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.
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
