[PATCH v2] shared/298: Wire btrfs support in get_free_sectors

[Nikolay Borisov <nborisov@suse.com>]

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 <nborisov@suse.com>
---

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 ++++++++++++++++++++++++++++++++++++++++++++++++++
 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
+# line:
+#     * spb - how many bytes per sector, this is used so that the numbers 
+# 		returned by the script are in sectors.
+#	  * devsize - size of the device in bytes, used to output the final 
+# 		hole (if any)
+
+function get_extent_size(line,  tmp) {
+	split(line, tmp)
+	return tmp[6]
+}
+
+function get_extent_offset(line,  tmp) {
+	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
+# line:
+#     * spb - how many bytes per sector, this is used so that the numbers 
+# 		returned by the script are in sectors.
+#	  * nodesize - size of metadata extents, used for internal calculations
+
+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)
+{
+	if (match(lines[0], bg_match)) {
+		#we don't have an extent at the beginning of of blockgroup, so we
+		#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"
+	;;
 	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