SLO GET disconnect fails to close sockets

[Alistair Coles]

Client disconnects during an SLO GET can leave unclosed sockets (since patch https://review.opendev.org/c/openstack/swift/+/755639)

To reproduce socket leak in saio:

create an SLO:

dd if=/dev/zero of=./junk_64MiB bs=8192 count=8192
swift upload --use-slo -S 8192000 test ./junk_64MiB

in another window start watching proxy server sockets:

$ sudo watch -n 1 'lsof -itcp -P|grep swift-pro'
Every 1.0s: lsof -itcp -P|grep swift-pro saio: Tue Dec 29 14:58:54 2020

swift-pro 11157 vagrant 53u IPv4 65243 0t0 TCP *:8090 (LISTEN)
swift-pro 11158 vagrant 74u IPv4 65323 0t0 TCP *:8080 (LISTEN)
swift-pro 11314 vagrant 53u IPv4 65243 0t0 TCP *:8090 (LISTEN)
swift-pro 11315 vagrant 74u IPv4 65323 0t0 TCP *:8080 (LISTEN)
curl the SLO and ctrl-C out, watch sockets accumulate:

swift auth
export OS_STORAGE_URL=http://saio:8080/v1/AUTH_test
export OS_AUTH_TOKEN=AUTH_tkae586b30b0fc4646b034dafc892d16f3
$ curl -XGET -i http://saio:8080/v1/AUTH_test/test/junk_64MiB -H "X-Auth-Token: AUTH_tkae586b30b0fc4646b034dafc892d16f3" -o junk --limit-rate 2m
  % Total % Received % Xferd Average Speed Time Time Time Current
                                 Dload Upload Total Spent Left Speed
  6 64.0M 6 4316k 0 0 2450k 0 0:00:26 0:00:01 0:00:25 2449k^C
Every 1.0s: lsof -itcp -P|grep swift-pro saio: Tue Dec 29 15:02:04 2020

swift-pro 11157 vagrant 53u IPv4 65243 0t0 TCP *:8090 (LISTEN)
swift-pro 11158 vagrant 74u IPv4 65323 0t0 TCP *:8080 (LISTEN)
swift-pro 11314 vagrant 53u IPv4 65243 0t0 TCP *:8090 (LISTEN)
swift-pro 11315 vagrant 72u IPv4 71976 0t0 TCP localhost:52782->localhost:11211 (ESTABLISHED)
swift-pro 11315 vagrant 73u IPv4 72064 0t0 TCP localhost:57488->saio:6020 (CLOSE_WAIT)
swift-pro 11315 vagrant 74u IPv4 65323 0t0 TCP *:8080 (LISTEN)

[Alistair Coles (alistair-coles)]

fix merged on master https://review.opendev.org/c/openstack/swift/+/768732

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/swift 2.27.0 release.