Merge "ueventd: Fix a race condition in handling device-mapper events." into udc-devandroid14-dev

4 files changed, 94 insertions, 39 deletions

diff --git a/fs_mgr/libdm/dm.cpp b/fs_mgr/libdm/dm.cpp
index deffae1ad..1e8c14fe2 100644
--- a/fs_mgr/libdm/dm.cpp
+++ b/fs_mgr/libdm/dm.cpp
@@ -243,6 +243,25 @@ bool DeviceMapper::GetDeviceUniquePath(const std::string& name, std::string* pat
     return true;
 }
 
+bool DeviceMapper::GetDeviceNameAndUuid(dev_t dev, std::string* name, std::string* uuid) {
+    struct dm_ioctl io;
+    InitIo(&io, {});
+    io.dev = dev;
+
+    if (ioctl(fd_, DM_DEV_STATUS, &io) < 0) {
+        PLOG(ERROR) << "Failed to find device dev: " << major(dev) << ":" << minor(dev);
+        return false;
+    }
+
+    if (name) {
+        *name = io.name;
+    }
+    if (uuid) {
+        *uuid = io.uuid;
+    }
+    return true;
+}
+
 std::optional<DeviceMapper::Info> DeviceMapper::GetDetailedInfo(const std::string& name) const {
     struct dm_ioctl io;
     InitIo(&io, name);
diff --git a/fs_mgr/libdm/dm_test.cpp b/fs_mgr/libdm/dm_test.cpp
index 788cf5174..c522eafae 100644
--- a/fs_mgr/libdm/dm_test.cpp
+++ b/fs_mgr/libdm/dm_test.cpp
@@ -30,6 +30,7 @@
 #include <thread>
 
 #include <android-base/file.h>
+#include <android-base/logging.h>
 #include <android-base/scopeguard.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
@@ -42,16 +43,40 @@
 using namespace std;
 using namespace std::chrono_literals;
 using namespace android::dm;
-using unique_fd = android::base::unique_fd;
+using android::base::make_scope_guard;
+using android::base::unique_fd;
+
+class DmTest : public ::testing::Test {
+  protected:
+    void SetUp() override {
+        const testing::TestInfo* const test_info =
+                testing::UnitTest::GetInstance()->current_test_info();
+        test_name_ = test_info->name();
+        test_full_name_ = test_info->test_suite_name() + "/"s + test_name_;
+
+        LOG(INFO) << "Starting test: " << test_full_name_;
+    }
+    void TearDown() override {
+        LOG(INFO) << "Tearing down test: " << test_full_name_;
+
+        auto& dm = DeviceMapper::Instance();
+        ASSERT_TRUE(dm.DeleteDeviceIfExists(test_name_));
+
+        LOG(INFO) << "Teardown complete for test: " << test_full_name_;
+    }
+
+    std::string test_name_;
+    std::string test_full_name_;
+};
 
-TEST(libdm, HasMinimumTargets) {
+TEST_F(DmTest, HasMinimumTargets) {
     DmTargetTypeInfo info;
 
     DeviceMapper& dm = DeviceMapper::Instance();
     ASSERT_TRUE(dm.GetTargetByName("linear", &info));
 }
 
-TEST(libdm, DmLinear) {
+TEST_F(DmTest, DmLinear) {
     unique_fd tmp1(CreateTempFile("file_1", 4096));
     ASSERT_GE(tmp1, 0);
     unique_fd tmp2(CreateTempFile("file_2", 4096));
@@ -127,7 +152,7 @@ TEST(libdm, DmLinear) {
     ASSERT_TRUE(dev.Destroy());
 }
 
-TEST(libdm, DmSuspendResume) {
+TEST_F(DmTest, DmSuspendResume) {
     unique_fd tmp1(CreateTempFile("file_suspend_resume", 512));
     ASSERT_GE(tmp1, 0);
 
@@ -156,7 +181,7 @@ TEST(libdm, DmSuspendResume) {
     ASSERT_EQ(dm.GetState(dev.name()), DmDeviceState::ACTIVE);
 }
 
