linux-stable.git/net/tipc/net.c, branch v3.18

tipc: remove include file port.h

2014-08-23T18:18:35+00:00

We move the inline functions in the file port.h to socket.c, and modify
their names accordingly.

We move struct tipc_port and some macros to socket.h.

Finally, we remove the file port.h.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: use registry when scanning sockets

2014-08-23T18:18:34+00:00

The functions tipc_port_get_ports() and tipc_port_reinit() scan over
all sockets/ports to access each of them. This is done by using a
dedicated linked list, 'tipc_socks' where all sockets are members. The
list is in turn protected by a spinlock, 'port_list_lock', while each
socket is locked by using port_lock at the moment of access.

In order to reduce complexity and risk of deadlock, we want to get
rid of the linked list and the accompanying spinlock.

This is what we do in this commit. Instead of the linked list, we use
the port registry to scan across the sockets. We also add usage of
bh_lock_sock() inside the scope of port_lock in both functions, as a
preparation for the complete removal of port_lock.

Finally, we move the functions from port.c to socket.c, and rename them
to tipc_sk_sock_show() and tipc_sk_reinit() repectively.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: same receive code path for connection protocol and data messages

2014-06-27T19:50:56+00:00

As a preparation to eliminate port_lock we need to bring reception
of connection protocol messages under proper protection of bh_lock_sock
or socket owner.

We fix this by letting those messages follow the same code path as
incoming data messages.

As a side effect of this change, the last reference to the function
net_route_msg() disappears, and we can eliminate that function.

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: introduce message evaluation function

2014-06-27T19:50:55+00:00

When a message arrives in a node and finds no destination
socket, we may need to drop it, reject it, or forward it after
a secondary destination lookup. The latter two cases currently
results in a code path that is perceived as complex, because it
follows a deep call chain via obscure functions such as
net_route_named_msg() and net_route_msg().

We now introduce a function, tipc_msg_eval(), that takes the
decision about whether such a message should be rejected or
forwarded, but leaves it to the caller to actually perform
the indicated action.

If the decision is 'reject', it is still the task of the recently
introduced function tipc_msg_reverse() to take the final decision
about whether the message is rejectable or not. In the latter case
it drops the message.

As a result of this change, we can finally eliminate the function
net_route_named_msg(), and hence become independent of net_route_msg().

Signed-off-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: merge port message reception into socket reception function

2014-05-14T19:19:48+00:00

In order to reduce complexity and save a call level during message
reception at port/socket level, we remove the function tipc_port_rcv()
and merge its functionality into tipc_sk_rcv().

Signed-off-by: Jon Maloy 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: convert allocations of global variables associated with bclink

2014-05-05T21:26:45+00:00

Convert allocations of global variables associated with bclink from
static way to dynamical way for the convenience of bclink instance
initialisation. Meanwhile, this also helps TIPC support name space
in the future easily.

Signed-off-by: Ying Xue 
Reviewed-by: Erik Hugne 
Reviewed-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: purge tipc_net_lock lock

2014-04-23T01:17:53+00:00

Now tipc routing hierarchy comprises the structures 'node', 'link'and
'bearer'. The whole hierarchy is protected by a big read/write lock,
tipc_net_lock, to ensure that nothing is added or removed while code
is accessing any of these structures. Obviously the locking policy
makes node, link and bearer components closely bound together so that
their relationship becomes unnecessarily complex. In the worst case,
such locking policy not only has a negative influence on performance,
but also it's prone to lead to deadlock occasionally.

In order o decouple the complex relationship between bearer and node
as well as link, the locking policy is adjusted as follows:

- Bearer level
  RTNL lock is used on update side, and RCU is used on read side.
  Meanwhile, all bearer instances including broadcast bearer are
  saved into bearer_list array.

- Node and link level
  All node instances are saved into two tipc_node_list and node_htable
  lists. The two lists are protected by node_list_lock on write side,
  and they are guarded with RCU lock on read side. All members in node
  structure including link instances are protected by node spin lock.

- The relationship between bearer and node
  When link accesses bearer, it first needs to find the bearer with
  its bearer identity from the bearer_list array. When bearer accesses
  node, it can iterate the node_htable hash list with the node
  address to find the corresponding node.

In the new locking policy, every component has its private locking
solution and the relationship between bearer and node is very simple,
that is, they can find each other with node address or bearer identity
from node_htable hash list or bearer_list array.

Until now above all changes have been done, so tipc_net_lock can be
removed safely.

Signed-off-by: Ying Xue 
Reviewed-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Tested-by: Erik Hugne 
Signed-off-by: David S. Miller

tipc: use RTNL lock to protect tipc_net_stop routine

2014-04-23T01:17:52+00:00

As the tipc network initialization(ie, tipc_net_start routine) is
under RTNL protection, its corresponding deinitialization part(ie,
tipc_net_stop routine) should be protected by RTNL too.

Signed-off-by: Ying Xue 
Reviewed-by: Jon Maloy 
Reviewed-by: Erik Hugne 
Tested-by: Erik Hugne 
Signed-off-by: David S. Miller

tipc: fix regression bug where node events are not being generated

2014-04-03T20:03:57+00:00

Commit 5902385a2440a55f005b266c93e0bb9398e5a62b ("tipc: obsolete
the remote management feature") introduces a regression where node
topology events are not being generated because the publication
that triggers this: {0, , } is no longer available.
This will break applications that rely on node events to discover
when nodes join/leave a cluster.

We fix this by advertising the node publication when TIPC enters
networking mode, and withdraws it upon shutdown.

Signed-off-by: Erik Hugne 
Reviewed-by: Jon Maloy 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: rename node create lock to protect node list and hlist

2014-03-27T17:08:37+00:00

When a node is created, tipc_net_lock read lock is first held and
then node_create_lock is grabbed in order to prevent the same node
from being created and inserted into both node list and hlist twice.
But when we query node from the two node lists, we only hold
tipc_net_lock read lock without grabbing node_create_lock. Obviously
this locking policy is unable to guarantee that the two node lists
are always synchronized especially when the operation of changing
and accessing them occurs in different contexts like currently doing.

Therefore, rename node_create_lock to node_list_lock to protect the
two node lists, that is, whenever node is inserted into them or node
is queried from them, the node_list_lock should be always held. As a
result, tipc_net_lock read lock becomes redundant and then can be
removed from the node query functions.

Signed-off-by: Ying Xue 
Reviewed-by: Erik Hugne 
Reviewed-by: Jon Maloy 
Signed-off-by: David S. Miller