[PATCH v2 1/2] common/casefold: Add infrastructure to test filename casefold feature

[PATCH v2 1/2] common/casefold: Add infrastructure to test filename casefold feature

[Gabriel Krisman Bertazi]

Add a set of basic helper functions to simplify the testing of
casefolding capable filesystems.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
---
 common/casefold | 108 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 common/casefold

diff --git a/common/casefold b/common/casefold
new file mode 100644
index 000000000000..34c1d4ae1af1
--- /dev/null
+++ b/common/casefold
@@ -0,0 +1,108 @@
+#-----------------------------------------------------------------------
+#
+# Common functions for testing filename casefold feature
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2018 Collabora, Ltd.  All Rights Reserved.
+#
+# Author: Gabriel Krisman Bertazi <krisman@collabora.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#-----------------------------------------------------------------------
+
+_has_casefold_feature_kernel_support() {
+    case $FSTYP in
+	ext4)
+	    test -f '/sys/fs/ext4/features/casefold'
+	    ;;
+	*)
+	    # defaults to unsupported
+	    false
+	    ;;
+    esac
+}
+
+_require_casefold_support() {
+    if ! _has_casefold_feature_kernel_support ; then
+	_notrun "$FSTYP does not support casefold feature"
+    fi
+
+    if ! _scratch_mkfs_casefold &>>seqres.full; then
+	_notrun "$FSTYP userspace tools do not support casefold"
+    fi
+
+    # Make sure the kernel can mount a filesystem with the encoding
+    # defined by the userspace tools.  This will fail if
+    # the userspace tool used a more recent encoding than the one
+    # supported in kernel space.
+    if ! _try_scratch_mount &>>seqres.full; then
+	_notrun \
+	    "kernel can't mount filesystem using the encoding set by userspace"
+    fi
+    _scratch_unmount
+}
+
+_scratch_mkfs_casefold () {
+    case $FSTYP in
+	ext4)
+	    _scratch_mkfs -O casefold $*
+	    ;;
+	*)
+	    _notrun "Don't know how to mkfs with casefold support on $FSTYP"
+	    ;;
+	esac
+}
+
+_scratch_mkfs_casefold_strict () {
+    case $FSTYP in
+	ext4)
+	    _scratch_mkfs -O casefold -E encoding_flags=strict
+	    ;;
+	*)
+	    _notrun \
+		"Don't know how to mkfs with casefold-strict support on $FSTYP"
+	    ;;
+	esac
+}
+
+_casefold_check_exact_name () {
+    # To get the exact disk name, we need some method that does a
+    # getdents() on the parent directory, such that we don't get
+    # normalized/casefolded results.  'Find' works ok.
+    basedir=$1
+    exact_name=$2
+    find ${basedir} | grep -q ${exact_name}
+}
+
+_try_set_casefold_attr () {
+    chattr +F "${1}" &>/dev/null
+}
+
+_try_unset_casefold_attr () {
+    chattr -F "${1}" &>/dev/null
+}
+
+_set_casefold_attr () {
+    _try_set_casefold_attr "${1}" || \
+	_fail "Unable to set casefold attribute on ${1}"
+}
+
+_unset_casefold_attr () {
+    _try_unset_casefold_attr "${1}" || \
+	_fail "Unable to unset casefold attribute on ${1}"
+}
+
+_is_casefolded_dir () {
+    lsattr -ld "${1}" | grep -q "Casefold"
+}
-- 
2.20.1

[PATCH v2 2/2] ext4/036: Add tests for filename casefolding feature

[Gabriel Krisman Bertazi]

From: "Lakshmipathi.G" <lakshmipathi.ganapathi@collabora.co.uk>

This new test implements verification for the per-directory
case-insensitive feature, as supported in the reference implementation
in Ext4.  Currently, this test only supports Ext4, but the plan is to
run it in other filesystems, once they support the feature.

For now, let it live in ext4 and we move to shared/ or generic/ when
other filesystems supporting this feature start to pop up.

Signed-off-by: Lakshmipathi.G <lakshmipathi.ganapathi@collabora.co.uk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
  [Rewrite to support feature design]
  [Refactor to simplify implementation]
---
 tests/ext4/036     | 469 +++++++++++++++++++++++++++++++++++++++++++++
 tests/ext4/036.out |   2 +
 tests/ext4/group   |   1 +
 3 files changed, 472 insertions(+)
 create mode 100755 tests/ext4/036
 create mode 100644 tests/ext4/036.out

