On Fri, Feb 08, 2019 at 01:44:04PM +0200, Nikolay Borisov wrote:
> Add support for btrfs in shared/298. Achieve this by introducing 2
> new awk scripts that parse relevant btrfs structures and print holes.
> Additionally modify the test to create larger - 3gb filesystem in the
> case of btrfs. This is needed so that distinct block groups are used
> for data and metadata.
>
> Signed-off-by: Nikolay Borisov <nbori...@suse.com>
Sorry for the late review.. I find that parsing btrfs extent and dev
tree is very btrfs-specific, it'd be great if btrfs folks could help
review the two awk scripts as well!
> ---
>
> V2:
> * Changed the way args are passed to mkfs.btrfs to preserve existing
> options, yet override data/metadata profile settings
>
> parse-dev-tree.awk | 47 +++++++++++++++++++
> parse-extent-tree.awk | 125
> ++++++++++++++++++++++++++++++++++++++++++++++++++
I'd prefer placing these files in src dir, instead of dumping them in
top dir directly.
> tests/shared/298 | 36 +++++++++++++--
> 3 files changed, 205 insertions(+), 3 deletions(-)
> create mode 100755 parse-dev-tree.awk
> create mode 100755 parse-extent-tree.awk
>
> diff --git a/parse-dev-tree.awk b/parse-dev-tree.awk
> new file mode 100755
> index 000000000000..52f9c0aadc25
> --- /dev/null
> +++ b/parse-dev-tree.awk
> @@ -0,0 +1,47 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2019 Nikolay Borisov, SUSE LLC. All Rights Reserved.
> +#
> +# Parses btrfs' device tree for holes, required parameters passed on command
I find this description not very useful, would you please describe the
expected output and format as well?
> +# line:
> +# * spb - how many bytes per sector, this is used so that the numbers
^^^ This is misleading, in shared/298 spb represents "sector
per block", but here it's really sector size.
> +# returned by the script are in sectors.
> +# * devsize - size of the device in bytes, used to output the final
This line is not aligned with above line, it contains leading tab.
> +# hole (if any)
> +
> +function get_extent_size(line, tmp) {
Would you please document the expected intput and output in comment as
well? So it's easier to review.
Also, is the 'tmp' argument really needed?
> + split(line, tmp)
> + return tmp[6]
> +}
> +
> +function get_extent_offset(line, tmp) {
Same here.
> + split(line, tmp)
> + gsub(/\)/,"", tmp[6])
> + return tmp[6]
> +}
> +
> +BEGIN {
> + dev_extent_match="^.item [0-9]* key \\([0-9]* DEV_EXTENT [0-9]*\\).*"
> + dev_extent_len_match="^\\s*chunk_objectid [0-9]* chunk_offset [0-9]*
> length [0-9]*$"
> +}
> +
> +{
> + if (match($0,dev_extent_match)) {
> + extent_offset = get_extent_offset($0)
> + if (prev_extent_end) {
> + hole_size = extent_offset - prev_extent_end
> + if (hole_size > 0) {
> + print prev_extent_end / spb, int((extent_offset
> - 1) / spb)
> + }
> + }
> + } else if (match($0, dev_extent_len_match)) {
> + extent_size = get_extent_size($0)
> + prev_extent_end = extent_offset + extent_size
> + }
> +}
> +
> +END {
> + if (prev_extent_end) {
> + print prev_extent_end / spb, int((devsize - 1) / spb)
> + }
> +}
> +
> diff --git a/parse-extent-tree.awk b/parse-extent-tree.awk
> new file mode 100755
> index 000000000000..01c61254cfef
> --- /dev/null
> +++ b/parse-extent-tree.awk
> @@ -0,0 +1,125 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2019 Nikolay Borisov, SUSE LLC. All Rights Reserved.
> +#
> +# Parses btrfs' extent tree for holes, required parameters passed on command
Same here, please provide more details.
> +# line:
> +# * spb - how many bytes per sector, this is used so that the numbers
And replace 'spb' with a more proper variable name.
