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* tcp: remove tcp_ecn_make_synack() socket argumentEric Dumazet2015-09-251-2/+10
| | | | | | | | | | | | | | SYNACK packets might be sent without holding socket lock. For DCTCP/ECN sake, we should call INET_ECN_xmit() while socket lock is owned, and only when we init/change congestion control. This also fixies a bug if congestion module is changed from dctcp to another one on a listener : we now clear ECN bits properly. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: use dctcp if enabled on the route to the initiatorDaniel Borkmann2015-08-311-3/+6
| | | | | | | | | | | | | | | | | | | | | | Currently, the following case doesn't use DCTCP, even if it should: A responder has f.e. Cubic as system wide default, but for a specific route to the initiating host, DCTCP is being set in RTAX_CC_ALGO. The initiating host then uses DCTCP as congestion control, but since the initiator sets ECT(0), tcp_ecn_create_request() doesn't set ecn_ok, and we have to fall back to Reno after 3WHS completes. We were thinking on how to solve this in a minimal, non-intrusive way without bloating tcp_ecn_create_request() needlessly: lets cache the CA ecn option flag in RTAX_FEATURES. In other words, when ECT(0) is set on the SYN packet, set ecn_ok=1 iff route RTAX_FEATURES contains the unexposed (internal-only) DST_FEATURE_ECN_CA. This allows to only do a single metric feature lookup inside tcp_ecn_create_request(). Joint work with Florian Westphal. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: do not slow start when cwnd equals ssthreshYuchung Cheng2015-07-091-3/+1
| | | | | | | | | | | | | | | In the original design slow start is only used to raise cwnd when cwnd is stricly below ssthresh. It makes little sense to slow start when cwnd == ssthresh: especially when hystart has set ssthresh in the initial ramp, or after recovery when cwnd resets to ssthresh. Not doing so will also help reduce the buffer bloat slightly. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Nandita Dukkipati <nanditad@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: add tcp_in_slow_start helperYuchung Cheng2015-07-091-1/+1
| | | | | | | | | | | | Add a helper to test the slow start condition in various congestion control modules and other places. This is to prepare a slight improvement in policy as to exactly when to slow start. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Nandita Dukkipati <nanditad@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fix child sockets to use system default congestion control if not setNeal Cardwell2015-05-311-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux 3.17 and earlier are explicitly engineered so that if the app doesn't specifically request a CC module on a listener before the SYN arrives, then the child gets the system default CC when the connection is established. See tcp_init_congestion_control() in 3.17 or earlier, which says "if no choice made yet assign the current value set as default". The change ("net: tcp: assign tcp cong_ops when tcp sk is created") altered these semantics, so that children got their parent listener's congestion control even if the system default had changed after the listener was created. This commit returns to those original semantics from 3.17 and earlier, since they are the original semantics from 2007 in 4d4d3d1e8 ("[TCP]: Congestion control initialization."), and some Linux congestion control workflows depend on that. In summary, if a listener socket specifically sets TCP_CONGESTION to "x", or the route locks the CC module to "x", then the child gets "x". Otherwise the child gets current system default from net.ipv4.tcp_congestion_control. That's the behavior in 3.17 and earlier, and this commit restores that. Fixes: 55d8694fa82c ("net: tcp: assign tcp cong_ops when tcp sk is created") Cc: Florian Westphal <fw@strlen.de> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Glenn Judd <glenn.judd@morganstanley.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2015-03-201-0/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/ethernet/emulex/benet/be_main.c net/core/sysctl_net_core.c net/ipv4/inet_diag.c The be_main.c conflict resolution was really tricky. The conflict hunks generated by GIT were very unhelpful, to say the least. It split functions in half and moved them around, when the real actual conflict only existed solely inside of one function, that being be_map_pci_bars(). So instead, to resolve this, I checked out be_main.c from the top of net-next, then I applied the be_main.c changes from 'net' since the last time I merged. And this worked beautifully. The inet_diag.c and sysctl_net_core.c conflicts were simple overlapping changes, and were easily to resolve. Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: fix tcp_cong_avoid_ai() credit accumulation bug with decreases in wNeal Cardwell2015-03-111-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent change to tcp_cong_avoid_ai() to handle stretch ACKs introduced a bug where snd_cwnd_cnt could accumulate a very large value while w was large, and then if w was reduced snd_cwnd could be incremented by a large delta, leading to a large burst and high packet loss. This was tickled when CUBIC's bictcp_update() sets "ca->cnt = 100 * cwnd". This bug crept in while preparing the upstream version of 814d488c6126. Testing: This patch has been tested in datacenter netperf transfers and live youtube.com and google.com servers. Fixes: 814d488c6126 ("tcp: fix the timid additive increase on stretch ACKs") Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: silence registration messagestephen hemminger2015-02-201-1/+1
