On 09.03.2023 19:32, Stefano Garzarella wrote:
> On Thu, Mar 09, 2023 at 07:20:20PM +0300, Arseniy Krasnov wrote:
>>
>>
>> On 09.03.2023 19:21, Stefano Garzarella wrote:
>>> On Thu, Mar 09, 2023 at 01:10:36PM +0300, Arseniy Krasnov wrote:
>>>> Hello,
>>>>
>>>> this patchset evolved from previous v2 version (see link below). It does
>>>> several updates to virtio/vsock:
>>>> 1) Changes 'virtio_transport_inc/dec_rx_pkt()' interface. Now instead of
>>>> using skbuff state ('head' and 'data' pointers) to update 'fwd_cnt'
>>>> and 'rx_bytes', integer value is passed as an input argument. This
>>>> makes code more simple, because in this case we don't need to udpate
>>>> skbuff state before calling 'virtio_transport_inc/dec_rx_pkt()'. In
>>>> more common words - we don't need to change skbuff state to update
>>>> 'rx_bytes' and 'fwd_cnt' correctly.
>>>> 2) For SOCK_STREAM, when copying data to user fails, current skbuff is
>>>> not dropped. Next read attempt will use same skbuff and last offset.
>>>> Instead of 'skb_dequeue()', 'skb_peek()' + '__skb_unlink()' are used.
>>>> This behaviour was implemented before skbuff support.
>>>> 3) For SOCK_SEQPACKET it removes unneeded 'skb_pull()' call, because for
>>>> this type of socket each skbuff is used only once: after removing it
>>>> from socket's queue, it will be freed anyway.
>>>>
>>>> Test for 2) also added:
>>>> Test tries to 'recv()' data to NULL buffer, then does 'recv()' with valid
>>>> buffer. For SOCK_STREAM second 'recv()' must return data, because skbuff
>>>> must not be dropped, but for SOCK_SEQPACKET skbuff will be dropped by
>>>> kernel, and 'recv()' will return EAGAIN.
>>>>
>>>> Link to v1 on lore:
>>>> https://lore.kernel.org/netdev/c2d3e204-89d9-88e9-8a15-3fe027e56b4b@xxxxxxxxxxxxxx/
>>>>
>>>> Link to v2 on lore:
>>>> https://lore.kernel.org/netdev/a7ab414b-5e41-c7b6-250b-e8401f335859@xxxxxxxxxxxxxx/
>>>>
>>>> Change log:
>>>>
>>>> v1 -> v2:
>>>> - For SOCK_SEQPACKET call 'skb_pull()' also in case of copy failure or
>>>> dropping skbuff (when we just waiting message end).
>>>> - Handle copy failure for SOCK_STREAM in the same manner (plus free
>>>> current skbuff).
>>>> - Replace bug repdroducer with new test in vsock_test.c
>>>>
>>>> v2 -> v3:
>>>> - Replace patch which removes 'skb->len' subtraction from function
>>>> 'virtio_transport_dec_rx_pkt()' with patch which updates functions
>>>> 'virtio_transport_inc/dec_rx_pkt()' by passing integer argument
>>>> instead of skbuff pointer.
>>>> - Replace patch which drops skbuff when copying to user fails with
>>>> patch which changes this behaviour by keeping skbuff in queue until
>>>> it has no data.
>>>> - Add patch for SOCK_SEQPACKET which removes redundant 'skb_pull()'
>>>> call on read.
>>>> - I remove "Fixes" tag from all patches, because all of them now change
>>>> code logic, not only fix something.
>>>
>>> Yes, but they solve the problem, so we should use the tag (I think at
>>> least in patch 1 and 3).
>>>
>>> We usually use the tag when we are fixing a problem introduced by a
>>> previous change. So we need to backport the patch to the stable branches
>>> as well, and we need the tag to figure out which branches have the patch
>>> or not.
>> Ahh, sorry. Ok. I see now :)
>
> No problem at all :-)
>
> I think also patch 2 can have the Fixes tag.
>
Done, fixed everything in v4.
Thanks, Arseniy
> Thanks,
> Stefano
>
>>
>> Thanks, Arseniy
>>>
>>> Thanks,
>>> Stefano
>>>
>>>>
>>>> Arseniy Krasnov (4):
>>>> virtio/vsock: don't use skbuff state to account credit
>>>> virtio/vsock: remove redundant 'skb_pull()' call
>>>> virtio/vsock: don't drop skbuff on copy failure
>>>> test/vsock: copy to user failure test
>>>>
>>>> net/vmw_vsock/virtio_transport_common.c | 29 +++---
>>>> tools/testing/vsock/vsock_test.c | 118 ++++++++++++++++++++++++
>>>> 2 files changed, 131 insertions(+), 16 deletions(-)
>>>>
>>>> --
>>>> 2.25.1
>>>>
>>>
>>
>