> +# returned by the script are in sectors.
> +# * nodesize - size of metadata extents, used for internal calculations
Indention issue too.
> +
> +function get_extent_size(line, tmp) {
> + if (line ~ data_match || line ~ bg_match) {
> + split(line, tmp)
> + gsub(/\)/,"", tmp[6])
> + return tmp[6]
> + } else if (line ~ metadata_match) {
> + return nodesize
> + }
> +}
> +
> +function get_extent_offset(line, tmp) {
> + split(line, tmp)
> + gsub(/\(/,"",tmp[4])
> + return tmp[4]
> +}
> +
> +function print_array( base_offset, bg_line)
Document the expected input and output of these functions too.
And why there're so many spaces before 'base_offset' argument?
> +{
> + if (match(lines[0], bg_match)) {
> + #we don't have an extent at the beginning of of blockgroup, so
> we
Add a space after '#' for comments.
> + #have a hole between blockgroup offset and first extent offset
> + bg_line = lines[0]
> + prev_size=0
> + prev_offset=get_extent_offset(bg_line)
> + delete lines[0]
> + } else {
> + #we have an extent at the beginning of block group, so
> initialize
> + #the prev_* vars correctly
> + bg_line = lines[1]
> + prev_size = get_extent_size(lines[0])
> + prev_offset = get_extent_offset(lines[0])
> + delete lines[1]
> + delete lines[0]
> + }
> +
> + bg_offset=get_extent_offset(bg_line)
> + bgend=bg_offset + get_extent_size(bg_line)
> +
> + for (i in lines) {
> + cur_size = get_extent_size(lines[i])
> + cur_offset = get_extent_offset(lines[i])
> + if (cur_offset != prev_offset + prev_size)
> + print int((prev_size + prev_offset) / spb),
> int((cur_offset-1) / spb)
> + prev_size = cur_size
> + prev_offset = cur_offset
> + }
> +
> + print int((prev_size + prev_offset) / spb), int((bgend-1) / spb)
> + total_printed++
> + delete lines
> +}
> +
> +BEGIN {
> + loi_match="^.item [0-9]* key \\([0-9]*
> (BLOCK_GROUP_ITEM|METADATA_ITEM|EXTENT_ITEM) [0-9]*\\).*"
> + metadata_match="^.item [0-9]* key \\([0-9]* METADATA_ITEM [0-9]*\\).*"
> + data_match="^.item [0-9]* key \\([0-9]* EXTENT_ITEM [0-9]*\\).*"
> + bg_match="^.item [0-9]* key \\([0-9]* BLOCK_GROUP_ITEM [0-9]*\\).*"
> + node_match="^node.*$"
> + leaf_match="^leaf [0-9]* flags"
> + line_count=0
> + total_printed=0
> + skip_lines=0
> +}
> +
> +{
> + #skip lines not belonging to a leaf
> + if (match($0,node_match)) {
> + skip_lines=1
> + } else if (match($0, leaf_match)) {
> + skip_lines=0
> + }
> +
> + if (!match($0,loi_match) || skip_lines == 1) next;
> +
> + #we have a line of interest, we need to parse it. First check if there
> is
> + #anything in the array
> + if (line_count==0) {
> + lines[line_count++]=$0;
> + } else {
> + prev_line=lines[line_count-1]
> + split(prev_line, prev_line_fields)
> + prev_objectid=prev_line_fields[4]
> + objectid=$4
> +
> + if (objectid == prev_objectid && match($0, bg_match)) {
> + if (total_printed>0) {
> + #We are adding a BG after we have added its
> first extent
> + #previously, consider this a record ending
> event and just print
> + #the array
> +
> + delete lines[line_count-1]
