MFC r271845:
Allow more commands to pass persistent reservation according to SPC-4 r37.
MFC r271869:
Fix inverted expression to report block size in mode page block descriptor.
MFC r271930: Allow SUBPAGE CODE field in MODE SENSE commands.
MFC r271940: Polish INQUIRY command fields validation.
MFC r271941:
Report proper errors codes for unsupported SERVICE ACTION values.
MFC r271942:
Don't report unsupported FUA_NV bit set in READ/WRITE commands as error.

While this bit is obsolete in SBC-3, SBC-2 allowed to silently ignore it.
MFC r271945:
Simplify legacy reservation handling.  Drop it on I_T nexus loss.
MFC r271951: Don't try to continue aborted commands if status was not set.
MFC r271954:
Deny ANCHOR flag set without UNMAP flag set in WRITE SAME commands.
MFC r271959: Pretend that we support BYTCHK=1 in WRITE AND VERIFY command.

Technically that is not true, but since we don't implement VERIFY there
at all, doing only WRITE part, this is a minor sin.
MFC r272033:
Fix ASCQ for "Logical unit not ready, manual intervention required" error.
MFC r272224: Fix page length reported for Block Limits VPD page.
MFC r272323:
If the checksum coverage field in the UDPLITE header is the length
of the complete UDPLITE packet, the packet has full checksum coverage.
So fix the condition.
MFC r272247:
Do not transfer unneeded training zero bytes in INQUIRY response.

It is an addition to r269631.
MFC r272355: Fix couple issues with ROD tokens content.