Re: [PATCH fstests] generic/755: test that inode's ctime is updated on unlink

[Jeff Layton <jlayton@kernel.org>]

On Fri, 2024-08-16 at 20:55 +0800, Zorro Lang wrote:
> On Tue, Aug 13, 2024 at 02:21:08PM -0400, Jeff Layton wrote:
> 
> Hi Jeff :)
> 
> Any description about this case test for?
> 

Yes. I should have put that info in the commit. Can you add it if the
patch otherwise looks OK?

    https://lore.kernel.org/linux-btrfs/20240812-btrfs-unlink-v1-1-ee5c2ef538eb@kernel.org/

Thanks,

> > Signed-off-by: Jeff Layton <jlayton@kernel.org>
> > ---
> > HCH suggested I roll a fstest for this problem that I found in btrfs the
> > other day. In principle, we probably could expand this to other dir
> > operations and to check the parent timestamps, but having to do all that
> > in C is a pain.  I didn't see a good way to use xfs_io for this,
> > however.
> 
> Is there a kernel commit or patch link about the bug which you found?
> 
> > ---
> >  src/Makefile          |  2 +-
> >  src/unlink-ctime.c    | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/755     | 26 ++++++++++++++++++++++++++
> >  tests/generic/755.out |  2 ++
> >  4 files changed, 79 insertions(+), 1 deletion(-)
> > 
> > diff --git a/src/Makefile b/src/Makefile
> > index 9979613711c9..c71fa41e4668 100644
> > --- a/src/Makefile
> > +++ b/src/Makefile
> > @@ -34,7 +34,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
> >  	attr_replace_test swapon mkswap t_attr_corruption t_open_tmpfiles \
> >  	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
> > +	uuid_ioctl t_snapshot_deleted_subvolume fiemap-fault unlink-ctime
> 
> The .gitignore need updating too.
> 
> >  
> >  EXTRA_EXECS = dmerror fill2attr fill2fs fill2fs_check scaleread.sh \
> >  	      btrfs_crc32c_forged_name.py popdir.pl popattr.py \
> > diff --git a/src/unlink-ctime.c b/src/unlink-ctime.c
> > new file mode 100644
> > index 000000000000..7661e340eaba
> > --- /dev/null
> > +++ b/src/unlink-ctime.c
> > @@ -0,0 +1,50 @@
> > +#define _GNU_SOURCE 1
> > +#include <stdio.h>
> > +#include <fcntl.h>
> > +#include <unistd.h>
> > +#include <errno.h>
> > +#include <sys/stat.h>
> > +
> > +int main(int argc, char **argv)
> > +{
> > +	int fd, ret;
> > +	struct statx before, after;
> > +
> > +	if (argc < 2) {
> > +		fprintf(stderr, "Must specify filename!\n");
> > +		return 1;
> > +	}
> > +
> > +	fd = open(argv[1], O_RDWR|O_CREAT, 0600);
> > +	if (fd < 0) {
> > +		perror("open");
> > +		return 1;
> > +	}
> > +
> > +	ret = statx(fd, "", AT_EMPTY_PATH, STATX_CTIME, &before);
> > +	if (ret) {
> > +		perror("statx");
> > +		return 1;
> > +	}
> > +
> > +	sleep(1);
> > +
> > +	ret = unlink(argv[1]);
> > +	if (ret) {
> > +		perror("unlink");
> > +		return 1;
> > +	}
> > +
> > +	ret = statx(fd, "", AT_EMPTY_PATH, STATX_CTIME, &after);
> 
> So you need to keep the "fd" after unlink. If so, there might not be a
> way through xfs_io to do that.
> 
> > +	if (ret) {
> > +		perror("statx");
> > +		return 1;
> > +	}
> > +
> > +	if (before.stx_ctime.tv_nsec == after.stx_ctime.tv_nsec &&
> > +	    before.stx_ctime.tv_sec == after.stx_ctime.tv_sec) {
> > +		printf("No change to ctime after unlink!\n");
> > +		return 1;
> > +	}
> > +	return 0;
> > +}
> > diff --git a/tests/generic/755 b/tests/generic/755
> > new file mode 100755
> > index 000000000000..500c51f99630
> > --- /dev/null
> > +++ b/tests/generic/755
> > @@ -0,0 +1,26 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (c) 2024, Jeff Layton <jlayton@kernel.org>
> > +#
> > +# FS QA Test No. 755
> > +#
> > +# Create a file, stat it and then unlink it. Does the ctime of the
> > +# target inode change?
> > +#
> > +. ./common/preamble
> > +_begin_fstest auto quick
>                              ^^^^^^
>                              unlink
> 
> > +
> > +# Import common functions.
> > +. ./common/filter
> > +. ./common/dmerror
> 
> Why dmerror and filter are needed? If not necessary, remove these
> 3 lines.
> 
> Others looks good to me.
> 
> Thanks,
> Zorro
> 
> > +
> > +_require_test
> > +_require_test_program unlink-ctime
> > +
> > +testfile="$TEST_DIR/unlink-ctime.$$"
> > +
> > +$here/src/unlink-ctime $testfile
> > +
> > +echo Silence is golden
> > +status=0
> > +exit
> > diff --git a/tests/generic/755.out b/tests/generic/755.out
> > new file mode 100644
> > index 000000000000..7c9ea51cd298
> > --- /dev/null
> > +++ b/tests/generic/755.out
> > @@ -0,0 +1,2 @@
> > +QA output created by 755
> > +Silence is golden
> > 
> > ---
> > base-commit: f5ada754d5838d29fd270257003d0d123a9d1cd2
> > change-id: 20240813-master-e3b46de630bd
> > 
> > Best regards,
> > -- 
> > Jeff Layton <jlayton@kernel.org>
> > 
> > 
> 

-- 
Jeff Layton <jlayton@kernel.org>