-TEST(libdm, DmVerityArgsAvb2) {
+TEST_F(DmTest, DmVerityArgsAvb2) {
     std::string device = "/dev/block/platform/soc/1da4000.ufshc/by-name/vendor_a";
     std::string algorithm = "sha1";
     std::string digest = "4be7e823b8c40f7bd5c8ccd5123f0722c5baca21";
@@ -178,7 +203,7 @@ TEST(libdm, DmVerityArgsAvb2) {
     EXPECT_EQ(target.GetParameterString(), expected);
 }
 
-TEST(libdm, DmSnapshotArgs) {
+TEST_F(DmTest, DmSnapshotArgs) {
     DmTargetSnapshot target1(0, 512, "base", "cow", SnapshotStorageMode::Persistent, 8);
     if (DmTargetSnapshot::ReportsOverflow("snapshot")) {
         EXPECT_EQ(target1.GetParameterString(), "base cow PO 8");
@@ -200,7 +225,7 @@ TEST(libdm, DmSnapshotArgs) {
     EXPECT_EQ(target3.name(), "snapshot-merge");
 }
 
-TEST(libdm, DmSnapshotOriginArgs) {
+TEST_F(DmTest, DmSnapshotOriginArgs) {
     DmTargetSnapshotOrigin target(0, 512, "base");
     EXPECT_EQ(target.GetParameterString(), "base");
     EXPECT_EQ(target.name(), "snapshot-origin");
@@ -330,7 +355,7 @@ bool CheckSnapshotAvailability() {
     return true;
 }
 
-TEST(libdm, DmSnapshot) {
+TEST_F(DmTest, DmSnapshot) {
     if (!CheckSnapshotAvailability()) {
         return;
     }
@@ -374,7 +399,7 @@ TEST(libdm, DmSnapshot) {
     ASSERT_EQ(read, data);
 }
 
-TEST(libdm, DmSnapshotOverflow) {
+TEST_F(DmTest, DmSnapshotOverflow) {
     if (!CheckSnapshotAvailability()) {
         return;
     }
@@ -421,7 +446,7 @@ TEST(libdm, DmSnapshotOverflow) {
     }
 }
 
-TEST(libdm, ParseStatusText) {
+TEST_F(DmTest, ParseStatusText) {
     DmTargetSnapshot::Status status;
 
     // Bad inputs
@@ -448,7 +473,7 @@ TEST(libdm, ParseStatusText) {
     EXPECT_TRUE(DmTargetSnapshot::ParseStatusText("Overflow", &status));
 }
 
-TEST(libdm, DmSnapshotMergePercent) {
+TEST_F(DmTest, DmSnapshotMergePercent) {
     DmTargetSnapshot::Status status;
 
     // Correct input
@@ -502,7 +527,7 @@ TEST(libdm, DmSnapshotMergePercent) {
     EXPECT_LE(DmTargetSnapshot::MergePercent(status, 0), 0.0);
 }
 
-TEST(libdm, CryptArgs) {
+TEST_F(DmTest, CryptArgs) {
     DmTargetCrypt target1(0, 512, "sha1", "abcdefgh", 50, "/dev/loop0", 100);
     ASSERT_EQ(target1.name(), "crypt");
     ASSERT_TRUE(target1.Valid());
@@ -518,7 +543,7 @@ TEST(libdm, CryptArgs) {
               "iv_large_sectors sector_size:64");
 }
 
-TEST(libdm, DefaultKeyArgs) {
+TEST_F(DmTest, DefaultKeyArgs) {
     DmTargetDefaultKey target(0, 4096, "aes-xts-plain64", "abcdef0123456789", "/dev/loop0", 0);
     target.SetSetDun();
     ASSERT_EQ(target.name(), "default-key");
@@ -529,7 +554,7 @@ TEST(libdm, DefaultKeyArgs) {
               "iv_large_sectors");
 }
 
-TEST(libdm, DefaultKeyLegacyArgs) {
+TEST_F(DmTest, DefaultKeyLegacyArgs) {
     DmTargetDefaultKey target(0, 4096, "AES-256-XTS", "abcdef0123456789", "/dev/loop0", 0);
     target.SetUseLegacyOptionsFormat();
     ASSERT_EQ(target.name(), "default-key");
@@ -537,7 +562,7 @@ TEST(libdm, DefaultKeyLegacyArgs) {
     ASSERT_EQ(target.GetParameterString(), "AES-256-XTS abcdef0123456789 /dev/loop0 0");
 }
 