|/ | | | | | | This message isn't really needed it justs waits time/space. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2015-02-051-12/+20
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/vxlan.c drivers/vhost/net.c include/linux/if_vlan.h net/core/dev.c The net/core/dev.c conflict was the overlap of one commit marking an existing function static whilst another was adding a new function. In the include/linux/if_vlan.h case, the type used for a local variable was changed in 'net', whereas the function got rewritten to fix a stacked vlan bug in 'net-next'. In drivers/vhost/net.c, Al Viro's iov_iter conversions in 'net-next' overlapped with an endainness fix for VHOST 1.0 in 'net'. In drivers/net/vxlan.c, vxlan_find_vni() added a 'flags' parameter in 'net-next' whereas in 'net' there was a bug fix to pass in the correct network namespace pointer in calls to this function. Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: fix stretch ACK bugs in RenoNeal Cardwell2015-01-281-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change Reno to properly handle stretch ACKs in additive increase mode by passing in the count of ACKed packets to tcp_cong_avoid_ai(). In addition, if snd_cwnd crosses snd_ssthresh during slow start processing, and we then exit slow start mode, we need to carry over any remaining "credit" for packets ACKed and apply that to additive increase by passing this remaining "acked" count to tcp_cong_avoid_ai(). Reported-by: Eyal Perry <eyalpe@mellanox.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: fix the timid additive increase on stretch ACKsNeal Cardwell2015-01-281-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tcp_cong_avoid_ai() was too timid (snd_cwnd increased too slowly) on "stretch ACKs" -- cases where the receiver ACKed more than 1 packet in a single ACK. For example, suppose w is 10 and we get a stretch ACK for 20 packets, so acked is 20. We ought to increase snd_cwnd by 2 (since acked/w = 20/10 = 2), but instead we were only increasing cwnd by 1. This patch fixes that behavior. Reported-by: Eyal Perry <eyalpe@mellanox.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: stretch ACK fixes prepNeal Cardwell2015-01-281-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LRO, GRO, delayed ACKs, and middleboxes can cause "stretch ACKs" that cover more than the RFC-specified maximum of 2 packets. These stretch ACKs can cause serious performance shortfalls in common congestion control algorithms that were designed and tuned years ago with receiver hosts that were not using LRO or GRO, and were instead politely ACKing every other packet. This patch series fixes Reno and CUBIC to handle stretch ACKs. This patch prepares for the upcoming stretch ACK bug fix patches. It adds an "acked" parameter to tcp_cong_avoid_ai() to allow for future fixes to tcp_cong_avoid_ai() to correctly handle stretch ACKs, and changes all congestion control algorithms to pass in 1 for the ACKed count. It also changes tcp_slow_start() to return the number of packet ACK "credits" that were not processed in slow start mode, and can be processed by the congestion control module in additive increase mode. In future patches we will fix tcp_cong_avoid_ai() to handle stretch ACKs, and fix Reno and CUBIC handling of stretch ACKs in slow start and additive increase mode. Reported-by: Eyal Perry <eyalpe@mellanox.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: tcp: add key management to congestion controlDaniel Borkmann2015-01-051-16/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds necessary infrastructure to the congestion control framework for later per route congestion control support. For a per route congestion control possibility, our aim is to store a unique u32 key identifier into dst metrics, which can then be mapped into a tcp_congestion_ops struct. We argue that having a RTAX key entry is the most simple, generic and easy way to manage, and also keeps the memory footprint of dst entries lower on 64 bit than with storing a pointer directly, for example. Having a unique key id also allows for decoupling actual TCP congestion control module management from the FIB layer, i.e. we don't have to care about expensive module refcounting inside the FIB at this point. We first thought of using an IDR store for the realization, which takes over dynamic assignment of unused key space and also performs the key to pointer mapping in RCU. While doing so, we stumbled upon the issue that due to the nature of dynamic key distribution, it just so happens, arguably in very rare occasions, that excessive module loads and unloads can lead to a possible reuse of previously used key space. Thus, previously stale keys in the dst metric are now being reassigned to a different congestion control algorithm, which might lead to unexpected behaviour. One way to