Hi Xiao,

On Thu, Dec 24, 2020 at 2:18 AM Xiao Ni [off-list ref] wrote:

[...]

[  789.709501] discard bio start : 70968, size : 191176
[  789.709507] first stripe index 69, start disk index 0, start disk
offset 70968
[  789.709509] last stripe index 256, end disk index 0, end disk offset
262144
[  789.709511] disk 0, dev start : 70968, dev end : 262144
[  789.709515] disk 1, dev start : 70656, dev end : 262144

For example, in this test case, it has 2 near copies. The
start_disk_offset for the first disk is 70968.
It should use the same offset address for second disk. But it uses the
start address of this chunk.
It discard more region. The patch in the attachment can fix this
problem. It split the region that
doesn't align with chunk size.

There is another problem. The stripe size should be calculated
differently for near layout and far layout.

@Song, do you want me to use a separate patch for this fix, or fix this
in the original patch?

Please fold in the changes in the original patches and resend the whole
set.

Thanks,
Song

Merry Christmas
Xiao