diff --git a/tests/ext4/036 b/tests/ext4/036
new file mode 100755
index 000000000000..3dae4212853b
--- /dev/null
+++ b/tests/ext4/036
@@ -0,0 +1,469 @@
+#! /bin/bash
+# FSQA Test No. 036
+#
+# Test the creation, mounting and basic functionality of file name
+# casefolding on Ext4
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2018 Collabora Ltd.  All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+#-----------------------------------------------------------------------
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+status=1 # failure is thea default
+
+. ./common/rc
+. ./common/casefold
+
+_supported_os Linux
+_require_scratch
+_require_casefold_support
+_require_check_dmesg
+
+sdev=$(_short_dev ${SCRATCH_DEV})
+test_casefold=${SCRATCH_MNT}
+
+filename1="file.txt"
+filename2="FILE.TXT"
+
+pt_file1=$(echo -e "coração")
+pt_file2=$(echo -e "corac\xcc\xa7\xc3\xa3o" | tr a-z A-Z)
+
+fr_file2=$(echo -e "french_caf\xc3\xa9.txt")
+fr_file1=$(echo -e "french_cafe\xcc\x81.txt")
+
+ar_file1=$(echo -e "arabic_\xdb\x92\xd9\x94.txt")
+ar_file2=$(echo -e "arabic_\xdb\x93.txt" | tr a-z A-Z)
+
+jp_file1=$(echo -e "japanese_\xe3\x82\xb2.txt")
+jp_file2=$(echo -e "japanese_\xe3\x82\xb1\xe3\x82\x99.txt")
+
+# '\xc3\x00' is an invalid sequence. Despite that, the sequences below
+# could match, if we ignored the error.  But we don't want to be greedy
+# at normalization, so at the first error we treat the entire sequence
+# as an opaque blob.  Therefore, these two must NOT match.
+blob_file1=$(echo -e "corac\xcc\xa7\xc3")
+blob_file2=$(echo -e "coraç\xc3")
+
+# Test helpers
+basic_create_lookup() {
+    touch "${basedir}/${1}"
+    stat  "${basedir}/${2}" &> /dev/null || \
+	_fail "Casefolded lookup of ${1} ${2} failed"
+    _casefold_check_exact_name "${basedir}" "${1}" || \
+	_fail "Created file with wrong name."
+
+}
+
+# CI search should fail.
+bad_basic_create_lookup() {
+    touch "${basedir}/${1}"
+    stat  "${basedir}/${2}" &> /dev/null && \
+	_fail "Lookup of ${1} using ${2} should have failed"
+}
+
+# Testcases
+test_casefold_lookup () {
+    basedir=${test_casefold}/casefold_lookup
+    mkdir -p ${basedir}
+
+    _set_casefold_attr ${basedir}
+
+    basic_create_lookup "${filename1}" "${filename2}"
+    basic_create_lookup "${pt_file1}" "${pt_file2}"
+    basic_create_lookup "${fr_file1}" "${fr_file2}"
+    basic_create_lookup "${ar_file1}" "${ar_file2}"
+    basic_create_lookup "${jp_file1}" "${jp_file2}"
+}
+
+test_bad_casefold_lookup () {
+    bad_basic_create_lookup ${blob_file1} ${blob_file2}
+}
+
+# remove and recreate
+test_create_and_remove() {
+    __create_and_remove() {
+	basic_create_lookup ${1}
+	rm -f  ${basedir}/"${1}"
+	stat   ${basedir}/"${1}" &> /dev/null && \
+	    _fail "File ${1} was not removed using exact name"
+
+	basic_create_lookup ${1}
+	rm -f  ${basedir}/"${2}"
+	stat   ${basedir}/"${1}" &> /dev/null && \
+	    _fail "File ${1} was not removed using inexact name"
+    }
+
+    basedir=${test_casefold}/create_and_remove
+    mkdir -p ${basedir}
+
+    _set_casefold_attr ${basedir}
+
+    __create_and_remove "${pt_file1}" "${pt_file2}"
+    __create_and_remove "${jp_file1}" "${jp_file2}"
+    __create_and_remove "${ar_file1}" "${ar_file2}"
+    __create_and_remove "${fr_file1}" "${fr_file2}"
+
+}
+
+test_casefold_flag_basic () {
+    basedir=${test_casefold}/basic
+    mkdir -p ${basedir}
+
+    _set_casefold_attr ${basedir}
+    _is_casefolded_dir ${basedir} || _fail "Casefold attribute wasn't set"
+
+    _unset_casefold_attr ${basedir}
+    _is_casefolded_dir ${basedir} && _fail "Casefold attribute is still set"
+}
+
+test_casefold_flag_removal () {
+    basedir=${test_casefold}/casefold_flag_removal
+    mkdir -p ${basedir}
+
+    _set_casefold_attr ${basedir}
+    touch ${basedir}/${filename1}
+
+    # Try to remove +F attribute on non empty directory
+    _try_unset_casefold_attr ${basedir} && \
+	_fail "Shouldn't be able to remove casefold attribute of non-empty directory"
+}
+
+# Test Inheritance of casefold flag
+test_casefold_flag_inheritance () {
+    dirpath1="d1/d2/d3"
+    dirpath2="D1/D2/D3"
+
+    basedir=${test_casefold}/flag_inheritance
+
+    mkdir -p ${basedir}
+    _set_casefold_attr ${basedir}
+
+    mkdir -p ${basedir}/${dirpath1}
+
+    _is_casefolded_dir ${basedir}/${dirpath1} || \
+	_fail "Casefold attribute should be inherited"
+    ls  ${basedir}/${dirpath2} &>/dev/null || \
+	_fail "Dir Lookup failed."
+    _casefold_check_exact_name "${basedir}" "${dirpath1}" || \
+	_fail "Created directories wrong name."
+
+    touch ${basedir}/${dirpath2}/${filename1}
+    ls  ${basedir}/${dirpath1}/${filename2} &>/dev/null || \
+	_fail "Couldn't create file on casefolded parent."
+}
+
+# Test nesting of sensitive directory inside insensitive directory.
+test_nesting_sensitive_insensitive_tree_simple() {
+    basedir=${test_casefold}/sd1
+    mkdir -p ${basedir}
+    _set_casefold_attr ${basedir}
+
+    mkdir -p ${basedir}/sd1
+    _set_casefold_attr ${basedir}/sd1
+
+    mkdir ${basedir}/sd1/sd2
+    _unset_casefold_attr ${basedir}/sd1/sd2
+
+    touch ${basedir}/sd1/sd2/${filename1}
+    ls ${basedir}/sd1/sd2/${filename1} &>/dev/null || \
+	_fail "Exact nested file lookup failed."
+    ls ${basedir}/sd1/SD2/${filename1} &>/dev/null || \
+	_fail "Nested file lookup failed."
+    ls ${basedir}/sd1/SD2/${filename2} &>/dev/null && \
+	_fail "Wrong file lookup passed, should have fail."
+}
+
+test_nesting_sensitive_insensitive_tree_complex() {
+    # Test nested-directories
+    basedir=${test_casefold}/nesting
+    mkdir -p ${basedir}
+
+    _set_casefold_attr ${basedir}
+
+    mkdir ${basedir}/nd1
+    _set_casefold_attr ${basedir}/nd1
+    mkdir ${basedir}/nd1/nd2
+    _unset_casefold_attr ${basedir}/nd1/nd2
+    mkdir ${basedir}/nd1/nd2/nd3
+    _set_casefold_attr ${basedir}/nd1/nd2/nd3
+    mkdir ${basedir}/nd1/nd2/nd3/nd4
+    _unset_casefold_attr ${basedir}/nd1/nd2/nd3/nd4
+    mkdir ${basedir}/nd1/nd2/nd3/nd4/nd5
+    _set_casefold_attr ${basedir}/nd1/nd2/nd3/nd4/nd5
+
+    ls ${basedir}/ND1/ND2/nd3/ND4/nd5 &>/dev/null || \
+	_fail "Nest-dir Lookup failed."
+    ls ${basedir}/nd1/nd2/nd3/nd4/ND5 &>/dev/null && \
+	_fail "ND5: Nest-dir Lookup passed, it should fail."
+    ls ${basedir}/nd1/nd2/nd3/ND4/nd5 &>/dev/null || \
+	_fail "Nest-dir Lookup failed."
+    ls ${basedir}/nd1/nd2/ND3/nd4/ND5 &>/dev/null && \
+	_fail "ND3: Nest-dir Lookup passed, it should fail."
+}
+
+test_symlink_with_inexact_name () {
+    basedir=${test_casefold}/symlink
+    mkdir -p ${basedir}
+
+    _set_casefold_attr ${basedir}
+
+    mkdir ${basedir}/ind1
+    mkdir ${basedir}/ind2
+    _set_casefold_attr ${basedir}/ind1
+    touch ${basedir}/ind1/target
+    ln -s ${basedir}/ind1/TARGET ${basedir}/ind2/link
+    [ -L ${basedir}/ind2/link ] || _fail "Not a symlink."
+    readlink -e ${basedir}/ind2/link &>/dev/null || _fail "Symlink failed"
+}
+
+
+# Name-preserving tests
+# We create a file with a name, delete it and create again with an
