Re: [LTP] [PATCH] unlink: Add error tests for EPERM and EROFS

[Avinesh Kumar <akumar@suse.de>]

Hi,

On Wednesday, April 10, 2024 11:03:19 AM CEST Yang Xu (Fujitsu) wrote:
> Hi Avinesh.
> 
> Thanks for your comments.
> 
> 
> > Hi Yang Xu,
> > some comments below
> > 
> > On Monday, April 1, 2024 4:49:48 AM CEST Yang Xu via ltp wrote:
> > 
> >> Add negative cases for unlink(), when errno is EPERM or EROFS.
> >>
> >>
> >>
> >> Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
> >> ---
> >> 
> >>   runtest/syscalls                            |  1 +
> >>   testcases/kernel/syscalls/unlink/.gitignore |  1 +
> >>   testcases/kernel/syscalls/unlink/unlink09.c | 86 +++++++++++++++++++++
> >>   3 files changed, 88 insertions(+)
> >>   create mode 100644 testcases/kernel/syscalls/unlink/unlink09.c
> >>
> >>
> >>
> >> diff --git a/runtest/syscalls b/runtest/syscalls
> >> index 4ed2b5602..b99ce7170 100644
> >> --- a/runtest/syscalls
> >> +++ b/runtest/syscalls
> >> @@ -1651,6 +1651,7 @@ unlink01 symlink01 -T unlink01
> >> 
> >>   unlink05 unlink05
> >>   unlink07 unlink07
> >>   unlink08 unlink08
> >> 
> >> +unlink09 unlink09
> >>
> >>
> >>
> >>   #unlinkat test cases
> >>   unlinkat01 unlinkat01
> >> 
> >> diff --git a/testcases/kernel/syscalls/unlink/.gitignore
> >> b/testcases/kernel/syscalls/unlink/.gitignore index 2e783580d..6038cc29d
> >> 100644
> >> --- a/testcases/kernel/syscalls/unlink/.gitignore
> >> +++ b/testcases/kernel/syscalls/unlink/.gitignore
> >> @@ -1,3 +1,4 @@
> >> 
> >>   /unlink05
> >>   /unlink07
> >>   /unlink08
> >> 
> >> +/unlink09
> >> diff --git a/testcases/kernel/syscalls/unlink/unlink09.c
> >> b/testcases/kernel/syscalls/unlink/unlink09.c new file mode 100644
> >> index 000000000..b7ff94ee6
> >> --- /dev/null
> >> +++ b/testcases/kernel/syscalls/unlink/unlink09.c
> >> @@ -0,0 +1,86 @@
> >> +// SPDX-License-Identifier: GPL-2.0-or-later
> >> +/*
> >> + * Copyright (c) 2024 FUJITSU LIMITED. All Rights Reserved.
> >> + * Author: Yang Xu <xuyang2018.jy@fujitsu.com>
> >> + */
> >> +
> >> +/*\
> >> + * [Description]
> >> + *
> >> + * Verify that unlink(2) fails with
> >> + *
> >> + * - EPERM when target file is marked as immutable or append-only
> >> + * - EROFS when target file is on a read-only filesystem.
> >> + */
> >> +
> >> +#include <errno.h>
> >> +#include <unistd.h>
> >> +#include <sys/ioctl.h>
> >> +#include "tst_test.h"
> >> +#include "tst_safe_macros.h"
> >> +#include "lapi/fs.h"
> > 
> > errno.h, unistd.h, ioctl.h and tst_safe_macros.h headers are already
> > included  via tst_test.h
> > 
> >   
> >> 
> >> +
> >> +#define TEST_EPERM_IMMUTABLE "test_eperm_immutable"
> >> +#define TEST_EPERM_APPEND_ONLY "test_eperm_append_only"
> >> +#define DIR_EROFS "erofs"
> >> +#define TEST_EROFS "erofs/test_erofs"
> >> +
> >> +static int fd_immutable;
> >> +static int fd_append_only;
> >> +
> >> +static struct test_case_t {
> >> +	char *filename;
> >> +	int expected_errno;
> >> +	char *desc;
> >> +} tcases[] = {
> >> +	{TEST_EPERM_IMMUTABLE, EPERM, "target file is immutable"},
> >> +	{TEST_EPERM_APPEND_ONLY, EPERM, "target file is append-only"},
> >> +	{TEST_EROFS, EROFS, "target file in read-only filesystem"},
> >> +};
> >> +
> >> +static void setup(void)
> >> +{
> >> +	int attr;
> >> +
> >> +	fd_immutable = SAFE_OPEN(TEST_EPERM_IMMUTABLE, O_CREAT, 0600);
> >> +	ioctl(fd_immutable, FS_IOC_GETFLAGS, &attr);
> >> +	attr |= FS_IMMUTABLE_FL;
> >> +	ioctl(fd_immutable, FS_IOC_SETFLAGS, &attr);
> >> +
> >> +	fd_append_only = SAFE_OPEN(TEST_EPERM_APPEND_ONLY, O_CREAT, 0600);
> >> +	ioctl(fd_append_only, FS_IOC_GETFLAGS, &attr);
> >> +	attr |= FS_APPEND_FL;
> >> +	ioctl(fd_append_only, FS_IOC_SETFLAGS, &attr);
> > 
> > We can use SAFE_IOCTL() in all places.
> > 
> >> +}
> >> +
> >> +static void cleanup(void)
> >> +{
> >> +	int attr;
> >> +
> >> +	ioctl(fd_immutable, FS_IOC_GETFLAGS, &attr);
> >> +	attr &= ~FS_IMMUTABLE_FL;
> >> +	ioctl(fd_immutable, FS_IOC_SETFLAGS, &attr);
> >> +	SAFE_CLOSE(fd_immutable);
> >> +
> >> +	ioctl(fd_append_only, FS_IOC_GETFLAGS, &attr);
> >> +	attr &= ~FS_APPEND_FL;
> >> +	ioctl(fd_append_only, FS_IOC_SETFLAGS, &attr);
> >> +	SAFE_CLOSE(fd_append_only);
> >> +}
> >> +
> >> +static void verify_unlink(unsigned int i)
> >> +{
> >> +	struct test_case_t *tc = &tcases[i];
> >> +
> >> +	TST_EXP_FAIL(unlink(tc->filename), tc->expected_errno, "%s",
> >> tc->desc);
> > 
> > If for whatever reason, unlink() call passes here, further test
> > iterations
> > will not work correctly as test file no longer exist. I guess we need to
> > handle  the restoring in this main test function. And cleanup() does not
> > need to reset any flags as it is called only once after all the
> > iterations.
> > 
> 
> In this case, every iteration uses a separate file. Even if unlink() 
> passes unexpectedly, other iteration will not be affected.
> So I think there is no need to restore the file.
> 
@@ -43,9 +44,9 @@ static void setup(void)
        int attr;
 
        fd_immutable = SAFE_OPEN(TEST_EPERM_IMMUTABLE, O_CREAT, 0600);
-       ioctl(fd_immutable, FS_IOC_GETFLAGS, &attr);
-       attr |= FS_IMMUTABLE_FL;
-       ioctl(fd_immutable, FS_IOC_SETFLAGS, &attr);
+       // ioctl(fd_immutable, FS_IOC_GETFLAGS, &attr);
+       // attr |= FS_IMMUTABLE_FL;
+       // ioctl(fd_immutable, FS_IOC_SETFLAGS, &attr);
 
        fd_append_only = SAFE_OPEN(TEST_EPERM_APPEND_ONLY, O_CREAT, 0600);
        ioctl(fd_append_only, FS_IOC_GETFLAGS, &attr);

just to cause the unlink() call pass and the file gets deleted.
If you run with this for i>=2, you will see the test failing with
ENOENT as the test file no longer available.

unlink09.c:82: TFAIL: target file is immutable succeeded
unlink09.c:82: TPASS: target file is append-only : EPERM (1)
unlink09.c:82: TPASS: target file in read-only filesystem : EROFS (30)
unlink09.c:82: TFAIL: target file is immutable expected EPERM: ENOENT (2)
unlink09.c:82: TPASS: target file is append-only : EPERM (1)
unlink09.c:82: TPASS: target file in read-only filesystem : EROFS (30)
unlink09.c:82: TFAIL: target file is immutable expected EPERM: ENOENT (2)
unlink09.c:82: TPASS: target file is append-only : EPERM (1)
unlink09.c:82: TPASS: target file in read-only filesystem : EROFS (30)


> The reset of flag is for the test file cleanup.
> 
> If flag is not reset, the test framework will throw a warning as following:
> tst_tmpdir.c:343: TWARN: tst_rmdir: rmobj(/tmp/LTP_unlYn0Rtu) failed:
> unlink(/tmp/LTP_unlYn0Rtu/test_eperm_append_only) failed; errno=1: EPERM 
> In tst_tmpdir.c, unlink is called to remove the temp file and dir. So if 
> flag is not reset, the temp file and dir will not be removed.
> 
okay, I agree, flag resetting is needed for deletion in the cleanup().

> Soon I will send out V2 patch.
> 
> Best regards
> Yang Xu
> 
> 
> >> +}
> >> +
> >> +static struct tst_test test = {
> >> +	.setup = setup,
> >> +	.tcnt = ARRAY_SIZE(tcases),
> >> +	.cleanup = cleanup,
> >> +	.test = verify_unlink,
> >> +	.needs_rofs = 1,
> >> +	.mntpoint = DIR_EROFS,
> >> +	.needs_root = 1,
> >> +};
> > 
> > 
> > 
> > Regards,
> > Avinesh
> > 
> > 

Regards,
Avinesh




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