[PATCH] fstests Fix build errors on kernels before v5.1

The FAN_REPORT_FID and fanotify_event_info_fid were introduced
in v5.1. Currently there is no check if the kernel supports it
making xfstests build to fail on older kernels.

Fixes: 29d120e41c3d ("generic: test fsnotify filesystem error reporting")

Signed-off-by: Lukas Herbolt <[email protected]>
---
 configure.ac          |  1 +
 include/builddefs.in  |  1 +
 m4/package_libcdev.m4 | 14 ++++++++++++++
 src/Makefile          |  6 +++++-
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 441f543c6089..feb24ddd8854 100644
--- a/configure.ac
+++ b/configure.ac
@@ -74,6 +74,7 @@ AC_NEED_INTERNAL_XFS_IOC_EXCHANGE_RANGE
 AC_HAVE_FICLONE
 AC_HAVE_TRIVIAL_AUTO_VAR_INIT
 AC_HAVE_FILE_GETATTR
+AC_HAVE_FANOTIFY_FID
 
 AC_CHECK_FUNCS([renameat2])
 AC_CHECK_FUNCS([reallocarray])
diff --git a/include/builddefs.in b/include/builddefs.in
index 708d75b24d76..8e9e2e3b4113 100644
--- a/include/builddefs.in
+++ b/include/builddefs.in
@@ -75,6 +75,7 @@ HAVE_RLIMIT_NOFILE = @have_rlimit_nofile@
 NEED_INTERNAL_XFS_IOC_EXCHANGE_RANGE = @need_internal_xfs_ioc_exchange_range@
 HAVE_FICLONE = @have_ficlone@
 HAVE_FILE_GETATTR = @have_file_getattr@
+HAVE_FANOTIFY_FID = @have_fanotify_fid@
 
 GCCFLAGS = -std=gnu11 -funsigned-char -fno-strict-aliasing -Wall
 SANITIZER_CFLAGS += @autovar_init_cflags@
diff --git a/m4/package_libcdev.m4 b/m4/package_libcdev.m4
index 17f57f427410..340cdad3faf9 100644
--- a/m4/package_libcdev.m4
+++ b/m4/package_libcdev.m4
@@ -102,3 +102,17 @@ AC_DEFUN([AC_HAVE_FILE_GETATTR],
        AC_MSG_RESULT(yes)],[AC_MSG_RESULT(no)])
     AC_SUBST(have_file_getattr)
   ])
+
+# Check if we have fanotify FID support (Linux 5.1+)
+AC_DEFUN([AC_HAVE_FANOTIFY_FID],
+  [ AC_MSG_CHECKING([for fanotify FID support])
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/fanotify.h>
+    ]], [[
+       int x = FAN_REPORT_FID;
+       struct fanotify_event_info_fid fid;
+       (void)x; (void)fid;
+    ]])],[have_fanotify_fid=yes
+       AC_MSG_RESULT(yes)],[AC_MSG_RESULT(no)])
+    AC_SUBST(have_fanotify_fid)
+  ])
diff --git a/src/Makefile b/src/Makefile
index 31ac43b215e9..847fb168181e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -36,7 +36,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
 	fscrypt-crypt-util bulkstat_null_ocount splice-test chprojid_fail \
 	detached_mounts_propagation ext4_resize t_readdir_3 splice2pipe \
 	uuid_ioctl t_snapshot_deleted_subvolume fiemap-fault min_dio_alignment \
-	rw_hint fs-monitor
+	rw_hint
 
 EXTRA_EXECS = dmerror fill2attr fill2fs fill2fs_check scaleread.sh \
 	      btrfs_crc32c_forged_name.py popdir.pl popattr.py \
@@ -107,6 +107,10 @@ ifeq ($(HAVE_FICLONE),yes)
      TARGETS += t_reflink_read_race
 endif
 
+ifeq ($(HAVE_FANOTIFY_FID),yes)
+     TARGETS += fs-monitor
+endif
+
 ifeq ($(HAVE_LIBBTRFSUTIL), true)
      LINUX_TARGETS += t_btrfs_received_uuid_ioctl
 endif

base-commit: acb6d4cb84205a8e3f19ca470cfcf7bf6d93a509
-- 
2.55.0