+# equivalent name.  If the negative dentry wasn't invalidated, the
+# file might be created using $1 instead of $2.
+test_name_preserve () {
+    __test_name_preserve () {
+	touch ${basedir}/${1}
+	rm ${basedir}/${1}
+
+	touch ${basedir}/${2}
+	_casefold_check_exact_name ${basedir} ${2} ||
+	    _fail "${2} was not created with exact name"
+    }
+    basedir=${test_casefold}/"test_name_preserve"
+    mkdir -p ${basedir}
+
+    _set_casefold_attr ${basedir}
+
+    __test_name_preserve "${pt_file1}" "${pt_file2}"
+    __test_name_preserve "${jp_file1}" "${jp_file2}"
+    __test_name_preserve "${ar_file1}" "${ar_file2}"
+    __test_name_preserve "${fr_file1}" "${fr_file2}"
+}
+
+test_dir_name_preserve () {
+
+    __test_dir_name_preserve () {
+	mkdir ${basedir}/${1}
+	rmdir ${basedir}/${1}
+
+	mkdir ${basedir}/${2}
+	_casefold_check_exact_name ${basedir} ${2} ||
+	    _fail "${2} was not created with exact name"
+    }
+
+    basedir=${test_casefold}/"dir-test_name_preserve"
+    mkdir -p ${basedir}
+
+    _set_casefold_attr ${basedir}
+
+    __test_dir_name_preserve "${pt_file1}" "${pt_file2}"
+    __test_dir_name_preserve "${jp_file1}" "${jp_file2}"
+    __test_dir_name_preserve "${ar_file1}" "${ar_file2}"
+    __test_dir_name_preserve "${fr_file1}" "${fr_file2}"
+}
+
+# Name reuse for CI search
+test_name_reuse () {
+    basedir=${test_casefold}/reuse
+
+    mkdir ${basedir}
+    _set_casefold_attr ${basedir}
+
+    reuse1=fileX
+    reuse2=FILEX
+
+    touch ${basedir}/${reuse1}
+    rm -f ${basedir}/${reuse1} || _fail "File lookup failed."
+    touch ${basedir}/${reuse2}
+    _casefold_check_exact_name "${basedir}" "${reuse2}" || \
+	_fail "File created with wrong name"
+    _casefold_check_exact_name "${basedir}" "${reuse1}" && \
+	_fail "File created with the old name"
+}
+
+# filepath same name
+test_create_with_same_name () {
+    basedir=${test_casefold}/same_name
+    mkdir ${basedir}
+
+    _set_casefold_attr ${basedir}
+
+    mkdir -p ${basedir}/same1/same1
+    touch ${basedir}/SAME1/sAME1/sAMe1
+    touch -c ${basedir}/SAME1/sAME1/same1 ||
+	_fail "Trying to create a new file instead of using old one"
+}
+
+# file Rename
+test_file_rename () {
+    basedir=${test_casefold}/rename
+    mkdir -p ${basedir}
+    _set_casefold_attr ${basedir}
+
+    mv ${basedir}/rename ${basedir}/rename &>/dev/null && \
+	_fail "mv to an equivalent name shouldn't work"
+    _casefold_check_exact_name ${basedir} "rename"  || \
+	_fail "Name shouldn't change."
+}
+
+test_casefold_openfd () {
+    # Test openfd with casefold.
+    # 1. Delete a file after gettings its fd.
+    # 2. Then create new dir with same name
+    ofd1="openfd"
+    ofd2="OPENFD"
+
+    basedir=${test_casefold}/openfd
+    mkdir -p ${basedir}
+    _set_casefold_attr ${basedir}
+
+    exec 3<> ${basedir}/${ofd1}
+    rm -rf ${basedir}/${ofd1}
+    mkdir ${basedir}/${ofd2}
+    [ -d ${basedir}/${ofd2} ]   || _fail "Not a directory"
+    _casefold_check_exact_name ${basedir} "${ofd2}" ||
+	_fail "openfd file was created using old name"
+    rm -rf ${basedir}/${ofd2}
+    exec 3>&-
+}
+
+test_casefold_openfd2 () {
+    # Test openfd with casefold.
+    # 1. Delete a file after gettings its fd.
+    # 2. Then create new file with same name
+    # 3. Read from open-fd and write into new file.
+
+    basedir=${test_casefold}/openfd2
+    mkdir ${basedir}
+    _set_casefold_attr ${basedir}
+
+    date > ${basedir}/${ofd1}
+    exec 3<> ${basedir}/${ofd1}
+    rm -rf ${basedir}/${ofd1}
+    touch ${basedir}/${ofd1}
+    [ -f ${basedir}/${ofd2} ] || _fail "Not a file"
+    read data <&3
+    echo $data >> ${basedir}/${ofd1}
+    exec 3>&-
+}
+
+test_hard_link_lookups () {
+    # Create hardlink for casefold dir file and inside regular dir.
+    basedir=${test_casefold}/hard_link
+    mkdir ${basedir}
+    _set_casefold_attr ${basedir}
+
+    touch ${basedir}/h1
+    ln ${basedir}/H1 ${SCRATCH_MNT}/h1
+    cnt=`stat -c %h ${basedir}/h1`
+    [ $cnt -eq 1 ] && _fail "Unable to create hardlink"
+
+    # Create hardlink for casefold dir file and inside regular dir.
+    touch ${SCRATCH_MNT}/h2
+    ln ${SCRATCH_MNT}/h2 ${basedir}/H2
+    cnt=`stat -c %h ${basedir}/h2`
+    [ $cnt -eq 1 ] && _fail "Unable to create hardlink"
+}
+
+test_xattrs_lookups () {
+    basedir=${test_casefold}/xattrs
+    mkdir ${basedir}
+    _set_casefold_attr ${basedir}
+
+    mkdir -p ${basedir}/x
+    setfattr -n user.foo -v bar ${basedir}/x
+    getfattr -n user.foo ${basedir}/x &>/dev/null || \
+	_fail "Casefold xattr lookup failed."
+
+    touch ${basedir}/x/f1
+    setfattr -n user.foo -v bar ${basedir}/x/f1
+    getfattr -n user.foo ${basedir}/x/f1 &>/dev/null || \
+	_fail "Casefold xattr lookup failed."
+}
+
+test_lookup_large_directory() {
+    # Perform Casefold lookup on large dir
+
+    basedir=${test_casefold}/large
+    mkdir ${basedir}
+    _set_casefold_attr ${basedir}
+
+    touch $(seq -f "${basedir}/file%g" 0 2000)
+    stat  $(seq -f "${basedir}/FILE%g" 0 2000) &>/dev/null || \
+	_fail "Case on large dir failed"
+}
+
+test_strict_mode_invalid_filename () {
+    __strict_mode_invalid_filename () {
+	touch  "${basedir}/${1}" &>/dev/null && \
+	    _fail "Invalid UTF-8 sequence ${1} should fail at creation time."
+    }
+
+    __strict_mode_invalid_filename ${blob1}
+    __strict_mode_invalid_filename ${blob2}
+}
+
+#############
+# Run tests #
+#############
+
+_scratch_mkfs_casefold 2>&1 1>/dev/null
+
+_scratch_mount
+
+_check_dmesg_for \
+    "\(${sdev}\): Using encoding defined by superblock: utf8" || \
+    _fail "Could not mount with encoding: utf8"
+
+test_casefold_flag_basic
+test_casefold_lookup
+test_bad_casefold_lookup
+test_create_and_remove
+test_casefold_flag_removal
+test_casefold_flag_inheritance
+test_nesting_sensitive_insensitive_tree_simple
+test_nesting_sensitive_insensitive_tree_complex
+test_symlink_with_inexact_name
+test_name_preserve
+test_dir_name_preserve
+test_name_reuse
+test_create_with_same_name
+test_file_rename
+test_casefold_openfd
+test_casefold_openfd2
+test_hard_link_lookups
+test_xattrs_lookups
+test_lookup_large_directory
+
+_scratch_unmount 2>&1
+_check_scratch_fs
+
+# Test Strict Mode
+_scratch_mkfs_casefold_strict 2>&1 1>/dev/null
+_scratch_mount 2>&1
+
+test_strict_mode_invalid_filename
+
+_scratch_unmount 2>&1
+_check_scratch_fs
+
+echo "Silence is golden"
+status=0
+exit
diff --git a/tests/ext4/036.out b/tests/ext4/036.out
new file mode 100644
index 000000000000..ed460d98f87c
--- /dev/null
+++ b/tests/ext4/036.out
@@ -0,0 +1,2 @@
+QA output created by 036
+Silence is golden
diff --git a/tests/ext4/group b/tests/ext4/group
index d27ec893333b..82639c13f8bb 100644
--- a/tests/ext4/group
+++ b/tests/ext4/group
@@ -38,6 +38,7 @@
 033 auto ioctl resize
 034 auto quick quota
 035 auto quick resize
+036 auto quick casefold
 271 auto rw quick
 301 aio auto ioctl rw stress defrag
 302 aio auto ioctl rw stress defrag
-- 
2.20.1

