dmhugedisk: Allow specifying of chunk size

Ext4 will want to use dmhugedisk infrastructure for testing resize
bugs.  Ext4 fs images are rather sparse (especially with smaller
block sizes) so the current chunk size of 512 sectors leads to large
space consumption.  Allow test to specify chunk size.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

diff --git a/common/dmhugedisk b/common/dmhugedisk
index 4d3b63fcfcca2c2cd2540b07fd03dca6b4c4a238..733b10cd22923c5b60e54e6deb83b081dc4e4135 100644 (file)
--- a/common/dmhugedisk
+++ b/common/dmhugedisk
@@ -31,6 +31,11 @@ _dmhugedisk_init()
 {
        test -z "$1" && _fatal "must specify sector count to _dmhugedisk_init"
        local dm_backing_dev=$SCRATCH_DEV
+       local chunk_size="$2"
+
+       if [ -z "$chunk_size" ]; then
+               chunk_size=512
+       fi
 
        $DMSETUP_PROG remove huge-test > /dev/null 2>&1
        $DMSETUP_PROG remove huge-test-zero > /dev/null 2>&1
@@ -41,7 +46,7 @@ _dmhugedisk_init()
        DMHUGEDISK_DEV='/dev/mapper/huge-test'
 
        DMHUGEDISK_ZERO_TABLE="0 $blk_dev_size zero"
-       DMHUGEDISK_DEV_TABLE="0 $blk_dev_size snapshot $DMHUGEDISK_ZERO $SCRATCH_DEV N 512"
+       DMHUGEDISK_DEV_TABLE="0 $blk_dev_size snapshot $DMHUGEDISK_ZERO $SCRATCH_DEV N $chunk_size"
 
        $DMSETUP_PROG create huge-test-zero --table "$DMHUGEDISK_ZERO_TABLE" || \
                _fatal "failed to create dm huge zero device"