Zero-filled blocks in HAMMER

[Tomohiro Kusumi]

This might be off topic as I brought this from tux3 ml archive,
but what does "FS converted zerod blocks to hole like hammerfs"
supposed to mean here ?

Is this talking about sparse file ?
(and do BSDs including DragonFly even support sparse file ?)

http://phunq.net/pipermail/tux3/2015-August/002327.html
> Also, if FS converted zerod blocks to hole like hammerfs, simply ENOSPC happens.


This is the result of
# dd if=/dev/zero of=xxx bs=16384 count=10
against a newly created fs, and there are 10 zero-filled data records,
which is what I was expecting to see in fs level from the way hammer
is implemented.

--
HAMMER zone statistics
        zone #  blocks       items              used[B]             used[%]
        zone 0  0            0                  0                   0
        zone 1  0            0                  0                   0
        zone 2  0            0                  0                   0
        zone 3  0            0                  0                   0
        zone 4  0            0                  0                   0
        zone 5  0            0                  0                   0
        zone 6  0            0                  0                   0
        zone 7  0            0                  0                   0
        zone 8  1            1                  4096                0.0488281
        zone 9  1            4                  572                 0.00681877
        zone 10 1            10                 163840              1.95312
        zone 11 0            0                  0                   0
        zone 12 0            0                  0                   0
        zone 13 0            0                  0                   0
        zone 14 0            0                  0                   0
        zone 15 0            0                  0                   0
        ----------------------------------------------------------------------
        total   3            15                 168508              0.669591