#! /bin/sh
# FS QA Test No. 016
#
# test end of log overwrite bug #796141
#
#-----------------------------------------------------------------------
# Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
#-----------------------------------------------------------------------
#
# creator
owner=dxm@sgi.com

#
# pv 796141
#
# create a new FS, mostly fill the log. Then wrap the log back to the
# start bit by bit to force wiping of stale blocks near the end of the
# log. Check the block after the log ends to check for corruption
#
# assumptions :
#    - given we're only touching a single inode, the block after the
#      log which is in the middle ag should never be touched.
#      if it changes, we assume the log is writing over it
#

seq=`basename $0`
echo "QA output created by $seq"

here=`pwd`
tmp=/tmp/$$
status=1

trap "_cleanup; exit \$status" 0 1 2 3 15

_cleanup()
{
    cd /
    rm -f $tmp.*
    echo "*** unmount"
    umount $SCRATCH_MNT 2>/dev/null
}

_block_filter()
{
    sed -e 's/[0-9][0-9]*\.\.[0-9][0-9]*/BLOCKRANGE/g'
}

_init()
{
    echo "*** reset partition"
    $here/src/devzero -b 2048 -n 50 -v 198 $SCRATCH_DEV
    echo "*** mkfs"
    force_opts="-dsize=50m -lsize=$log_size"
    echo mkfs_xfs $force_opts $SCRATCH_DEV >>$seq.full
    _scratch_mkfs_xfs $force_opts >$tmp.mkfs0 2>&1
    [ $? -ne 0 ] && \
        _notrun "Cannot mkfs for this test using MKFS_OPTIONS specified"
    _filter_mkfs <$tmp.mkfs0 >/dev/null 2>$tmp.mkfs
    . $tmp.mkfs
    [ $logsunit -ne 0 ] && \
        _notrun "Cannot run this test using log MKFS_OPTIONS specified"
}

_log_traffic()
{
    count=$1
    echo "*** generate log traffic"

    out=$SCRATCH_MNT/$$.tmp

    echo "   *** mount"
    if ! _scratch_mount
    then
        echo "failed to mount $SCRATCH_DEV"
        exit 1
    fi

    # having any quota enabled (acct/enfd) means extra log traffic - evil!
    $here/src/feature -U $SCRATCH_DEV && \
		_notrun "UQuota are enabled, test needs controlled log traffic"
    $here/src/feature -G $SCRATCH_DEV && \
		_notrun "GQuota are enabled, test needs controlled log traffic"
    $here/src/feature -P $SCRATCH_DEV && \
		_notrun "PQuota are enabled, test needs controlled log traffic"

    echo "   *** fiddle"
    while [ $count -ge 0 ]
    do
        touch $out
        rm $out
        let "count = count - 1"
    done

    echo "   *** unmount"
    if ! umount $SCRATCH_DEV
    then
        echo "failed to unmount $SCRATCH_DEV"
        exit 1
    fi
}

_log_size()
{
    _scratch_xfs_logprint -tb | $AWK_PROG '
        /log file: / || /log device: / { print $7}
    '
}

_log_head()
{
    _scratch_xfs_logprint -tb | $AWK_PROG '
        /head:/ { print $5 }
    '
}

# Get log stripe unit for v2 logs; if none specified,
# (or v1 log) just return "1" block

_log_sunit()
{
    if [ ${lsunit:-0} -eq 0 ]; then
        echo $dbsize
    else
        expr $lsunit \* $dbsize
    fi
}

_after_log()
{
    xfs_db -r $1 -c "sb" -c "print" | $AWK_PROG '
        /logstart/  { logstart = $3 }
        /logblocks/ { logblocks = $3 }
        END {
            print logstart + logblocks
        }
    '
}

_check_corrupt()
{
    f="c6c6c6c6"
    echo "*** check for corruption"
    echo "expect $f..." >>$seq.full
    xfs_db -r -c "fsblock $2" -c "print" $1 | head | tee -a $seq.full | \
        grep -q -v "$f $f $f $f $f $f $f $f" && \
            _fail "!!! block $2 corrupted!"
}

# get standard environment, filters and checks
. ./common.rc
. ./common.filter

# real QA test starts here
_supported_fs xfs
_supported_os Linux

rm -f $seq.full

# mkfs sizes
log_size=2097152
log_size_bb=`expr $log_size / 512`

_require_scratch
_init

block=`_after_log $SCRATCH_DEV`
echo "fsblock after log = $block"               >>$seq.full
_check_corrupt $SCRATCH_DEV $block

actual_log_size=`_log_size`
echo "log size = $actual_log_size BB"                      >>$seq.full
head=`_log_head`
echo "log position = $head"                     >>$seq.full
lsunit=`_log_sunit`
echo "log sunit = $lsunit"			>>$seq.full

# sanity checks
[ $actual_log_size -eq $log_size_bb ] || \
    _fail "!!! unexpected log size $size"
[ $head -eq 2 -o $head -eq $((lsunit/512)) ] || \
    _fail "!!! unexpected initial log position $head vs. $((lsunit/512))"

# find how how many blocks per op for 100 ops
# ignore the fact that it will also include an unmount record etc...
# this should be small overall
echo "    lots of traffic for sampling" >>$seq.full
sample_size_ops=100
_log_traffic $sample_size_ops
head1=`_log_head`
num_blocks=`expr $head1 - $head`
blocks_per_op=`echo "scale=3; $num_blocks / $sample_size_ops" | bc`
echo "blocks_per_op = $blocks_per_op" >>$seq.full
num_expected_ops=`echo "$log_size_bb / $blocks_per_op" | bc`
echo "num_expected_ops = $num_expected_ops" >>$seq.full
num_expected_to_go=`echo "$num_expected_ops - $sample_size_ops" | bc`
echo "num_expected_to_go = $num_expected_to_go" >>$seq.full

echo "    lots more traffic" >>$seq.full
_log_traffic $num_expected_to_go
head=`_log_head`
echo "log position = $head"                     >>$seq.full

# e.g. 3891
near_end_min=`echo "0.95 * $log_size_bb" | bc | sed 's/\..*//'`
echo "near_end_min = $near_end_min" >>$seq.full

[ $head -gt $near_end_min -a $head -lt $log_size_bb ] || \
    _fail "!!! unexpected near end log position $head"

for c in `seq 0 20`
do
    echo "   little traffic"            >>$seq.full
    _log_traffic 2
    head=`_log_head`
    echo "log position = $head"         >>$seq.full
    _check_corrupt $SCRATCH_DEV $block
done

[ $head -lt 1000 ] || \
    _fail "!!! unexpected wrapped log position $head"

# success, all done
status=0
exit