resolve this would have been to walk FIBs on the actually rare occasion of a module unload and reset the metric keys for each FIB in each netns, but that's just very costly. Therefore, we argue a better solution is to reuse the unique congestion control algorithm name member and map that into u32 key space through jhash. For that, we split the flags attribute (as it currently uses 2 bits only anyway) into two u32 attributes, flags and key, so that we can keep the cacheline boundary of 2 cachelines on x86_64 and cache the precalculated key at registration time for the fast path. On average we might expect 2 - 4 modules being loaded worst case perhaps 15, so a key collision possibility is extremely low, and guaranteed collision-free on LE/BE for all in-tree modules. Overall this results in much simpler code, and all without the overhead of an IDR. Due to the deterministic nature, modules can now be unloaded, the congestion control algorithm for a specific but unloaded key will fall back to the default one, and on module reload time it will switch back to the expected algorithm transparently. Joint work with Florian Westphal. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: tcp: refactor reinitialization of congestion controlDaniel Borkmann2015-01-051-10/+14
|/ | | | | | | | | | | We can just move this to an extra function and make the code a bit more readable, no functional change. Joint work with Florian Westphal. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: spelling s/plugable/pluggableFabian Frederick2014-11-041-1/+1
| | | | | Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Change tcp_slow_start function to return voidLi RongQing2014-09-301-3/+1
| | | | | | | No caller uses the return value, so make this function return void. Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: tcp: assign tcp cong_ops when tcp sk is createdFlorian Westphal2014-09-291-24/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Split assignment and initialization from one into two functions. This is required by followup patches that add Datacenter TCP (DCTCP) congestion control algorithm - we need to be able to determine if the connection is moderated by DCTCP before the 3WHS has finished. As we walk the available congestion control list during the assignment, we are always guaranteed to have Reno present as it's fixed compiled-in. Therefore, since we're doing the early assignment, we don't have a real use for the Reno alias tcp_init_congestion_ops anymore and can thus remove it. Actual usage of the congestion control operations are being made after the 3WHS has finished, in some cases however we can access get_info() via diag if implemented, therefore we need to zero out the private area for those modules. Joint work with Daniel Borkmann and Glenn Judd. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: whitespace fixesstephen hemminger2014-09-011-4/+1
| | | | | | | | Fix places where there is space before tab, long lines, and awkward if(){, double spacing etc. Add blank line after declaration/initialization. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: remove in_flight parameter from cong_avoid() methodsEric Dumazet2014-05-031-2/+2
| | | | | | | | | | | | Commit e114a710aa505 ("tcp: fix cwnd limited checking to improve congestion control") obsoleted in_flight parameter from tcp_is_cwnd_limited() and its callers. This patch does the removal as promised. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fix cwnd limited checking to improve congestion controlEric Dumazet2014-05-021-20/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Yuchung discovered tcp_is_cwnd_limited() was returning false in slow start phase even if the application filled the socket write queue. All congestion modules take into account tcp_is_cwnd_limited() before increasing cwnd, so this behavior limits slow start from probing the bandwidth at full speed. The problem is that even if write queue is full (aka we are _not_ application limited), cwnd can be under utilized if TSO should auto defer or TCP Small queues decided to hold packets. So the in_flight can be kept to smaller value, and we can get to the point tcp_is_cwnd_limited() returns false. With TCP Small Queues and FQ/pacing, this issue is more visible. We fix this by having tcp_cwnd_validate(), which is supposed to track such things, take into account unsent_segs, the number of segs that we are not sending at the moment due to TSO or TSQ, but intend to send real soon. Then when we are cwnd-limited, remember this fact while we are processing the window of ACKs that comes back. For example, suppose we have a brand new connection with cwnd=10; we are in slow start, and we send a flight of 9 packets. By the time we have received ACKs for all 9 packets we want our cwnd to be 18. We implement this by setting tp->lsnd_pending to 9, and considering ourselves to be cwnd-limited while cwnd is less than twice tp->lsnd_pending (2*9 -> 18). This makes tcp_is_cwnd_limited() more understandable, by removing the GSO/TSO kludge, that tried to work around the issue. Note the in_flight parameter can be removed in a followup cleanup patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-03-051-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/wireless/ath/ath9k/recv.c