Re: [LTP] [PATCH v1] listmount04.c: Update case support mnt_id_req.mnt_ns_fd

[Petr Vorel <pvorel@suse.cz>]

Hi all,

first, we have a different patch increasing value to 6.11.
https://lore.kernel.org/ltp/20251203081226.1148236-1-masahiro.yamada@canonical.com/

> On Fri, Nov 28, 2025 at 11:26:07AM +0800, Li Wang wrote:
> > Hi Wei,


> > On Thu, Nov 27, 2025 at 9:41 AM Wei Gao via ltp <ltp@lists.linux.it> wrote:

> > > New kernel commit lead test case failure with following error message:
> > > listmount04.c:128: TFAIL: invalid mnt_id_req.spare expected EINVAL: EBADF
> > > (9)

> > > Detail of new kernel commit:
> > > commit: 78f0e33cd6c939a555aa80dbed2fec6b333a7660
> > > fs/namespace: correctly handle errors returned by grab_requested_mnt_ns

> > > Signed-off-by: Wei Gao <wegao@suse.com>
> > > ---
> > >  configure.ac                                   |  1 +
> > >  .../kernel/syscalls/listmount/listmount04.c    | 18 ++++++++++++------
> > >  2 files changed, 13 insertions(+), 6 deletions(-)

> > > diff --git a/configure.ac b/configure.ac
> > > index 0480f46ca..fcff90799 100644
> > > --- a/configure.ac
> > > +++ b/configure.ac
> > > @@ -263,6 +263,7 @@ AC_CHECK_TYPES([struct cachestat],,,[#include
> > > <sys/mman.h>])

> > >  # Defined in <linux/mount.h>, but include/lapi/mount.h includes
> > > <sys/mount.h> */
> > >  AC_CHECK_TYPES([struct mnt_id_req],,,[#include <sys/mount.h>])
> > > +AC_CHECK_MEMBERS([struct mnt_id_req.mnt_ns_fd],,,[#include <sys/mount.h>])
> > >  AC_CHECK_TYPES([struct statmount],,,[#include <sys/mount.h>])
> > >  AC_CHECK_MEMBERS([struct statmount.mnt_ns_id],,,[#include <unistd.h>
> > >  #include <linux/mount.h>])
> > > diff --git a/testcases/kernel/syscalls/listmount/listmount04.c
> > > b/testcases/kernel/syscalls/listmount/listmount04.c
> > > index a52bad064..3be3be4f2 100644
> > > --- a/testcases/kernel/syscalls/listmount/listmount04.c
> > > +++ b/testcases/kernel/syscalls/listmount/listmount04.c
> > > @@ -18,6 +18,7 @@
> > >  #include "lapi/mount.h"
> > >  #include "lapi/syscalls.h"

> > > +#ifdef HAVE_STRUCT_MNT_ID_REQ_MNT_NS_FD
> > >  #define MNT_SIZE 32

> > >  static struct mnt_id_req *request;
> > > @@ -26,7 +27,7 @@ static uint64_t mnt_ids[MNT_SIZE];
> > >  static struct tcase {
> > >         int req_usage;
> > >         uint32_t size;
> > > -       uint32_t spare;
> > > +       uint32_t mnt_ns_fd;
> > >         uint64_t mnt_id;
> > >         uint64_t param;
> > >         uint64_t *mnt_ids;
> > > @@ -73,12 +74,12 @@ static struct tcase {
> > >         {
> > >                 .req_usage = 1,
> > >                 .size = MNT_ID_REQ_SIZE_VER0,
> > > -               .spare = -1,
> > > +               .mnt_ns_fd = -1,
> > >                 .mnt_id = LSMT_ROOT,
> > >                 .mnt_ids = mnt_ids,
> > >                 .nr_mnt_ids = MNT_SIZE,
> > > -               .exp_errno = EINVAL,
> > > -               .msg = "invalid mnt_id_req.spare",
> > > +               .exp_errno = EBADF,
> > > +               .msg = "invalid mnt_id_req.mnt_ns_fd bad file descriptor",
> > >         },
> > >         {
> > >                 .req_usage = 1,
> > > @@ -122,7 +123,7 @@ static void run(unsigned int n)
> > >                 req->mnt_id = tc->mnt_id;
> > >                 req->param = tc->param;
> > >                 req->size = tc->size;
> > > -               req->spare = tc->spare;
> > > +               req->mnt_ns_fd = tc->mnt_ns_fd;
> > >         }

