[Devel] [RH7 PATCH 0/6] RFC ploop: Barrier fix patch set v3

[Dmitry Monakhov]

Here is 3'rd version of barrier fix patches based on recent fixes.
This is an RFC version. I do not have time to test it before tomorrow,
Max please review is briefly and tell be your oppinion about general idea.
Basic idea is to use post_submit state to issue empty FLUSH barrier in order
to complete FUA requests. This allow us to unify all engines (direct and kaio).

This makes FUA processing optimal:
SUBMIT:FUA       :W1{b1,b2,b3,b4..},WAIT,post_submit:FLUSH
SUBMIT_ALLOC:FUA :W1{b1,b2,b3,b4..},WAIT,post_submit:FLUSH, WBI:FUA
RELOC_S: R1, W2,WAIT,post_submit:FLUSH, WBI:FUA
RELOC_A: R1, W2,WAIT,post_submit:FLUSH, WBI:FUA, W1:NULLIFY,WAIT,post_submit:FLUSH


#POST_SUBMIT CHANGES:
ploop-generalize-post_submit-stage.patch
ploop-generalize-issue_flush.patch
ploop-add-delayed-flush-support.patch
ploop-io_kaio-support-PLOOP_REQ_DEL_FLUSH.patch
#RELOC_XXX FIXES
ploop-fixup-barrier-handling-during-relocation.patch
patch-ploop_state_debugging.patch.patch