Re: [PATCH v2 0/8] Block layer thread-safety, continued

[Paolo Bonzini]

On 19/04/21 10:55, Emanuele Giuseppe Esposito wrote:
> This and the following serie of patches are based on Paolo's
> v1 patches sent in 2017[*]. They have been ported to the current QEMU
> version, but the goal remains the same:
> - make the block layer thread-safe (patches 1-5), and
> - remove aio_context_acquire/release (patches 6-8).
>
> [*] = https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg01398.html
>
> Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>

This looks good to me, though the commit message of patch 8 needs to be 
rewritten.

Paolo

> ---
> v1 (2017) -> v2 (2021):
> - v1 Patch "block-backup: add reqs_lock" has been dropped, because now
>    is completely different from the old version and all functions
>    that were affected by it have been moved or deleted.
>    It will be replaced by another serie that aims to thread safety to
>    block/block-copy.c
> - remaining v1 patches will be integrated in next serie.
> - Patch "block: do not acquire AioContext in check_to_replace_node"
>    moves part of the logic of check_to_replace_node to the caller,
>    so that the function can be included in the aio_context_acquire/release
>    block that follows.
>
> Emanuele Giuseppe Esposito (8):
>    block: prepare write threshold code for thread safety
>    block: protect write threshold QMP commands from concurrent requests
>    util: use RCU accessors for notifiers
>    block: make before-write notifiers thread-safe
>    block: add a few more notes on locking
>    block: do not acquire AioContext in check_to_replace_node
>    block/replication: do not acquire AioContext
>    block: do not take AioContext around reopen
>
>   block.c                   | 28 ++++++--------------
>   block/block-backend.c     |  4 ---
>   block/io.c                | 12 +++++++++
>   block/mirror.c            |  9 -------
>   block/replication.c       | 54 +++++++++------------------------------
>   block/write-threshold.c   | 39 ++++++++++++++--------------
>   blockdev.c                | 26 +++++++++----------
>   include/block/block.h     |  1 +
>   include/block/block_int.h | 42 +++++++++++++++++++++++++++++-
>   util/notify.c             | 13 +++++-----
>   10 files changed, 113 insertions(+), 115 deletions(-)