Re: [PATCH v2 2/2] ext4/036: Add tests for filename casefolding feature

[Christoph Hellwig]

On Thu, Jun 06, 2019 at 03:31:38PM -0400, Gabriel Krisman Bertazi wrote:
> From: "Lakshmipathi.G" <lakshmipathi.ganapathi@collabora.co.uk>
> 
> This new test implements verification for the per-directory
> case-insensitive feature, as supported in the reference implementation
> in Ext4.  Currently, this test only supports Ext4, but the plan is to
> run it in other filesystems, once they support the feature.
> 
> For now, let it live in ext4 and we move to shared/ or generic/ when
> other filesystems supporting this feature start to pop up.

Please keep it in shared/ from the start.  There isn't really anything
ext4 specific.  In fact xfs already supports CI file systems, just
without utf8 tables for now.

Re: [PATCH v2 2/2] ext4/036: Add tests for filename casefolding feature

[Theodore Ts'o]

On Thu, Jun 06, 2019 at 10:23:31PM -0700, Christoph Hellwig wrote:
> On Thu, Jun 06, 2019 at 03:31:38PM -0400, Gabriel Krisman Bertazi wrote:
> > 
> > For now, let it live in ext4 and we move to shared/ or generic/ when
> > other filesystems supporting this feature start to pop up.
> 
> Please keep it in shared/ from the start.  There isn't really anything
> ext4 specific.  In fact xfs already supports CI file systems, just
> without utf8 tables for now.

Agreed; the only things which are fs specific are things which you've
already done a great job abstracting away in common/casefold.

      	  	      	       	       - Ted

Re: [PATCH v2 2/2] ext4/036: Add tests for filename casefolding feature

[Eryu Guan]

On Thu, Jun 06, 2019 at 03:31:38PM -0400, Gabriel Krisman Bertazi wrote:
> From: "Lakshmipathi.G" <lakshmipathi.ganapathi@collabora.co.uk>
> 
> This new test implements verification for the per-directory
> case-insensitive feature, as supported in the reference implementation
> in Ext4.  Currently, this test only supports Ext4, but the plan is to
> run it in other filesystems, once they support the feature.
> 
> For now, let it live in ext4 and we move to shared/ or generic/ when
> other filesystems supporting this feature start to pop up.
> 
> Signed-off-by: Lakshmipathi.G <lakshmipathi.ganapathi@collabora.co.uk>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
>   [Rewrite to support feature design]
>   [Refactor to simplify implementation]
> ---
>  tests/ext4/036     | 469 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/ext4/036.out |   2 +
>  tests/ext4/group   |   1 +
>  3 files changed, 472 insertions(+)
>  create mode 100755 tests/ext4/036
>  create mode 100644 tests/ext4/036.out
> 
> diff --git a/tests/ext4/036 b/tests/ext4/036
> new file mode 100755
> index 000000000000..3dae4212853b
> --- /dev/null
> +++ b/tests/ext4/036
> @@ -0,0 +1,469 @@
> +#! /bin/bash
> +# FSQA Test No. 036
> +#
> +# Test the creation, mounting and basic functionality of file name
> +# casefolding on Ext4
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2018 Collabora Ltd.  All Rights Reserved.
> +#
> +# This program is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU General Public License as
> +# published by the Free Software Foundation.
> +#
> +# This program is distributed in the hope that it would be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; if not, write the Free Software Foundation,
> +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> +#
> +#-----------------------------------------------------------------------

Same here, use SPDX tags.

> +
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +status=1 # failure is thea default
> +
> +. ./common/rc
> +. ./common/casefold
> +
> +_supported_os Linux
> +_require_scratch
> +_require_casefold_support
> +_require_check_dmesg
> +
> +sdev=$(_short_dev ${SCRATCH_DEV})
> +test_casefold=${SCRATCH_MNT}

This doesn't look necessary, just use $SCRATCH_MNT in the test?

> +
> +filename1="file.txt"
> +filename2="FILE.TXT"
> +
> +pt_file1=$(echo -e "coração")
> +pt_file2=$(echo -e "corac\xcc\xa7\xc3\xa3o" | tr a-z A-Z)
> +
> +fr_file2=$(echo -e "french_caf\xc3\xa9.txt")
> +fr_file1=$(echo -e "french_cafe\xcc\x81.txt")
> +
> +ar_file1=$(echo -e "arabic_\xdb\x92\xd9\x94.txt")
> +ar_file2=$(echo -e "arabic_\xdb\x93.txt" | tr a-z A-Z)
> +
> +jp_file1=$(echo -e "japanese_\xe3\x82\xb2.txt")
> +jp_file2=$(echo -e "japanese_\xe3\x82\xb1\xe3\x82\x99.txt")
> +
> +# '\xc3\x00' is an invalid sequence. Despite that, the sequences below
> +# could match, if we ignored the error.  But we don't want to be greedy
> +# at normalization, so at the first error we treat the entire sequence
> +# as an opaque blob.  Therefore, these two must NOT match.
> +blob_file1=$(echo -e "corac\xcc\xa7\xc3")
> +blob_file2=$(echo -e "coraç\xc3")
> +
> +# Test helpers
> +basic_create_lookup() {
> +    touch "${basedir}/${1}"

Please assign one of the function params to basedir and declare it as a
local variable.

> +    stat  "${basedir}/${2}" &> /dev/null || \
> +	_fail "Casefolded lookup of ${1} ${2} failed"

In fstests, we usually don't do _fail in tests, we just let test prints
error messages and the test harness will capture the outputs & compare
them with the golden image (.out file), so we know which part of the
test fails and test could continue to run. e.g.

> +    _casefold_check_exact_name "${basedir}" "${1}" || \
> +	_fail "Created file with wrong name."

	stat "$basedir/$2" | _filter_scratch
	_casefold_check_exact_name "$basedir" "$1" || \
		echo "Created \"$basedir/$2\" with wrong name"

To use _filter_scratch we need to source common/filter after sourcing
common/rc.

> +
> +}
> +
> +# CI search should fail.
> +bad_basic_create_lookup() {
> +    touch "${basedir}/${1}"
> +    stat  "${basedir}/${2}" &> /dev/null && \
> +	_fail "Lookup of ${1} using ${2} should have failed"
> +}
> +
> +# Testcases
> +test_casefold_lookup () {
                      ^^^ no space here.
> +    basedir=${test_casefold}/casefold_lookup
> +    mkdir -p ${basedir}
> +
> +    _set_casefold_attr ${basedir}

Same here, if _set_casefold_attr fails with some error messages to
stderr, the test harness would capture that, just put the expected
output to .out file if any.

> +
> +    basic_create_lookup "${filename1}" "${filename2}"
> +    basic_create_lookup "${pt_file1}" "${pt_file2}"
> +    basic_create_lookup "${fr_file1}" "${fr_file2}"
> +    basic_create_lookup "${ar_file1}" "${ar_file2}"
> +    basic_create_lookup "${jp_file1}" "${jp_file2}"
> +}
> +
> +test_bad_casefold_lookup () {
> +    bad_basic_create_lookup ${blob_file1} ${blob_file2}
> +}
> +
> +# remove and recreate
> +test_create_and_remove() {
> +    __create_and_remove() {

In fstests, functions and/or variables starting with "_" are reserved
for global names, do_create_and_remove should be fine. And move it out
of the outer function?

> +	basic_create_lookup ${1}
> +	rm -f  ${basedir}/"${1}"
> +	stat   ${basedir}/"${1}" &> /dev/null && \
> +	    _fail "File ${1} was not removed using exact name"
> +
> +	basic_create_lookup ${1}
> +	rm -f  ${basedir}/"${2}"
> +	stat   ${basedir}/"${1}" &> /dev/null && \
> +	    _fail "File ${1} was not removed using inexact name"
> +    }
> +
> +    basedir=${test_casefold}/create_and_remove
> +    mkdir -p ${basedir}
> +
> +    _set_casefold_attr ${basedir}
> +
> +    __create_and_remove "${pt_file1}" "${pt_file2}"
> +    __create_and_remove "${jp_file1}" "${jp_file2}"
> +    __create_and_remove "${ar_file1}" "${ar_file2}"
> +    __create_and_remove "${fr_file1}" "${fr_file2}"
> +
> +}
> +
> +test_casefold_flag_basic () {
> +    basedir=${test_casefold}/basic
> +    mkdir -p ${basedir}
> +
> +    _set_casefold_attr ${basedir}
> +    _is_casefolded_dir ${basedir} || _fail "Casefold attribute wasn't set"
> +
> +    _unset_casefold_attr ${basedir}
> +    _is_casefolded_dir ${basedir} && _fail "Casefold attribute is still set"
> +}
> +
> +test_casefold_flag_removal () {
> +    basedir=${test_casefold}/casefold_flag_removal
> +    mkdir -p ${basedir}
> +
> +    _set_casefold_attr ${basedir}
> +    touch ${basedir}/${filename1}
> +
> +    # Try to remove +F attribute on non empty directory
> +    _try_unset_casefold_attr ${basedir} && \
> +	_fail "Shouldn't be able to remove casefold attribute of non-empty directory"

So here we could just do "_unset_casefold_attr $basename" and log the
expected error message (maybe with some filters to make the output
deterministic) in .out file and we can get rid of the _try functions.

> +}
> +
> +# Test Inheritance of casefold flag
> +test_casefold_flag_inheritance () {
> +    dirpath1="d1/d2/d3"
> +    dirpath2="D1/D2/D3"
> +
> +    basedir=${test_casefold}/flag_inheritance
> +
> +    mkdir -p ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    mkdir -p ${basedir}/${dirpath1}
> +
> +    _is_casefolded_dir ${basedir}/${dirpath1} || \
> +	_fail "Casefold attribute should be inherited"
> +    ls  ${basedir}/${dirpath2} &>/dev/null || \
> +	_fail "Dir Lookup failed."
> +    _casefold_check_exact_name "${basedir}" "${dirpath1}" || \
> +	_fail "Created directories wrong name."
> +
> +    touch ${basedir}/${dirpath2}/${filename1}
> +    ls  ${basedir}/${dirpath1}/${filename2} &>/dev/null || \
> +	_fail "Couldn't create file on casefolded parent."
> +}
> +
> +# Test nesting of sensitive directory inside insensitive directory.
> +test_nesting_sensitive_insensitive_tree_simple() {
> +    basedir=${test_casefold}/sd1
> +    mkdir -p ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    mkdir -p ${basedir}/sd1
> +    _set_casefold_attr ${basedir}/sd1
> +
> +    mkdir ${basedir}/sd1/sd2
> +    _unset_casefold_attr ${basedir}/sd1/sd2
> +
> +    touch ${basedir}/sd1/sd2/${filename1}
> +    ls ${basedir}/sd1/sd2/${filename1} &>/dev/null || \
> +	_fail "Exact nested file lookup failed."
> +    ls ${basedir}/sd1/SD2/${filename1} &>/dev/null || \
> +	_fail "Nested file lookup failed."
> +    ls ${basedir}/sd1/SD2/${filename2} &>/dev/null && \
> +	_fail "Wrong file lookup passed, should have fail."
> +}
> +
> +test_nesting_sensitive_insensitive_tree_complex() {
> +    # Test nested-directories
> +    basedir=${test_casefold}/nesting
> +    mkdir -p ${basedir}
> +
> +    _set_casefold_attr ${basedir}
> +
> +    mkdir ${basedir}/nd1
> +    _set_casefold_attr ${basedir}/nd1
> +    mkdir ${basedir}/nd1/nd2
> +    _unset_casefold_attr ${basedir}/nd1/nd2
> +    mkdir ${basedir}/nd1/nd2/nd3
> +    _set_casefold_attr ${basedir}/nd1/nd2/nd3
> +    mkdir ${basedir}/nd1/nd2/nd3/nd4
> +    _unset_casefold_attr ${basedir}/nd1/nd2/nd3/nd4
> +    mkdir ${basedir}/nd1/nd2/nd3/nd4/nd5
> +    _set_casefold_attr ${basedir}/nd1/nd2/nd3/nd4/nd5
> +
> +    ls ${basedir}/ND1/ND2/nd3/ND4/nd5 &>/dev/null || \
> +	_fail "Nest-dir Lookup failed."
> +    ls ${basedir}/nd1/nd2/nd3/nd4/ND5 &>/dev/null && \
> +	_fail "ND5: Nest-dir Lookup passed, it should fail."
> +    ls ${basedir}/nd1/nd2/nd3/ND4/nd5 &>/dev/null || \
> +	_fail "Nest-dir Lookup failed."
> +    ls ${basedir}/nd1/nd2/ND3/nd4/ND5 &>/dev/null && \
> +	_fail "ND3: Nest-dir Lookup passed, it should fail."
> +}
> +
> +test_symlink_with_inexact_name () {
> +    basedir=${test_casefold}/symlink
> +    mkdir -p ${basedir}
> +
> +    _set_casefold_attr ${basedir}
> +
> +    mkdir ${basedir}/ind1
> +    mkdir ${basedir}/ind2
> +    _set_casefold_attr ${basedir}/ind1
> +    touch ${basedir}/ind1/target
> +    ln -s ${basedir}/ind1/TARGET ${basedir}/ind2/link
> +    [ -L ${basedir}/ind2/link ] || _fail "Not a symlink."
> +    readlink -e ${basedir}/ind2/link &>/dev/null || _fail "Symlink failed"
> +}
> +
> +
> +# Name-preserving tests
> +# We create a file with a name, delete it and create again with an
> +# equivalent name.  If the negative dentry wasn't invalidated, the
> +# file might be created using $1 instead of $2.
> +test_name_preserve () {
> +    __test_name_preserve () {
> +	touch ${basedir}/${1}
> +	rm ${basedir}/${1}
> +
> +	touch ${basedir}/${2}
> +	_casefold_check_exact_name ${basedir} ${2} ||
> +	    _fail "${2} was not created with exact name"
> +    }
> +    basedir=${test_casefold}/"test_name_preserve"
> +    mkdir -p ${basedir}
> +
> +    _set_casefold_attr ${basedir}
> +
> +    __test_name_preserve "${pt_file1}" "${pt_file2}"
> +    __test_name_preserve "${jp_file1}" "${jp_file2}"
> +    __test_name_preserve "${ar_file1}" "${ar_file2}"
> +    __test_name_preserve "${fr_file1}" "${fr_file2}"
> +}
> +
> +test_dir_name_preserve () {
> +
> +    __test_dir_name_preserve () {
> +	mkdir ${basedir}/${1}
> +	rmdir ${basedir}/${1}
> +
> +	mkdir ${basedir}/${2}
> +	_casefold_check_exact_name ${basedir} ${2} ||
> +	    _fail "${2} was not created with exact name"
> +    }
> +
> +    basedir=${test_casefold}/"dir-test_name_preserve"
> +    mkdir -p ${basedir}
> +
> +    _set_casefold_attr ${basedir}
> +
> +    __test_dir_name_preserve "${pt_file1}" "${pt_file2}"
> +    __test_dir_name_preserve "${jp_file1}" "${jp_file2}"
> +    __test_dir_name_preserve "${ar_file1}" "${ar_file2}"
> +    __test_dir_name_preserve "${fr_file1}" "${fr_file2}"
> +}
> +
> +# Name reuse for CI search
> +test_name_reuse () {
> +    basedir=${test_casefold}/reuse
> +
> +    mkdir ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    reuse1=fileX
> +    reuse2=FILEX
> +
> +    touch ${basedir}/${reuse1}
> +    rm -f ${basedir}/${reuse1} || _fail "File lookup failed."
> +    touch ${basedir}/${reuse2}
> +    _casefold_check_exact_name "${basedir}" "${reuse2}" || \
> +	_fail "File created with wrong name"
> +    _casefold_check_exact_name "${basedir}" "${reuse1}" && \
> +	_fail "File created with the old name"
> +}
> +
> +# filepath same name
> +test_create_with_same_name () {
> +    basedir=${test_casefold}/same_name
> +    mkdir ${basedir}
> +
> +    _set_casefold_attr ${basedir}
> +
> +    mkdir -p ${basedir}/same1/same1
> +    touch ${basedir}/SAME1/sAME1/sAMe1
> +    touch -c ${basedir}/SAME1/sAME1/same1 ||
> +	_fail "Trying to create a new file instead of using old one"
> +}
> +
> +# file Rename
> +test_file_rename () {
> +    basedir=${test_casefold}/rename
> +    mkdir -p ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    mv ${basedir}/rename ${basedir}/rename &>/dev/null && \
> +	_fail "mv to an equivalent name shouldn't work"
> +    _casefold_check_exact_name ${basedir} "rename"  || \
> +	_fail "Name shouldn't change."
> +}
> +
> +test_casefold_openfd () {
> +    # Test openfd with casefold.
> +    # 1. Delete a file after gettings its fd.
> +    # 2. Then create new dir with same name
> +    ofd1="openfd"
> +    ofd2="OPENFD"
> +
> +    basedir=${test_casefold}/openfd
> +    mkdir -p ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    exec 3<> ${basedir}/${ofd1}
> +    rm -rf ${basedir}/${ofd1}
> +    mkdir ${basedir}/${ofd2}
> +    [ -d ${basedir}/${ofd2} ]   || _fail "Not a directory"
> +    _casefold_check_exact_name ${basedir} "${ofd2}" ||
> +	_fail "openfd file was created using old name"
> +    rm -rf ${basedir}/${ofd2}
> +    exec 3>&-
> +}
> +
> +test_casefold_openfd2 () {
> +    # Test openfd with casefold.
> +    # 1. Delete a file after gettings its fd.
> +    # 2. Then create new file with same name
> +    # 3. Read from open-fd and write into new file.
> +
> +    basedir=${test_casefold}/openfd2
> +    mkdir ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    date > ${basedir}/${ofd1}
> +    exec 3<> ${basedir}/${ofd1}
> +    rm -rf ${basedir}/${ofd1}
> +    touch ${basedir}/${ofd1}
> +    [ -f ${basedir}/${ofd2} ] || _fail "Not a file"
> +    read data <&3
> +    echo $data >> ${basedir}/${ofd1}
> +    exec 3>&-
> +}
> +
> +test_hard_link_lookups () {
> +    # Create hardlink for casefold dir file and inside regular dir.
> +    basedir=${test_casefold}/hard_link
> +    mkdir ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    touch ${basedir}/h1
> +    ln ${basedir}/H1 ${SCRATCH_MNT}/h1
> +    cnt=`stat -c %h ${basedir}/h1`
> +    [ $cnt -eq 1 ] && _fail "Unable to create hardlink"
> +
> +    # Create hardlink for casefold dir file and inside regular dir.
> +    touch ${SCRATCH_MNT}/h2
> +    ln ${SCRATCH_MNT}/h2 ${basedir}/H2
> +    cnt=`stat -c %h ${basedir}/h2`
> +    [ $cnt -eq 1 ] && _fail "Unable to create hardlink"
> +}
> +
> +test_xattrs_lookups () {
> +    basedir=${test_casefold}/xattrs
> +    mkdir ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    mkdir -p ${basedir}/x
> +    setfattr -n user.foo -v bar ${basedir}/x
> +    getfattr -n user.foo ${basedir}/x &>/dev/null || \

