From 33912c2639ad76660988c8ca97e4d18fca89b668 Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 21 May 2022 08:45:15 +0100 Subject: rxrpc: Allow list of in-use local UDP endpoints to be viewed in /proc Allow the list of in-use local UDP endpoints in the current network namespace to be viewed in /proc. To aid with this, the endpoint list is converted to an hlist and RCU-safe manipulation is used so that the list can be read with only the RCU read lock held. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller --- net/rxrpc/local_object.c | 37 ++++++++++++++++++------------------- 1 file changed, 18 insertions(+), 19 deletions(-) (limited to 'net/rxrpc/local_object.c') diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c index 6a1611b0e303..ea6f338bd131 100644 --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -82,7 +82,7 @@ static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet, atomic_set(&local->usage, 1); atomic_set(&local->active_users, 1); local->rxnet = rxnet; - INIT_LIST_HEAD(&local->link); + INIT_HLIST_NODE(&local->link); INIT_WORK(&local->processor, rxrpc_local_processor); init_rwsem(&local->defrag_sem); skb_queue_head_init(&local->reject_queue); @@ -180,7 +180,7 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, { struct rxrpc_local *local; struct rxrpc_net *rxnet = rxrpc_net(net); - struct list_head *cursor; + struct hlist_node *cursor; const char *age; long diff; int ret; @@ -190,16 +190,12 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, mutex_lock(&rxnet->local_mutex); - for (cursor = rxnet->local_endpoints.next; - cursor != &rxnet->local_endpoints; - cursor = cursor->next) { - local = list_entry(cursor, struct rxrpc_local, link); + hlist_for_each(cursor, &rxnet->local_endpoints) { + local = hlist_entry(cursor, struct rxrpc_local, link); diff = rxrpc_local_cmp_key(local, srx); - if (diff < 0) + if (diff != 0) continue; - if (diff > 0) - break; /* Services aren't allowed to share transport sockets, so * reject that here. It is possible that the object is dying - @@ -211,9 +207,10 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, goto addr_in_use; } - /* Found a match. We replace a dying object. Attempting to - * bind the transport socket may still fail if we're attempting - * to use a local address that the dying object is still using. + /* Found a match. We want to replace a dying object. + * Attempting to bind the transport socket may still fail if + * we're attempting to use a local address that the dying + * object is still using. */ if (!rxrpc_use_local(local)) break; @@ -230,10 +227,12 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net, if (ret < 0) goto sock_error; - if (cursor != &rxnet->local_endpoints) - list_replace_init(cursor, &local->link); - else - list_add_tail(&local->link, cursor); + if (cursor) { + hlist_replace_rcu(cursor, &local->link); + cursor->pprev = NULL; + } else { + hlist_add_head_rcu(&local->link, &rxnet->local_endpoints); + } age = "new"; found: @@ -374,7 +373,7 @@ static void rxrpc_local_destroyer(struct rxrpc_local *local) local->dead = true; mutex_lock(&rxnet->local_mutex); - list_del_init(&local->link); + hlist_del_init_rcu(&local->link); mutex_unlock(&rxnet->local_mutex); rxrpc_clean_up_local_conns(local); @@ -458,9 +457,9 @@ void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet) flush_workqueue(rxrpc_workqueue); - if (!list_empty(&rxnet->local_endpoints)) { + if (!hlist_empty(&rxnet->local_endpoints)) { mutex_lock(&rxnet->local_mutex); - list_for_each_entry(local, &rxnet->local_endpoints, link) { + hlist_for_each_entry(local, &rxnet->local_endpoints, link) { pr_err("AF_RXRPC: Leaked local %p {%d}\n", local, atomic_read(&local->usage)); } -- cgit v1.2.3