summaryrefslogtreecommitdiffstats
path: root/include/net/dst.h (follow)
Commit message (Collapse)AuthorAgeFilesLines
* dst.h: Remove extern from function prototypesJoe Perches2013-09-201-13/+12
| | | | | | | | | | | | | There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tunnels: harmonize cleanup done on skb on rx pathNicolas Dichtel2013-09-041-5/+7
| | | | | | | | The goal of this patch is to harmonize cleanup done on a skbuff on rx path. Before this patch, behaviors were different depending of the tunnel type. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Fix dst_neigh_lookup/dst_neigh_lookup_skb return value handling bugZhouyi Zhou2013-03-151-2/+4
| | | | | | | | | | | | | | | | | When neighbour table is full, dst_neigh_lookup/dst_neigh_lookup_skb will return -ENOBUFS which is absolutely non zero, while all the code in kernel which use above functions assume failure only on zero return which will cause panic. (for example: : https://bugzilla.kernel.org/show_bug.cgi?id=54731). This patch corrects above error with smallest changes to kernel source code and also correct two return value check missing bugs in drivers/infiniband/hw/cxgb4/cm.c Tested on my x86_64 SMP machine Reported-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Tested-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Signed-off-by: Zhouyi Zhou <zhouzhouyi@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: fix race condition regarding dst->expires and dst->from.YOSHIFUJI Hideaki / 吉藤英明2013-02-201-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Eric Dumazet wrote: | Some strange crashes happen in rt6_check_expired(), with access | to random addresses. | | At first glance, it looks like the RTF_EXPIRES and | stuff added in commit 1716a96101c49186b | (ipv6: fix problem with expired dst cache) | are racy : same dst could be manipulated at the same time | on different cpus. | | At some point, our stack believes rt->dst.from contains a dst pointer, | while its really a jiffie value (as rt->dst.expires shares the same area | of memory) | | rt6_update_expires() should be fixed, or am I missing something ? | | CC Neil because of https://bugzilla.redhat.com/show_bug.cgi?id=892060 Because we do not have any locks for dst_entry, we cannot change essential structure in the entry; e.g., we cannot change reference to other entity. To fix this issue, split 'from' and 'expires' field in dst_entry out of union. Once it is 'from' is assigned in the constructor, keep the reference until the very last stage of the life time of the object. Of course, it is unsafe to change 'from', so make rt6_set_from simple just for fresh entries. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: Neil Horman <nhorman@tuxdriver.com> CC: Gao Feng <gaofeng@cn.fujitsu.com> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reported-by: Steinar H. Gunderson <sesse@google.com> Reviewed-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xfrm: Add a state resolution packet queueSteffen Klassert2013-02-061-0/+1
| | | | | | | | | | | | | | | | | As the default, we blackhole packets until the key manager resolves the states. This patch implements a packet queue where IPsec packets are queued until the states are resolved. We generate a dummy xfrm bundle, the output routine of the returned route enqueues the packet to a per policy queue and arms a timer that checks for state resolution when dst_output() is called. Once the states are resolved, the packets are sent out of the queue. If the states are not resolved after some time, the queue is flushed. This patch keeps the defaut behaviour to blackhole packets as long as we have no states. To enable the packet queue the sysctl xfrm_larval_drop must be switched off. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2012-08-221-1/+1
|\
| * net: force dst_default_metrics to const sectionEric Dumazet2012-08-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While investigating on network performance problems, I found this little gem : $ nm -v vmlinux | grep -1 dst_default_metrics ffffffff82736540 b busy.46605 ffffffff82736560 B dst_default_metrics ffffffff82736598 b dst_busy_list Apparently, declaring a const array without initializer put it in (writeable) bss section, in middle of possibly often dirtied cache lines. Since we really want dst_default_metrics be const to avoid any possible false sharing and catch any buggy writes, I force a null initializer. ffffffff818a4c20 R dst_default_metrics Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: output path optimizationsEric Dumazet2012-08-081-3/+7
