Re: [PATCH] xfstests: test for atime-related mount options

[Koen De Wit <koen.de.wit@oracle.com>]

Thanks for the review, Eric!
Comments inline.

On 02/13/2014 05:42 PM, Eric Sandeen wrote:
> On 2/13/14, 9:23 AM, Koen De Wit wrote:
>> Tests the noatime, relatime, strictatime and nodiratime mount options.
>>
>> There is an extra check for Btrfs to ensure that the access time is
>> never updated on read-only subvolumes. (Regression test for bug fixed
>> with commit 93fd63c2f001ca6797c6b15b696a484b165b4800)
>>
>> Signed-off-by: Koen De Wit <koen.de.wit@oracle.com>
>> ---
>>   tests/generic/323     |  186 +++++++++++++++++++++++++++++++++++++++++++++++++
>>   tests/generic/323.out |    2 +
>>   tests/generic/group   |    1 +
>>   3 files changed, 189 insertions(+), 0 deletions(-)
>>   create mode 100644 tests/generic/323
>>   create mode 100644 tests/generic/323.out
>>
>> diff --git a/tests/generic/323 b/tests/generic/323
>> new file mode 100644
>> index 0000000..423b141
>> --- /dev/null
>> +++ b/tests/generic/323
>> @@ -0,0 +1,186 @@
>> +# Tests the noatime, relatime, strictatime and nodiratime mount options.
>> +# There is an extra check for Btrfs to ensure that the access time is
>> +# never updated on read-only subvolumes. (Regression test for bug fixed
>> +# with commit 93fd63c2f001ca6797c6b15b696a484b165b4800)
>> +#
>> +#-----------------------------------------------------------------------
>> +# Copyright (c) 2014, Oracle and/or its affiliates.  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"
>> +
>> +here=`pwd`
>> +tmp=/tmp/$$
>> +status=1	# failure is the default!
>> +trap "_cleanup; exit \$status" 0 1 2 3 15
>> +
>> +_cleanup()
>> +{
>> +    cd /
>> +    rm -f $*
>> +}
> is "$*" really what you meant?  Normally this is $tmp.*
>
> $* is positional parameters for the script, and I don't think it takes any.

That's a typo indeed. Fixed in v2.

>> +
>> +# get standard environment, filters and checks
>> +. ./common/rc
>> +. ./common/filter
>> +
>> +# real QA test starts here
>> +
>> +_supported_fs generic
>> +_supported_os Linux
>> +_require_scratch
>> +
>> +rm -f $seqres.full
>> +
>> +_stat() {
>> +    stat --printf="%x;%y;%z" $1
>> +}
>> +
>> +_compare_stat_times() {
>> +    updated=$1      # 3 chars indicating if access, modify and
>> +                    # change times should be updated (Y) or not (N)
>> +    IFS=';' read -a first_stat <<< "$2"   # Convert first stat to array
>> +    IFS=';' read -a second_stat <<< "$3"  # Convert second stat to array
>> +    test_step=$4    # Will be printed to output stream in case of an
>> +                    # error, to make debugging easier
>> +    types=( access modify change )
>> +
>> +    for i in 0 1 2; do
>> +        if [ "${first_stat[$i]}" == "${second_stat[$i]}" ]; then
>> +            if [ "${updated:$i:1}" == "Y" ]; then
>> +                echo -n "ERROR: ${types[$i]} time has not been updated "
>> +                echo $test_step
>> +            fi
>> +        else
>> +            if [ "${updated:$i:1}" == "N" ]; then
>> +                echo -n "ERROR: ${types[$i]} time has changed "
>> +                echo $test_step
>> +            fi
>> +        fi
>> +    done
>> +}
>> +
>> +_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
>> +_scratch_mount
>> +
>> +cat /proc/mounts | grep "$SCRATCH_MNT" | grep relatime >> $seqres.full
>> +[ $? -ne 0 ] && echo "The relatime mount option should be the default."
> Ok, I guess "relatime" in /proc/mounts is from core vfs code and should be there for the foreseeable future, so seems ok.
>
> But - relatime was added in v2.6.20, and made default in 2.6.30.  So testing older kernels may not go as expected; it'd probably be best to catch situations where relatime isn't available (< 2.6.20) or not default (< 2.6.30), by explicitly mounting with relatime, and skipping relatime/strictatime tests if that fails?

 From the mailing list discussions in the last days, I think we can conclude it's best to specify the relatime mount option explicitly and include a new _require_relatime method as proposed by Dave Chinner. I implemented it this way in v2.

> The rest of the test is awfully dense, but nice long understandable variable names, so that's good.  ;)
>
> I wonder if in the spirit of testing a btrfs RO snapshot, you could also add a readonly mount test, to be sure that an RO mount doesn't update atime.  Of course it shouldn't, but it might be worth adding for basic sanity?

Good idea! I added a read-only mount test in v2.

Thanks,
Koen.