drivers/net/wireless/mwifiex/pcie.c net/ipv6/sit.c The SIT driver conflict consists of a bug fix being done by hand in 'net' (missing u64_stats_init()) whilst in 'net-next' a helper was created (netdev_alloc_pcpu_stats()) which takes care of this. The two wireless conflicts were overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: reduce the bloat caused by tcp_is_cwnd_limited()Eric Dumazet2014-02-241-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tcp_is_cwnd_limited() allows GSO/TSO enabled flows to increase their cwnd to allow a full size (64KB) TSO packet to be sent. Non GSO flows only allow an extra room of 3 MSS. For most flows with a BDP below 10 MSS, this results in a bloat of cwnd reaching 90, and an inflate of RTT. Thanks to TSO auto sizing, we can restrict the bloat to the number of MSS contained in a TSO packet (tp->xmit_size_goal_segs), to keep original intent without performance impact. Because we keep cwnd small, it helps to keep TSO packet size to their optimal value. Example for a 10Mbit flow, with low TCP Small queue limits (no more than 2 skb in qdisc/device tx ring) Before patch : lpk51:~# ./ss -i dst lpk52:44862 | grep cwnd cubic wscale:6,6 rto:215 rtt:15.875/2.5 mss:1448 cwnd:96 ssthresh:96 send 70.1Mbps unacked:14 rcv_space:29200 After patch : lpk51:~# ./ss -i dst lpk52:52916 | grep cwnd cubic wscale:6,6 rto:206 rtt:5.206/0.036 mss:1448 cwnd:15 ssthresh:14 send 33.4Mbps unacked:4 rcv_space:29200 Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: Van Jacobson <vanj@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: remove unused min_cwnd member of tcp_congestion_opsStanislav Fomichev2014-02-131-10/+0
|/ | | | | | | | | | Commit 684bad110757 "tcp: use PRR to reduce cwin in CWR state" removed all calls to min_cwnd, so we can safely remove it. Also, remove tcp_reno_min_cwnd because it was only used for min_cwnd. Signed-off-by: Stanislav Fomichev <stfomichev@yandex-team.ru> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: properly handle stretch acks in slow startYuchung Cheng2013-11-041-30/+17
| | | | | | | | | | | | | | | | | | | | | | | | | Slow start now increases cwnd by 1 if an ACK acknowledges some packets, regardless the number of packets. Consequently slow start performance is highly dependent on the degree of the stretch ACKs caused by receiver or network ACK compression mechanisms (e.g., delayed-ACK, GRO, etc). But slow start algorithm is to send twice the amount of packets of packets left so it should process a stretch ACK of degree N as if N ACKs of degree 1, then exits when cwnd exceeds ssthresh. A follow up patch will use the remainder of the N (if greater than 1) to adjust cwnd in the congestion avoidance phase. In addition this patch retires the experimental limited slow start (LSS) feature. LSS has multiple drawbacks but questionable benefit. The fractional cwnd increase in LSS requires a loop in slow start even though it's rarely used. Configuring such an increase step via a global sysctl on different BDPS seems hard. Finally and most importantly the slow start overshoot concern is now better covered by the Hybrid slow start (hystart) enabled by default. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: remove Appropriate Byte Count supportStephen Hemminger2013-02-051-29/+1
| | | | | | | | | | TCP Appropriate Byte Count was added by me, but later disabled. There is no point in maintaining it since it is a potential source of bugs and Linux already implements other better window protection heuristics. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fix an infinite loop in tcp_slow_start()Eric Dumazet2013-02-031-4/+10
| | | | | | | | | | | | | | Since commit 9dc274151a548 (tcp: fix ABC in tcp_slow_start()), a nul snd_cwnd triggers an infinite loop in tcp_slow_start() Avoid this infinite loop and log a one time error for further analysis. FRTO code is suspected to cause this bug. Reported-by: Pasi Kärkkäinen <pasik@iki.fi> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-12-131-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial branch from Jiri Kosina: "Usual stuff -- comment/printk typo fixes, documentation updates, dead code elimination." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) HOWTO: fix double words typo x86 mtrr: fix comment typo in mtrr_bp_init propagate name change to comments in kernel source doc: Update the name of profiling based on sysfs treewide: Fix typos in various drivers treewide: Fix typos in various Kconfig wireless: mwifiex: Fix typo in wireless/mwifiex driver messages: i2o: Fix typo in messages/i2o scripts/kernel-doc: check that non-void fcts describe their return value Kernel-doc: Convention: Use a "Return" section to describe return values radeon: Fix typo and copy/paste error in comments doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c various: Fix spelling of "asynchronous" in comments. Fix misspellings of "whether" in comments. eisa: Fix spelling of "asynchronous". various: Fix spelling of "registered" in comments. doc: fix quite a few typos within Documentation target: iscsi: fix comment typos in target/iscsi drivers treewide: fix typo of "suport" in various comments and Kconfig treewide: fix typo of "suppport" in various comments ...