|/ | | | | | | | | | | | | | | | | | | | | | 1) Avoid dirtying neighbour's confirmed field. TCP workloads hits this cache line for each incoming ACK. Lets write n->confirmed only if there is a jiffie change. 2) Optimize neigh_hh_output() for the common Ethernet case, were hh_len is less than 16 bytes. Replace the memcpy() call by two inlined 64bit load/stores on x86_64. Bench results using udpflood test, with -C option (MSG_CONFIRM flag added to sendto(), to reproduce the n->confirmed dirtying on UDP) 24 threads doing 1.000.000 UDP sendto() on dummy device, 4 runs. before : 2.247s, 2.235s, 2.247s, 2.318s after : 1.884s, 1.905s, 1.891s, 1.895s Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Kill routes during PMTU/redirect updates.David S. Miller2012-07-201-0/+1
| | | | | | | Mark them obsolete so there will be a re-lookup to fetch the FIB nexthop exception info. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Document dst->obsolete better.David S. Miller2012-07-201-1/+13
| | | | | | | | | Add a big comment explaining how the field works, and use defines instead of magic constants for the values assigned to it. Suggested by Joe Perches. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Kill set_dst_metric_rtt().David S. Miller2012-07-111-6/+0
| | | | | | No longer used. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Kill dst->_neighbour, accessors, and final uses.David S. Miller2012-07-051-16/+1
| | | | | | No longer used. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Add optional SKB arg to dst_ops->neigh_lookup().David S. Miller2012-07-051-1/+7
| | | | | | | Causes the handler to use the daddr in the ipv4/ipv6 header when the route gateway is unspecified (local subnet). Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Do delayed neigh confirmation.David S. Miller2012-07-051-8/+21
| | | | | | | | | | | | | | When a dst_confirm() happens, mark the confirmation as pending in the dst. Then on the next packet out, when we have the neigh in-hand, do the update. This removes the dependency in dst_confirm() of dst's having an attached neigh. While we're here, remove the explicit 'dst' NULL check, all except 2 or 3 call sites ensure it's not NULL. So just fix those cases up. Signed-off-by: David S. Miller <davem@davemloft.net>
* include/net/dst.h: neaten asterisk placementEldad Zack2012-06-171-9/+8
| | | | | | | Fix code style - place the asterisk where it belongs. Signed-off-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: fix incorrect ipsec fragmentGao feng2012-05-271-0/+1
| | | | | | | | | | | | | | | | | | | | | | | Since commit ad0081e43a "ipv6: Fragment locally generated tunnel-mode IPSec6 packets as needed" the fragment of packets is incorrect. because tunnel mode needs IPsec headers and trailer for all fragments, while on transport mode it is sufficient to add the headers to the first fragment and the trailer to the last. so modify mtu and maxfraglen base on ipsec mode and if fragment is first or last. with my test,it work well(every fragment's size is the mtu) and does not trigger slow fragment path. Changes from v1: though optimization, mtu_prev and maxfraglen_prev can be delete. replace xfrm mode codes with dst_entry's new frag DST_XFRM_TUNNEL. add fuction ip6_append_data_mtu to make codes clearer. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* set fake_rtable's dst to NULL to avoid kernel OopsPeter Huang (Peng)2012-04-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | bridge: set fake_rtable's dst to NULL to avoid kernel Oops when bridge is deleted before tap/vif device's delete, kernel may encounter an oops because of NULL reference to fake_rtable's dst. Set fake_rtable's dst to NULL before sending packets out can solve this problem. v4 reformat, change br_drop_fake_rtable(skb) to {} v3 enrich commit header v2 introducing new flag DST_FAKE_RTABLE to dst_entry struct. [ Use "do { } while (0)" for nop br_drop_fake_rtable() implementation -DaveM ] Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Peter Huang <peter.huangpeng@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: fix problem with expired dst cacheGao feng2012-04-131-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet. this dst cache will not check expire because it has no RTF_EXPIRES flag. So this dst cache will always be used until the dst gc run. Change the struct dst_entry,add a union contains new pointer from and expires. When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use. we can use this field to point to where the dst cache copy from. The dst.from is only used in IPV6. rt6_check_expired check if rt6_info.dst.from is expired. ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. ip6_dst_destroy release the ort. Add some functions to operate the RTF_EXPIRES flag and expires(from) together. and change the code to use these new adding functions. Changes from v5: modify ip6_route_add and ndisc_router_discovery to use new adding functions. Only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* BUG: headers with BUG/BUG_ON etc. need linux/bug.hPaul Gortmaker2012-03-041-0/+1
| | | | | | | | | | | | | If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any other BUG variant in a static inline (i.e. not in a #define) then that header really should be including <linux/bug.h> and not just expecting it to be implicitly present. We can make this change risk-free, since if the files using these headers didn't have exposure to linux/bug.h already, they would have been causing compile failures/warnings. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2011-12-231-0/+1
|\ | | | | | | | | | | | | | | | | | | Conflicts: net/bluetooth/l2cap_core.c Just two overlapping changes, one added an initialization of a local variable, and another change added a new local variable. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: introduce DST_NOPEER dst flagEric Dumazet2011-12-231-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chris Boot reported crashes occurring in ipv6_select_ident(). [ 461.457562] RIP: 0010:[<ffffffff812dde61>] [<ffffffff812dde61>] ipv6_select_ident+0x31/0xa7 [ 461.578229] Call Trace: [ 461.580742] <IRQ> [ 461.582870] [<ffffffff812efa7f>] ? udp6_ufo_fragment+0x124/0x1a2 [ 461.589054] [<ffffffff812dbfe0>] ? ipv6_gso_segment+0xc0/0x155 [ 461.595140] [<ffffffff812700c6>] ? skb_gso_segment+0x208/0x28b [ 461.601198] [<ffffffffa03f236b>] ? ipv6_confirm+0x146/0x15e [nf_conntrack_ipv6] [ 461.608786] [<ffffffff81291c4d>] ? nf_iterate+0x41/0x77 [ 461.614227] [<ffffffff81271d64>] ? dev_hard_start_xmit+0x357/0x543 [ 461.620659] [<ffffffff81291cf6>] ? nf_hook_slow+0x73/0x111 [ 461.626440] [<ffffffffa0379745>] ? br_parse_ip_options+0x19a/0x19a [bridge] [ 461.633581] [<ffffffff812722ff>] ? dev_queue_xmit+0x3af/0x459 [ 461.639577] [<ffffffffa03747d2>] ? br_dev_queue_push_xmit+0x72/0x76 [bridge] [ 461.646887] [<ffffffffa03791e3>] ? br_nf_post_routing+0x17d/0x18f [bridge] [ 461.653997] [<ffffffff81291c4d>] ? nf_iterate+0x41/0x77 [ 461.659473] [<ffffffffa0374760>] ? br_flood+0xfa/0xfa [bridge] [ 461.665485] [<ffffffff81291cf6>] ? nf_hook_slow+0x73/0x111 [ 461.671234] [<ffffffffa0374760>] ? br_flood+0xfa/0xfa [bridge] [ 461.677299] [<ffffffffa0379215>] ? nf_bridge_update_protocol+0x20/0x20 [bridge] [ 461.684891] [<ffffffffa03bb0e5>] ? nf_ct_zone+0xa/0x17 [nf_conntrack] [ 461.691520] [<ffffffffa0374760>] ? br_flood+0xfa/0xfa [bridge] [ 461.697572] [<ffffffffa0374812>] ? NF_HOOK.constprop.8+0x3c/0x56 [bridge] [ 461.704616] [<ffffffffa0379031>] ? nf_bridge_push_encap_header+0x1c/0x26 [bridge] [ 461.712329] [<ffffffffa037929f>] ? br_nf_forward_finish+0x8a/0x95 [bridge] [ 461.719490] [<ffffffffa037900a>] ? nf_bridge_pull_encap_header+0x1c/0x27 [bridge] [ 461.727223] [<ffffffffa0379974>] ? br_nf_forward_ip+0x1c0/0x1d4 [bridge] [ 461.734292] [<ffffffff81291c4d>] ? nf_iterate+0x41/0x77 [ 461.739758] [<ffffffffa03748cc>] ? __br_deliver+0xa0/0xa0 [bridge] [ 461.746203] [<ffffffff81291cf6>] ? nf_hook_slow+0x73/0x111 [ 461.751950] [<ffffffffa03748cc>] ? __br_deliver+0xa0/0xa0 [bridge] [ 461.758378] [<ffffffffa037533a>] ? NF_HOOK.constprop.4+0x56/0x56 [bridge] This is caused by bridge netfilter special dst_entry (fake_rtable), a special shared entry, where attaching an inetpeer makes no sense. Problem is present since commit 87c48fa3b46 (ipv6: make fragment identifications less predictable) Introduce DST_NOPEER dst flag and make sure ipv6_select_ident() and __ip_select_ident() fallback to the 'no peer attached' handling. Reported-by: Chris Boot <bootc@bootc.net> Tested-by: Chris Boot <bootc@bootc.net> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: Rename dst_get_neighbour{, _raw} to dst_get_neighbour_noref{, _raw}.David Miller2011-12-051-3/+3
