The blocks may exceed the block limits offered by the target,
query unmap/write zero max blocks by inquiry
SCSI_INQUIRY_PAGECODE_BLOCK_LIMITS command, than use a loop to do the
job.
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
The new tool 'iscsi-discard' is used to excute unmap or write zeros
on an ISCSI target. The parameters look like the command 'blkdiscard'
(from util-linux).
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>