Add syncs when creating parent directories
vold creates some directories for storing encryption keys if they don't
already exist, potentially including parent directories:
/metadata/vold/metadata_encryption
/data/misc/vold/volume_keys/$volume_uuid
/data/misc_de/$user/vold/volume_keys/$volume_uuid
/data/misc_ce/$user/vold/volume_keys/$volume_uuid
Currently fs_mkdirs() is used for this. However, fs_mkdirs() doesn't
include the fsync()s of the parent directories that are needed to ensure
that the new directories are persisted to disk right away -- which is
important for encryption keys.
Add a utility function MkdirsSync() which does what is needed, and make
the appropriate places call it.
Test: Booted and checked log for "Created directory" message.
Also ran 'atest vold_tests' to run the new unit test.
Change-Id: Ie9917b616433080139b8db3fd6877203ee6faf77
diff --git a/FsCrypt.cpp b/FsCrypt.cpp
index 31533c7..a56d196 100644
--- a/FsCrypt.cpp
+++ b/FsCrypt.cpp
@@ -652,18 +652,12 @@
if (!android::vold::readSecdiscardable(secdiscardable_path, &secdiscardable_hash))
return false;
} else {
- if (fs_mkdirs(secdiscardable_path.c_str(), 0700) != 0) {
- PLOG(ERROR) << "Creating directories for: " << secdiscardable_path;
- return false;
- }
+ if (!android::vold::MkdirsSync(secdiscardable_path, 0700)) return false;
if (!android::vold::createSecdiscardable(secdiscardable_path, &secdiscardable_hash))
return false;
}
auto key_path = volkey_path(misc_path, volume_uuid);
- if (fs_mkdirs(key_path.c_str(), 0700) != 0) {
- PLOG(ERROR) << "Creating directories for: " << key_path;
- return false;
- }
+ if (!android::vold::MkdirsSync(key_path, 0700)) return false;
android::vold::KeyAuthentication auth("", secdiscardable_hash);
EncryptionOptions options;
diff --git a/MetadataCrypt.cpp b/MetadataCrypt.cpp
index 24c7476..dc50679 100644
--- a/MetadataCrypt.cpp
+++ b/MetadataCrypt.cpp
@@ -111,10 +111,7 @@
std::string sKey;
auto dir = metadata_key_dir + "/key";
LOG(DEBUG) << "metadata_key_dir/key: " << dir;
- if (fs_mkdirs(dir.c_str(), 0700)) {
- PLOG(ERROR) << "Creating directories: " << dir;
- return false;
- }
+ if (!MkdirsSync(dir, 0700)) return false;
auto temp = metadata_key_dir + "/tmp";
return retrieveOrGenerateKey(dir, temp, kEmptyAuthentication, gen, key);
}
diff --git a/Utils.cpp b/Utils.cpp
index c1fbf8f..cef0f39 100644
--- a/Utils.cpp
+++ b/Utils.cpp
@@ -1375,6 +1375,36 @@
return FsyncDirectory(android::base::Dirname(path));
}
+// Creates all parent directories of |path| that don't already exist. Assigns
+// the specified |mode| to any new directories, and also fsync()s their parent
+// directories so that the new directories get written to disk right away.
+bool MkdirsSync(const std::string& path, mode_t mode) {
+ if (path[0] != '/') {
+ LOG(ERROR) << "MkdirsSync() needs an absolute path, but got " << path;
+ return false;
+ }
+ std::vector<std::string> components = android::base::Split(android::base::Dirname(path), "/");
+
+ std::string current_dir = "/";
+ for (const std::string& component : components) {
+ if (component.empty()) continue;
+
+ std::string parent_dir = current_dir;
+ if (current_dir != "/") current_dir += "/";
+ current_dir += component;
+
+ if (!pathExists(current_dir)) {
+ if (mkdir(current_dir.c_str(), mode) != 0) {
+ PLOG(ERROR) << "Failed to create " << current_dir;
+ return false;
+ }
+ if (!FsyncDirectory(parent_dir)) return false;
+ LOG(DEBUG) << "Created directory " << current_dir;
+ }
+ }
+ return true;
+}
+
bool writeStringToFile(const std::string& payload, const std::string& filename) {
android::base::unique_fd fd(TEMP_FAILURE_RETRY(
open(filename.c_str(), O_WRONLY | O_CREAT | O_NOFOLLOW | O_TRUNC | O_CLOEXEC, 0666)));
diff --git a/Utils.h b/Utils.h
index 87beced..4771593 100644
--- a/Utils.h
+++ b/Utils.h
@@ -185,6 +185,8 @@
bool FsyncParentDirectory(const std::string& path);
+bool MkdirsSync(const std::string& path, mode_t mode);
+
bool writeStringToFile(const std::string& payload, const std::string& filename);
void ConfigureMaxDirtyRatioForFuse(const std::string& fuse_mount, unsigned int max_ratio);
diff --git a/tests/Utils_test.cpp b/tests/Utils_test.cpp
index d18dc67..35b40cd 100644
--- a/tests/Utils_test.cpp
+++ b/tests/Utils_test.cpp
@@ -14,6 +14,7 @@
* limitations under the License.
*/
+#include <android-base/file.h>
#include <gtest/gtest.h>
#include "../Utils.h"
@@ -43,5 +44,23 @@
ASSERT_EQ("QUUX", tmp);
}
+TEST_F(UtilsTest, MkdirsSyncTest) {
+ TemporaryDir temp_dir;
+ std::string temp_dir_path;
+
+ ASSERT_TRUE(android::base::Realpath(temp_dir.path, &temp_dir_path));
+
+ ASSERT_FALSE(pathExists(temp_dir_path + "/a"));
+ ASSERT_TRUE(MkdirsSync(temp_dir_path + "/a/b/c", 0700));
+ ASSERT_TRUE(pathExists(temp_dir_path + "/a"));
+ ASSERT_TRUE(pathExists(temp_dir_path + "/a/b"));
+ // The final component of the path should not be created; only the previous
+ // components should be.
+ ASSERT_FALSE(pathExists(temp_dir_path + "/a/b/c"));
+
+ // Currently, MkdirsSync() only supports absolute paths.
+ ASSERT_FALSE(MkdirsSync("foo", 0700));
+}
+
} // namespace vold
} // namespace android