|/ | | | | | | | To reflect the fact that a refrence is not obtained to the resulting neighbour entry. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Roland Dreier <roland@purestorage.com>
* net: Move mtu handling down to the protocol depended handlersSteffen Klassert2011-11-261-6/+1
| | | | | | | | | We move all mtu handling from dst_mtu() down to the protocol layer. So each protocol can implement the mtu handling in a different manner. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Rename the dst_opt default_mtu method to mtuSteffen Klassert2011-11-261-1/+1
| | | | | | | | | We plan to invoke the dst_opt->default_mtu() method unconditioally from dst_mtu(). So rename the method to dst_opt->mtu() to match the name with the new meaning. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* rps: Add flag to skb to indicate rxhash is based on L4 tupleTom Herbert2011-08-181-1/+8
| | | | | | | | | | | The l4_rxhash flag was added to the skb structure to indicate that the rxhash value was computed over the 4 tuple for the packet which includes the port information in the encapsulated transport packet. This is used by the stack to preserve the rxhash value in __skb_rx_tunnel. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: fix NULL dereferences in check_peer_redir()Eric Dumazet2011-08-031-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | Gergely Kalman reported crashes in check_peer_redir(). It appears commit f39925dbde778 (ipv4: Cache learned redirect information in inetpeer.) added a race, leading to possible NULL ptr dereference. Since we can now change dst neighbour, we should make sure a reader can safely use a neighbour. Add RCU protection to dst neighbour, and make sure check_peer_redir() can be called safely by different cpus in parallel. As neighbours are already freed after one RCU grace period, this patch should not add typical RCU penalty (cache cold effects) Many thanks to Gergely for providing a pretty report pointing to the bug. Reported-by: Gergely Kalman <synapse@hippy.csoma.elte.hu> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Add ->neigh_lookup() operation to dst_opsDavid S. Miller2011-07-181-0/+5
| | | | | | | | In the future dst entries will be neigh-less. In that environment we need to have an easy transition point for current users of dst->neighbour outside of the packet output fast path. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Abstract dst->neighbour accesses behind helpers.David S. Miller2011-07-181-3/+15
| | | | | | dst_{get,set}_neighbour() Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Embed hh_cache inside of struct neighbour.David S. Miller2011-07-141-9/+9
| | | | | | | | | | | | | | | Now that there is a one-to-one correspondance between neighbour and hh_cache entries, we no longer need: 1) dynamic allocation 2) attachment to dst->hh 3) refcounting Initialization of the hh_cache entry is indicated by hh_len being non-zero, and such initialization is always done with the neighbour's lock held as a writer. Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: Don't put artificial limit on routing table size.David S. Miller2011-07-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | IPV6, unlike IPV4, doesn't have a routing cache. Routing table entries, as well as clones made in response to route lookup requests, all live in the same table. And all of these things are together collected in the destination cache table for ipv6. This means that routing table entries count against the garbage collection limits, even though such entries cannot ever be reclaimed and are added explicitly by the administrator (rather than being created in response to lookups). Therefore it makes no sense to count ipv6 routing table entries against the GC limits. Add a DST_NOCOUNT destination cache entry flag, and skip the counting if it is set. Use this flag bit in ipv6 when adding routing table entries. Signed-off-by: David S. Miller <davem@davemloft.net>