> + print_array()
> + #we now start a new array with current and
> previous lines
> + line_count=0
> + lines[line_count++]=prev_line
> + lines[line_count++]=$0
> + } else {
> + #first 2 added lines are EXTENT and BG that
> match, in this case
> + #just add them
> + lines[line_count++]=$0
> +
> + }
> + } else if (match($0, bg_match)) {
> + #ordinary end of record
> + print_array()
> + line_count=0
> + lines[line_count++]=$0
> + } else {
> + lines[line_count++]=$0
> + }
> + }
> +}
> +
> +END {
> + print_array()
> +}
> diff --git a/tests/shared/298 b/tests/shared/298
> index e7b7b233de45..8c053aa34adb 100755
> --- a/tests/shared/298
> +++ b/tests/shared/298
> @@ -15,14 +15,24 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
>
> . ./common/rc
>
> -_supported_fs ext4 xfs
> +_supported_fs ext4 xfs btrfs
> _supported_os Linux
> _require_test
> _require_loop
> _require_fstrim
> _require_xfs_io_command "fiemap"
> -_require_fs_space $TEST_DIR 307200
> +if [ "$FSTYP" = "btrfs" ]; then
> + # 3g for btrfs to have distinct bgs
> + _require_fs_space $TEST_DIR 3145728
> + fssize=3000
> +else
> + _require_fs_space $TEST_DIR 307200
> + fssize=300
> +fi
> +
> [ "$FSTYP" = "ext4" ] && _require_dumpe2fs
> +[ "$FSTYP" = "btrfs" ] && _require_btrfs_command inspect-internal dump-super
> +[ "$FSTYP" = "btrfs" ] && _require_btrfs_command inspect-internal dump-tree
>
> _cleanup()
> {
> @@ -61,6 +71,25 @@ get_free_sectors()
> $AWK_PROG -v spb=$sectors_per_block -v agsize=$agsize \
> '{ print spb * ($1 * agsize + $2), spb * ($1 * agsize + $2 +
> $3) - 1 }'
> ;;
> + btrfs)
> + local device_size=$($BTRFS_UTIL_PROG filesystem show --raw
> $loop_mnt 2>&1 \
> + | sed -n "s/^.*size \([0-9]*\).*$/\1/p")
> +
> + local nodesize=$($BTRFS_UTIL_PROG inspect-internal dump-super
> $img_file \
> + | sed -n 's/nodesize\s*\(.*\)/\1/p')
> +
> + # Get holes within block groups
> + local btrfs_free=$($BTRFS_UTIL_PROG inspect-internal dump-tree
> -t extent $img_file \
> + | $AWK_PROG -v spb=512 -v nodesize=$nodesize -f
> parse-extent-tree.awk)
> +
> + btrfs_free+="\n"
> +
> + # Get holes within unallocated space on disk
> + btrfs_free+=$($BTRFS_UTIL_PROG inspect-internal dump-tree -t
> dev $img_file \
> + | $AWK_PROG -v spb=512 -v devsize=$device_size -f
> parse-dev-tree.awk)
> +
> + echo -e "$btrfs_free"
I don't think the "$btrfs_free" variable is needed, we could just let
awk print the result out.
Thanks,
Eryu
> + ;;
> esac
> }
>
> @@ -105,7 +134,7 @@ here=`pwd`
> tmp=`mktemp -d`
>
> img_file=$TEST_DIR/$$.fs
> -dd if=/dev/zero of=$img_file bs=1M count=300 &> /dev/null
> +dd if=/dev/zero of=$img_file bs=1M count=$fssize &> /dev/null
>
> loop_dev=$(_create_loop_device $img_file)
> loop_mnt=$tmp/loop_mnt
> @@ -118,6 +147,7 @@ merged_sectors="$tmp/merged_free_sectors"
> mkdir $loop_mnt
>
> [ "$FSTYP" = "xfs" ] && MKFS_OPTIONS="-f $MKFS_OPTIONS"
> +[ "$FSTYP" = "btrfs" ] && MKFS_OPTIONS="$MKFS_OPTIONS -f -dsingle -msingle"
>
> _mkfs_dev $loop_dev
> _mount $loop_dev $loop_mnt
> --
> 2.7.4
>
