device: fs: add vhost-user-fs e2e test

Add unit tests for vhost-user-fs device mount, verifying successful
mounting of vhost-user fs device with sandbox abled. Test without
sandbox is not prepared, since the vhost-user-fs device need to run as
root.

A new test scenario(mount_rw) has been added to e2e test. This scenario
mounts virtiofs in the guest, then verifies data by reading from the
host's shared directory. It also creates a file in the guest, writes
data to it, and has the host verify the written data. This scenario is
tested using both in-process virtiofs and vhost-user-fs devices.

Additionally, the copy_file functionality has been refactored into a
separate scenario that runs on both virtio-fs and vhost-user-fs devices.

BUG=b:355159487
TEST=tools/dev_container tools/presubmit

Change-Id: Icc09355fee1aae464b98fa153a98cbdd4a9e117d
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/5746575
Reviewed-by: Keiichi Watanabe <keiichiw@chromium.org>
Commit-Queue: Yuan Yao <yuanyaogoog@chromium.org>

e2e_tests/fixture/src/vm.rs

@@ -282,6 +282,14 @@ impl Config {
         ));
         self
     }
+
+    #[cfg(any(target_os = "android", target_os = "linux"))]
+    pub fn with_vhost_user_fs(mut self, socket_path: &Path, tag: &str) -> Self {
+        self.extra_args.push("--vhost-user-fs".to_string());
+        self.extra_args
+            .push(format!("{},tag={}", socket_path.to_str().unwrap(), tag));
+        self
+    }
 }
 
 static PREP_ONCE: Once = Once::new();

e2e_tests/tests/fs.rs

@@ -4,27 +4,80 @@
 
 //! Testing virtio-fs.
 
+#![cfg(any(target_os = "android", target_os = "linux"))]
+
+use std::path::Path;
+
+use fixture::vhost_user::CmdType;
+use fixture::vhost_user::Config as VuConfig;
+use fixture::vhost_user::VhostUserBackend;
 use fixture::vm::Config;
 use fixture::vm::TestVm;
+use tempfile::NamedTempFile;
+use tempfile::TempDir;
 
-/// Tests file copy on virtiofs
+/// Tests file copy
 ///
 /// 1. Create `original.txt` on a temporal directory.
 /// 2. Start a VM with a virtiofs device for the temporal directory.
 /// 3. Copy `original.txt` to `new.txt` in the guest.
 /// 4. Check that `new.txt` is created in the host.
-#[test]
-fn copy_file() {
+fn copy_file(mut vm: TestVm, tag: &str, dir: TempDir) {
     const ORIGINAL_FILE_NAME: &str = "original.txt";
     const NEW_FILE_NAME: &str = "new.txt";
     const TEST_DATA: &str = "virtiofs works!";
 
-    let temp_dir = tempfile::tempdir().unwrap();
-    let orig_file = temp_dir.path().join(ORIGINAL_FILE_NAME);
+    let orig_file = dir.path().join(ORIGINAL_FILE_NAME);
 
     std::fs::write(orig_file, TEST_DATA).unwrap();
 
+    // TODO(b/269137600): Split this into multiple lines instead of connecting commands with `&&`.
+    vm.exec_in_guest(&format!(
+        "mount -t virtiofs {tag} /mnt && cp /mnt/{} /mnt/{} && sync",
+        ORIGINAL_FILE_NAME, NEW_FILE_NAME,
+    ))
+    .unwrap();
+
+    let new_file = dir.path().join(NEW_FILE_NAME);
+    let contents = std::fs::read(new_file).unwrap();
+    assert_eq!(TEST_DATA.as_bytes(), &contents);
+}
+
+/// Tests mount/read/create/write
+/// 1. Create `read_file.txt` with test data in host's temporal directory.
+/// 2. Start a VM with a virtiofs device for the temporal directory.
+/// 3. Guest reads read_file.txt file & verify the content is test data
+/// 4. Guest creates a write_file.txt file in shared directory
+/// 5. Host reads file from host's temporal directory & verify content is test data
+fn mount_rw(mut vm: TestVm, tag: &str, dir: TempDir) {
+    const READ_FILE_NAME: &str = "read_test.txt";
+    const WRITE_FILE_NAME: &str = "write_test.txt";
+    const TEST_DATA: &str = "hello world";
+
+    let read_test_file = dir.path().join(READ_FILE_NAME);
+    let write_test_file = dir.path().join(WRITE_FILE_NAME);
+    std::fs::write(read_test_file, TEST_DATA).unwrap();
+
+    assert_eq!(
+        vm.exec_in_guest(&format!(
+            "mount -t virtiofs {tag} /mnt && cat /mnt/read_test.txt"
+        ))
+        .unwrap()
+        .stdout
+        .trim(),
+        TEST_DATA
+    );
+
+    const IN_FS_WRITE_FILE_PATH: &str = "/mnt/write_test.txt";
+    let _ = vm.exec_in_guest(&format!("echo -n {TEST_DATA} > {IN_FS_WRITE_FILE_PATH}"));
+    let read_contents = std::fs::read(write_test_file).unwrap();
+    assert_eq!(TEST_DATA.as_bytes(), &read_contents);
+}
+
+#[test]
+fn fs_copy_file() {
     let tag = "mtdtest";
+    let temp_dir = tempfile::tempdir().unwrap();
 
     let config = Config::new().extra_args(vec![
         "--shared-dir".to_string(),
@@ -34,17 +87,25 @@ fn copy_file() {
         ),
     ]);
 
