kernel/linux.git/include/net/sock.h, branch v4.6.4

soreuseport: fix ordering for mixed v4/v6 sockets

2016-04-15T01:14:03+00:00

With the SO_REUSEPORT socket option, it is possible to create sockets in the AF_INET and AF_INET6 domains which are bound to the same IPv4 address. This is only possible with SO_REUSEPORT and when not using IPV6_V6ONLY on the AF_INET6 sockets. Prior to the commits referenced below, an incoming IPv4 packet would always be routed to a socket of type AF_INET when this mixed-mode was used. After those changes, the same packet would be routed to the most recently bound socket (if this happened to be an AF_INET6 socket, it would have an IPv4 mapped IPv6 address). The change in behavior occurred because the recent SO_REUSEPORT optimizations short-circuit the socket scoring logic as soon as they find a match. They did not take into account the scoring logic that favors AF_INET sockets over AF_INET6 sockets in the event of a tie. To fix this problem, this patch changes the insertion order of AF_INET and AF_INET6 addresses in the TCP and UDP socket lists when the sockets have SO_REUSEPORT set. AF_INET sockets will be inserted at the head of the list and AF_INET6 sockets with SO_REUSEPORT set will always be inserted at the tail of the list. This will force AF_INET sockets to always be considered first. Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection") Fixes: 125e80b88687 ("soreuseport: fast reuseport TCP socket selection") Reported-by: Maciej Żenczykowski Signed-off-by: Craig Gallek Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

sock: struct proto hash function may error

2016-02-11T08:54:14+00:00

In order to support fast reuseport lookups in TCP, the hash function defined in struct proto must be capable of returning an error code. This patch changes the function signature of all related hash functions to return an integer and handles or propagates this return value at all call sites. Signed-off-by: Craig Gallek Signed-off-by: David S. Miller

net: sock: remove dead cgroup methods from struct proto

2016-01-21T22:16:51+00:00

The cgroup methods are no longer used after baac50bbc3cd ("net: tcp_memcontrol: simplify linkage between socket and page counter"). The hunk to delete them was included in the original patch but must have gotten lost during conflict resolution on the way upstream. Fixes: baac50bbc3cd ("net: tcp_memcontrol: simplify linkage between socket and page counter") Signed-off-by: Johannes Weiner Signed-off-by: David S. Miller

mm: memcontrol: generalize the socket accounting jump label

2016-01-15T00:00:49+00:00

The unified hierarchy memory controller is going to use this jump label as well to control the networking callbacks. Move it to the memory controller code and give it a more generic name. Signed-off-by: Johannes Weiner Acked-by: Michal Hocko Reviewed-by: Vladimir Davydov Acked-by: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

net: tcp_memcontrol: simplify linkage between socket and page counter

2016-01-15T00:00:49+00:00

There won't be any separate counters for socket memory consumed by protocols other than TCP in the future. Remove the indirection and link sockets directly to their owning memory cgroup. Signed-off-by: Johannes Weiner Reviewed-by: Vladimir Davydov Acked-by: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

net: tcp_memcontrol: sanitize tcp memory accounting callbacks

2016-01-15T00:00:49+00:00

There won't be a tcp control soft limit, so integrating the memcg code into the global skmem limiting scheme complicates things unnecessarily. Replace this with simple and clear charge and uncharge calls--hidden behind a jump label--to account skb memory. Note that this is not purely aesthetic: as a result of shoehorning the per-memcg code into the same memory accounting functions that handle the global level, the old code would compare the per-memcg consumption against the smaller of the per-memcg limit and the global limit. This allowed the total consumption of multiple sockets to exceed the global limit, as long as the individual sockets stayed within bounds. After this change, the code will always compare the per-memcg consumption to the per-memcg limit, and the global consumption to the global limit, and thus close this loophole. Without a soft limit, the per-memcg memory pressure state in sockets is generally questionable. However, we did it until now, so we continue to enter it when the hard limit is hit, and packets are dropped, to let other sockets in the cgroup know that they shouldn't grow their transmit windows, either. However, keep it simple in the new callback model and leave memory pressure lazily when the next packet is accepted (as opposed to doing it synchroneously when packets are processed). When packets are dropped, network performance will already be in the toilet, so that should be a reasonable trade-off. As described above, consumption is now checked on the per-memcg level and the global level separately. Likewise, memory pressure states are maintained on both the per-memcg level and the global level, and a socket is considered under pressure when either level asserts as much. Signed-off-by: Johannes Weiner Reviewed-by: Vladimir Davydov Acked-by: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

net: tcp_memcontrol: simplify the per-memcg limit access

2016-01-15T00:00:49+00:00

tcp_memcontrol replicates the global sysctl_mem limit array per cgroup, but it only ever sets these entries to the value of the memory_allocated page_counter limit. Use the latter directly. Signed-off-by: Johannes Weiner Reviewed-by: Vladimir Davydov Acked-by: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

net: tcp_memcontrol: remove dead per-memcg count of allocated sockets

2016-01-15T00:00:49+00:00

The number of allocated sockets is used for calculations in the soft limit phase, where packets are accepted but the socket is under memory pressure. Since there is no soft limit phase in tcp_memcontrol, and memory pressure is only entered when packets are already dropped, this is actually dead code. Remove it. As this is the last user of parent_cg_proto(), remove that too. Signed-off-by: Johannes Weiner Acked-by: David S. Miller Reviewed-by: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

net: tcp_memcontrol: remove bogus hierarchy pressure propagation

2016-01-15T00:00:49+00:00

When a cgroup currently breaches its socket memory limit, it enters memory pressure mode for itself and its *ancestors*. This throttles transmission in unrelated sibling and cousin subtrees that have nothing to do with the breached limit. On the contrary, breaching a limit should make that group and its *children* enter memory pressure mode. But this happens already, albeit lazily: if an ancestor limit is breached, siblings will enter memory pressure on their own once the next packet arrives for them. So no additional hierarchy code is needed. Remove the bogus stuff. Signed-off-by: Johannes Weiner Acked-by: David S. Miller Reviewed-by: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

net: tcp_memcontrol: properly detect ancestor socket pressure

2016-01-15T00:00:49+00:00

When charging socket memory, the code currently checks only the local page counter for excess to determine whether the memcg is under socket pressure. But even if the local counter is fine, one of the ancestors could have breached its limit, which should also force this child to enter socket pressure. This currently doesn't happen. Fix this by using page_counter_try_charge() first. If that fails, it means that either the local counter or one of the ancestors are in excess of their limit, and the child should enter socket pressure. Fixes: 3e32cb2e0a12 ("mm: memcontrol: lockless page counters") Signed-off-by: Johannes Weiner Acked-by: David S. Miller Reviewed-by: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds