On Thu, Jul 02, 2020 at 03:08:01PM +0800, Xiao Yang wrote: > Hi Ira, Darrick > > I have one question about S_DAX flag: > Current statx() can only query S_DAX flag on regular file, > why don't we set S_DAX flag for directory in kernel? :-) This was the kind of confusion I was trying to avoid by having dax.txt spell out exactly what S_DAX meant (it's the incore flag that means that *regular file access* is done via direct CPU access and not via pagecache. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/filesystems/dax.txt --D > > Best Regards, > Xiao Yang > On 2020/7/2 14:35, Xiao Yang wrote: > > With new kernel(e.g. v5.8-rc1), statx() can be used to qurey S_SAX flag > > on regular file, so add a test to verify the feature. > > > > Reference: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=712b2698e4c024b561694cbcc1abba13eb0fd9ce > > > > Signed-off-by: Xiao Yang <yangx.jy@xxxxxxxxxxxxxx> > > --- > > > > Note: this patch depends on the following patch set: > > https://www.spinics.net/lists/fstests/msg14252.html > > > > tests/generic/604 | 100 ++++++++++++++++++++++++++++++++++++++++++ > > tests/generic/604.out | 2 + > > tests/generic/group | 1 + > > 3 files changed, 103 insertions(+) > > create mode 100644 tests/generic/604 > > create mode 100644 tests/generic/604.out > > > > diff --git a/tests/generic/604 b/tests/generic/604 > > new file mode 100644 > > index 00000000..b0baa781 > > --- /dev/null > > +++ b/tests/generic/604 > > @@ -0,0 +1,100 @@ > > +#! /bin/bash > > +# SPDX-License-Identifier: GPL-2.0 > > +# Copyright (c) 2020 Fujitsu. All Rights Reserved. > > +# > > +# FS QA Test 604 > > +# > > +# By the following cases, verify if statx() can query S_SAX flag > > +# on regular file correctly. > > +# 1) With dax=always option, FS_XFLAG_DAX is ignored and S_SAX flag > > +# always exists on regular file. > > +# 2) With dax=inode option, setting/clearing FS_XFLAG_DAX can change > > +# S_SAX flag on regular file. > > +# 3) With dax=never option, FS_XFLAG_DAX is ignored and S_SAX flag > > +# never exists on regular file. > > +# > > +seq=`basename $0` > > +seqres=$RESULT_DIR/$seq > > +echo "QA output created by $seq" > > + > > +here=`pwd` > > +tmp=/tmp/$$ > > +status=1 # failure is the default! > > +trap "_cleanup; exit \$status" 0 1 2 3 15 > > + > > +_cleanup() > > +{ > > + cd / > > + rm -f $tmp.* > > +} > > + > > +# get standard environment, filters and checks > > +. ./common/rc > > +. ./common/filter > > + > > +# remove previous $seqres.full before test > > +rm -f $seqres.full > > + > > +_supported_fs generic > > +_supported_os Linux > > +_require_scratch_dax_mountopt "dax=always" > > +_require_scratch_dax_iflag > > +_require_xfs_io_command "statx" "-r" > > + > > +PARENT_DIR=$SCRATCH_MNT/testdir > > +TEST_FILE=$PARENT_DIR/testfile > > + > > +check_s_dax() > > +{ > > + local exp_s_dax=$1 > > + > > + local attributes=$($XFS_IO_PROG -c 'statx -r' $TEST_FILE | awk '/stat.attributes / { print $3 }') > > + if [ $exp_s_dax -eq 0 ]; then > > + (( attributes & 0x2000 )) && echo "$TEST_FILE has unexpected S_DAX flag" > > + else > > + (( attributes & 0x2000 )) || echo "$TEST_FILE doen't have expected S_DAX flag" > > + fi > > +} > > + > > +test_s_dax() > > +{ > > + local dax_option=$1 > > + local exp_s_dax1=$2 > > + local exp_s_dax2=$3 > > + > > + # Mount with specified dax option > > + _scratch_mount "-o $dax_option" > > + > > + # Prepare directory > > + mkdir -p $PARENT_DIR > > + > > + rm -f $TEST_FILE > > + $XFS_IO_PROG -c "chattr +x" $PARENT_DIR > > + touch $TEST_FILE > > + # Check if setting FS_XFLAG_DAX changes S_DAX flag > > + check_s_dax $exp_s_dax1 > > + > > + rm -f $TEST_FILE > > + $XFS_IO_PROG -c "chattr -x" $PARENT_DIR > > + touch $TEST_FILE > > + # Check if clearing FS_XFLAG_DAX changes S_DAX flag > > + check_s_dax $exp_s_dax2 > > + > > + _scratch_unmount > > +} > > + > > +do_tests() > > +{ > > + test_s_dax "dax=always" 1 1 > > + test_s_dax "dax=inode" 1 0 > > + test_s_dax "dax=never" 0 0 > > +} > > + > > +_scratch_mkfs >> $seqres.full 2>&1 > > + > > +do_tests > > + > > +# success, all done > > +echo "Silence is golden" > > +status=0 > > +exit > > diff --git a/tests/generic/604.out b/tests/generic/604.out > > new file mode 100644 > > index 00000000..c06a1c7f > > --- /dev/null > > +++ b/tests/generic/604.out > > @@ -0,0 +1,2 @@ > > +QA output created by 604 > > +Silence is golden > > diff --git a/tests/generic/group b/tests/generic/group > > index 1d0d5606..676e0d2e 100644 > > --- a/tests/generic/group > > +++ b/tests/generic/group > > @@ -606,3 +606,4 @@ > > 601 auto quick quota > > 602 auto quick encrypt > > 603 auto attr quick dax > > +604 auto attr quick dax > > >
