linux/net/ipv4
Eric Dumazet 99779c24bf tcp: fix SO_RCVLOWAT hangs with fat skbs
[ Upstream commit 24adbc1676 ]

We autotune rcvbuf whenever SO_RCVLOWAT is set to account for 100%
overhead in tcp_set_rcvlowat()

This works well when skb->len/skb->truesize ratio is bigger than 0.5

But if we receive packets with small MSS, we can end up in a situation
where not enough bytes are available in the receive queue to satisfy
RCVLOWAT setting.
As our sk_rcvbuf limit is hit, we send zero windows in ACK packets,
preventing remote peer from sending more data.

Even autotuning does not help, because it only triggers at the time
user process drains the queue. If no EPOLLIN is generated, this
can not happen.

Note poll() has a similar issue, after commit
c7004482e8 ("tcp: Respect SO_RCVLOWAT in tcp_poll().")

Fixes: 03f45c883c ("tcp: avoid extra wakeups for SO_RCVLOWAT users")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-20 08:18:38 +02:00
..
bpfilter bpfilter: remove trailing newline 2018-07-24 14:10:42 -07:00
netfilter netfilter: arp_tables: init netns pointer in xt_tgdtor_param struct 2020-01-23 08:21:33 +01:00
af_inet.c net: don't clear sock->sk early to avoid trouble in strparser 2020-01-27 14:50:52 +01:00
ah4.c
arp.c proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
cipso_ipv4.c netlabel: cope with NULL catmap 2020-05-20 08:18:35 +02:00
datagram.c inet: stop leaking jiffies on the wire 2019-11-10 11:27:37 +01:00
devinet.c net: ipv4: devinet: Fix crash when add/del multicast IP with autojoin 2020-04-21 09:03:03 +02:00
esp4_offload.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-07-27 09:33:37 -07:00
esp4.c esp4: add length check for UDP encapsulation 2019-05-25 18:23:41 +02:00
fib_frontend.c ipv4: fix route update on metric change. 2019-11-10 11:27:50 +01:00
fib_lookup.h
fib_notifier.c
fib_rules.c net: fib_rules: add extack support 2018-04-23 10:21:24 -04:00
fib_semantics.c ipv4: Fix table id reference in fib_sync_down_addr 2019-11-12 19:20:27 +01:00
fib_trie.c ipv4: fix a RCU-list lock in fib_triestat_seq_show 2020-04-13 10:44:57 +02:00
fou.c net: fou: do not use guehdr after iptunnel_pull_offloads in gue_udp_recv 2019-04-27 09:36:31 +02:00
gre_demux.c gre: fix uninit-value in __iptunnel_pull_header 2020-03-18 07:14:11 +01:00
gre_offload.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-03 10:29:26 +09:00
icmp.c net: icmp: fix data-race in cmp_global_allow() 2020-01-04 19:13:30 +01:00
igmp.c ipv4/igmp: fix v1/v2 switchback timeout based on rfc3376, 8.12 2019-12-01 09:17:05 +01:00
inet_connection_sock.c net: memcg: fix lockdep splat in inet_csk_accept() 2020-03-18 07:14:14 +01:00
inet_diag.c inet_diag: return classid for all socket types 2020-03-18 07:14:11 +01:00
inet_fragment.c net: IP defrag: encapsulate rbtree defrag code into callable functions 2019-04-27 09:36:33 +02:00
inet_hashtables.c tcp/dccp: fix possible race __inet_lookup_established() 2020-01-04 19:13:41 +01:00
inet_timewait_sock.c soreuseport: initialise timewait reuseport field 2018-04-07 22:32:32 -04:00
inetpeer.c inetpeer: fix data-race in inet_putpeer / inet_putpeer 2020-01-04 19:13:29 +01:00
ip_forward.c net: clear skb->tstamp in forwarding paths 2019-01-09 17:38:31 +01:00
ip_fragment.c net: IP defrag: encapsulate rbtree defrag code into callable functions 2019-04-27 09:36:33 +02:00
ip_gre.c net: ip_gre: Accept IFLA_INFO_DATA-less configuration 2020-04-02 15:28:13 +02:00
ip_input.c vrf: check accept_source_route on the original netdevice 2019-04-17 08:38:42 +02:00
ip_options.c vrf: check accept_source_route on the original netdevice 2019-04-17 08:38:42 +02:00
ip_output.c net: always initialize pagedlen 2020-01-27 14:50:03 +01:00
ip_sockglue.c net: bpfilter: fix iptables failure if bpfilter_umh is disabled 2019-12-01 09:17:18 +01:00
ip_tunnel_core.c ip_tunnel: allow not to count pkts on tstats by setting skb's dev to NULL 2019-08-04 09:30:57 +02:00
ip_tunnel.c net, ip_tunnel: fix interface lookup with no key 2020-04-13 10:44:57 +02:00
