kernel/linux.git/include/net/inet_hashtables.h, branch v4.4.242

tcp/dccp: fix hashdance race for passive sessions

2015-10-23T12:42:21+00:00

Multiple cpus can process duplicates of incoming ACK messages matching a SYN_RECV request socket. This is a rare event under normal operations, but definitely can happen. Only one must win the race, otherwise corruption would occur. To fix this without adding new atomic ops, we use logic in inet_ehash_nolisten() to detect the request was present in the same ehash bucket where we try to insert the new child. If request socket was not found, we have to undo the child creation. This actually removes a spin_lock()/spin_unlock() pair in reqsk_queue_unlink() for the fast path. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp/dccp: install syn_recv requests into ehash table

2015-10-03T11:32:41+00:00

In this patch, we insert request sockets into TCP/DCCP regular ehash table (where ESTABLISHED and TIMEWAIT sockets are) instead of using the per listener hash table. ACK packets find SYN_RECV pseudo sockets without having to find and lock the listener. In nominal conditions, this halves pressure on listener lock. Note that this will allow for SO_REUSEPORT refinements, so that we can select a listener using cpu/numa affinities instead of the prior 'consistent hash', since only SYN packets will apply this selection logic. We will shrink listen_sock in the following patch to ease code review. Signed-off-by: Eric Dumazet Cc: Ying Cai Cc: Willem de Bruijn Signed-off-by: David S. Miller

inet: constify __inet_inherit_port() sock argument

2015-09-29T23:53:08+00:00

socket is not touched, make it const. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

inet: simplify timewait refcounting

2015-07-09T22:12:20+00:00

timewait sockets have a complex refcounting logic. Once we realize it should be similar to established and syn_recv sockets, we can use sk_nulls_del_node_init_rcu() and remove inet_twsk_unhash() In particular, deferred inet_twsk_put() added in commit 13475a30b66cd ("tcp: connect() race with timewait reuse") looks unecessary : When removing a timewait socket from ehash or bhash, caller must own a reference on the socket anyway. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: fix/cleanup inet_ehash_locks_alloc()

2015-05-26T23:48:46+00:00

If tcp ehash table is constrained to a very small number of buckets (eg boot parameter thash_entries=128), then we can crash if spinlock array has more entries. While we are at it, un-inline inet_ehash_locks_alloc() and make following changes : - Budget 2 cache lines per cpu worth of 'spinlocks' - Try to kmalloc() the array to avoid extra TLB pressure. (Most servers at Google allocate 8192 bytes for this hash table) - Get rid of various #ifdef Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

inet_hashinfo: remove bsocket counter

2015-05-21T22:55:32+00:00

We no longer need bsocket atomic counter, as inet_csk_get_port() calls bind_conflict() regardless of its value, after commit 2b05ad33e1e624e ("tcp: bind() fix autoselection to share ports") This patch removes overhead of maintaining this counter and double inet_csk_get_port() calls under pressure. Signed-off-by: Eric Dumazet Cc: Marcelo Ricardo Leitner Cc: Flavio Leitner Acked-by: Flavio Leitner Signed-off-by: David S. Miller

inet: get rid of last __inet_hash_connect() argument

2015-03-19T02:00:35+00:00

We now always call __inet_hash_nolisten(), no need to pass it as an argument. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: get rid of __inet6_hash()

2015-03-19T02:00:35+00:00

We can now use inet_hash() and __inet_hash() instead of private functions. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

inet: add IPv6 support to sk_ehashfn()

2015-03-19T02:00:34+00:00

Intent is to converge IPv4 & IPv6 inet_hash functions to factorize code. IPv4 sockets initialize sk_rcv_saddr and sk_v6_daddr in this patch, thanks to new sk_daddr_set() and sk_rcv_saddr_set() helpers. __inet6_hash can now use sk_ehashfn() instead of a private inet6_sk_ehashfn() and will simply use __inet_hash() in a following patch. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: introduce sk_ehashfn() helper

2015-03-19T02:00:34+00:00

Goal is to unify IPv4/IPv6 inet_hash handling, and use common helpers for all kind of sockets (full sockets, timewait and request sockets) inet_sk_ehashfn() becomes sk_ehashfn() but still only copes with IPv4 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller