linux/net, branch v3.3.6

tcp: change tcp_adv_win_scale and tcp_rmem[2]

2012-05-12T16:32:19Z

[ Upstream commit b49960a05e32121d29316cfdf653894b88ac9190 ] tcp_adv_win_scale default value is 2, meaning we expect a good citizen skb to have skb->len / skb->truesize ratio of 75% (3/4) In 2.6 kernels we (mis)accounted for typical MSS=1460 frame : 1536 + 64 + 256 = 1856 'estimated truesize', and 1856 * 3/4 = 1392. So these skbs were considered as not bloated. With recent truesize fixes, a typical MSS=1460 frame truesize is now the more precise : 2048 + 256 = 2304. But 2304 * 3/4 = 1728. So these skb are not good citizen anymore, because 1460 < 1728 (GRO can escape this problem because it build skbs with a too low truesize.) This also means tcp advertises a too optimistic window for a given allocated rcvspace : When receiving frames, sk_rmem_alloc can hit sk_rcvbuf limit and we call tcp_prune_queue()/tcp_collapse() too often, especially when application is slow to drain its receive queue or in case of losses (netperf is fast, scp is slow). This is a major latency source. We should adjust the len/truesize ratio to 50% instead of 75% This patch : 1) changes tcp_adv_win_scale default to 1 instead of 2 2) increase tcp_rmem[2] limit from 4MB to 6MB to take into account better truesize tracking and to allow autotuning tcp receive window to reach same value than before. Note that same amount of kernel memory is consumed compared to 2.6 kernels. Signed-off-by: Eric Dumazet Cc: Neal Cardwell Cc: Tom Herbert Cc: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: fix infinite cwnd in tcp_complete_cwr()

2012-05-12T16:32:19Z

[ Upstream commit 1cebce36d660c83bd1353e41f3e66abd4686f215 ] When the cwnd reduction is done, ssthresh may be infinite if TCP enters CWR via ECN or F-RTO. If cwnd is not undone, i.e., undo_marker is set, tcp_complete_cwr() falsely set cwnd to the infinite ssthresh value. The correct operation is to keep cwnd intact because it has been updated in ECN or F-RTO. Signed-off-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: l2tp: unlock socket lock before returning from l2tp_ip_sendmsg

2012-05-12T16:32:18Z

[ Upstream commit 84768edbb2721637620b2d84501bb0d5aed603f1 ] l2tp_ip_sendmsg could return without releasing socket lock, making it all the way to userspace, and generating the following warning: [ 130.891594] ================================================ [ 130.894569] [ BUG: lock held when returning to user space! ] [ 130.897257] 3.4.0-rc5-next-20120501-sasha #104 Tainted: G W [ 130.900336] ------------------------------------------------ [ 130.902996] trinity/8384 is leaving the kernel with locks still held! [ 130.906106] 1 lock held by trinity/8384: [ 130.907924] #0: (sk_lock-AF_INET){+.+.+.}, at: [] l2tp_ip_sendmsg+0x2f/0x550 Introduced by commit 2f16270 ("l2tp: Fix locking in l2tp_ip.c"). Signed-off-by: Sasha Levin Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: In unregister_netdevice_notifier unregister the netdevices.

2012-05-12T16:32:18Z

[ Upstream commit 7d3d43dab4e978d8d9ad1acf8af15c9b1c4b0f0f ] We already synthesize events in register_netdevice_notifier and synthesizing events in unregister_netdevice_notifier allows to us remove the need for special case cleanup code. This change should be safe as it adds no new cases for existing callers of unregiser_netdevice_notifier to handle. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netem: fix possible skb leak

