user/sven/linux.git/net/tipc/name_table.c, branch v4.14

tipc: adjust the policy of holding subscription kref

2017-03-29T01:03:33Z

When a new subscription object is inserted into name_seq->subscriptions list, it's under name_seq->lock protection; when a subscription is deleted from the list, it's also under the same lock protection; similarly, when accessing a subscription by going through subscriptions list, the entire process is also protected by the name_seq->lock. Therefore, if subscription refcount is increased before it's inserted into subscriptions list, and its refcount is decreased after it's deleted from the list, it will be unnecessary to hold refcount at all before accessing subscription object which is obtained by going through subscriptions list under name_seq->lock protection. Signed-off-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: add functionality to lookup multicast destination nodes

2017-01-20T17:10:16Z

As a further preparation for the upcoming 'replicast' functionality, we add some necessary structs and functions for looking up and returning a list of all nodes that host destinations for a given multicast message. Reviewed-by: Parthasarathy Bhuvaragan Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: modify struct tipc_plist to be more versatile

2017-01-03T16:13:05Z

During multicast reception we currently use a simple linked list with push/pop semantics to store port numbers. We now see a need for a more generic list for storing values of type u32. We therefore make some modifications to this list, while replacing the prefix 'tipc_plist_' with 'u32_'. We also add a couple of new functions which will come to use in the next commits. Acked-by: Parthasarathy Bhuvaragan Acked-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: move netlink policies to netlink.c

2016-03-07T19:56:41Z

Make the c files less cluttered and enable netlink attributes to be shared between files. Signed-off-by: Richard Alpe Reviewed-by: Jon Maloy Acked-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

tipc: remove struct tipc_name_seq from struct tipc_subscription

2016-02-06T08:40:43Z

Until now, struct tipc_subscriber has duplicate fields for type, upper and lower (as member of struct tipc_name_seq) at: 1. as member seq in struct tipc_subscription 2. as member seq in struct tipc_subscr, which is contained in struct tipc_event The former structure contains the type, upper and lower values in network byte order and the later contains the intact copy of the request. The struct tipc_subscription contains a field swap to determine if request needs network byte order conversion. Thus by using swap, we can convert the request when required instead of duplicating it. In this commit, 1. we remove the references to these elements as members of struct tipc_subscription and replace them with elements from struct tipc_subscr. 2. provide new functions to convert the user request into network byte order. Acked-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

tipc: reduce code dependency between binding table and node layer

2015-11-20T19:06:10Z

The file name_distr.c currently contains three functions, named_cluster_distribute(), tipc_publ_subcscribe() and tipc_publ_unsubscribe() that all directly access fields in struct tipc_node. We want to eliminate such dependencies, so we move those functions to the file node.c and rename them to tipc_node_broadcast(), tipc_node_subscribe() and tipc_node_unsubscribe() respectively. Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller

tipc: rename functions defined in subscr.c

2015-05-04T19:04:00Z

When a topology server accepts a connection request from its client, it allocates a connection instance and a tipc_subscriber structure object. The former is used to communicate with client, and the latter is often treated as a subscriber which manages all subscription events requested from a same client. When a topology server receives a request of subscribing name services from a client through the connection, it creates a tipc_subscription structure instance which is seen as a subscription recording what name services are subscribed. In order to manage all subscriptions from a same client, topology server links them into the subscrp_list of the subscriber. So subscriber and subscription completely represents different meanings respectively, but function names associated with them make us so confused that we are unable to easily tell which function is against subscriber and which is to subscription. So we want to eliminate the confusion by renaming them. Signed-off-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix a potential deadlock when nametable is purged