> > >         TST_EXP_FAIL(tst_syscall(__NR_listmount, req, tc->mnt_ids,
> > > @@ -133,9 +134,14 @@ static void run(unsigned int n)
> > >  static struct tst_test test = {
> > >         .test = run,
> > >         .tcnt = ARRAY_SIZE(tcases),
> > > -       .min_kver = "6.8",
> > > +       .min_kver = "6.18",


FYI this is a runtime check, but the problem is with kernel headers.
include/lapi/mount.h [1] uses <sys/mount.h> (see LTP include/lapi/mount.h [1]
and the reason why we did endup using <sys/mount.h> instead of <linux/mount.h>
[2] [3]), but glibc (since certain version, unlike musl) includes <linux/mount.h>.
Therefore while the problem is on current Debian testing with linux-libc-dev all
6.17.9-1 (it was working in previous builds with linux-libc-dev all 6.17.8-1).
But OTOH my openSUSE Tumbleweed VM with 6.18.0-rc6-4.gfea0d97 works without this
patch. Also SLE16 with 6.12 based kernel works without this patch.

tst_test.c:2028: TINFO: Tested kernel: 6.18.0-rc6-4.gfea0d97-default #1 SMP PREEMPT_DYNAMIC Sat Nov 22 19:46:55 UTC 2025 (fea0d97) x86_64
tst_kconfig.c:88: TINFO: Parsing kernel config '/proc/config.gz'
tst_kconfig.c:676: TINFO: CONFIG_FAULT_INJECTION kernel option detected which might slow the execution
tst_test.c:1846: TINFO: Overall timeout per run is 0h 02m 00s
listmount04.c:128: TPASS: request points to unaccessible memory : EFAULT (14)
listmount04.c:128: TPASS: mnt_ids points to unaccessible memory : EFAULT (14)
listmount04.c:128: TPASS: invalid flags : EINVAL (22)
listmount04.c:128: TPASS: insufficient mnt_id_req.size : EINVAL (22)
listmount04.c:128: TPASS: invalid mnt_id_req.spare : EINVAL (22)
listmount04.c:128: TPASS: invalid mnt_id_req.param : EINVAL (22)
listmount04.c:128: TPASS: invalid mnt_id_req.mnt_id : EINVAL (22)
listmount04.c:128: TPASS: non-existant mnt_id : ENOENT (2)

[1] https://github.com/linux-test-project/ltp/blob/master/include/lapi/mount.h
[2] https://github.com/linux-test-project/ltp/commit/a2300dc0f51f46ffb07a465d8734639dbe3af044
[3] https://github.com/linux-test-project/ltp/commit/1feeb57811a4aa2f56ad85edf69a8ea870867c65

> > Reviewed-by: Li Wang <liwang@redhat.com>

> > This patch looks good, I have one question do we need to cover the 'spare'
> > field test for kernels between 6.8 to 6.18?
> I think only keep tracking latest feature's change can make our life
> easy for this case :)

Due the above IMHO we should consider support for <6.11, 6.17> as well.
We have similar crazy approach for a struct change in include/lapi/fanotify.h,
see FSID_VAL_MEMBER().

Kind regards,
Petr

> >         .bufs = (struct tst_buffers []) {
> > >                 { &request, .size = MNT_ID_REQ_SIZE_VER0 },
> > >                 {},
> > >         },
> > >  };
> > > +
> > > +#else
> > > +       TST_TEST_TCONF(
> > > +               "This system does not support mnt_id_req.mnt_ns_fd.");
> > > +#endif /* HAVE_STRUCT_MNT_ID_REQ_MNT_NS_FD */
> > > --
> > > 2.51.0


> > > --
> > > Mailing list info: https://lists.linux.it/listinfo/ltp



> > -- 
> > Regards,
> > Li Wang

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp