xfs/217: prevent enospc failures on small test devices

I'm running xfstests against a ramdisk, so I'm limited in size of
the test and scratch devices. While there are large enough to hold a
filesystem image with a 2GB log, the way the log changes position in
an image file as the size of the filesystem increases means that the
aggregated disk space of xfs/217 is more than enough to run a 4GB
TEST_DEV out of space and hence fail the test.

To avoid this problem, punch out the image file between every mkfs
iteration so that it only consumes the space needed by each
individual mkfs tests, not an aggregation of them all.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/tests/xfs/217 b/tests/xfs/217
index 6c439c09b388ccb5403b806d75d952b430c69db5..ab55a30a79f8cf4439d151108ddcb2e3cb8ddfad 100755 (executable)
--- a/tests/xfs/217
+++ b/tests/xfs/217
@@ -63,6 +63,10 @@ _do_mkfs()
                mount -o loop -t xfs $LOOP_DEV $LOOP_MNT
                echo "test write" > $LOOP_MNT/test
                umount -d $LOOP_MNT > /dev/null 2>&1
+
+               # punch out the previous blocks so that we keep the amount of
+               # disk space the test requires down to a minimum.
+               $XFS_IO_PROG -f -c "unresvsp 0 16383g" $LOOP_DEV
        done
 }
 # make large holey file