2012-05-12T16:32:18Z

[ Upstream commit 116a0fc31c6c9b8fc821be5a96e5bf0b43260131 ] skb_checksum_help(skb) can return an error, we must free skb in this case. qdisc_drop(skb, sch) can also be feeded with a NULL skb (if skb_unshare() failed), so lets use this generic helper. Signed-off-by: Eric Dumazet Cc: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

mac80211: fix AP mode EAP tx for VLAN stations

2012-05-07T15:53:37Z

commit 66f2c99af3d6f2d0aa1120884cf1c60613ef61c0 upstream. EAP frames for stations in an AP VLAN are sent on the main AP interface to avoid race conditions wrt. moving stations. For that to work properly, sta_info_get_bss must be used instead of sta_info_get when sending EAP packets. Previously this was only done for cooked monitor injected packets, so this patch adds a check for tx->skb->protocol to the same place. Signed-off-by: Felix Fietkau Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman

nl80211: ensure interface is up in various APIs

2012-05-07T15:53:22Z

commit 2b5f8b0b44e17e625cfba1e7b88db44f4dcc0441 upstream. [backported by Ben Greear] The nl80211 handling code should ensure as much as it can that the interface is in a valid state, it can certainly ensure the interface is running. Not doing so can cause calls through mac80211 into the driver that result in warnings and unspecified behaviour in the driver. Reported-by: Ben Greear Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: Ben Greear Signed-off-by: Greg Kroah-Hartman

tcp: avoid order-1 allocations on wifi and tx path

2012-04-27T17:17:06Z

[ This combines upstream commit a21d45726acacc963d8baddf74607d9b74e2b723 and the follow-on bug fix commit a21d45726acacc963d8baddf74607d9b74e2b723 ] Marc Merlin reported many order-1 allocations failures in TX path on its wireless setup, that dont make any sense with MTU=1500 network, and non SG capable hardware. After investigation, it turns out TCP uses sk_stream_alloc_skb() and used as a convention skb_tailroom(skb) to know how many bytes of data payload could be put in this skb (for non SG capable devices) Note : these skb used kmalloc-4096 (MTU=1500 + MAX_HEADER + sizeof(struct skb_shared_info) being above 2048) Later, mac80211 layer need to add some bytes at the tail of skb (IEEE80211_ENCRYPT_TAILROOM = 18 bytes) and since no more tailroom is available has to call pskb_expand_head() and request order-1 allocations. This patch changes sk_stream_alloc_skb() so that only sk->sk_prot->max_header bytes of headroom are reserved, and use a new skb field, avail_size to hold the data payload limit. This way, order-0 allocations done by TCP stack can leave more than 2 KB of tailroom and no more allocation is performed in mac80211 layer (or any layer needing some tailroom) avail_size is unioned with mark/dropcount, since mark will be set later in IP stack for output packets. Therefore, skb size is unchanged. Reported-by: Marc MERLIN Tested-by: Marc MERLIN Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: allow pskb_expand_head() to get maximum tailroom

2012-04-27T17:17:06Z

[ Upstream commit 87151b8689d890dfb495081f7be9b9e257f7a2df ] Marc Merlin reported many order-1 allocations failures in TX path on its wireless setup, that dont make any sense with MTU=1500 network, and non SG capable hardware. Turns out part of the problem comes from pskb_expand_head() not using ksize() to get exact head size given by kmalloc(). Doing the same thing than __alloc_skb() allows more tailroom in skb and can prevent future reallocations. As a bonus, struct skb_shared_info becomes cache line aligned. Reported-by: Marc MERLIN Tested-by: Marc MERLIN Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: fix TCP_MAXSEG for established IPv6 passive sockets

2012-04-27T17:17:05Z

[ Upstream commit d135c522f1234f62e81be29cebdf59e9955139ad ] Commit f5fff5d forgot to fix TCP_MAXSEG behavior IPv6 sockets, so IPv6 TCP server sockets that used TCP_MAXSEG would find that the advmss of child sockets would be incorrect. This commit mirrors the advmss logic from tcp_v4_syn_recv_sock in tcp_v6_syn_recv_sock. Eventually this logic should probably be shared between IPv4 and IPv6, but this at least fixes this issue. Signed-off-by: Neal Cardwell Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman