--- v1
+++ v3
@@ -1,6 +1,6 @@
This patchset implements support of MSG_EOR bit for SEQPACKET
AF_VSOCK sockets over virtio transport.
- Idea is to distinguish concepts of 'messages' and 'records'.
+ First we need to define 'messages' and 'records' like this:
Message is result of sending calls: 'write()', 'send()', 'sendmsg()'
etc. It has fixed maximum length, and it bounds are visible using
return from receive calls: 'read()', 'recv()', 'recvmsg()' etc.
@@ -9,28 +9,54 @@
and bounds of record are visible via MSG_EOR flag returned from
'recvmsg()' call. Sender passes MSG_EOR to sending system call and
receiver will see MSG_EOR when corresponding message will be processed.
+ Idea of patchset comes from POSIX: it says that SEQPACKET
+supports record boundaries which are visible for receiver using
+MSG_EOR bit. So, it looks like MSG_EOR is enough thing for SEQPACKET
+and we don't need to maintain boundaries of corresponding send -
+receive system calls. But, for 'sendXXX()' and 'recXXX()' POSIX says,
+that all these calls operates with messages, e.g. 'sendXXX()' sends
+message, while 'recXXX()' reads messages and for SEQPACKET, 'recXXX()'
+must read one entire message from socket, dropping all out of size
+bytes. Thus, both message boundaries and MSG_EOR bit must be supported
+to follow POSIX rules.
To support MSG_EOR new bit was added along with existing
'VIRTIO_VSOCK_SEQ_EOR': 'VIRTIO_VSOCK_SEQ_EOM'(end-of-message) - now it
works in the same way as 'VIRTIO_VSOCK_SEQ_EOR'. But 'VIRTIO_VSOCK_SEQ_EOR'
is used to mark 'MSG_EOR' bit passed from userspace.
This patchset includes simple test for MSG_EOR.
- Also i've added new vsock test for '-EAGAIN' receive result.
- Arseny Krasnov(7):
- virtio/vsock: add 'VIRTIO_VSOCK_SEQ_EOM' bit
- vsock: rename implementation from 'record' to 'message'
+ Arseny Krasnov(6):
+ virtio/vsock: rename 'EOR' to 'EOM' bit.
+ virtio/vsock: add 'VIRTIO_VSOCK_SEQ_EOR' bit.
vhost/vsock: support MSG_EOR bit processing
- virito/vsock: support MSG_EOR bit processing
+ virtio/vsock: support MSG_EOR bit processing
af_vsock: rename variables in receive loop
vsock_test: update message bounds test for MSG_EOR
- vsock_test: 'SO_RCVTIMEO' test for SEQPACKET
- drivers/vhost/vsock.c | 28 +++++++----
- include/uapi/linux/virtio_vsock.h | 1 +
- net/vmw_vsock/af_vsock.c | 10 ++--
- net/vmw_vsock/virtio_transport_common.c | 23 +++++----
- tools/testing/vsock/vsock_test.c | 57 ++++++++++++++++++++++-
- 5 files changed, 96 insertions(+), 23 deletions(-)
+ drivers/vhost/vsock.c | 22 +++++++++++++---------
+ include/uapi/linux/virtio_vsock.h | 3 ++-
+ net/vmw_vsock/af_vsock.c | 10 +++++-----
+ net/vmw_vsock/virtio_transport_common.c | 23 +++++++++++++++--------
+ tools/testing/vsock/vsock_test.c | 8 +++++++-
+ 5 files changed, 42 insertions(+), 24 deletions(-)
+
+ v2 -> v3:
+ - 'virtio/vsock: rename 'EOR' to 'EOM' bit.' - commit message updated.
+ - 'VIRTIO_VSOCK_SEQ_EOR' bit add moved to separate patch.
+ - 'vhost/vsock: support MSG_EOR bit processing' - commit message
+ updated.
+ - 'vhost/vsock: support MSG_EOR bit processing' - removed unneeded
+ 'le32_to_cpu()', because input argument was already in CPU
+ endianness.
+
+ v1 -> v2:
+ - 'VIRTIO_VSOCK_SEQ_EOR' is renamed to 'VIRTIO_VSOCK_SEQ_EOM', to
+ support backward compatibility.
+ - use bitmask of flags to restore in vhost.c, instead of separated
+ bool variable for each flag.
+ - test for EAGAIN removed, as logically it is not part of this
+ patchset(will be sent separately).
+ - cover letter updated(added part with POSIX description).
Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>