Use $SETFATTR_PROG and $GETFATTR_PROG and _require_attrs in the
beginning.

> +	_fail "Casefold xattr lookup failed."
> +
> +    touch ${basedir}/x/f1
> +    setfattr -n user.foo -v bar ${basedir}/x/f1
> +    getfattr -n user.foo ${basedir}/x/f1 &>/dev/null || \
> +	_fail "Casefold xattr lookup failed."
> +}
> +
> +test_lookup_large_directory() {
> +    # Perform Casefold lookup on large dir
> +
> +    basedir=${test_casefold}/large
> +    mkdir ${basedir}
> +    _set_casefold_attr ${basedir}
> +
> +    touch $(seq -f "${basedir}/file%g" 0 2000)
> +    stat  $(seq -f "${basedir}/FILE%g" 0 2000) &>/dev/null || \
> +	_fail "Case on large dir failed"
> +}
> +
> +test_strict_mode_invalid_filename () {
> +    __strict_mode_invalid_filename () {
> +	touch  "${basedir}/${1}" &>/dev/null && \
> +	    _fail "Invalid UTF-8 sequence ${1} should fail at creation time."
> +    }
> +
> +    __strict_mode_invalid_filename ${blob1}
> +    __strict_mode_invalid_filename ${blob2}
> +}
> +
> +#############
> +# Run tests #
> +#############
> +
> +_scratch_mkfs_casefold 2>&1 1>/dev/null
> +
> +_scratch_mount
> +
> +_check_dmesg_for \
> +    "\(${sdev}\): Using encoding defined by superblock: utf8" || \
> +    _fail "Could not mount with encoding: utf8"
> +
> +test_casefold_flag_basic
> +test_casefold_lookup
> +test_bad_casefold_lookup
> +test_create_and_remove
> +test_casefold_flag_removal
> +test_casefold_flag_inheritance
> +test_nesting_sensitive_insensitive_tree_simple
> +test_nesting_sensitive_insensitive_tree_complex
> +test_symlink_with_inexact_name
> +test_name_preserve
> +test_dir_name_preserve
> +test_name_reuse
> +test_create_with_same_name
> +test_file_rename
> +test_casefold_openfd
> +test_casefold_openfd2
> +test_hard_link_lookups
> +test_xattrs_lookups
> +test_lookup_large_directory
> +
> +_scratch_unmount 2>&1

No need to do redirection, test harness captures both stdout and stderr.

> +_check_scratch_fs
> +
> +# Test Strict Mode
> +_scratch_mkfs_casefold_strict 2>&1 1>/dev/null

Better to redirect mkfs output to $seqres.full for debug purpose, e.g.

