Unverified Commit 1768f9bd authored by Christian Brauner's avatar Christian Brauner
Browse files

selftests: fourth test for mounting detached mounts onto detached mounts 

Add a test to verify that detached mounts behave correctly.

Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-13-dbcfcb98c676@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 4fd0aea1

tools/testing/selftests/mount_setattr/mount_setattr_test.c

+30 −0
Original line number Diff line number Diff line
@@ -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