net: Namespace-ify sysctl_optmem_max

optmem_max being used in tx zerocopy,
we want to be able to control it on a netns basis.

Following patch changes two tests.

Tested:

oqq130:~# cat /proc/sys/net/core/optmem_max
131072
oqq130:~# echo 1000000 >/proc/sys/net/core/optmem_max
oqq130:~# cat /proc/sys/net/core/optmem_max
1000000
oqq130:~# unshare -n
oqq130:~# cat /proc/sys/net/core/optmem_max
131072
oqq130:~# exit
logout
oqq130:~# cat /proc/sys/net/core/optmem_max
1000000

cos-patch: bug
Change-Id: Iec5bcddee62109cfe2725febadbfa4950654672a
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit f5769faeec36b9d5b9df2c3e4f05a76d04ffd9c9)
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/62583
Tested-by: Mina Almasry <almasrymina@google.com>
(cherry picked from commit 2f588762a5611884321e7244d8362315ad1f139f)
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/62740
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
9 files changed