* dst: catch uninitialized metricsStephen Hemminger2011-05-241-0/+2
| | | | | | | | Catch cases where dst_metric_set() and other functions are called but _metrics is NULL. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Kill RT_CACHE_DEBUGDavid S. Miller2011-05-191-7/+0
| | | | | | | | | | | | | It's way past it's usefulness. And this gets rid of a bunch of stray ->rt_{dst,src} references. Even the comment documenting the macro was inaccurate (stated default was 1 when it's 0). If reintroduced, it should be done properly, with dynamic debug facilities. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Make dst_alloc() take more explicit initializations.David S. Miller2011-04-291-1/+2
| | | | | | | Now the dst->dev, dev->obsolete, and dst->flags values can be specified as well. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Remove __KERNEL__ cpp checks from include/netDavid S. Miller2011-04-241-3/+0
| | | | | | | | | | | These header files are never installed to user consumption, so any __KERNEL__ cpp checks are superfluous. Projects should also not copy these files into their userland utility sources and try to use them there. If they insist on doing so, the onus is on them to sanitize the headers as needed. Signed-off-by: David S. Miller <davem@davemloft.net>
* dst: Clone child entry in skb_dst_popSteffen Klassert2011-03-281-1/+1
| | | | | | | | | We clone the child entry in skb_dst_pop before we call skb_dst_drop(). Otherwise we might kill the child right before we return it to the caller. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* xfrm: Return dst directly from xfrm_lookup()David S. Miller2011-03-021-6/+8
| | | | | | Instead of on the stack. Signed-off-by: David S. Miller <davem@davemloft.net>
* xfrm: Handle blackhole route creation via afinfo.David S. Miller2011-03-011-8/+0
| | | | | | | That way we don't have to potentially do this in every xfrm_lookup() caller. Signed-off-by: David S. Miller <davem@davemloft.net>
* xfrm: Kill XFRM_LOOKUP_WAIT flag.David S. Miller2011-03-011-2/+1
| | | | | | This can be determined from the flow flags instead. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Make flow cache paths use a const struct flowi.David S. Miller2011-02-231-4/+6
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Add initial_ref arg to dst_alloc().David S. Miller2011-02-181-1/+1
| | | | | | | | | | This allows avoiding multiple writes to the initial __refcnt. The most simplest cases of wanting an initial reference of "1" in ipv4 and ipv6 have been converted, the rest have been left along and kept at the existing "0". Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Remove bogus barrier() in dst_allfrag().David S. Miller2011-02-091-2/+0
| | | | | | | I simply missed this one when modifying the other dst metric interfaces earlier. Signed-off-by: David S. Miller <davem@davemloft.net>
* inetpeer: Move ICMP rate limiting state into inet_peer entries.David S. Miller2011-02-051-2/+0
| | | | | | | | | | Like metrics, the ICMP rate limiting bits are cached state about a destination. So move it into the inet_peer entries. If an inet_peer cannot be bound (the reason is memory allocation failure or similar), the policy is to allow. Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Attach FIB info to dst_default_metrics when possibleDavid S. Miller2011-01-281-0/+1
| | | | | | | If there are no explicit metrics attached to a route, hook fi->fib_info up to dst_default_metrics. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Implement read-only protection and COW'ing of metrics.David S. Miller2011-01-271-37/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Routing metrics are now copy-on-write. Initially a route entry points it's metrics at a read-only location. If a routing table entry exists, it will point there. Else it will point at the all zero metric place-holder called 'dst_default_metrics'. The writeability state of the metrics is stored in the low bits of the metrics pointer, we have two bits left to spare if we want to store more states. For the initial implementation, COW is implemented simply via kmalloc. However future enhancements will change this to place the writable metrics somewhere else, in order to increase sharing. Very likely this "somewhere else" will be the inetpeer cache. Note