common/xfs: Add require_xfs_db_write_array function

xfsprogs commit 4222d00("db: write via array indexing doesn't
work") fixes a bug that xfs_db write can't support array indexing.
This function will check whether the bug is fixed on the current
xfsprogs.

xfs/444 applies the function, and skips if this bug exists.

Signed-off-by: yang xu <xuyang.jy@cn.fujitsu.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

common/xfs

@@ -701,3 +701,23 @@ _scratch_xfs_set_sb_field()
 {
 	_scratch_xfs_set_metadata_field "$1" "$2" "sb 0"
 }
+
+# Before xfsprogs commit 4222d000ed("db: write via array indexing doesn't
+# work"), xfs_db command to write a specific AGFL index doesn't work. It's a
+# bug in a diagnostic tool that is only used by XFS developers as a test
+# infrastructure, so it's fine to treat it as a infrastructure dependency as
+# all other _require rules.
+_require_xfs_db_write_array()
+{
+	local supported=0
+
+	_require_test
+	touch $TEST_DIR/$seq.img
+	$MKFS_XFS_PROG -d file,name=$TEST_DIR/$seq.img,size=512m >/dev/null 2>&1
+	$XFS_DB_PROG -x -c "agfl 0" -c "write bno[32] 78" $TEST_DIR/$seq.img \
+		>/dev/null 2>&1
+	$XFS_DB_PROG -x -c "agfl 0" -c "print bno[32]" $TEST_DIR/$seq.img \
+		| grep -q "bno\[32\] = 78" && supported=1
+	rm -f $TEST_DIR/$seq.img
+	[ $supported -eq 0 ] && _notrun "xfs_db write can't support array"
+}

tests/xfs/444

@@ -54,6 +54,7 @@ _supported_os Linux
 _require_check_dmesg
 _require_scratch
 _require_test_program "punch-alternating"
+_require_xfs_db_write_array
 
 # This is only a v5 filesystem problem
 _require_scratch_xfs_crc