Date:   Thu, 6 Jan 2022 00:06:19 +0800
From:   Zorro Lang <zlang@redhat.com>
To:     Theodore Ts'o <tytso@mit.edu>, guan@eryu.me,
        fstests@vger.kernel.org,
        Ext4 Developers List <linux-ext4@vger.kernel.org>,
        Eric Whitney <enwlinux@gmail.com>
Subject: Re: [PATCH] ext4/033: test EXT4_IOC_RESIZE_FS by calling the ioctl
 directly
Message-ID: <20220105160619.r66lacgq7b7ucyuk@zlang-mailbox>
Mail-Followup-To: Theodore Ts'o <tytso@mit.edu>, guan@eryu.me,
        fstests@vger.kernel.org,
        Ext4 Developers List <linux-ext4@vger.kernel.org>,
        Eric Whitney <enwlinux@gmail.com>
References: <Yb9M3aIb9cJGIJaB@desktop>
 <20211220204059.2248577-1-tytso@mit.edu>
 <20220105155743.6knpj4zsbmy62uwj@zlang-mailbox>
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In-Reply-To: <20220105155743.6knpj4zsbmy62uwj@zlang-mailbox>
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On Wed, Jan 05, 2022 at 11:57:43PM +0800, Zorro Lang wrote:
> On Mon, Dec 20, 2021 at 03:40:59PM -0500, Theodore Ts'o wrote:
> > E2fsprogs commits 4ea80d031c7e ("resize2fs: adjust new size of the
> > file system to allow a successful resize") and 50088b1996cc
> > ("resize2fs: attempt to keep the # of inodes valid by removing the
> > last bg") will automatically reduce the requested new size of the file
> > system by up to a single block group to avoid overflowing the 32-bit
> > inode count.   This interferes with ext4/033's test of kernel commit
> > 4f2f76f75143 ("ext4: Forbid overflowing inode count when # resizing".)
> > 
> > Address this by creating a new test program, ext4_resize which calls
> > the EXT4_IOC_RESIZE_FS ioctl directly so we can correctly test the
> > kernel's online resize code.
> > 
> > Reported-by: Eric Whitney <enwlinux@gmail.com>
> > Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> > ---
> >  .gitignore        |  1 +
> >  src/Makefile      |  2 +-
> >  src/ext4_resize.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/ext4/033    | 16 ++++++++++-----
> >  4 files changed, 63 insertions(+), 6 deletions(-)
> >  create mode 100644 src/ext4_resize.c
> > 
> > diff --git a/.gitignore b/.gitignore
> > index 9e6d2fd5..65b93307 100644
> > --- a/.gitignore
> > +++ b/.gitignore
> > @@ -77,6 +77,7 @@ tags
> >  /src/dirperf
> >  /src/dirstress
> >  /src/e4compact
> > +/src/ext4_resize
> >  /src/fault
> >  /src/feature
> >  /src/fiemap-tester
> > diff --git a/src/Makefile b/src/Makefile
> > index 25ab061d..1737ed0e 100644
> > --- a/src/Makefile
> > +++ b/src/Makefile
> > @@ -31,7 +31,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
> >  	dio-invalidate-cache stat_test t_encrypted_d_revalidate \
> >  	attr_replace_test swapon mkswap t_attr_corruption t_open_tmpfiles \
> >  	fscrypt-crypt-util bulkstat_null_ocount splice-test chprojid_fail \
> > -	detached_mounts_propagation
> > +	detached_mounts_propagation ext4_resize
> >  
> >  EXTRA_EXECS = dmerror fill2attr fill2fs fill2fs_check scaleread.sh \
> >  	      btrfs_crc32c_forged_name.py
> > diff --git a/src/ext4_resize.c b/src/ext4_resize.c
> > new file mode 100644
> > index 00000000..1ac51e6f
> > --- /dev/null
> > +++ b/src/ext4_resize.c
> > @@ -0,0 +1,50 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +/*
> > + * Test program which uses the raw ext4 resize_fs ioctl directly.
> > + */
> > +
> > +#include <stdio.h>
> > +#include <fcntl.h>
> > +#include <errno.h>
> > +#include <unistd.h>
> > +#include <stdint.h>
> > +#include <stdlib.h>
> > +#include <sys/ioctl.h>
> > +#include <sys/mount.h>
> > +
> > +typedef unsigned long long __u64;
> > +
> > +#ifndef EXT4_IOC_RESIZE_FS
> > +#define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
> > +#endif
> 
> This patch looks good to me, I just want to ask if we'd better to try to include
> ext2fs/ext2fs.h at here? And of course, check it in configure.ac.
> The EXT4_IOC_RESIZE_FS looks like defined in ext2fs/ext2_fs.h which comes from
> e2fsprogs-devel package. I can't find this definition from kernel-hearders package.