> Thanks,
> -Eric
>
>> +
>> +if [ "$FSTYP" = "btrfs" ]; then
>> +    TPATH=$SCRATCH_MNT/sub1
>> +    $BTRFS_UTIL_PROG subvolume create $TPATH > $seqres.full
>> +else
>> +    TPATH=$SCRATCH_MNT
>> +fi
>> +
>> +mkdir $TPATH/dir1
>> +echo "aaa" > $TPATH/dir1/file1
>> +file1_stat_before_first_access=`_stat $TPATH/dir1/file1`
>> +
>> +# Accessing file1 the first time
>> +cat $TPATH/dir1/file1 > /dev/null
>> +file1_stat_after_first_access=`_stat $TPATH/dir1/file1`
>> +_compare_stat_times YNN "$file1_stat_before_first_access" \
>> +    "$file1_stat_after_first_access" "after accessing file1 first time"
>> +
>> +# Accessing file1 a second time
>> +cat $TPATH/dir1/file1 > /dev/null
>> +file1_stat_after_second_access=`_stat $TPATH/dir1/file1`
>> +_compare_stat_times NNN "$file1_stat_after_first_access" \
>> +    "$file1_stat_after_second_access" "after accessing file1 second time"
>> +
>> +# Remounting with nodiratime option
>> +_scratch_unmount
>> +_scratch_mount "-o nodiratime"
>> +file1_stat_after_remount=`_stat $TPATH/dir1/file1`
>> +_compare_stat_times NNN "$file1_stat_after_second_access" \
>> +    "$file1_stat_after_remount" "for file1 after remount"
>> +
>> +# Creating dir2 and file2, checking directory stats
>> +mkdir $TPATH/dir2
>> +dir2_stat_before_file_creation=`_stat $TPATH/dir2`
>> +echo "bbb" > $TPATH/dir2/file2
>> +dir2_stat_after_file_creation=`_stat $TPATH/dir2`
>> +_compare_stat_times NYY "$dir2_stat_before_file_creation" \
>> +    "$dir2_stat_after_file_creation" "for dir2 after file creation"
>> +
>> +# Accessing file2
>> +file2_stat_before_first_access=`_stat $TPATH/dir2/file2`
>> +cat $TPATH/dir2/file2 > /dev/null
>> +file2_stat_after_first_access=`_stat $TPATH/dir2/file2`
>> +_compare_stat_times YNN "$file2_stat_before_first_access" \
>> +    "$file2_stat_after_first_access" "after accessing file2"
>> +dir2_stat_after_file_access=`_stat $TPATH/dir2`
>> +_compare_stat_times NNN "$dir2_stat_after_file_creation" \
>> +    "$dir2_stat_after_file_access" "for dir2 after file access"
>> +
>> +# Remounting with noatime option, creating a file and accessing it
>> +_scratch_unmount
>> +_scratch_mount "-o noatime"
>> +echo "ccc" > $TPATH/dir2/file3
>> +file3_stat_before_first_access=`_stat $TPATH/dir2/file3`
>> +cat $TPATH/dir2/file3 > /dev/null
>> +file3_stat_after_first_access=`_stat $TPATH/dir2/file3`
>> +_compare_stat_times NNN "$file3_stat_before_first_access" \
>> +    "$file3_stat_after_first_access" "after accessing file3 first time"
>> +
>> +# Checking that the modify and change times are still updated
>> +file1_stat_before_modify=`_stat $TPATH/dir1/file1`
>> +echo "xyz" > $TPATH/dir1/file1
>> +file1_stat_after_modify=`_stat $TPATH/dir1/file1`
>> +_compare_stat_times NYY "$file1_stat_before_modify" \
>> +    "$file1_stat_after_modify" "after modifying file1"
>> +mv $TPATH/dir1/file1 $TPATH/dir1/file1_renamed
>> +file1_stat_after_change=`_stat $TPATH/dir1/file1_renamed`
>> +_compare_stat_times NNY "$file1_stat_after_modify" \
>> +    "$file1_stat_after_change" "after changing file1"
>> +
>> +# Remounting with strictatime option and
>> +# accessing a previously created file twice
>> +_scratch_unmount
>> +_scratch_mount "-o strictatime"
>> +cat $TPATH/dir2/file3 > /dev/null
>> +file3_stat_after_second_access=`_stat $TPATH/dir2/file3`
>> +_compare_stat_times YNN "$file3_stat_after_first_access" \
>> +    "$file3_stat_after_second_access" "after accessing file3 second time"
>> +cat $TPATH/dir2/file3 > /dev/null
>> +file3_stat_after_third_access=`_stat $TPATH/dir2/file3`
>> +_compare_stat_times YNN "$file3_stat_after_second_access" \
>> +    "$file3_stat_after_third_access" "after accessing file3 third time"
>> +
>> +# Btrfs only: Creating readonly snapshot. Access time should never
>> +# be updated, even when the strictatime mount option is active
>> +if [ "$FSTYP" = "btrfs" ]; then
>> +    SPATH=$SCRATCH_MNT/snap1
>> +    btrfs subvol snapshot -r $TPATH $SPATH >> $seqres.full
>> +    dir2_stat_readonly_before_access=`_stat $SPATH/dir2`
>> +    ls $SPATH/dir2 >> $seqres.full
>> +    cat $SPATH/dir2/file3 >> $seqres.full
>> +    dir2_stat_readonly_after_access=`_stat $SPATH/dir2`
>> +    _compare_stat_times NNN "$dir2_stat_readonly_before_access" \
>> +        "$dir2_stat_readonly_after_access" "for dir in readonly subvol"
>> +    file3_stat_readonly_after_access=`_stat $SPATH/dir2/file3`
>> +    _compare_stat_times NNN "$file3_stat_after_third_access" \
>> +        "$file3_stat_readonly_after_access" "for file in readonly subvol"
>> +fi
>> +
>> +# success, all done
>> +_scratch_unmount
>> +echo "Silence is golden"
>> +status=0
>> +exit
>> diff --git a/tests/generic/323.out b/tests/generic/323.out
>> new file mode 100644
>> index 0000000..5dba9b5
>> --- /dev/null
>> +++ b/tests/generic/323.out
>> @@ -0,0 +1,2 @@
>> +QA output created by 323
>> +Silence is golden
>> diff --git a/tests/generic/group b/tests/generic/group
>> index f492461..3a72ee4 100644
>> --- a/tests/generic/group
>> +++ b/tests/generic/group
>> @@ -125,3 +125,4 @@
>>   320 auto rw
>>   321 auto quick metadata log
>>   322 auto quick metadata log
>> +323 atime auto quick
>>