Add a test to verify that detached mounts behave correctly.
Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
---
.../selftests/mount_setattr/mount_setattr_test.c | 30 ++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/tools/testing/selftests/mount_setattr/mount_setattr_test.c b/tools/testing/selftests/mount_setattr/mount_setattr_test.c
index 66eed84c6a01..0ee4e5b27c68 100644
--- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c
+++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c
@@ -1909,4 +1909,34 @@ TEST_F(mount_setattr, move_mount_detached_fail)
EXPECT_EQ(close(fd_tree_subdir), 0);
}
+TEST_F(mount_setattr, attach_detached_mount_then_umount_then_close)
+{
+ int fd_tree = -EBADF;
+ struct statx stx;
+
+ fd_tree = sys_open_tree(-EBADF, "/mnt",
+ AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW |
+ AT_RECURSIVE | OPEN_TREE_CLOEXEC |
+ OPEN_TREE_CLONE);
+ ASSERT_GE(fd_tree, 0);
+
+ ASSERT_EQ(statx(fd_tree, "A", 0, 0, &stx), 0);
+ /* We copied with AT_RECURSIVE so /mnt/A must be a mountpoint. */
+ ASSERT_TRUE(stx.stx_attributes & STATX_ATTR_MOUNT_ROOT);
+
+ /* Attach the mount to the caller's mount namespace. */
+ ASSERT_EQ(move_mount(fd_tree, "", -EBADF, "/tmp/target1", MOVE_MOUNT_F_EMPTY_PATH), 0);
+
+ ASSERT_EQ(statx(-EBADF, "/tmp/target1", 0, 0, &stx), 0);
+ ASSERT_TRUE(stx.stx_attributes & STATX_ATTR_MOUNT_ROOT);
+
+ ASSERT_EQ(umount2("/tmp/target1", MNT_DETACH), 0);
+
+ /*
+ * This tests whether dissolve_on_fput() handles a NULL mount
+ * namespace correctly, i.e., that it doesn't splat.
+ */
+ EXPECT_EQ(close(fd_tree), 0);
+}
+
TEST_HARNESS_MAIN
--
2.47.2
