[SRU][noble:linux-gcp][PATCH v2 0/2] Backport sysctl_tcp_rto_min_us

[Vinicius Peixoto]

BugLink: https://bugs.launchpad.net/bugs/2076950

[Impact]

Google has requested backports for the following upstream patches:

f086edef71be7174a16c1ed67ac65a085cda28b1 tcp: add sysctl_tcp_rto_min_us
512bd0f9f926a05c724a9fd72bc4e14213845e01 tcp: derive delack_max with tcp_rto_min helper

[Fix]

Noble:
* Backported due to context conflicts
Jammy: 
* Clean cherry-pick for pre-req commit bbf80d713fe7 ("tcp: derive
  delack_max from rto_min")
* Fixed the same context conflicts as Noble, plus a few others
  due to other missing commits that add unrelated TCP sysctls

[Test plan]
* Build and boot tested
* Tested if the new sysctl was added:
    $ sysctl net.ipv4.tcp_rto_min_us
    net.ipv4.tcp_rto_min_us = 200000
    $ sysctl -w net.ipv4.tcp_rto_min_us=50000
    net.ipv4.tcp_rto_min_us = 50000
* Ran the kernel selftests in tools/testing/selftests/net to ensure
  basic network functionality wasn't compromised

[Where problems could occur]
Since this this adds new networking functionality, any problems here
would impact networking on affected systems.

[Other info]
#SF 00392021

v1 -> v2:
  - Fix wrong commit hash in the [Impact] section of the cover letter
  - Fix typo in the [Fix] section of the cover letter
  - Add a BugLink entry to all commits
  - Fix commit hashes in the "cherry-picked from ..." sections
    of the patches

Kevin Yang (2):
  tcp: derive delack_max with tcp_rto_min helper
  tcp: add sysctl_tcp_rto_min_us

 Documentation/networking/ip-sysctl.rst | 13 +++++++++++++
 include/net/netns/ipv4.h               |  1 +
 net/ipv4/sysctl_net_ipv4.c             |  8 ++++++++
 net/ipv4/tcp.c                         |  4 +++-
 net/ipv4/tcp_ipv4.c                    |  1 +
 net/ipv4/tcp_output.c                  | 11 ++---------
 6 files changed, 28 insertions(+), 10 deletions(-)

-- 
2.43.0