ip_vti.c vti4: removed duplicate log message. 2020-04-29 16:31:08 +02:00
ipcomp.c
ipconfig.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
ipip.c ipip: validate header length in ipip_tunnel_xmit 2019-08-09 17:52:30 +02:00
ipmr_base.c net: ipmr: fix unresolved entry dumps 2018-10-17 22:35:42 -07:00
ipmr.c ipmr: Fix skb headroom in ipmr_get_route(). 2019-11-20 18:45:11 +01:00
Kconfig vti[6]: fix packet tx through bpf_redirect() in XinY cases 2020-04-02 15:28:18 +02:00
Makefile net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
metrics.c net: metrics: add proper netlink validation 2018-06-05 12:29:43 -04:00
netfilter.c netfilter: utils: move nf_ip_checksum* from ipv4 to utils 2018-07-16 17:51:48 +02:00
netlink.c ipv4: Add ICMPv6 support when parse route ipproto 2019-03-10 07:17:17 +01:00
ping.c net: add helpers checking if socket can be bound to nonlocal address 2018-08-01 09:50:04 -07:00
proc.c tcp: tcp_fragment() should apply sane memory limits 2019-06-17 19:51:56 +02:00
protocol.c
raw_diag.c inet_diag: return classid for all socket types 2020-03-18 07:14:11 +01:00
raw.c ipv4: Use return value of inet_iif() for __raw_v4_lookup in the while loop 2019-07-03 13:14:46 +02:00
route.c net: ipv4: really enforce backoff for redirects 2020-05-20 08:18:38 +02:00
syncookies.c tcp: handle inet_csk_reqsk_queue_add() failures 2019-03-19 13:12:39 +01:00
sysctl_net_ipv4.c tcp: add tcp_min_snd_mss sysctl 2019-06-17 19:51:56 +02:00
tcp_bbr.c tcp_bbr: improve arithmetic division in bbr_update_bw() 2020-01-29 16:43:17 +01:00
tcp_bic.c
tcp_cdg.c
tcp_cong.c tcp: fix tcp_set_congestion_control() use from bpf hook 2019-07-28 08:29:26 +02:00
tcp_cubic.c
tcp_dctcp.c tcp: Ensure DCTCP reacts to losses 2019-04-17 08:38:41 +02:00
tcp_diag.c tcp: annotate tp->rcv_nxt lockless reads 2020-01-09 10:19:08 +01:00
tcp_fastopen.c
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c net/tcp/illinois: replace broken algorithm reference link 2018-02-28 12:03:47 -05:00
tcp_input.c tcp: fix SO_RCVLOWAT hangs with fat skbs 2020-05-20 08:18:38 +02:00
tcp_ipv4.c tcp: annotate tp->rcv_nxt lockless reads 2020-01-09 10:19:08 +01:00
tcp_lp.c
tcp_metrics.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
tcp_minisocks.c tcp: annotate tp->rcv_nxt lockless reads 2020-01-09 10:19:08 +01:00
tcp_nv.c tcp_nv: fix potential integer overflow in tcpnv_acked 2018-01-31 10:26:30 -05:00
tcp_offload.c tcp: Don't coalesce decrypted and encrypted SKBs 2018-07-16 00:12:09 -07:00
tcp_output.c tcp: do not leave dangling pointers in tp->highest_sack 2020-01-29 16:43:17 +01:00
tcp_rate.c tcp: expose both send and receive intervals for rate sample 2018-07-11 23:01:56 -07:00
tcp_recovery.c tcp: add stat of data packet reordering events 2018-08-01 09:56:10 -07:00
tcp_scalable.c
tcp_timer.c tcp: fix SNMP TCP timeout under-estimation 2019-12-13 08:52:20 +01:00
tcp_ulp.c tcp, ulp: fix leftover icsk_ulp_ops preventing sock from reattach 2018-08-16 14:58:08 -07:00
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c tcp: fix SO_RCVLOWAT hangs with fat skbs 2020-05-20 08:18:38 +02:00
tunnel4.c inet: whitespace cleanup 2018-02-28 11:43:28 -05:00
udp_diag.c inet_diag: return classid for all socket types 2020-03-18 07:14:11 +01:00
udp_impl.h
udp_offload.c net/udp_gso: Allow TX timestamp with UDP GSO 2020-01-27 14:50:56 +01:00
udp_tunnel.c
udp.c Revert "udp: do rmem bulk free even if the rx sk queue is empty" 2020-01-29 16:43:17 +01:00
udplite.c proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
xfrm4_input.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c xfrm: reset transport header back to network header after all input transforms ahave been applied 2018-09-04 10:26:30 +02:00
xfrm4_mode_tunnel.c xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto 2018-03-07 10:54:29 +01:00
xfrm4_output.c xfrm: Always set XFRM_TRANSFORMED in xfrm{4,6}_output_finish 2020-04-29 16:31:23 +02:00
xfrm4_policy.c net: add bool confirm_neigh parameter for dst_ops.update_pmtu 2020-01-04 19:13:37 +01:00
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c