When build kernel selftests on Ubuntu 24.04, I got a compiler error:

mount-notify_test.c:22:3: error: conflicting types for ‘__kernel_fsid_t’; have ‘struct <anonymous>’
   22 | } __kernel_fsid_t;
      |   ^~~~~~~~~~~~~~~
In file included from .../linux/usr/include/asm/posix_types_64.h:18,
                 from .../linux/usr/include/asm/posix_types.h:7,
                 from .../linux/usr/include/linux/posix_types.h:36,
                 from .../linux/usr/include/linux/types.h:9,
                 from .../linux/usr/include/linux/stat.h:5,
                 from /usr/include/x86_64-linux-gnu/bits/statx.h:31,
                 from /usr/include/x86_64-linux-gnu/sys/stat.h:465,
                 from mount-notify_test.c:9:
.../linux/usr/include/asm-generic/posix_types.h:81:3: note: previous declaration of ‘__kernel_fsid_t’ with type ‘__kernel_fsid_t’
   81 | } __kernel_fsid_t;
      |   ^~~~~~~~~~~~~~~

Signed-off-by: Chen Linxuan <chenlinxuan@uniontech.com>
---
 .../selftests/filesystems/mount-notify/mount-notify_test.c | 7 -------
 .../filesystems/mount-notify/mount-notify_test_ns.c        | 7 -------
 2 files changed, 14 deletions(-)

diff --git a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
index b4cb494206e5d..2d197ad8cb75a 100644
--- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
+++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
@@ -15,13 +15,6 @@
 #include "../statmount/statmount.h"
 #include "../utils.h"
 
-// Needed for linux/fanotify.h
-#ifndef __kernel_fsid_t
-typedef struct {
-	int	val[2];
-} __kernel_fsid_t;
-#endif
-
 #include <sys/fanotify.h>
 
 static const char root_mntpoint_templ[] = "/tmp/mount-notify_test_root.XXXXXX";
diff --git a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
index 1bd090e9c8dd5..d6a6a7ee87028 100644
--- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
+++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
@@ -16,13 +16,6 @@
 #include "../statmount/statmount.h"
 #include "../utils.h"
 
-// Needed for linux/fanotify.h
-#ifndef __kernel_fsid_t
-typedef struct {
-	int	val[2];
-} __kernel_fsid_t;
-#endif
-
 #include <sys/fanotify.h>
 
 static const char root_mntpoint_templ[] = "/tmp/mount-notify_test_root.XXXXXX";
-- 
2.43.0

On 6/20/25 8:43 AM, Chen Linxuan wrote:
> When build kernel selftests on Ubuntu 24.04, I got a compiler error:
> 
> mount-notify_test.c:22:3: error: conflicting types for ‘__kernel_fsid_t’; have ‘struct <anonymous>’
>    22 | } __kernel_fsid_t;
>       |   ^~~~~~~~~~~~~~~
> In file included from .../linux/usr/include/asm/posix_types_64.h:18,
>                  from .../linux/usr/include/asm/posix_types.h:7,
>                  from .../linux/usr/include/linux/posix_types.h:36,
>                  from .../linux/usr/include/linux/types.h:9,
>                  from .../linux/usr/include/linux/stat.h:5,
>                  from /usr/include/x86_64-linux-gnu/bits/statx.h:31,
>                  from /usr/include/x86_64-linux-gnu/sys/stat.h:465,
>                  from mount-notify_test.c:9:
> .../linux/usr/include/asm-generic/posix_types.h:81:3: note: previous declaration of ‘__kernel_fsid_t’ with type ‘__kernel_fsid_t’
>    81 | } __kernel_fsid_t;
>       |   ^~~~~~~~~~~~~~~
> 
> Signed-off-by: Chen Linxuan <chenlinxuan@uniontech.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>

> ---
>  .../selftests/filesystems/mount-notify/mount-notify_test.c | 7 -------
>  .../filesystems/mount-notify/mount-notify_test_ns.c        | 7 -------
>  2 files changed, 14 deletions(-)
> 
> diff --git a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
> index b4cb494206e5d..2d197ad8cb75a 100644
> --- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
> +++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test.c
> @@ -15,13 +15,6 @@
>  #include "../statmount/statmount.h"
>  #include "../utils.h"
>  
> -// Needed for linux/fanotify.h
> -#ifndef __kernel_fsid_t
> -typedef struct {
> -	int	val[2];
> -} __kernel_fsid_t;
> -#endif
> -
>  #include <sys/fanotify.h>
>  
>  static const char root_mntpoint_templ[] = "/tmp/mount-notify_test_root.XXXXXX";
> diff --git a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
> index 1bd090e9c8dd5..d6a6a7ee87028 100644
> --- a/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
> +++ b/tools/testing/selftests/filesystems/mount-notify/mount-notify_test_ns.c
> @@ -16,13 +16,6 @@
>  #include "../statmount/statmount.h"
>  #include "../utils.h"
>  
> -// Needed for linux/fanotify.h
> -#ifndef __kernel_fsid_t
> -typedef struct {
> -	int	val[2];
> -} __kernel_fsid_t;
> -#endif
> -
>  #include <sys/fanotify.h>
>  
>  static const char root_mntpoint_templ[] = "/tmp/mount-notify_test_root.XXXXXX";