linux/include/net/ip_vs.h, branch v3.12

ipvs: make the service replacement more robust

2013-09-18T19:39:03Z

commit 578bc3ef1e473a ("ipvs: reorganize dest trash") added IP_VS_DEST_STATE_REMOVING flag and RCU callback named ip_vs_dest_wait_readers() to keep dests and services after removal for at least a RCU grace period. But we have the following corner cases: - we can not reuse the same dest if its service is removed while IP_VS_DEST_STATE_REMOVING is still set because another dest removal in the first grace period can not extend this period. It can happen when ipvsadm -C && ipvsadm -R is used. - dest->svc can be replaced but ip_vs_in_stats() and ip_vs_out_stats() have no explicit read memory barriers when accessing dest->svc. It can happen that dest->svc was just freed (replaced) while we use it to update the stats. We solve the problems as follows: - IP_VS_DEST_STATE_REMOVING is removed and we ensure a fixed idle period for the dest (IP_VS_DEST_TRASH_PERIOD). idle_start will remember when for first time after deletion we noticed dest->refcnt=0. Later, the connections can grab a reference while in RCU grace period but if refcnt becomes 0 we can safely free the dest and its svc. - dest->svc becomes RCU pointer. As result, we add explicit RCU locking in ip_vs_in_stats() and ip_vs_out_stats(). - __ip_vs_unbind_svc is renamed to __ip_vs_svc_put(), it now can free the service immediately or after a RCU grace period. dest->svc is not set to NULL anymore. As result, unlinked dests and their services are freed always after IP_VS_DEST_TRASH_PERIOD period, unused services are freed after a RCU grace period. Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman

ipvs: fix overflow on dest weight multiply

2013-09-18T19:38:53Z

Schedulers such as lblc and lblcr require the weight to be as high as the maximum number of active connections. In commit b552f7e3a9524abcbcdf ("ipvs: unify the formula to estimate the overhead of processing connections"), the consideration of inactconns and activeconns was cleaned up to always count activeconns as 256 times more important than inactconns. In cases where 3000 or more connections are expected, a weight of 3000 * 256 * 3000 connections overflows the 32-bit signed result used to determine if rescheduling is required. On amd64, this merely changes the multiply and comparison instructions to 64-bit. On x86, a 64-bit result is already present from imull, so only a few more comparison instructions are emitted. Signed-off-by: Simon Kirby Acked-by: Julian Anastasov Signed-off-by: Simon Horman

ipvs: add sync_persist_mode flag

2013-06-26T09:01:46Z

Add sync_persist_mode flag to reduce sync traffic by syncing only persistent templates. Signed-off-by: Julian Anastasov Tested-by: Aleksey Chudov Signed-off-by: Simon Horman

ipvs: replace the SCTP state machine

2013-06-26T09:01:46Z

Convert the SCTP state table, so that it is more readable. Change the states to be according to the diagram in RFC 2960 and add more states suitable for middle box. Still, such change in states adds incompatibility if systems in sync setup include this change and others do not include it. With this change we also have proper transitions in INPUT-ONLY mode (DR/TUN) where we see packets only from client. Now we should not switch to 10-second CLOSED state at a time when we should stay in ESTABLISHED state. The short names for states are because we have 16-char space in ipvsadm and 11-char limit for the connection list format. It is a sequence of the TCP implementation where the longest state name is ESTABLISHED. Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman

ipvs: sloppy TCP and SCTP

2013-06-26T09:01:46Z

This adds support for sloppy TCP and SCTP modes to IPVS. When enabled (sysctls net.ipv4.vs.sloppy_tcp and net.ipv4.vs.sloppy_sctp), allows IPVS to create connection state on any packet, not just a TCP SYN (or SCTP INIT). This allows connections to fail over from one IPVS director to another mid-flight. Signed-off-by: Alexander Frolkin Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman

ipvs: provide iph to schedulers

2013-06-26T09:01:45Z

Before now the schedulers needed access only to IP addresses and it was easy to get them from skb by using ip_vs_fill_iph_addr_only. New changes for the SH scheduler will need the protocol and ports which is difficult to get from skb for the IPv6 case. As we have all the data in the iph structure, to avoid the same slow lookups provide the iph to schedulers. Signed-off-by: Julian Anastasov Acked-by: Hans Schillstrom Signed-off-by: Simon Horman

ipvs: change type of netns_ipvs->sysctl_sync_qlen_max

2013-05-25T23:17:33Z

This member of struct netns_ipvs is calculated from nr_free_buffer_pages so change its type to unsigned long in case of overflow. Also, type of its related proc var sync_qlen_max and the return type of function sysctl_sync_qlen_max() should be changed to unsigned long, too. Besides, the type of ipvs_master_sync_state->sync_queue_len should be changed to unsigned long accordingly. Signed-off-by: Zhang Yanfei Cc: Julian Anastasov Cc: David Miller Signed-off-by: Andrew Morton Signed-off-by: Simon Horman

ipvs: fix sparse warnings for some parameters

2013-04-23T02:43:05Z

Some service fields are in network order: - netmask: used once in network order and also as prefix len for IPv6 - port Other parameters are in host order: - struct ip_vs_flags: flags and mask moved between user and kernel only - sync state: moved between user and kernel only - syncid: sent over network as single octet Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman

ipvs: convert services to rcu

2013-04-01T22:23:58Z

This is the final step in RCU conversion. Things that are removed: - svc->usecnt: now svc is accessed under RCU read lock - svc->inc: and some unused code - ip_vs_bind_pe and ip_vs_unbind_pe: no ability to replace PE - __ip_vs_svc_lock: replaced with RCU - IP_VS_WAIT_WHILE: now readers lookup svcs and dests under RCU and work in parallel with configuration Other changes: - before now, a RCU read-side critical section included the calling of the schedule method, now it is extended to include service lookup - ip_vs_svc_table and ip_vs_svc_fwm_table are now using hlist - svc->pe and svc->scheduler remain to the end (of grace period), the schedulers are prepared for such RCU readers even after done_service is called but they need to use synchronize_rcu because last ip_vs_scheduler_put can happen while RCU read-side critical sections use an outdated svc->scheduler pointer - as planned, update_service is removed - empty services can be freed immediately after grace period. If dests were present, the services are freed from the dest trash code Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman

ipvs: convert dests to rcu

2013-04-01T22:23:57Z

In previous commits the schedulers started to access svc->destinations with _rcu list traversal primitives because the IP_VS_WAIT_WHILE macro still plays the role of grace period. Now it is time to finish the updating part, i.e. adding and deleting of dests with _rcu suffix before removing the IP_VS_WAIT_WHILE in next commit. We use the same rule for conns as for the schedulers: dests can be searched in RCU read-side critical section where ip_vs_dest_hold can be called by ip_vs_bind_dest. Some things are not perfect, for example, calling functions like ip_vs_lookup_dest from updating code under RCU, just because we use some function both from reader and from updater. Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman