[PATCH net-next v6 0/5] vsock: SOCK_LINGER rework

[Michal Luczaj <mhal@rbox.co>]

Change vsock's lingerning to wait on close() until all data is sent, i.e.
until workers picked all the packets for processing.

Changes in v6:
- Make vsock_wait_sent() return bool, parametrize enable_so_linger() with
  timeout, don't open code DIV_ROUND_UP [Stefano]
- Link to v5: https://lore.kernel.org/r/20250521-vsock-linger-v5-0-94827860d1d6@rbox.co

Changes in v5:
- Move unsent_bytes fetching logic to utils.c
- Add a helper for enabling SO_LINGER
- Accommodate for close() taking a long time for reasons unrelated to
  lingering
- Separate and redo the testcase [Stefano]
- Enrich the comment [Stefano]
- Link to v4: https://lore.kernel.org/r/20250501-vsock-linger-v4-0-beabbd8a0847@rbox.co

Changes in v4:
- While in virtio, stick to virtio_transport_unsent_bytes() [Stefano]
- Squash the indentation reduction [Stefano]
- Pull SOCK_LINGER check into vsock_linger() [Stefano]
- Don't explicitly pass sk->sk_lingertime [Stefano]
- Link to v3: https://lore.kernel.org/r/20250430-vsock-linger-v3-0-ddbe73b53457@rbox.co

Changes in v3:
- Set "vsock/virtio" topic where appropriate
- Do not claim that Hyper-V and VMCI ever lingered [Stefano]
- Move lingering to af_vsock core [Stefano] 
- Link to v2: https://lore.kernel.org/r/20250421-vsock-linger-v2-0-fe9febd64668@rbox.co

Changes in v2:
- Comment that some transports do not implement unsent_bytes [Stefano]
- Reduce the indentation of virtio_transport_wait_close() [Stefano] 
- Do not linger on shutdown(), expand the commit messages [Paolo]
- Link to v1: https://lore.kernel.org/r/20250407-vsock-linger-v1-0-1458038e3492@rbox.co

Changes in v1:
- Do not assume `unsent_bytes()` is implemented by all transports [Stefano]
- Link to v0: https://lore.kernel.org/netdev/df2d51fd-03e7-477f-8aea-938446f47864@rbox.co/

Signed-off-by: Michal Luczaj <mhal@rbox.co>
---
Michal Luczaj (5):
      vsock/virtio: Linger on unsent data
      vsock: Move lingering logic to af_vsock core
      vsock/test: Introduce vsock_wait_sent() helper
      vsock/test: Introduce enable_so_linger() helper
      vsock/test: Add test for an unexpectedly lingering close()

 include/net/af_vsock.h                  |  1 +
 net/vmw_vsock/af_vsock.c                | 33 +++++++++++++
 net/vmw_vsock/virtio_transport_common.c | 21 +--------
 tools/testing/vsock/util.c              | 38 +++++++++++++++
 tools/testing/vsock/util.h              |  2 +
 tools/testing/vsock/vsock_test.c        | 83 +++++++++++++++++++++++----------
 6 files changed, 134 insertions(+), 44 deletions(-)
---
base-commit: f44092606a3f153bb7e6b277006b1f4a5b914cfc
change-id: 20250304-vsock-linger-9026e5f9986c

Best regards,
-- 
Michal Luczaj <mhal@rbox.co>