[PATCH 0/7] block/nbd: decouple reconnect from drain

[Roman Kagan <rvkagan@yandex-team.ru>]

The reconnection logic doesn't need to stop while in a drained section.
Moreover it has to be active during the drained section, as the requests
that were caught in-flight with the connection to the server broken can
only usefully get drained if the connection is restored.  Otherwise such
requests can only either stall resulting in a deadlock (before
8c517de24a), or be aborted defeating the purpose of the reconnection
machinery (after 8c517de24a).

This series aims to just stop messing with the drained section in the
reconnection code.

While doing so it undoes the effect of 5ad81b4946 ("nbd: Restrict
connection_co reentrance"); as I've missed the point of that commit I'd
appreciate more scrutiny in this area.

Roman Kagan (7):
  block/nbd: avoid touching freed connect_thread
  block/nbd: use uniformly nbd_client_connecting_wait
  block/nbd: assert attach/detach runs in the proper context
  block/nbd: transfer reconnection stuff across aio_context switch
  block/nbd: better document a case in nbd_co_establish_connection
  block/nbd: decouple reconnect from drain
  block/nbd: stop manipulating in_flight counter

 block/nbd.c  | 191 +++++++++++++++++++++++----------------------------
 nbd/client.c |   2 -
 2 files changed, 86 insertions(+), 107 deletions(-)

-- 
2.30.2