tests: fix idmapped mount_setattr test

The test treated zero as a successful run when it really should treat
non-zero as a successful run. A mount's idmapping can't change once it
has been attached to the filesystem.

Link: https://lore.kernel.org/r/20220203131411.3093040-2-brauner@kernel.org
Fixes: 01eadc8dd96d ("tests: add mount_setattr() selftests")
Cc: Seth Forshee <seth.forshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/tools/testing/selftests/mount_setattr/mount_setattr_test.c b/tools/testing/selftests/mount_setattr/mount_setattr_test.c
index f31205f..8c5fea6 100644 (file)
--- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c
+++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c
@@ -1236,7 +1236,7 @@ static int get_userns_fd(unsigned long nsid, unsigned long hostid, unsigned long
 }
 
 /**
- * Validate that an attached mount in our mount namespace can be idmapped.
+ * Validate that an attached mount in our mount namespace cannot be idmapped.
  * (The kernel enforces that the mount's mount namespace and the caller's mount
  *  namespace match.)
  */
@@ -1259,7 +1259,7 @@ TEST_F(mount_setattr_idmapped, attached_mount_inside_current_mount_namespace)
 
        attr.userns_fd  = get_userns_fd(0, 10000, 10000);
        ASSERT_GE(attr.userns_fd, 0);
-       ASSERT_EQ(sys_mount_setattr(open_tree_fd, "", AT_EMPTY_PATH, &attr, sizeof(attr)), 0);
+       ASSERT_NE(sys_mount_setattr(open_tree_fd, "", AT_EMPTY_PATH, &attr, sizeof(attr)), 0);
        ASSERT_EQ(close(attr.userns_fd), 0);
        ASSERT_EQ(close(open_tree_fd), 0);
 }