Re: [PATCH 00/15] Protect the block layer with a rwlock: part 3

[Emanuele Giuseppe Esposito <eesposit@redhat.com>]

Ok, as I expected simple changes in a previous based-on serie provoke a
cascade of changes that inevitably affect these patches too.

While I strongly suggest to have an initial look at these patches
because it gives an idea on what am I trying to accomplish, I would not
go looking at nitpicks and trivial errors that came up from the based-on
series (ie "just as in the previous serie, fix this").

The order of the series is:
1. Still more coroutine and various fixes in block layer
2. Protect the block layer with a rwlock: part 1
3. Protect the block layer with a rwlock: part 2
4. Protect the block layer with a rwlock: part 3

Thank you,
Emanuele

Am 16/11/2022 um 15:07 schrieb Emanuele Giuseppe Esposito:
> Please read "Protect the block layer with a rwlock: part 1" and
> "Protect the block layer with a rwlock: part 2" for an
> additional introduction and aim of this series.
> 
> In this serie, we cover the remaining BlockDriver IO callbacks that were not
> running in coroutine, therefore not using the graph rdlock.
> Therefore convert them to coroutines, using either g_c_w or a new
> variant introduced in this serie (see below).
> 
> We need to convert these callbacks into coroutine because non-coroutine code
> is tied to the main thread, even though it will still delegate I/O accesses to
> the iothread (via the bdrv_coroutine_enter call in generated_co_wrappers).
> Making callbacks run in coroutines provides more flexibility, because they run
> entirely in iothreads and can use CoMutexes for mutual exclusion.
> 
> Here we introduce generated_co_wrapper_simple, a simplification of g_c_w that
> only considers the case where the caller is not in a coroutine.
> This simplifies and clarifies a lot when the caller is a coroutine or not, and
> in the future will hopefully replace g_c_w.
> 
> While we are at it, try to directly call the _co_ counterpart of a g_c_w when
> we know already that the function always run in a coroutine.
> 
> Based-on: <20221116135331.3052923-1-eesposit@redhat.com>
> 
> Thank you,
> Emanuele
> 
> Emanuele Giuseppe Esposito (15):
>   block/qed: add missing graph rdlock in qed_need_check_timer_entry
>   block: rename refresh_total_sectors in bdrv_refresh_total_sectors
>   block-backend: use bdrv_getlength instead of blk_getlength
>   block: convert bdrv_refresh_total_sectors in generated_co_wrapper
>   block: use bdrv_co_refresh_total_sectors when possible
>   block: convert bdrv_get_allocated_file_size in
>     generated_co_wrapper_simple
>   block: convert bdrv_get_info in generated_co_wrapper
>   block: convert bdrv_is_inserted in generated_co_wrapper_simple
>   block-coroutine-wrapper: support void functions
>   block: convert bdrv_eject in generated_co_wrapper_simple
>   block: convert bdrv_lock_medium in generated_co_wrapper_simple
>   block: convert bdrv_debug_event in generated_co_wrapper
>   block: convert bdrv_io_plug in generated_co_wrapper_simple
>   block: convert bdrv_io_unplug in generated_co_wrapper_simple
>   block: rename newly converted BlockDriver IO coroutine functions
> 
>  block.c                            | 93 +++++++++++++++++++-----------
>  block/blkdebug.c                   |  4 +-
>  block/blkio.c                      |  6 +-
>  block/blklogwrites.c               |  2 +-
>  block/blkreplay.c                  |  2 +-
>  block/blkverify.c                  |  2 +-
>  block/block-backend.c              | 43 ++++++++------
>  block/commit.c                     |  4 +-
>  block/copy-on-read.c               | 12 ++--
>  block/crypto.c                     |  6 +-
>  block/curl.c                       |  8 +--
>  block/file-posix.c                 | 48 +++++++--------
>  block/file-win32.c                 |  8 +--
>  block/filter-compress.c            | 10 ++--
>  block/gluster.c                    | 16 ++---
>  block/io.c                         | 78 +++++++++++++------------
>  block/iscsi.c                      |  8 +--
>  block/meson.build                  |  1 +
>  block/mirror.c                     | 17 ++++--
>  block/nbd.c                        |  6 +-
>  block/nfs.c                        |  2 +-
>  block/null.c                       |  8 +--
>  block/nvme.c                       |  6 +-
>  block/preallocate.c                |  2 +-
>  block/qcow.c                       |  2 +-
>  block/qcow2-refcount.c             |  2 +-
>  block/qcow2.c                      |  6 +-
>  block/qed.c                        |  7 ++-
>  block/quorum.c                     |  2 +-
>  block/raw-format.c                 | 14 ++---
>  block/rbd.c                        |  4 +-
>  block/replication.c                |  2 +-
>  block/ssh.c                        |  2 +-
>  block/stream.c                     |  4 +-
>  block/throttle.c                   |  2 +-
>  block/vdi.c                        |  2 +-
>  block/vhdx.c                       |  2 +-
>  block/vmdk.c                       |  4 +-
>  block/vpc.c                        |  2 +-
>  blockdev.c                         |  8 ++-
>  hw/scsi/scsi-disk.c                |  5 ++
>  include/block/block-io.h           | 40 +++++++++----
>  include/block/block_int-common.h   | 37 +++++++-----
>  include/block/block_int-io.h       |  5 +-
>  include/sysemu/block-backend-io.h  | 32 +++++++---
>  scripts/block-coroutine-wrapper.py | 19 ++++--
>  tests/unit/test-block-iothread.c   |  7 +++
>  47 files changed, 364 insertions(+), 238 deletions(-)
>