Re: [Qemu-block] [PATCH 00/10] Block layer thread-safety, part 2

[Paolo Bonzini]

On 27/06/2017 17:22, Paolo Bonzini wrote:
> This part takes care of drivers and devices, making sure that they can
> accept concurrent I/O from multiple AioContext.
> 
> The following drivers are thread-safe without using any QemuMutex/CoMutex:
> crypto, gluster, null, rbd, win32-aio.  NBD has already been fixed,
> because the patch fixed an unrelated testcase.
> 
> The following drivers already use mutexes for everything except possibly
> snapshots, which do not (yet?) need protection: bochs, cloop, dmg, qcow,
> parallels, vhdx, vmdk, curl, iscsi, nfs.
> 
> The following drivers already use mutexes for _almost_ everything: vpc
> (missing get_block_status), vdi (missing bitmap access), vvfat (missing
> commit), not protected), qcow2 (must call CoQueue APIs under CoMutex).
> They are fixed by patches 1-5.
> 
> The following drivers must be changed to use CoMutex to protect internal
> data: qed (patches 6-8), sheepdog (patch 9).
> 
> The following driver must be changed to support I/O from any AioContext:
> ssh.  It is fixed by patch 10.
> 
> Paolo

Nevermind---my tests were confused by some pre-existing failures in
qemu-iotests (068 for qcow2, caused by the patch dropped in v2 of the
pull request; 181 for vmdk and vpc).  This series is no good.

Paolo

> Paolo Bonzini (10):
>   qcow2: call CoQueue APIs under CoMutex
>   coroutine-lock: add qemu_co_rwlock_downgrade and
>     qemu_co_rwlock_upgrade
>   vdi: make it thread-safe
>   vpc: make it thread-safe
>   vvfat: make it thread-safe
>   qed: move tail of qed_aio_write_main to qed_aio_write_{cow,alloc}
>   block: invoke .bdrv_drain callback in coroutine context and from
>     AioContext
>   qed: protect table cache with CoMutex
>   sheepdog: add queue_lock
>   ssh: support I/O from any AioContext
> 
>  block/io.c                 |  42 +++++++---
>  block/qcow2.c              |   4 +-
>  block/qed-cluster.c        |   4 +-
>  block/qed-l2-cache.c       |   6 ++
>  block/qed-table.c          |  24 ++++--
>  block/qed.c                | 195 
> +++++++++++++++++++++++++++------------------
>  block/qed.h                |  11 ++-
>  block/sheepdog.c           |  21 ++++-
>  block/ssh.c                |  24 ++++--
>  block/vdi.c                |  48 +++++------
>  block/vpc.c                |  20 ++---
>  block/vvfat.c              |   8 +-
>  include/block/block_int.h  |   2 +-
>  include/qemu/coroutine.h   |  18 +++++
>  util/qemu-coroutine-lock.c |  35 ++++++++
>  15 files changed, 316 insertions(+), 146 deletions(-)
>