2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 05:04:00 +08:00
linux-next/net
David S. Miller cc3baecb21 RxRPC rewrite
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIVAwUAV3zeiPSw1s6N8H32AQI9Iw//RxwhAzb+ovNIizPqcFRt4BIS3Or6unov
 Bx9jtq+U1POWZWtlIHYZKDH8ndxMnC56NkEHmpIK3uEiqJ6BoQPpDdfN+hhREysV
 Hoa+JOkMgufPBanU/JyKY/4vsmlvLuoOdppN1OA/kx1KECux9xJWIrvFsCUQGeat
 nDsdWChHkZAm/GDPZiFvxEBVaxDe2dmnDMBFTst1RsrH2uICSqM4k5srmjc3NPAY
 bsTqZeQGTIK1V9MggwBHxHFMvvERlGDpcrpoMRjeTzMmCpCg5endJoSu3hdNjHUO
 o5Fi50dhLI5jo84DQiXL0wM4SLND0QQygl+QeU3zlJYtsQsF6WxPnIEGqlGr3+WV
 I4wjDc5lxECyQIjCsrCo5ZwJ47Kqmm/ZQ4uGd9JooAVhqhP7/2dhFH0zXywJZzKs
 zo+dWTF5Xvde+mlknm1RCTgkdx3msPH9EVkEoO4FOPOAg6lhIMQFFXLXZfGr9oX6
 V99t+8t8YhDPTbL4AQnzh/aMHtbpM6be4TYiRRjT6iZLuvWOPW/zpp/1hmyeEkbU
 KZNDunC2tH030Fx5toGi3b2i8M5SJdyex9Udg/YsNexpWmyHMS49PoGk9ZnRRPA+
 xn9+xIVsqTh+xbiyCOPJqlQMMK9ayF7isT2N8T19qoVJxurdE/tMBdtKrJ5uTJFT
 W0n8KV46a+4=
 =1ZSd
 -----END PGP SIGNATURE-----

Merge tag 'rxrpc-rewrite-20160706' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
rxrpc: Improve conn/call lookup and fix call number generation [ver #3]

I've fixed a couple of patch descriptions and excised the patch that
duplicated the connections list for reconsideration at a later date.

For reference, the excised patch is sitting on the rxrpc-experimental
branch of my git tree, based on top of the rxrpc-rewrite branch.  Diffing
it against yesterday's tag shows no differences.

Would you prefer the patch set to be emailed afresh instead of a git-pull
request?

David
---
Here's the next part of the AF_RXRPC rewrite.  The two main purposes of
this set are to fix the call number handling and to make use of RCU when
looking up the connection or call to pass a received packet to.

Important changes in this set include:

 (1) Avoidance of placing stack data into SG lists in rxkad so that kernel
     stacks can become vmalloc'd (Herbert Xu).

 (2) Calls cease pinning the connection they used as soon as possible,
     which allows the connection to be discarded sooner and allows the call
     channel on that connection to be reused earlier.

 (3) Make each call channel on a connection have a separate and independent
     call number space rather than having a shared number space for the
     connection.  Call numbers should increment monotonically per channel
     on the client, and the server should ignore a call with a lower call
     number for that channel than the latest it has seen.  The RESPONSE
     packet sets the minimum values of each call ID counter on a
     connection.

 (4) Look up calls by indexing the channel array on a connection rather
     than by keeping calls in an rbtree on that connection.  Also look up
     calls using the channel array rather than using a hashtable.

     The call hashtable can then be removed.

 (5) Call terminal statuses are cached in the channel array for the last
     call.  It is assumed that if we the server have seen call N, then the
     client no longer cares about call N-1 on the same channel.

     This will allow retransmission of the terminal status in future
     without the need to keep the rxrpc_call struct around.

 (6) Peer lookups are moved out of common connection handling code and into
     service connection handling code as client connections (a) must point
     to a peer before they can be used and (b) are looked up by a
     machine-unique connection ID directly, so we only need to look up the
     peer first if we're going to deal with a service call.

 (7) The reference count on a connection is held elevated by 1 whilst it is
     alive (ie. idle unused connections have a refcount of 1).  The reaper
     will attempt to change the refcount from 1->0 and skip if this cannot
     be done, whilst look ups only increment the refcount if it's non-zero.

     This makes the implementation of RCU lookups easier as we don't have
     to get a ref on the connection or a lock on the connection list to
     prevent a connection being reaped whilst we're contemplating queueing
     a packet that initiates a new service call upon it.

     If we need to get a connection, but there's a dead connection in the
     tree, we use rb_replace_node() to replace the dead one with a new one.

 (8) Use a seqlock to validate the walk over the service connection rbtree
     attached to a peer when it's being walked in RCU mode.

 (9) Make the incoming call/connection packet handling code use RCU mode
     and locks and make it only take a reference if the call/connection
     gets queued on a workqueue.

The intention is that the next set will introduce the connection lifetime
management and capacity limits to prevent clients from overloading the
server.

There are some fixes too:

 (1) Verifying that a packet coming in to a client connection came from the
     expected source.

 (2) Fix handling of connection failure in client call creation where we
     don't reinitialise the list linkage block and a second attempt to
     unlink the failed connection oopses and also we don't set the state
     correctly, which causes an assertion failure.

 (3) New service calls were being added to the socket's accept queue under
     the wrong lock.

Changes:

 (V2) In rxrpc_find_service_conn_rcu() initialised the sequence number to 0.

      Fixed the RCU handling in conn_service.c by introducing and using
      rb_replace_node_rcu() as an RCU-safe alternative in
      rxrpc_publish_service_conn().

