This fixes the problem that blockdev-create on a local file blocks the
main loop despite being a background job. This was caused by file-posix
preallocating the image with blocking syscalls rather than moving this
to the thread pool and yielding the coroutine meanwhile.

v2:
- Add locking to qcow2_co_discard()
- Extra qcow2 fix and cleanup related to the locking code
- Use tracked requests infrastructure for serialising I/O requests
  against truncate in newly allocated areas

Kevin Wolf (6):
  qcow2: Fix qcow2_truncate() error return value
  block: Convert .bdrv_truncate callback to coroutine_fn
  qcow2: Remove coroutine trampoline for preallocate_co()
  block: Move bdrv_truncate() implementation to io.c
  block: Use tracked request for truncate
  file-posix: Make .bdrv_co_truncate asynchronous

 include/block/block.h     |   4 +
 include/block/block_int.h |   7 +-
 include/block/raw-aio.h   |   4 +-
 block.c                   |  64 +----------
 block/copy-on-read.c      |   8 +-
 block/crypto.c            |   9 +-
 block/file-posix.c        | 277 ++++++++++++++++++++++++++--------------------
 block/file-win32.c        |   6 +-
 block/gluster.c           |  14 ++-
 block/io.c                | 134 ++++++++++++++++++++++
 block/iscsi.c             |   8 +-
 block/nfs.c               |   7 +-
 block/qcow2.c             | 124 +++++++++------------
 block/qed.c               |   8 +-
 block/raw-format.c        |   8 +-
 block/rbd.c               |   8 +-
 block/sheepdog.c          |  12 +-
 block/ssh.c               |   6 +-
 18 files changed, 405 insertions(+), 303 deletions(-)

-- 
2.13.6

On Tue, Jun 26, 2018 at 04:24:28PM +0200, Kevin Wolf wrote:
> This fixes the problem that blockdev-create on a local file blocks the
> main loop despite being a background job. This was caused by file-posix
> preallocating the image with blocking syscalls rather than moving this
> to the thread pool and yielding the coroutine meanwhile.
> 
> v2:
> - Add locking to qcow2_co_discard()
> - Extra qcow2 fix and cleanup related to the locking code
> - Use tracked requests infrastructure for serialising I/O requests
>   against truncate in newly allocated areas

Looks good!

Am 27.06.2018 um 13:58 hat Stefan Hajnoczi geschrieben:
> On Tue, Jun 26, 2018 at 04:24:28PM +0200, Kevin Wolf wrote:
> > This fixes the problem that blockdev-create on a local file blocks the
> > main loop despite being a background job. This was caused by file-posix
> > preallocating the image with blocking syscalls rather than moving this
> > to the thread pool and yielding the coroutine meanwhile.
> > 
> > v2:
> > - Add locking to qcow2_co_discard()
> > - Extra qcow2 fix and cleanup related to the locking code
> > - Use tracked requests infrastructure for serialising I/O requests
> >   against truncate in newly allocated areas
> 
> Looks good!

Thanks for the review! Applied to my block branch.

Kevin