Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: a3c751a50fe6bbe50eb7622a14b18b361804ee0c ("vfs: allow unprivileged whiteout creation")
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master

in testcase: ltp
with following parameters:

	disk: 1HDD
	fs: xfs
	test: syscalls_part3

test-description: The LTP testsuite contains a collection of tools for testing the Linux kernel and related features.
test-url: http://linux-test-project.github.io/


on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):




If you fix the issue, kindly add following tag
Reported-by: kernel test robot <rong.a.chen@intel.com>


<<<test_start>>>
tag=mknod07 stime=1591434172
cmdline="mknod07"
contacts=""
analysis=exit
<<<test_output>>>
mke2fs 1.43.4 (31-Jan-2017)
mknod07     0  TINFO  :  Using test device LTP_DEV='/dev/loop0'
mknod07     0  TINFO  :  Formatting /dev/loop0 with ext2 opts='' extra opts=''
mknod07     1  TPASS  :  mknod failed as expected: TEST_ERRNO=EACCES(13): Permission denied
mknod07     2  TPASS  :  mknod failed as expected: TEST_ERRNO=EACCES(13): Permission denied
mknod07     3  TFAIL  :  mknod07.c:155: mknod succeeded unexpectedly
mknod07     4  TPASS  :  mknod failed as expected: TEST_ERRNO=EPERM(1): Operation not permitted
mknod07     5  TPASS  :  mknod failed as expected: TEST_ERRNO=EROFS(30): Read-only file system
mknod07     6  TPASS  :  mknod failed as expected: TEST_ERRNO=ELOOP(40): Too many levels of symbolic links
<<<execution_status>>>
initiation_status="ok"
duration=0 termination_type=exited termination_id=1 corefile=no
cutime=0 cstime=2
<<<test_end>>>




To reproduce:

        # build kernel
	cd linux
	cp config-5.7.0-rc4-00001-ga3c751a50fe6b .config
	make HOSTCC=gcc-9 CC=gcc-9 ARCH=x86_64 olddefconfig prepare modules_prepare bzImage modules
	make HOSTCC=gcc-9 CC=gcc-9 ARCH=x86_64 INSTALL_MOD_PATH=<mod-install-dir> modules_install
	cd <mod-install-dir>
	find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz


        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> -m modules.cgz job-script # job-script is attached in this email



Thanks,
Rong Chen