On Mon, Oct 23, 2023 at 5:03 PM Zorro Lang <zlang@xxxxxxxxxx> wrote:
>
> On Mon, Oct 23, 2023 at 01:49:16PM +0300, Amir Goldstein wrote:
> > Check parsing and display of spaces and escaped colons and commans in
> > lowerdir mount option.
> >
> > This is a regression test for two bugs introduced in v6.5 with the
> > conversion to new mount api.
> >
> > There is another regression of new mount api related to libmount parsing
> > of escaped commas, but this needs a fix in libmount - this test only
> > verifies the fixes in the kernel, so it uses LIBMOUNT_FORCE_MOUNT2=always
> > to force mount(2) and kernel pasring of the comma separated options list.
> >
> > Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
> > ---
> >
> > Zorro,
> >
> > I've fixed the libmount issue by splitting the combined test cases
> > to two test cases that corresspond to the two kernel fix commits.
> >
> > The first test case (lowerdir_spaces) is agnostic to libmount version.
> >
> > The second test case (lowerdir_commas) explicitly opts-in to mount(2)
> > syscall.
> >
> > ATM, using LIBMOUNT_FORCE_MOUNT2=always, as the second test cases does,
> > would be our recommended workaround for the escaped commas regression
> > in v6.5, until libmount gets a fix to detect overlayfs escaped commas.
> >
> > Thanks,
> > Amir.
> >
> > tests/overlay/083 | 71 +++++++++++++++++++++++++++++++++++++++++++
> > tests/overlay/083.out | 2 ++
> > 2 files changed, 73 insertions(+)
> > create mode 100755 tests/overlay/083
> > create mode 100644 tests/overlay/083.out
> >
> > diff --git a/tests/overlay/083 b/tests/overlay/083
> > new file mode 100755
> > index 00000000..0f434951
> > --- /dev/null
> > +++ b/tests/overlay/083
> > @@ -0,0 +1,71 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (C) 2023 CTERA Networks. All Rights Reserved.
> > +#
> > +# FS QA Test 083
> > +#
> > +# Test regressions in parsing and display of special chars in mount options.
> > +#
> > +# The following kernel commits from v6.5 introduced regressions:
> > +# b36a5780cb44 ("ovl: modify layer parameter parsing")
> > +# 1784fbc2ed9c ("ovl: port to new mount api")
> > +#
> > +
> > +. ./common/preamble
> > +_begin_fstest auto quick mount
> > +
> > +# Import common functions.
> > +. ./common/filter
> > +
> > +# real QA test starts here
> > +_supported_fs overlay
> > +_fixed_by_kernel_commit 32db51070850 \
> > + "ovl: fix regression in showing lowerdir mount option"
> > +_fixed_by_kernel_commit c34706acf40b \
> > + "ovl: fix regression in parsing of mount options with escaped comma"
> > +
> > +# _overlay_check_* helpers do not handle special chars well
> > +_require_scratch_nocheck
> > +
> > +# Remove all files from previous tests
> > +_scratch_mkfs
> > +
> > +# Create lowerdirs with special characters
> > +lowerdir_spaces="$OVL_BASE_SCRATCH_MNT/lower1 with spaces"
> > +lowerdir_colons="$OVL_BASE_SCRATCH_MNT/lower2:with::colons"
> > +lowerdir_commas="$OVL_BASE_SCRATCH_MNT/lower3,with,,commas"
> > +lowerdir_colons_esc="$OVL_BASE_SCRATCH_MNT/lower2\:with\:\:colons"
> > +lowerdir_commas_esc="$OVL_BASE_SCRATCH_MNT/lower3\,with\,\,commas"
> > +upperdir=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER
> > +workdir=$OVL_BASE_SCRATCH_MNT/$OVL_WORK
> > +mkdir -p "$lowerdir_spaces" "$lowerdir_colons" "$lowerdir_commas"
> > +
> > +# _overlay_mount_* helpers do not handle special chars well, so execute mount directly.
> > +# if escaped colons are not parsed correctly, mount will fail.
