On 02/04/2020 05.29, Martin K. Petersen wrote:
Konstantin,
The corresponding exported primitive is called
blkdev_issue_assign_range().
What exact semantics of that?
REQ_OP_ALLOCATE will be used to compel a device to allocate a block
range. What a given block contains after successful allocation is
undefined (depends on the device implementation).
Ok. Then REQ_OP_ALLOCATE should be accounted as discard rather than write.
That's decided by helper op_is_discard() which is used only by statistics.
It seems REQ_OP_SECURE_ERASE also should be accounted in this way.
For block allocation with deterministic zeroing, one must keep using
REQ_OP_WRITE_ZEROES with the NOUNMAP flag set.
