[Qemu-devel] [PATCH 0/5] Auto-fragment large transactions at the block layer

[Eric Blake]

We have max_transfer documented in BlockLimits, but while we
honor it during pwrite_zeroes, we were blindly ignoring it
during pwritev and preadv, leading to multiple drivers having
to implement fragmentation themselves.  This series moves
fragmentation to the block layer, then fixes the NBD driver to
use it; if you like this but it needs a v2, you can request that
I further do other drivers (I know at least iscsi and qcow2 do
some self-fragmenting and/or error reporting that can be
simplified by deferring fragmentation to the block layer).

Prequisite: Kevin's block branch, plus my work on byte-based
block limits (v2 at the moment):
https://lists.gnu.org/archive/html/qemu-devel/2016-06/msg04006.html

Also available as a tag at:
git fetch git://repo.or.cz/qemu/ericb.git nbd-fragment-v1

Eric Blake (5):
  block: Fragment reads to max transfer length
  block: Fragment writes to max transfer length
  raw_bsd: Don't advertise flags not supported by protocol layer
  nbd: Rely on block layer to break up large requests
  nbd: Drop unused offset parameter

 include/block/nbd.h |  1 -
 nbd/nbd-internal.h  |  4 +--
 block/io.c          | 84 +++++++++++++++++++++++++++++++++++++++--------------
 block/nbd-client.c  | 78 ++++++++++++++-----------------------------------
 block/nbd.c         | 12 ++------
 block/raw_bsd.c     |  6 ++--
 nbd/common.c        |  3 +-
 7 files changed, 95 insertions(+), 93 deletions(-)

-- 
2.5.5