_scratch_mkfs_casefold_strict >>$seqres.full 2>&1

> +_scratch_mount 2>&1

No need to do redirection here either.

> +
> +test_strict_mode_invalid_filename
> +
> +_scratch_unmount 2>&1

Same here.

> +_check_scratch_fs

And if we do fsck after each test phase, we could replace
_require_scratch with _require_scratch_nocheck to let harness know
there's no need to do fsck again after test.

Thanks,
Eryu

> +
> +echo "Silence is golden"
> +status=0
> +exit
> diff --git a/tests/ext4/036.out b/tests/ext4/036.out
> new file mode 100644
> index 000000000000..ed460d98f87c
> --- /dev/null
> +++ b/tests/ext4/036.out
> @@ -0,0 +1,2 @@
> +QA output created by 036
> +Silence is golden
> diff --git a/tests/ext4/group b/tests/ext4/group
> index d27ec893333b..82639c13f8bb 100644
> --- a/tests/ext4/group
> +++ b/tests/ext4/group
> @@ -38,6 +38,7 @@
>  033 auto ioctl resize
>  034 auto quick quota
>  035 auto quick resize
> +036 auto quick casefold
>  271 auto rw quick
>  301 aio auto ioctl rw stress defrag
>  302 aio auto ioctl rw stress defrag
> -- 
> 2.20.1
> 

Re: [PATCH v2 1/2] common/casefold: Add infrastructure to test filename casefold feature

[Eryu Guan]

On Thu, Jun 06, 2019 at 03:31:37PM -0400, Gabriel Krisman Bertazi wrote:
> Add a set of basic helper functions to simplify the testing of
> casefolding capable filesystems.
> 
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
> ---
>  common/casefold | 108 ++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 108 insertions(+)
>  create mode 100644 common/casefold
> 
> diff --git a/common/casefold b/common/casefold
> new file mode 100644
> index 000000000000..34c1d4ae1af1
> --- /dev/null
> +++ b/common/casefold
> @@ -0,0 +1,108 @@
> +#-----------------------------------------------------------------------
> +#
> +# Common functions for testing filename casefold feature
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2018 Collabora, Ltd.  All Rights Reserved.
                   ^^^^ 2019?
> +#
> +# Author: Gabriel Krisman Bertazi <krisman@collabora.com>
> +#
> +# This program is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU General Public License as
> +# published by the Free Software Foundation.
> +#
> +# This program is distributed in the hope that it would be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; if not, write the Free Software Foundation,
> +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> +#-----------------------------------------------------------------------

Please use the SPDX tags to specify licence, you could take common/rc as
a reference.

> +
> +_has_casefold_feature_kernel_support() {

The name seems a bit long to me, just _has_casefold_kernel_support()?

> +    case $FSTYP in
> +	ext4)
> +	    test -f '/sys/fs/ext4/features/casefold'
> +	    ;;
> +	*)
> +	    # defaults to unsupported
> +	    false
> +	    ;;
> +    esac

Please use 8-spaces tab for indention. The same for the new test.

> +}
> +
> +_require_casefold_support() {

_require_scratch_casefold(), as the function test casefold support
against scratch device, so add "scratch" in the function name to
indicate that.

> +    if ! _has_casefold_feature_kernel_support ; then
> +	_notrun "$FSTYP does not support casefold feature"
> +    fi
> +
> +    if ! _scratch_mkfs_casefold &>>seqres.full; then
> +	_notrun "$FSTYP userspace tools do not support casefold"
> +    fi
> +
> +    # Make sure the kernel can mount a filesystem with the encoding
> +    # defined by the userspace tools.  This will fail if
> +    # the userspace tool used a more recent encoding than the one
> +    # supported in kernel space.
> +    if ! _try_scratch_mount &>>seqres.full; then
> +	_notrun \
> +	    "kernel can't mount filesystem using the encoding set by userspace"
> +    fi
> +    _scratch_unmount
> +}
> +
> +_scratch_mkfs_casefold () {
> +    case $FSTYP in
> +	ext4)
> +	    _scratch_mkfs -O casefold $*
> +	    ;;
> +	*)
> +	    _notrun "Don't know how to mkfs with casefold support on $FSTYP"
> +	    ;;
> +	esac
> +}
> +
> +_scratch_mkfs_casefold_strict () {
> +    case $FSTYP in
> +	ext4)
> +	    _scratch_mkfs -O casefold -E encoding_flags=strict
> +	    ;;
> +	*)
> +	    _notrun \
> +		"Don't know how to mkfs with casefold-strict support on $FSTYP"
> +	    ;;
> +	esac
> +}
> +
> +_casefold_check_exact_name () {
> +    # To get the exact disk name, we need some method that does a
> +    # getdents() on the parent directory, such that we don't get
> +    # normalized/casefolded results.  'Find' works ok.

I think these could go before the helper.

> +    basedir=$1
> +    exact_name=$2

Declare local variables as "local", the same for all other local
variables, both in this casefold file and in the new test.

> +    find ${basedir} | grep -q ${exact_name}
> +}
> +
> +_try_set_casefold_attr () {
> +    chattr +F "${1}" &>/dev/null

$CHATTR_PROG

And need to require chattr in _require_scratch_casefold() too, e.g.

	_require_command "$CHATTR_PROG" chattr
> +}
> +
> +_try_unset_casefold_attr () {
> +    chattr -F "${1}" &>/dev/null

Same here. And I don't think we should redirect chattr output in these
helper functions, just let callers handle the outputs.

> +}
> +
> +_set_casefold_attr () {
> +    _try_set_casefold_attr "${1}" || \
> +	_fail "Unable to set casefold attribute on ${1}"
> +}
> +
> +_unset_casefold_attr () {
> +    _try_unset_casefold_attr "${1}" || \
> +	_fail "Unable to unset casefold attribute on ${1}"
> +}

And no need to _fail here. IMHO, just two helpers like:

_set_casefold_attr()
{
	$CHATTR_PROG +F "${1}"
}

_unset_casefold_attr()
{
	$CHATTR_PROG -F "${1}"
}

And let callers deal with the outputs/results. More comments on this in
next patch.

> +
> +_is_casefolded_dir () {
> +    lsattr -ld "${1}" | grep -q "Casefold"
> +}

$LSATTR_PROG, and do 

	_require_command "$LSATTR_PROG" lsattr

in _require_scratch_casefold() as well.

Thanks,
Eryu
> -- 
> 2.20.1
>