also that this means that metrics updates may transiently fail if we cannot COW the metrics successfully. But even by itself, this patch should decrease memory usage and increase cache locality especially for routing workloads. In those cases the read-only metric copies stay in place and never get written to. TCP workloads where metrics get updated, and those rare cases where PMTU triggers occur, will take a very slight performance hit. But that hit will be alleviated when the long-term writable metrics move to a more sharable location. Since the metrics storage went from a u32 array of RTAX_MAX entries to what is essentially a pointer, some retooling of the dst_entry layout was necessary. Most importantly, we need to preserve the alignment of the reference count so that it doesn't share cache lines with the read-mostly state, as per Eric Dumazet's alignment assertion checks. The only non-trivial bit here is the move of the 'flags' member into the writeable cacheline. This is OK since we are always accessing the flags around the same moment when we made a modification to the reference count. Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of git://1984.lsi.us.es/net-next-2.6Patrick McHardy2011-01-141-10/+50
|\ | | | | | | | | | | | | Conflicts: net/ipv4/route.c Signed-off-by: Patrick McHardy <kaber@trash.net>
| * net: Abstract default MTU metric calculation behind an accessor.David S. Miller2010-12-141-7/+8
| | | | | | | | | | | | | | | | | | | | | | Like RTAX_ADVMSS, make the default calculation go through a dst_ops method rather than caching the computation in the routing cache entries. Now dst metrics are pretty much left as-is when new entries are created, thus optimizing metric sharing becomes a real possibility. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: Abstract default ADVMSS behind an accessor.David S. Miller2010-12-131-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make all RTAX_ADVMSS metric accesses go through a new helper function, dst_metric_advmss(). Leave the actual default metric as "zero" in the real metric slot, and compute the actual default value dynamically via a new dst_ops AF specific callback. For stacked IPSEC routes, we use the advmss of the path which preserves existing behavior. Unlike ipv4/ipv6, DecNET ties the advmss to the mtu and thus updates advmss on pmtu updates. This inconsistency in advmss handling results in more raw metric accesses than I wish we ended up with. Signed-off-by: David S. Miller <davem@davemloft.net>
| * ipv4: Don't pre-seed hoplimit metric.David S. Miller2010-12-131-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Always go through a new ip4_dst_hoplimit() helper, just like ipv6. This allowed several simplifications: 1) The interim dst_metric_hoplimit() can go as it's no longer userd. 2) The sysctl_ip_default_ttl entry no longer needs to use ipv4_doint_and_flush, since the sysctl is not cached in routing cache metrics any longer. 3) ipv4_doint_and_flush no longer needs to be exported and therefore can be marked static. When ipv4_doint_and_flush_strategy was removed some time ago, the external declaration in ip.h was mistakenly left around so kill that off too. We have to move the sysctl_ip_default_ttl declaration into ipv4's route cache definition header net/route.h, because currently net/ip.h (where the declaration lives now) has a back dependency on net/route.h Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: Abstract RTAX_HOPLIMIT metric accesses behind helper.David S. Miller2010-12-131-1/+14
| | | | | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: Abstract away all dst_entry metrics accesses.David S. Miller2010-12-091-3/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use helper functions to hide all direct accesses, especially writes, to dst_entry metrics values. This will allow us to: 1) More easily change how the metrics are stored. 2) Implement COW for metrics. In particular this will help us put metrics into the inetpeer cache if that is what we end up doing. We can make the _metrics member a pointer instead of an array, initially have it point at the read-only metrics in the FIB, and then on the first set grab an inetpeer entry and point the _metrics member there. Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 16:03:57 +0100