Linux Virtualization - May 2021 - [RFC PATCH v9 19/19] af_vsock: serialize writes to shared socket

On Thu, May 13, 2021 at 05:48:19PM +0300, Arseny Krasnov
wrote:
>
>On 13.05.2021 17:46, Stefano Garzarella wrote:
>> On Thu, May 13, 2021 at 04:01:50PM +0200, Stefano Garzarella wrote:
>>> On Sat, May 08, 2021 at 07:37:35PM +0300, Arseny Krasnov wrote:
>>>> This add logic, that serializes write access to single socket
>>>> by multiple threads. It is implemented be adding field with TID
>>>> of current writer. When writer tries to send something, it
checks
>>>> that field is -1(free), else it sleep in the same way as
waiting
>>>> for free space at peers' side.
>>>>
>>>> Signed-off-by: Arseny Krasnov <arseny.krasnov at
kaspersky.com>
>>>> ---
>>>> include/net/af_vsock.h   |  1 +
>>>> net/vmw_vsock/af_vsock.c | 10 +++++++++-
>>>> 2 files changed, 10 insertions(+), 1 deletion(-)
>>> I think you forgot to move this patch at the beginning of the
series.
>>> It's important because in this way we can backport to stable
branches
>>> easily.
>>>
>>> About the implementation, can't we just add a mutex that we
hold until
>>> we have sent all the payload?
>> Re-thinking, I guess we can't because we have the timeout to deal
>> with...
>Yes, i forgot about why i've implemented it using 'tid_owner' :)
It is not clear to me if we need to do this also for stream.

I think will be better to follow af_inet/af_unix, but I need to check 
their implementation.

Thanks,
Stefano