| * treewide: fix typo of "suport" in various comments and KconfigMasanari Iida2012-11-191-1/+1
| | | | | | | | | | Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | net: Allow userns root to control ipv4Eric W. Biederman2012-11-181-1/+2
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow an unpriviled user who has created a user namespace, and then created a network namespace to effectively use the new network namespace, by reducing capable(CAP_NET_ADMIN) and capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns, CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls. Settings that merely control a single network device are allowed. Either the network device is a logical network device where restrictions make no difference or the network device is hardware NIC that has been explicity moved from the initial network namespace. In general policy and network stack state changes are allowed while resource control is left unchanged. Allow creating raw sockets. Allow the SIOCSARP ioctl to control the arp cache. Allow the SIOCSIFFLAG ioctl to allow setting network device flags. Allow the SIOCSIFADDR ioctl to allow setting a netdevice ipv4 address. Allow the SIOCSIFBRDADDR ioctl to allow setting a netdevice ipv4 broadcast address. Allow the SIOCSIFDSTADDR ioctl to allow setting a netdevice ipv4 destination address. Allow the SIOCSIFNETMASK ioctl to allow setting a netdevice ipv4 netmask. Allow the SIOCADDRT and SIOCDELRT ioctls to allow adding and deleting ipv4 routes. Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for adding, changing and deleting gre tunnels. Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for adding, changing and deleting ipip tunnels. Allow the SIOCADDTUNNEL, SIOCCHGTUNNEL and SIOCDELTUNNEL ioctls for adding, changing and deleting ipsec virtual tunnel interfaces. Allow setting the MRT_INIT, MRT_DONE, MRT_ADD_VIF, MRT_DEL_VIF, MRT_ADD_MFC, MRT_DEL_MFC, MRT_ASSERT, MRT_PIM, MRT_TABLE socket options on multicast routing sockets. Allow setting and receiving IPOPT_CIPSO, IP_OPT_SEC, IP_OPT_SID and arbitrary ip options. Allow setting IP_SEC_POLICY/IP_XFRM_POLICY ipv4 socket option. Allow setting the IP_TRANSPARENT ipv4 socket option. Allow setting the TCP_REPAIR socket option. Allow setting the TCP_CONGESTION socket option. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Apply device TSO segment limit earlierBen Hutchings2012-08-021-1/+2
| | | | | | | | | Cache the device gso_max_segs in sock::sk_gso_max_segs and use it to limit the size of TSO skbs. This avoids the need to fall back to software GSO for local TCP senders. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fix ABC in tcp_slow_start()Eric Dumazet2012-07-201-2/+3
| | | | | | | | | | | | | | | | | | | | | When/if sysctl_tcp_abc > 1, we expect to increase cwnd by 2 if the received ACK acknowledges more than 2*MSS bytes, in tcp_slow_start() Problem is this RFC 3465 statement is not correctly coded, as the while () loop increases snd_cwnd one by one. Add a new variable to avoid this off-by one error. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: John Heffner <johnwheffner@gmail.com> Cc: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: bool conversionsEric Dumazet2012-05-171-3/+3
| | | | | | | | | | | bool conversions where possible. __inline__ -> inline space cleanups Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: ipv4: Standardize prefixes for message loggingJoe Perches2012-03-121-3/+5
| | | | | | | | | | | | | | | | Add #define pr_fmt(fmt) as appropriate. Add "IPv4: ", "TCP: ", and "IPsec: " to appropriate files. Standardize on "UDPLite: " for appropriate uses. Some prefixes were previously "UDPLITE: " and "UDP-Lite: ". Add KBUILD_MODNAME ": " to icmp and gre. Remove embedded prefixes as appropriate. Add missing "\n" to pr_info in gre.c. