[RFC,00/18] iscsi lock/xmit/recv cleanups

Message

Mike Christie Dec. 13, 2020, 3:08 a.m. UTC

The following patches made over Linus's current tree cleanup the
locking in libiscsi so we again, for the main IO path, have the frwd
lock only used in the xmit/queue path and the back lock used in the
completion path and no taskqueuelock. The EH paths still use both
the frwd/back lock though.

These patches are still not ready for merging. I have now tested
iscsi_tcp, ib_iser, and be2iscsi. Manish tested qedi but it failed.
However, this version should work for qedi and bnx2i. I had forgot to
convert one of the mgmt task paths those drivers use.

V2:
- Fix issue where we used the back lock to make sure all recv
completion paths saw the window reopened flag.
- Fix ping_task path, so it accounts for send/completion race Lee
had fixed.
- Fix bug hit with qedi and bnx2i during testing where I forgot to
allow this drivers to preallocate mgmt task resources.
- Tested ib_iser and be2iscsi.