#! /bin/bash
# FS QA Test No. 289
#
# Test overhead & df output for extN filesystems
#
#-----------------------------------------------------------------------
# Copyright (c) 2012 Red Hat, Inc.  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
#-----------------------------------------------------------------------
#
# creator
owner=sandeen@redhat.com

seq=`basename $0`
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

# real QA test starts here

# Modify as appropriate.
_supported_fs ext2 ext3 ext4
_supported_os Linux
_require_scratch

rm -f $seq.full

_scratch_mkfs >> $seq.full 2>&1

# Get the honest truth about block counts straight from metadata on disk
TOTAL_BLOCKS=`dumpe2fs -h $SCRATCH_DEV 2>/dev/null \
		| awk '/Block count:/{print $3}'`

FREE_BLOCKS=`dumpe2fs -h $SCRATCH_DEV 2>/dev/null \
		| awk '/Free blocks:/{print $3}'`

# nb: kernels today don't count journal blocks  as overhead, but should.
# For most filesystems this will still be within tolerance.
# Overhead is all the blocks (already) used by the fs itself:
OVERHEAD=$(($TOTAL_BLOCKS-$FREE_BLOCKS))

#  bsddf|minixdf
#         Set the behaviour  for  the  statfs  system  call.  The  minixdf
#         behaviour is to return in the f_blocks field the total number of
#         blocks of the filesystem, while the bsddf  behaviour  (which  is
#         the default) is to subtract the overhead blocks used by the ext2
#         filesystem and not available for file storage.

# stat -f output looks like this; we get f_blocks from that, which
# varies depending on the df mount options used below:

#   File: "/mnt/test"
#    ID: affc5f2b2f57652 Namelen: 255     Type: ext2/ext3
# Block size: 4096       Fundamental block size: 4096
# Blocks: Total: 5162741    Free: 5118725    Available: 4856465
# Inodes: Total: 1313760    Free: 1313749

_scratch_mount "-o minixdf"
MINIX_F_BLOCKS=`stat -f $SCRATCH_MNT | awk '/^Blocks/{print $3}'`
umount $SCRATCH_MNT

_scratch_mount "-o bsddf"
BSD_F_BLOCKS=`stat -f $SCRATCH_MNT | awk '/^Blocks/{print $3}'`
umount $SCRATCH_MNT

# Echo data to $seq.full for analysis
echo "Overhead is $OVERHEAD blocks out of $TOTAL_BLOCKS ($FREE_BLOCKS free)" >> $seq.full
echo "MINIX free blocks $MINIX_F_BLOCKS" >> $seq.full
echo "BSD free blocks $BSD_F_BLOCKS" >> $seq.full

# minix should be exactly equal (hence tolerance of 0)
_within_tolerance "minix f_blocks" $MINIX_F_BLOCKS $TOTAL_BLOCKS 0 -v
# bsd should be within ... we'll say 1% for some slop
_within_tolerance "bsd f_blocks" $BSD_F_BLOCKS $(($TOTAL_BLOCKS-$OVERHEAD)) 1% -v

# success, all done
status=0
exit