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Convert printks to pr_<level>Joe Perches2012-03-111-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | Use a more current kernel messaging style. Convert a printk block to print_hex_dump. Coalesce formats, align arguments. Use %s, __func__ instead of embedding function names. Some messages that were prefixed with <foo>_close are now prefixed with <foo>_fini. Some ah4 and esp messages are now not prefixed with "ip ". The intent of this patch is to later add something like #define pr_fmt(fmt) "IPv4: " fmt. to standardize the output messages. Text size is trivially reduced. (x86-32 allyesconfig) $ size net/ipv4/built-in.o* text data bss dec hex filename 887888 31558 249696 1169142 11d6f6 net/ipv4/built-in.o.new 887934 31558 249800 1169292 11d78c net/ipv4/built-in.o.old Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: do not scale TSO segment size with reordering degreeNeal Cardwell2011-11-291-1/+1
| | | | | | | | | | | | | | | | Since 2005 (c1b4a7e69576d65efc31a8cea0714173c2841244) tcp_tso_should_defer has been using tcp_max_burst() as a target limit for deciding how large to make outgoing TSO packets when not using sysctl_tcp_tso_win_divisor. But since 2008 (dd9e0dda66ba38a2ddd1405ac279894260dc5c36) tcp_max_burst() returns the reordering degree. We should not have tcp_tso_should_defer attempt to build larger segments just because there is more reordering. This commit splits the notion of deferral size used in TSO from the notion of burst size used in cwnd moderation, and returns the TSO deferral limit to its original value. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/ipv4: Eliminate kstrdup memory leakJulia Lawall2010-08-271-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The string clone is only used as a temporary copy of the argument val within the while loop, and so it should be freed before leaving the function. The call to strsep, however, modifies clone, so a pointer to the front of the string is kept in saved_clone, to make it possible to free it. The sematic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r exists@ local idexpression x; expression E; identifier l; statement S; @@ *x= \(kasprintf\|kstrdup\)(...); ... if (x == NULL) S ... when != kfree(x) when != E = x if (...) { <... when != kfree(x) * goto l; ...> * return ...; } // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* Networking: use CAP_NET_ADMIN when deciding to call request_moduleEric Paris2009-08-141-2/+2
| | | | | | | | | | | | | | | | | | | The networking code checks CAP_SYS_MODULE before using request_module() to try to load a kernel module. While this seems reasonable it's actually weakening system security since we have to allow CAP_SYS_MODULE for things like /sbin/ip and bluetoothd which need to be able to trigger module loads. CAP_SYS_MODULE actually grants those binaries the ability to directly load any code into the kernel. We should instead be protecting modprobe and the modules on disk, rather than granting random programs the ability to load code directly into the kernel. Instead we are going to gate those networking checks on CAP_NET_ADMIN which still limits them to root but which does not grant those processes the ability to load arbitrary code into the kernel. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Paul Moore <paul.moore@hp.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: James Morris <jmorris@namei.org>
* tcp: add helper for AI algorithmIlpo Järvinen2009-03-021-7/+14
| | | | | | | | | | | | | | | | | | | | It seems that implementation in yeah was inconsistent to what other did as it would increase cwnd one ack earlier than the others do. Size benefits: bictcp_cong_avoid | -36 tcp_cong_avoid_ai | +52 bictcp_cong_avoid | -34 tcp_scalable_cong_avoid | -36 tcp_veno_cong_avoid | -12 tcp_yeah_cong_avoid | -38 = -104 bytes total Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Remove CONFIG_KMOD from net/ (towards removing CONFIG_KMOD entirely)Johannes Berg2008-10-161-2/+2
| | | | | | | | | | | Some code here depends on CONFIG_KMOD to not try to load protocol modules or similar, replace by CONFIG_MODULES where more than just request_module depends on CONFIG_KMOD and and also use try_then_request_module in ebtables. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Limit cwnd growth when deferring for GSOJohn Heffner2008-04-291-1/+2
| | | | | | | | This fixes inappropriately large cwnd growth on sender-limited flows when GSO is enabled, limiting cwnd growth to 64k. Signed-off-by: John Heffner <johnwheffner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Allow send-limited cwnd to grow up to max_burst when gso disabledJohn Heffner2008-04-291-7/+4
| | | | | | | | | This changes the logic in tcp_is_cwnd_limited() so that cwnd may grow up to tcp_max_burst() even when sk_can_gso() is false, or when sysctl_tcp_tso_win_divisor != 0. Signed-off-by: John Heffner <johnwheffner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Uninline tcp_is_cwnd_limitedIlpo Järvinen2008-01-281-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | net/ipv4/tcp_cong.c: tcp_reno_cong_avoid | -65 1 function changed, 65 bytes removed, diff: -65 net/ipv4/arp.c: arp_ignore | -5 1 function changed, 5 bytes removed, diff: -5 net/ipv4/tcp_bic.c: bictcp_cong_avoid | -57 1 function changed, 57 bytes removed, diff: -57 net/ipv4/tcp_cubic.c: bictcp_cong_avoid | -61 1 function changed, 61 bytes removed, diff: -61 net/ipv4/tcp_highspeed.c: hstcp_cong_avoid | -63 1 function changed, 63 bytes removed, diff: -63 net/ipv4/tcp_hybla.c: hybla_cong_avoid | -85 1 function changed, 85 bytes removed, diff: -85 net/ipv4/tcp_htcp.c: htcp_cong_avoid | -57 1 function changed, 57 bytes removed, diff: -57 net/ipv4/tcp_veno.c: tcp_veno_cong_avoid | -52 1 function changed, 52 bytes removed, diff: -52 net/ipv4/tcp_scalable.c: tcp_scalable_cong_avoid | -61 1 function changed, 61 bytes removed, diff: -61 net/ipv4/tcp_yeah.c: tcp_yeah_cong_avoid | -75 1 function changed, 75 bytes removed, diff: -75 net/ipv4/tcp_illinois.c: tcp_illinois_cong_avoid | -54 1 function changed, 54 bytes removed, diff: -54 net/dccp/ccids/ccid3.c: ccid3_update_send_interval | -7 ccid3_hc_tx_packet_recv | +7 2 functions changed, 7 bytes added, 7 bytes removed, diff: +0 net/ipv4/tcp_cong.c: tcp_is_cwnd_limited | +88 1 function changed, 88 bytes added, diff: +88 built-in.o: 14 functions changed, 95 bytes added, 642 bytes removed, diff: -547 ...Again some gcc artifacts visible as well. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Cong.ctrl modules: remove unused good_ack from cong_avoidIlpo Järvinen2008-01-281-1/+1
| | | | | | Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: remove unused argument to cong_avoid opStephen Hemminger2007-07-181-2/+1
| | | | | | | | | None of the existing TCP congestion controls use the rtt value pased in the ca_ops->cong_avoid interface. Which is lucky because seq_rtt could have been -1 when handling a duplicate ack. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP] slow start: Make comments and code logic clearer.Stephen Hemminger2007-05-171-18/+22
| | | | | | | Add more comments to describe our version of tcp_slow_start(). Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Congestion control API update.Stephen Hemminger2007-04-251-7/+7
| | | | | | | | | | | Do some simple changes to make congestion control API faster/cleaner. * use ktime_t rather than timeval * merge rtt sampling into existing ack callback this means one indirect call versus two per ack. * use flags bits to store options/settings Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Add RFC3742 Limited Slow-Start, controlled by variable ↵John Heffner2007-04-251-9/+22
| | | | | | | sysctl_tcp_max_ssthresh. Signed-off-by: John Heffner <jheffner@psc.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
* [TCP]: Congestion control initialization.Stephen Hemminger2007-04-231-10/+13
| | | | | | | | | | | | | Change to defer congestion control initialization. If setsockopt() was used to change TCP_CONGESTION before connection is established, then protocols that use sequence numbers to keep track of one RTT interval (vegas, illinois, ...) get confused. Change the init hook to be called after handshake. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* Various typo fixes.Robert P. J. Day2007-02-171-1/+1
| | | | | | | | Correct mis-spellings of "algorithm", "appear", "consistent" and (shame, shame) "kernel". Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-23 18:09:43 +0000