[Qemu-devel] [RFC 0/3] NBD reconnect

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Hi all.

Here is a draft of NBD reconnect, to negotiate overall design. It is done
through implementing new error action: reconnect.

New action works as follows:

Firstly, not stopping the vm, it tries to bdrv_reconnect several times
with given pause. Then, if we failed to reconnect fallthrough to 'stop'
error action.

My RFC doubts:
1. introducing new .bdrv_reconnect(). Is bdrv_reopen() appropriate for
   the feature? I'm not sure, because it is not recursive, and don't
   really reopen files..
2. introducing new error action. Anyway, I'll have to add some configuration
   parameters (see 03), so, the feature may be just an option to 'stop'
   action, rather than separate error action.

Vladimir Sementsov-Ogievskiy (3):
  block: add bdrv_reconnect
  nbd: add .bdrv_reconnect handler
  blk: add 'reconnect' error action

 qapi/block-core.json      |  4 ++--
 include/block/block.h     |  2 ++
 include/block/block_int.h |  3 +++
 block.c                   | 22 +++++++++++++++++
 block/block-backend.c     | 48 ++++++++++++++++++++++++++++++++++++-
 block/nbd.c               | 60 ++++++++++++++++++++++++++++++++++-------------
 hw/scsi/scsi-disk.c       |  4 +++-
 7 files changed, 123 insertions(+), 20 deletions(-)

-- 
2.11.1