[LTP] [PATCH v2 2/2] fanotify13: fix test failure when running iterations

[Amir Goldstein]

On Fri, May 29, 2026 at 6:31 PM Petr Vorel <pvorel@suse.cz> wrote:
>
> Hi Amir,
>
> > The test case for FAN_DELETE_SELF deletes the objects created in
> > do_setup() so we need to re-create them for the next iteration.
>
> > This bring up a problem with ext2 and filesystem that do not support
> > RENAME_EXCHANGE because overlayfs fails to re-create objects over a
> > whiteout.
>
> > It is generally not interesting to test overlayfs over such base fs,
> > but for now, let just exclude this type of base fs from the delete
> > self event test case.
>
> > Reported-by: AnonymeMeow <anonymemeow@gmail.com>
> > Link: https://lore.kernel.org/linux-fsdevel/20260527195056.337081-1-anonymemeow@gmail.com/
> > Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> > ---
>
> > Changes since v1:
> > - Address LTP AI Reviewer comments
>
> >  .../kernel/syscalls/fanotify/fanotify13.c     | 38 +++++++++++++++----
> >  1 file changed, 30 insertions(+), 8 deletions(-)
>
> > diff --git a/testcases/kernel/syscalls/fanotify/fanotify13.c b/testcases/kernel/syscalls/fanotify/fanotify13.c
> > index 76d40eaf7..a00240a33 100644
> > --- a/testcases/kernel/syscalls/fanotify/fanotify13.c
> > +++ b/testcases/kernel/syscalls/fanotify/fanotify13.c
> > @@ -110,6 +110,7 @@ static int nofid_fd;
> >  static int fanotify_fd;
> >  static int at_handle_fid;
> >  static int filesystem_mark_unsupported;
> > +static int rename_exchange_unsupported;
> >  static char events_buf[BUF_SIZE];
> >  static struct event_t event_set[EVENT_MAX];
>
> > @@ -191,6 +192,13 @@ static void do_test(unsigned int number)
> >               return;
> >       }
>
> > +     if (tst_variant && (tc->mask & FAN_DELETE_SELF) &&
> > +         (!ovl_bind_mounted || rename_exchange_unsupported)) {
> > +             /* The eviction of base fs inodes is defered due to overlay held reference */
> > +             tst_res(TCONF, "overlayfs base fs cannot be watched for delete self events");
> > +             return;
> > +     }
> > +
> >       if (filesystem_mark_unsupported && mark->flag != FAN_MARK_INODE) {
> >               FANOTIFY_MARK_FLAGS_ERR_MSG(mark, filesystem_mark_unsupported);
> >               return;
> > @@ -212,11 +220,6 @@ static void do_test(unsigned int number)
> >                       tst_res(TCONF, "overlayfs base fs cannot be watched with mount mark");
> >                       goto out;
> >               }
> > -             if (tc->mask & FAN_DELETE_SELF) {
> > -                     /* The eviction of base fs inodes is defered due to overlay held reference */
> > -                     tst_res(TCONF, "overlayfs base fs cannot be watched for delete self events");
> > -                     goto out;
> > -             }
> >               SAFE_MOUNT(OVL_MNT, MOUNT_PATH, "none", MS_BIND, NULL);
> >       }
>
> > @@ -340,10 +343,18 @@ static void do_test(unsigned int number)
> >                       "Did not get an expected event (expected: %llx)",
> >                       event_set[i].expected_mask);
> >       }
> > +
> > +     if (tc->mask & FAN_DELETE_SELF) {
> > +             create_objects();
> > +             get_object_stats();
> > +     }
> >  out:
> >       SAFE_CLOSE(fanotify_fd);
> >  }
>
> > +#define TST_VARIANT_OVL_LOWER (tst_variant & 1)
> > +#define TST_VARIANT_OVL_WATCH (tst_variant > 2)
> > +
> >  static void do_setup(void)
> >  {
> >       const char *mnt;
> > @@ -371,10 +382,9 @@ static void do_setup(void)
> >               if (!ovl_mounted)
> >                       return;
>
> > -             mnt = tst_variant & 1 ? OVL_LOWER : OVL_UPPER;
> > +             mnt = TST_VARIANT_OVL_LOWER ? OVL_LOWER : OVL_UPPER;
> >       } else {
> >               mnt = OVL_BASE_MNTPOINT;
> > -
> >       }
> >       REQUIRE_FANOTIFY_INIT_FLAGS_SUPPORTED_ON_FS(FAN_REPORT_FID, mnt);
> >       SAFE_MKDIR(MOUNT_PATH, 0755);
> > @@ -386,7 +396,19 @@ static void do_setup(void)
> >       /* Create file and directory objects for testing on base fs */
> >       create_objects();
>
> > -     if (tst_variant > 2) {
> > +     /* RENAME_EXCHANGE is required for create over whiteout in overlayfs */
> > +     if (TST_VARIANT_OVL_LOWER) {
> > +             rename_exchange_unsupported = renameat2(AT_FDCWD, FILE_PATH_ONE,
>
> LGTM, but renameat2() was added in Musl v1.2.6 (released just 2 months ago),
> therefore it fails in our CI:
>
> fanotify13.c:401:47: warning: implicit declaration of function 'renameat2'; did you mean 'renameat'? [-Wimplicit-function-declaration]
>   401 |                 rename_exchange_unsupported = renameat2(AT_FDCWD, FILE_PATH_ONE,
>       |                                               ^~~~~~~~~
>       |                                               renameat
>
> Could you please either use renameat() or use renameat2() as a raw syscall?

renameat() has no flags argument.

>
> We even have it in testcases/kernel/syscalls/renameat2/renameat2.h, this
> function should be moved to include/lapi/renameat2.h or include/lapi/stdio.h
> (header which includes it). If I have time on Monday, I can do the cleanup and
> fix it.
>

Sounds good. Please change the test to use the common header.

Thanks,
Amir.