> As you're the expert of this part, please correct me if it's wrong :)

Oh, I just noticed that this patch has been merged. I have no idea why this email become
*unread* status in my mutt, cause I thought it's a new patch. Please ignore this review.

> 
> Thanks,
> Zorro
> 
> > +
> > +int main(int argc, char **argv)
> > +{
> > +	__u64	new_size;
> > +	int	error, fd;
> > +	char	*tmp = NULL;
> > +
> > +	if (argc != 3) {
> > +		fputs("insufficient arguments\n", stderr);
> > +		return 1;
> > +	}
> > +	fd = open(argv[1], O_RDONLY);
> > +	if (!fd) {
> > +		perror(argv[1]);
> > +		return 1;
> > +	}
> > +
> > +	new_size = strtoull(argv[2], &tmp, 10);
> > +	if ((errno) || (*tmp != '\0')) {
> > +		fprintf(stderr, "%s: invalid new size\n", argv[0]);
> > +		return 1;
> > +	}
> > +
> > +	error = ioctl(fd, EXT4_IOC_RESIZE_FS, &new_size);
> > +	if (error < 0) {
> > +		perror("EXT4_IOC_RESIZE_FS");
> > +		return 1;
> > +	}
> > +	return 0;
> > +}
> > diff --git a/tests/ext4/033 b/tests/ext4/033
> > index 1bc14c03..22041a17 100755
> > --- a/tests/ext4/033
> > +++ b/tests/ext4/033
> > @@ -5,7 +5,8 @@
> >  # FS QA Test 033
> >  #
> >  # Test s_inodes_count overflow for huge filesystems. This bug was fixed
> > -# by commit "ext4: Forbid overflowing inode count when resizing".
> > +# by commit 4f2f76f75143 ("ext4: Forbid overflowing inode count when
> > +# resizing".)
> >  #
> >  . ./common/preamble
> >  _begin_fstest auto ioctl resize
> > @@ -28,7 +29,9 @@ _supported_fs ext4
> >  _require_scratch_nocheck
> >  _require_dmhugedisk
> >  _require_dumpe2fs
> > -_require_command "$RESIZE2FS_PROG" resize2fs
> > +_require_test_program ext4_resize
> > +
> > +EXT4_RESIZE=$here/src/ext4_resize
> >  
> >  # Figure out whether device is large enough
> >  devsize=$(blockdev --getsize64 $SCRATCH_DEV)
> > @@ -68,7 +71,8 @@ $DUMPE2FS_PROG -h $DMHUGEDISK_DEV >> $seqres.full 2>&1
> >  
> >  # This should fail, s_inodes_count would just overflow!
> >  echo "Resizing to inode limit + 1..."
> > -$RESIZE2FS_PROG $DMHUGEDISK_DEV $((limit_groups*group_blocks)) >> $seqres.full 2>&1
> > +echo $EXT4_RESIZE $SCRATCH_MNT $((limit_groups*group_blocks)) >> $seqres.full 2>&1
> > +$EXT4_RESIZE $SCRATCH_MNT $((limit_groups*group_blocks)) >> $seqres.full 2>&1
> >  if [ $? -eq 0 ]; then
> >  	echo "Resizing succeeded but it should fail!"
> >  	exit
> > @@ -76,7 +80,8 @@ fi
> >  
> >  # This should succeed, we are maxing out inodes
> >  echo "Resizing to max group count..."
> > -$RESIZE2FS_PROG $DMHUGEDISK_DEV $(((limit_groups-1)*group_blocks)) >> $seqres.full 2>&1
> > +echo $EXT4_RESIZE $SCRATCH_MNT $(((limit_groups-1)*group_blocks)) >> $seqres.full 2>&1
> > +$EXT4_RESIZE $SCRATCH_MNT $(((limit_groups-1)*group_blocks)) >> $seqres.full 2>&1
> >  if [ $? -ne 0 ]; then
> >  	echo "Resizing failed!"
> >  	exit
> > @@ -87,7 +92,8 @@ $DUMPE2FS_PROG -h $DMHUGEDISK_DEV >> $seqres.full 2>&1
> >  
> >  # This should fail, s_inodes_count would overflow by quite a bit!
> >  echo "Resizing to device size..."
> > -$RESIZE2FS_PROG $DMHUGEDISK_DEV >> $seqres.full 2>&1
> > +echo $EXT4_RESIZE $SCRATCH_MNT $(((limit_groups + 16)*group_blocks)) >> $seqres.full 2>&1
> > +$EXT4_RESIZE $SCRATCH_MNT $(((limit_groups + 16)*group_blocks)) >> $seqres.full 2>&1
> >  if [ $? -eq 0 ]; then
> >  	echo "Resizing succeeded but it should fail!"
> >  	exit
> > -- 
> > 2.31.0
> >