
		if (StartsWith(entry.blk_device, "/dev/block") &&
		!Realpath(entry.blk_device, &block_device)) {
		PWARNING << __FUNCTION__ << "(): failed to realpath " << entry.blk_device;
		block_device = entry.blk_device;
		}
		if (data_block_device == block_device) {
		if (umount2(entry.mount_point.c_str(), 0) != 0) {
		PERROR << __FUNCTION__ << "(): Failed to umount " << entry.mount_point;
		umount_done = false;
		@@ -1598,7 +1603,8 @@ static bool fs_mgr_unmount_all_data_mounts(const std::string& block_device) {
		return true;
		}
		if (t.duration() > timeout) {
		LERROR << __FUNCTION__ << "(): Timed out unmounting all mounts on " << block_device;
		LERROR << __FUNCTION__ << "(): Timed out unmounting all mounts on "
		<< data_block_device;
		Fstab remaining_mounts;
		if (!ReadFstabFromFile("/proc/mounts", &remaining_mounts)) {
		LERROR << __FUNCTION__ << "(): Can't read /proc/mounts";
		@@ -1637,14 +1643,11 @@ static bool UnwindDmDeviceStack(const std::string& block_device,
		return true;
		}

		FstabEntry* fs_mgr_get_mounted_entry_for_userdata(Fstab* fstab, const FstabEntry& mounted_entry) {
		if (mounted_entry.mount_point != "/data") {
		LERROR << mounted_entry.mount_point << " is not /data";
		return nullptr;
		}
		FstabEntry* fs_mgr_get_mounted_entry_for_userdata(Fstab* fstab,
		const std::string& data_block_device) {
		std::vector<std::string> dm_stack;
		if (!UnwindDmDeviceStack(mounted_entry.blk_device, &dm_stack)) {
		LERROR << "Failed to unwind dm-device stack for " << mounted_entry.blk_device;
		if (!UnwindDmDeviceStack(data_block_device, &dm_stack)) {
		LERROR << "Failed to unwind dm-device stack for " << data_block_device;
		return nullptr;
		}
		for (auto& entry : *fstab) {
		@@ -1658,15 +1661,15 @@ FstabEntry* fs_mgr_get_mounted_entry_for_userdata(Fstab* fstab, const FstabEntry
		continue;
		}
		block_device = entry.blk_device;
		} else if (!Readlink(entry.blk_device, &block_device)) {
		PWARNING << "Failed to read link " << entry.blk_device;
		} else if (!Realpath(entry.blk_device, &block_device)) {
		PWARNING << "Failed to realpath " << entry.blk_device;
		block_device = entry.blk_device;
		}
		if (std::find(dm_stack.begin(), dm_stack.end(), block_device) != dm_stack.end()) {
		return &entry;
		}
		}
		LERROR << "Didn't find entry that was used to mount /data onto " << mounted_entry.blk_device;
		LERROR << "Didn't find entry that was used to mount /data onto " << data_block_device;
		return nullptr;
		}

		@@ -1677,14 +1680,17 @@ int fs_mgr_remount_userdata_into_checkpointing(Fstab* fstab) {
		LERROR << "Can't read /proc/mounts";
		return -1;
		}
		std::string block_device;
		auto mounted_entry = GetEntryForMountPoint(&proc_mounts, "/data");
		if (mounted_entry == nullptr) {
		LERROR << "/data is not mounted";
		return -1;
		}
		block_device = mounted_entry->blk_device;
		auto fstab_entry = fs_mgr_get_mounted_entry_for_userdata(fstab, *mounted_entry);
		std::string block_device;
		if (!Realpath(mounted_entry->blk_device, &block_device)) {
		PERROR << "Failed to realpath " << mounted_entry->blk_device;
		return -1;
		}
		auto fstab_entry = fs_mgr_get_mounted_entry_for_userdata(fstab, block_device);
		if (fstab_entry == nullptr) {
		LERROR << "Can't find /data in fstab";
		return -1;

fs_mgr/include/fs_mgr.h

+2 −3

Original line number	Diff line number	Diff line
		@@ -107,10 +107,9 @@ enum FsMgrUmountStatus : int {
		// it destroys verity devices from device mapper after the device is unmounted.
		int fs_mgr_umount_all(android::fs_mgr::Fstab* fstab);

		// Finds a entry in \|fstab\| that was used to mount a /data \|mounted_entry\| from
		// /proc/mounts.
		// Finds a entry in \|fstab\| that was used to mount a /data on \|data_block_device\|.
		android::fs_mgr::FstabEntry* fs_mgr_get_mounted_entry_for_userdata(
		android::fs_mgr::Fstab* fstab, const android::fs_mgr::FstabEntry& mounted_entry);
		android::fs_mgr::Fstab* fstab, const std::string& data_block_device);
		int fs_mgr_remount_userdata_into_checkpointing(android::fs_mgr::Fstab* fstab);

		// Finds the dm_bow device on which this block device is stacked, or returns

fs_mgr/tests/fs_mgr_test.cpp

+3 −1

Original line number	Diff line number	Diff line
		@@ -1006,6 +1006,8 @@ TEST(fs_mgr, UserdataMountedFromDefaultFstab) {
		ASSERT_TRUE(ReadFstabFromFile("/proc/mounts", &proc_mounts)) << "Failed to read /proc/mounts";
		auto mounted_entry = GetEntryForMountPoint(&proc_mounts, "/data");
		ASSERT_NE(mounted_entry, nullptr) << "/data is not mounted";
		ASSERT_NE(nullptr, fs_mgr_get_mounted_entry_for_userdata(&fstab, *mounted_entry))
		std::string block_device;
		ASSERT_TRUE(android::base::Realpath(mounted_entry->blk_device, &block_device));
		ASSERT_NE(nullptr, fs_mgr_get_mounted_entry_for_userdata(&fstab, block_device))
		<< "/data wasn't mounted from default fstab";
		}