      Modified and used rcu_dereference_raw() to avoid RCU sparse warnings
      in rxrpc_find_service_conn_rcu().

      Added in some missing RCU dereference wrappers.  It seems to be
      necessary to turn on CONFIG_PROVE_RCU_REPEATEDLY as well as
      CONFIG_SPARSE_RCU_POINTER to get the static __rcu annotation checking
      to happen.

      Fixed some other sparse warnings, including a missing ntohs() in
      jumbo packet processing.

 (V3) Fixed some commit descriptions.

      Excised the patch that duplicated the connection list to separate out
      the procfs list for reconsideration at a later date.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-08 23:52:12 -04:00
..
6lowpan 6lowpan: add support for 802.15.4 short addr handling 2016-06-15 20:41:24 -07:00
9p remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
802
8021q net: introduce default neigh_construct/destroy ndo calls for L2 upper devices 2016-07-05 09:06:28 -07:00
appletalk appletalk: fix erroneous return value 2016-02-18 14:59:34 -05:00
atm net: add dev arg to ndo_neigh_construct/destroy 2016-07-05 09:06:28 -07:00
ax25 AX.25: Close socket connection on session completion 2016-06-18 20:55:34 -07:00
batman-adv This feature patchset includes the following changes: 2016-07-04 23:33:59 -07:00
bluetooth net: add netdev_lockdep_set_classes() helper 2016-06-09 13:28:37 -07:00
bridge Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-06 10:35:22 -07:00
caif caif: Remove unneeded header file 2016-06-28 05:26:14 -04:00
can can: only call can_stat_update with procfs 2016-06-23 11:23:49 +02:00
ceph libceph: use %s instead of %pE in dout()s 2016-05-30 23:00:23 +02:00
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-06 10:35:22 -07:00
dcb
dccp dccp: do not assume DCCP code is non preemptible 2016-05-02 17:02:25 -04:00
decnet net: fix decnet rtnexthop parsing 2016-07-05 14:08:47 -07:00
dns_resolver KEYS: Add a facility to restrict new links into a keyring 2016-04-11 22:37:37 +01:00
dsa net: dsa: Initialize CPU port ethtool ops per tree 2016-06-08 11:23:42 -07:00
ethernet eth: Pull header from first fragment via eth_get_headlen 2016-02-24 13:58:05 -05:00
hsr net/hsr: Use setup_timer and mod_timer. 2016-05-16 14:00:43 -04:00
ieee802154 net: add dev arg to ndo_neigh_construct/destroy 2016-07-05 09:06:28 -07:00
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-06 10:35:22 -07:00
ipv6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-06 10:35:22 -07:00
ipx
irda TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
iucv af_iucv: use paged SKBs for big inbound messages 2016-06-15 12:21:05 -07:00
kcm bpf: refactor bpf_prog_get and type check into helper 2016-07-01 16:00:47 -04:00
key
l2tp ipv6: use TOS marks from sockets for routing decision 2016-06-11 15:33:26 -07:00
l3mdev net: vrf: Implement get_saddr for IPv6 2016-06-17 21:25:29 -07:00
lapb net/lapb: tuse %*ph to dump buffers 2016-05-29 22:33:25 -07:00
llc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-09 15:59:24 -04:00
mac80211 cfg80211: Add mesh peer AID setting API 2016-07-06 15:04:52 +02:00
mac802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-03-19 10:05:34 -07:00
mpls mpls: allow routes on ipgre devices 2016-06-16 17:12:07 -07:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2016-07-06 09:15:15 -07:00
netlabel netlabel: fix a problem with netlbl_secattr_catmap_setrng() 2016-04-05 16:10:47 -04:00
netlink net/netlink/af_netlink.h: Remove unused structure. 2016-06-09 22:26:24 -07:00
netrom
nfc nfc: nci: Add nci_nfcc_loopback to the nci core 2016-05-04 01:48:16 +02:00
openvswitch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-06-30 05:03:36 -04:00
packet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-06 10:35:22 -07:00
phonet sock: struct proto hash function may error 2016-02-11 03:54:14 -05:00
qrtr Merge tag 'qcom-soc-for-4.7-2' into net-next 2016-05-17 14:11:19 -04:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-06 10:35:22 -07:00
rfkill rfkill: Use switch to demux userspace operations 2016-04-05 10:48:53 +02:00
rose
rxrpc rxrpc: Kill off the call hash table 2016-07-06 11:23:54 +01:00
sched hfsc: reduce hfsc_sched to 14 cachelines 2016-07-08 23:08:39 -04:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-06-30 05:03:36 -04:00
sunrpc rpc: share one xps between all backchannels 2016-06-15 10:32:25 -04:00
switchdev switchdev: pass pointer to fib_info instead of copy 2016-05-17 13:58:49 -04:00
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-06 10:35:22 -07:00
unix Merge branch 'overlayfs-af_unix-fix' into overlayfs-linus 2016-06-12 12:05:21 +02:00
vmw_vsock vsock: make listener child lock ordering explicit 2016-06-27 10:44:46 -04:00
wimax
wireless cfg80211: Add mesh peer AID setting API 2016-07-06 15:04:52 +02:00
x25 net: fix a kernel infoleak in x25 module 2016-05-09 22:45:33 -04:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-05-09 15:59:24 -04:00
compat.c packet: compat support for sock_fprog 2016-06-09 23:41:03 -07:00
Kconfig bpf: add generic constant blinding for use in jits 2016-05-16 13:49:32 -04:00
Makefile net: Add Qualcomm IPC router 2016-05-08 23:46:14 -04:00
socket.c fs: poll/select/recvmmsg: use timespec64 for timeout events 2016-05-19 19:12:14 -07:00
sysctl_net.c