-    let mut vm = TestVm::new(config).unwrap();
-    // TODO(b/269137600): Split this into multiple lines instead of connecting commands with `&&`.
-    vm.exec_in_guest(&format!(
-        "mount -t virtiofs {tag} /mnt && cp /mnt/{} /mnt/{} && sync",
-        ORIGINAL_FILE_NAME, NEW_FILE_NAME,
-    ))
-    .unwrap();
+    let vm = TestVm::new(config).unwrap();
+    copy_file(vm, tag, temp_dir)
+}
 
-    let new_file = temp_dir.path().join(NEW_FILE_NAME);
-    let contents = std::fs::read(new_file).unwrap();
-    assert_eq!(TEST_DATA.as_bytes(), &contents);
+#[test]
+fn fs_mount_rw() {
+    let tag = "mtdtest";
+    let temp_dir = tempfile::tempdir().unwrap();
+
+    let config = Config::new().extra_args(vec![
+        "--shared-dir".to_string(),
+        format!(
+            "{}:{tag}:type=fs:cache=auto",
+            temp_dir.path().to_str().unwrap()
+        ),
+    ]);
+
+    let vm = TestVm::new(config).unwrap();
+    mount_rw(vm, tag, temp_dir)
 }
 
 /// Tests file ownership seen by the VM.
@@ -54,15 +115,14 @@ fn copy_file() {
 /// 3. Start a VM with a virtiofs device for the temporal directory.
 /// 4. Check that `user_file.txt`'s uid is <mapped-uid> in the VM.
 /// 5. Verify gid similarly.
-#[cfg(any(target_os = "android", target_os = "linux"))]
 #[test]
 fn file_ugid() {
     const FILE_NAME: &str = "user_file.txt";
     let uid = base::geteuid();
     let gid = base::getegid();
     let mapped_uid: u32 = rand::random();
     let mapped_gid: u32 = rand::random();
-    let uid_map = format!("{} {} 1", mapped_uid, uid);
+    let uid_map: String = format!("{} {} 1", mapped_uid, uid);
     let gid_map = format!("{} {} 1", mapped_gid, gid);
 
     let temp_dir = tempfile::tempdir().unwrap();
@@ -101,3 +161,55 @@ fn file_ugid() {
     assert!(output.stdout.contains(&format!("Uid: ({}/", mapped_uid)));
     assert!(output.stdout.contains(&format!("Gid: ({}/", mapped_gid)));
 }
+
+pub fn create_vu_fs_config(socket: &Path, shared_dir: &Path, tag: &str) -> VuConfig {
+    let uid = base::geteuid();
+    let gid = base::getegid();
+    let socket_path = socket.to_str().unwrap();
+    let shared_dir_path = shared_dir.to_str().unwrap();
+    println!("socket={socket_path}, tag={tag}, shared_dir={shared_dir_path}");
+    VuConfig::new(CmdType::Device, "vhost-user-fs").extra_args(vec![
+        "fs".to_string(),
+        format!("--socket={socket_path}"),
+        format!("--shared-dir={shared_dir_path}"),
+        format!("--tag={tag}"),
+        format!("--uid-map=0 {uid} 1"),
+        format!("--gid-map=0 {gid} 1"),
+    ])
+}
+
+/// Tests vhost-user fs device copy file.
+#[test]
+fn vhost_user_fs_copy_file() {
+    let socket = NamedTempFile::new().unwrap();
+    let temp_dir = tempfile::tempdir().unwrap();
+
+    let config = Config::new();
+    let tag = "mtdtest";
+
+    let vu_config = create_vu_fs_config(socket.path(), temp_dir.path(), tag);
+    let _vu_device = VhostUserBackend::new(vu_config).unwrap();
+
+    let config = config.with_vhost_user_fs(socket.path(), tag);
+    let vm = TestVm::new(config).unwrap();
+
+    copy_file(vm, tag, temp_dir);
+}
+
+/// Tests vhost-user fs device mount and read write.
+#[test]
+fn vhost_user_fs_mount_rw() {
+    let socket = NamedTempFile::new().unwrap();
+    let temp_dir = tempfile::tempdir().unwrap();
+
+    let config = Config::new();
+    let tag = "mtdtest";
+
+    let vu_config = create_vu_fs_config(socket.path(), temp_dir.path(), tag);
+    let _vu_device = VhostUserBackend::new(vu_config).unwrap();
+
+    let config = config.with_vhost_user_fs(socket.path(), tag);
+    let vm = TestVm::new(config).unwrap();
+
+    mount_rw(vm, tag, temp_dir);
+}