lwn.git/net/rxrpc, branch doc/4.9

rxrpc: checking for IS_ERR() instead of NULL

2016-07-15T21:16:25+00:00

The rxrpc_lookup_peer() function returns NULL on error, it never returns error pointers. Fixes: 8496af50eb38 ('rxrpc: Use RCU to access a peer's service connection tree') Signed-off-by: Dan Carpenter Signed-off-by: David Howells Signed-off-by: David S. Miller

rxrpc: Fix error handling in af_rxrpc_init()

2016-07-12T18:07:38+00:00

security initialized after alloc workqueue, so we should exit security before destroy workqueue in the error handing. Fixes: 648af7fca159 ("rxrpc: Absorb the rxkad security module") Signed-off-by: Wei Yongjun Signed-off-by: David S. Miller

rxrpc: Kill off the call hash table

2016-07-06T10:23:54+00:00

The call hash table is now no longer used as calls are looked up directly by channel slot on the connection, so kill it off. Signed-off-by: David Howells

rxrpc: Use RCU to access a peer's service connection tree

2016-07-06T09:51:14+00:00

Move to using RCU access to a peer's service connection tree when routing an incoming packet. This is done using a seqlock to trigger retrying of the tree walk if a change happened. Further, we no longer get a ref on the connection looked up in the data_ready handler unless we queue the connection's work item - and then only if the refcount > 0. Note that I'm avoiding the use of a hash table for service connections because each service connection is addressed by a 62-bit number (constructed from epoch and connection ID >> 2) that would allow the client to engage in bucket stuffing, given knowledge of the hash algorithm. Peers, however, are hashed as the network address is less controllable by the client. The total number of peers will also be limited in a future commit. Signed-off-by: David Howells

rxrpc: Move data_ready peer lookup into rxrpc_find_connection()

2016-07-06T09:51:14+00:00

Move the peer lookup done in input.c by data_ready into rxrpc_find_connection(). Signed-off-by: David Howells

rxrpc: Prune the contents of the rxrpc_conn_proto struct

2016-07-06T09:51:14+00:00

Prune the contents of the rxrpc_conn_proto struct. Most of the fields aren't used anymore. Signed-off-by: David Howells

rxrpc: Maintain an extra ref on a conn for the cache list

2016-07-06T09:50:04+00:00

Overhaul the usage count accounting for the rxrpc_connection struct to make it easier to implement RCU access from the data_ready handler. The problem is that currently we're using a lock to prevent the garbage collector from trying to clean up a connection that we're contemplating unidling. We could just stick incoming packets on the connection we find, but we've then got a problem that we may race when dispatching a work item to process it as we need to give that a ref to prevent the rxrpc_connection struct from disappearing in the meantime. Further, incoming packets may get discarded if attached to an rxrpc_connection struct that is going away. Whilst this is not a total disaster - the client will presumably resend - it would delay processing of the call. This would affect the AFS client filesystem's service manager operation. To this end: (1) We now maintain an extra count on the connection usage count whilst it is on the connection list. This mean it is not in use when its refcount is 1. (2) When trying to reuse an old connection, we only increment the refcount if it is greater than 0. If it is 0, we replace it in the tree with a new candidate connection. (3) Two connection flags are added to indicate whether or not a connection is in the local's client connection tree (used by sendmsg) or the peer's service connection tree (used by data_ready). This makes sure that we don't try and remove a connection if it got replaced. The flags are tested under lock with the removal operation to prevent the reaper from killing the rxrpc_connection struct whilst someone else is trying to effect a replacement. This could probably be alleviated by using memory barriers between the flag set/test and the rb_tree ops. The rb_tree op would still need to be under the lock, however. (4) When trying to reap an old connection, we try to flip the usage count from 1 to 0. If it's not 1 at that point, then it must've come back to life temporarily and we ignore it. Signed-off-by: David Howells

rxrpc: Move peer lookup from call-accept to new-incoming-conn

2016-07-06T09:49:57+00:00

Move the lookup of a peer from a call that's being accepted into the function that creates a new incoming connection. This will allow us to avoid incrementing the peer's usage count in some cases in future. Note that I haven't bother to integrate rxrpc_get_addr_from_skb() with rxrpc_extract_addr_from_skb() as I'm going to delete the former in the very near future. Signed-off-by: David Howells

rxrpc: Split service connection code out into its own file

2016-07-06T09:49:35+00:00

Split the service-specific connection code out into into its own file. The client-specific code has already been split out. This will leave just the common code in the original file. Signed-off-by: David Howells

rxrpc: Split client connection code out into its own file

2016-07-06T09:43:52+00:00

Split the client-specific connection code out into its own file. It will behave somewhat differently from the service-specific connection code, so it makes sense to separate them. Signed-off-by: David Howells