2015-03-18T02:11:26Z

[ 28.531768] ============================================= [ 28.532322] [ INFO: possible recursive locking detected ] [ 28.532322] 3.19.0+ #194 Not tainted [ 28.532322] --------------------------------------------- [ 28.532322] insmod/583 is trying to acquire lock: [ 28.532322] (&(&nseq->lock)->rlock){+.....}, at: [] tipc_nametbl_remove_publ+0x49/0x2e0 [tipc] [ 28.532322] [ 28.532322] but task is already holding lock: [ 28.532322] (&(&nseq->lock)->rlock){+.....}, at: [] tipc_nametbl_stop+0xfc/0x1f0 [tipc] [ 28.532322] [ 28.532322] other info that might help us debug this: [ 28.532322] Possible unsafe locking scenario: [ 28.532322] [ 28.532322] CPU0 [ 28.532322] ---- [ 28.532322] lock(&(&nseq->lock)->rlock); [ 28.532322] lock(&(&nseq->lock)->rlock); [ 28.532322] [ 28.532322] *** DEADLOCK *** [ 28.532322] [ 28.532322] May be due to missing lock nesting notation [ 28.532322] [ 28.532322] 3 locks held by insmod/583: [ 28.532322] #0: (net_mutex){+.+.+.}, at: [] register_pernet_subsys+0x1f/0x50 [ 28.532322] #1: (&(&tn->nametbl_lock)->rlock){+.....}, at: [] tipc_nametbl_stop+0xb1/0x1f0 [tipc] [ 28.532322] #2: (&(&nseq->lock)->rlock){+.....}, at: [] tipc_nametbl_stop+0xfc/0x1f0 [tipc] [ 28.532322] [ 28.532322] stack backtrace: [ 28.532322] CPU: 1 PID: 583 Comm: insmod Not tainted 3.19.0+ #194 [ 28.532322] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 28.532322] ffffffff82394460 ffff8800144cb928 ffffffff81792f3e 0000000000000007 [ 28.532322] ffffffff82394460 ffff8800144cba28 ffffffff810a8080 ffff8800144cb998 [ 28.532322] ffffffff810a4df3 ffff880013e9cb10 ffffffff82b0d330 ffff880013e9cb38 [ 28.532322] Call Trace: [ 28.532322] [] dump_stack+0x4c/0x65 [ 28.532322] [] __lock_acquire+0x740/0x1ca0 [ 28.532322] [] ? __bfs+0x23/0x270 [ 28.532322] [] ? check_irq_usage+0x96/0xe0 [ 28.532322] [] ? __lock_acquire+0x1133/0x1ca0 [ 28.532322] [] ? tipc_nametbl_remove_publ+0x49/0x2e0 [tipc] [ 28.532322] [] lock_acquire+0x9c/0x140 [ 28.532322] [] ? tipc_nametbl_remove_publ+0x49/0x2e0 [tipc] [ 28.532322] [] _raw_spin_lock_bh+0x3f/0x50 [ 28.532322] [] ? tipc_nametbl_remove_publ+0x49/0x2e0 [tipc] [ 28.532322] [] tipc_nametbl_remove_publ+0x49/0x2e0 [tipc] [ 28.532322] [] tipc_nametbl_stop+0x13e/0x1f0 [tipc] [ 28.532322] [] ? tipc_nametbl_stop+0x5/0x1f0 [tipc] [ 28.532322] [] tipc_init_net+0x13b/0x150 [tipc] [ 28.532322] [] ? tipc_init_net+0x5/0x150 [tipc] [ 28.532322] [] ops_init+0x4e/0x150 [ 28.532322] [] ? trace_hardirqs_on+0xd/0x10 [ 28.532322] [] register_pernet_operations+0xf3/0x190 [ 28.532322] [] register_pernet_subsys+0x2e/0x50 [ 28.532322] [] tipc_init+0x6a/0x1000 [tipc] [ 28.532322] [] ? 0xffffffffa0024000 [ 28.532322] [] do_one_initcall+0x89/0x1c0 [ 28.532322] [] ? kmem_cache_alloc_trace+0x50/0x1b0 [ 28.532322] [] ? do_init_module+0x2b/0x200 [ 28.532322] [] do_init_module+0x64/0x200 [ 28.532322] [] load_module+0x12f3/0x18e0 [ 28.532322] [] ? show_initstate+0x50/0x50 [ 28.532322] [] SyS_init_module+0xd9/0x110 [ 28.532322] [] sysenter_dispatch+0x7/0x1f Before tipc_purge_publications() calls tipc_nametbl_remove_publ() to remove a publication with a name sequence, the name sequence's lock is held. However, when tipc_nametbl_remove_publ() calling tipc_nameseq_remove_publ() to remove the publication, it first tries to query name sequence instance with the publication, and then holds the lock of the found name sequence. But as the lock may be already taken in tipc_purge_publications(), deadlock happens like above scenario demonstrated. As tipc_nameseq_remove_publ() doesn't grab name sequence's lock, the deadlock can be avoided if it's directly invoked by tipc_purge_publications(). Fixes: 97ede29e80ee ("tipc: convert name table read-write lock to RCU") Signed-off-by: Ying Xue Reviewed-by: Erik Hugne Signed-off-by: David S. Miller

tipc: nl compat add noop and remove legacy nl framework

2015-02-09T21:20:49Z

Add TIPC_CMD_NOOP to compat layer and remove the old framework. All legacy nl commands are now converted to the compat layer in netlink_compat.c. Signed-off-by: Richard Alpe Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: convert legacy nl name table dump to nl compat

2015-02-09T21:20:48Z

Add functionality for printing a dump header and convert TIPC_CMD_SHOW_NAME_TABLE to compat dumpit. Signed-off-by: Richard Alpe Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Reviewed-by: Jon Maloy Signed-off-by: David S. Miller