-TEST(libdm, DeleteDeviceWithTimeout) {
+TEST_F(DmTest, DeleteDeviceWithTimeout) {
     unique_fd tmp(CreateTempFile("file_1", 4096));
     ASSERT_GE(tmp, 0);
     LoopDevice loop(tmp, 10s);
@@ -561,7 +586,7 @@ TEST(libdm, DeleteDeviceWithTimeout) {
     ASSERT_EQ(ENOENT, errno);
 }
 
-TEST(libdm, IsDmBlockDevice) {
+TEST_F(DmTest, IsDmBlockDevice) {
     unique_fd tmp(CreateTempFile("file_1", 4096));
     ASSERT_GE(tmp, 0);
     LoopDevice loop(tmp, 10s);
@@ -580,7 +605,7 @@ TEST(libdm, IsDmBlockDevice) {
     ASSERT_FALSE(dm.IsDmBlockDevice(loop.device()));
 }
 
-TEST(libdm, GetDmDeviceNameByPath) {
+TEST_F(DmTest, GetDmDeviceNameByPath) {
     unique_fd tmp(CreateTempFile("file_1", 4096));
     ASSERT_GE(tmp, 0);
     LoopDevice loop(tmp, 10s);
@@ -601,7 +626,7 @@ TEST(libdm, GetDmDeviceNameByPath) {
     ASSERT_EQ("libdm-test-dm-linear", *name);
 }
 
-TEST(libdm, GetParentBlockDeviceByPath) {
+TEST_F(DmTest, GetParentBlockDeviceByPath) {
     unique_fd tmp(CreateTempFile("file_1", 4096));
     ASSERT_GE(tmp, 0);
     LoopDevice loop(tmp, 10s);
@@ -621,7 +646,7 @@ TEST(libdm, GetParentBlockDeviceByPath) {
     ASSERT_EQ(loop.device(), *sub_block_device);
 }
 
-TEST(libdm, DeleteDeviceDeferredNoReferences) {
+TEST_F(DmTest, DeleteDeviceDeferredNoReferences) {
     unique_fd tmp(CreateTempFile("file_1", 4096));
     ASSERT_GE(tmp, 0);
     LoopDevice loop(tmp, 10s);
@@ -647,7 +672,7 @@ TEST(libdm, DeleteDeviceDeferredNoReferences) {
     ASSERT_EQ(ENOENT, errno);
 }
 
-TEST(libdm, DeleteDeviceDeferredWaitsForLastReference) {
+TEST_F(DmTest, DeleteDeviceDeferredWaitsForLastReference) {
     unique_fd tmp(CreateTempFile("file_1", 4096));
     ASSERT_GE(tmp, 0);
     LoopDevice loop(tmp, 10s);
@@ -682,7 +707,7 @@ TEST(libdm, DeleteDeviceDeferredWaitsForLastReference) {
     ASSERT_EQ(ENOENT, errno);
 }
 
-TEST(libdm, CreateEmptyDevice) {
+TEST_F(DmTest, CreateEmptyDevice) {
     DeviceMapper& dm = DeviceMapper::Instance();
     ASSERT_TRUE(dm.CreateEmptyDevice("empty-device"));
     auto guard =
@@ -692,9 +717,7 @@ TEST(libdm, CreateEmptyDevice) {
     ASSERT_EQ(DmDeviceState::SUSPENDED, dm.GetState("empty-device"));
 }
 
-TEST(libdm, UeventAfterLoadTable) {
-    static const char* kDeviceName = "libdm-test-uevent-load-table";
-
+TEST_F(DmTest, UeventAfterLoadTable) {
     struct utsname u;
     ASSERT_EQ(uname(&u), 0);
 
@@ -706,18 +729,31 @@ TEST(libdm, UeventAfterLoadTable) {
     }
 
     DeviceMapper& dm = DeviceMapper::Instance();
-    ASSERT_TRUE(dm.CreateEmptyDevice(kDeviceName));
+    ASSERT_TRUE(dm.CreateEmptyDevice(test_name_));
 
     DmTable table;
     table.Emplace<DmTargetError>(0, 1);
-    ASSERT_TRUE(dm.LoadTable(kDeviceName, table));
+    ASSERT_TRUE(dm.LoadTable(test_name_, table));
 
     std::string ignore_path;
-    ASSERT_TRUE(dm.WaitForDevice(kDeviceName, 5s, &ignore_path));
+    ASSERT_TRUE(dm.WaitForDevice(test_name_, 5s, &ignore_path));
 
-    auto info = dm.GetDetailedInfo(kDeviceName);
+    auto info = dm.GetDetailedInfo(test_name_);
     ASSERT_TRUE(info.has_value());
     ASSERT_TRUE(info->IsSuspended());
 
-    ASSERT_TRUE(dm.DeleteDevice(kDeviceName));
+    ASSERT_TRUE(dm.DeleteDevice(test_name_));
+}
+
+TEST_F(DmTest, GetNameAndUuid) {
+    auto& dm = DeviceMapper::Instance();
+    ASSERT_TRUE(dm.CreatePlaceholderDevice(test_name_));
+
+    dev_t dev;
+    ASSERT_TRUE(dm.GetDeviceNumber(test_name_, &dev));
+
+    std::string name, uuid;
+    ASSERT_TRUE(dm.GetDeviceNameAndUuid(dev, &name, &uuid));
+    ASSERT_EQ(name, test_name_);
+    ASSERT_FALSE(uuid.empty());
 }
diff --git a/fs_mgr/libdm/include/libdm/dm.h b/fs_mgr/libdm/include/libdm/dm.h
index dbef8f902..3e7ecc645 100644
--- a/fs_mgr/libdm/include/libdm/dm.h
+++ b/fs_mgr/libdm/include/libdm/dm.h
@@ -298,6 +298,8 @@ class DeviceMapper final : public IDeviceMapper {
     // a placeholder table containing dm-error.
     bool CreatePlaceholderDevice(const std::string& name);
 
+    bool GetDeviceNameAndUuid(dev_t dev, std::string* name, std::string* uuid);
+
   private:
     // Maximum possible device mapper targets registered in the kernel.
     // This is only used to read the list of targets from kernel so we allocate
diff --git a/init/devices.cpp b/init/devices.cpp
index 39442a0e8..d29ffd604 100644
--- a/init/devices.cpp
+++ b/init/devices.cpp
@@ -32,6 +32,7 @@
 #include <android-base/logging.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
+#include <libdm/dm.h>
 #include <private/android_filesystem_config.h>
 #include <selinux/android.h>
 #include <selinux/selinux.h>
@@ -112,17 +113,14 @@ static bool FindVbdDevicePrefix(const std::string& path, std::string* result) {
 // the supplied buffer with the dm module's instantiated name.
 // If it doesn't start with a virtual block device, or there is some
 // error, return false.
-static bool FindDmDevice(const std::string& path, std::string* name, std::string* uuid) {
-    if (!StartsWith(path, "/devices/virtual/block/dm-")) return false;
+static bool FindDmDevice(const Uevent& uevent, std::string* name, std::string* uuid) {
+    if (!StartsWith(uevent.path, "/devices/virtual/block/dm-")) return false;
+    if (uevent.action == "remove") return false;  // Avoid error spam from ioctl
 
-    if (!ReadFileToString("/sys" + path + "/dm/name", name)) {
-        return false;
-    }
-    ReadFileToString("/sys" + path + "/dm/uuid", uuid);
+    dev_t dev = makedev(uevent.major, uevent.minor);
 
-    *name = android::base::Trim(*name);
-    *uuid = android::base::Trim(*uuid);
-    return true;
+    auto& dm = android::dm::DeviceMapper::Instance();
+    return dm.GetDeviceNameAndUuid(dev, name, uuid);
 }
 
 Permissions::Permissions(const std::string& name, mode_t perm, uid_t uid, gid_t gid,
@@ -392,7 +390,7 @@ std::vector<std::string> DeviceHandler::GetBlockDeviceSymlinks(const Uevent& uev
         type = "pci";
     } else if (FindVbdDevicePrefix(uevent.path, &device)) {
         type = "vbd";
-    } else if (FindDmDevice(uevent.path, &partition, &uuid)) {
+    } else if (FindDmDevice(uevent, &partition, &uuid)) {
         std::vector<std::string> symlinks = {"/dev/block/mapper/" + partition};
         if (!uuid.empty()) {
             symlinks.emplace_back("/dev/block/mapper/by-uuid/" + uuid);