> > +$MOUNT_PROG -t overlay ovl_esc_test $SCRATCH_MNT \
> > + -o"upperdir=$upperdir,workdir=$workdir" \
> > + -o"lowerdir=$lowerdir_colons_esc:$lowerdir_spaces" \
> > + 2>&1 | tee -a $seqres.full
> > +
> > +# if spaces are not escaped when showing mount options,
> > +# mount command will not show the word 'spaces' after the spaces
> > +$MOUNT_PROG -t overlay | grep ovl_esc_test | tee -a $seqres.full | grep -v spaces && \
> > + echo "ERROR: escaped spaces truncated from lowerdir mount option"
> > +$UMOUNT_PROG $SCRATCH_MNT
> > +
> > +# Kernel commit c34706acf40b fixes parsing of mount options with escaped comma
> > +# when the mount options string is provided via data argument to mount(2) syscall.
> > +# With libmount >= 2.39, libmount itself will try to split the comma separated
> > +# options list provided to mount(8) commnad line and call fsconfig(2) for each
> > +# mount option seperately. Since libmount does not obay to overlayfs escaped
> > +# commas format, it will call fsconfig(2) with the wrong path (i.e. ".../lower3")
> > +# and this test will fail, but the failure would indicate a libmount issue, not
> > +# a kernel issue. Therefore, force libmount to use mount(2) syscall, so we only
> > +# test the kernel fix.
> > +LIBMOUNT_FORCE_MOUNT2=always $MOUNT_PROG -t overlay $OVL_BASE_SCRATCH_DEV $SCRATCH_MNT \
> > + -o"upperdir=$upperdir,workdir=$workdir,lowerdir=$lowerdir_commas_esc" 2>> $seqres.full || \
> > + echo "ERROR: incorrect parsing of escaped comma in lowerdir mount option"
>
> Hi Amir, Please check, this part still fails as:
>
> # ./check -overlay overlay/083
> FSTYP -- overlay
> PLATFORM -- Linux/x86_64 hp-dl380pg8-01 6.6.0-rc6-mainline+ #7 SMP PREEMPT_DYNAMIC Thu Oct 19 22:34:28 CST 2023
> MKFS_OPTIONS -- /mnt/scratch
> MOUNT_OPTIONS -- -o context=system_u:object_r:root_t:s0 /mnt/scratch /mnt/scratch/ovl-mnt
>
> overlay/083 0s ... - output mismatch (see /root/git/xfstests/results//overlay/083.out.bad)
> --- tests/overlay/083.out 2023-10-23 21:18:46.765059777 +0800
> +++ /root/git/xfstests/results//overlay/083.out.bad 2023-10-23 21:51:39.030561512 +0800
> @@ -1,2 +1,3 @@
> QA output created by 083
> +ERROR: incorrect parsing of escaped comma in lowerdir mount option
> Silence is golden
> ...
> (Run 'diff -u /root/git/xfstests/tests/overlay/083.out /root/git/xfstests/results//overlay/083.out.bad' to see the entire diff)
>
> HINT: You _MAY_ be missing kernel fix:
> 32db51070850 ovl: fix regression in showing lowerdir mount option
>
> HINT: You _MAY_ be missing kernel fix:
> c34706acf40b ovl: fix regression in parsing of mount options with escaped comma
>
> Ran: overlay/083
> Failures: overlay/083
> Failed 1 of 1 tests
>
> # cat results/overlay/083.full
> ovl_esc_test on /mnt/scratch/ovl-mnt type overlay (rw,relatime,seclabel,lowerdir=/mnt/scratch/lower2\:with\:\:colons:/mnt/scratch/lower1 with spaces,upperdir=/mnt/scratch/ovl-upper,workdir=/mnt/scratch/ovl-work,uuid=on)
> mount: /mnt/scratch/ovl-mnt: mount(2) system call failed: Stale file handle.
> dmesg(1) may have more information after failed mount system call.
>
> # dmesg
> [341033.046302] run fstests overlay/083 at 2023-10-23 22:00:11
> [341033.458188] XFS (loop0): Mounting V5 Filesystem 23e1781e-f5ce-4c2b-8801-3b586f459ee8
> [341033.464410] XFS (loop0): Ending clean mount
> [341033.506666] overlayfs: failed to verify origin (/lower3,with,,commas, ino=16908385, err=-116)
> [341033.507626] overlayfs: failed to verify upper root origin
> [341033.540865] XFS (loop1): Unmounting Filesystem 58e81b68-81dd-48cd-ab23-ce30ec77e689
> [341033.554488] XFS (loop0): Unmounting Filesystem 23e1781e-f5ce-4c2b-8801-3b586f459ee8
>
Oh, you must have CONFIG_OVERLAY_FS_INDEX=y.
I did not check this config.
I will send a fix soon.
Thanks,
Amir.
