From 56b3d975bbce65f655c5612b4822da671f9fd9b2 Mon Sep 17 00:00:00 2001 From: Philippe De Muyter Date: Tue, 10 Jul 2007 23:07:31 -0700 Subject: [NET]: Make all initialized struct seq_operations const. Make all initialized struct seq_operations in net/ const Signed-off-by: Philippe De Muyter Signed-off-by: David S. Miller --- net/unix/af_unix.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/unix/af_unix.c') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index d70fa30d4294..3654b647ac79 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2048,7 +2048,7 @@ static int unix_seq_show(struct seq_file *seq, void *v) return 0; } -static struct seq_operations unix_seq_ops = { +static const struct seq_operations unix_seq_ops = { .start = unix_seq_start, .next = unix_seq_next, .stop = unix_seq_stop, -- cgit v1.2.3 From 1fd05ba5a2f2aa8e7b9b52ef55df850e2e7d54c9 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 11 Jul 2007 14:22:39 -0700 Subject: [AF_UNIX]: Rewrite garbage collector, fixes race. Throw out the old mark & sweep garbage collector and put in a refcounting cycle detecting one. The old one had a race with recvmsg, that resulted in false positives and hence data loss. The old algorithm operated on all unix sockets in the system, so any additional locking would have meant performance problems for all users of these. The new algorithm instead only operates on "in flight" sockets, which are very rare, and the additional locking for these doesn't negatively impact the vast majority of users. In fact it's probable, that there weren't *any* heavy senders of sockets over sockets, otherwise the above race would have been discovered long ago. The patch works OK with the app that exposed the race with the old code. The garbage collection has also been verified to work in a few simple cases. Signed-off-by: Miklos Szeredi Signed-off-by: David S. Miller --- net/unix/af_unix.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'net/unix/af_unix.c') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 3654b647ac79..65ebccc0a698 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -592,7 +592,8 @@ static struct sock * unix_create1(struct socket *sock) u->dentry = NULL; u->mnt = NULL; spin_lock_init(&u->lock); - atomic_set(&u->inflight, sock ? 0 : -1); + atomic_set(&u->inflight, 0); + INIT_LIST_HEAD(&u->link); mutex_init(&u->readlock); /* single task reading lock */ init_waitqueue_head(&u->peer_wait); unix_insert_socket(unix_sockets_unbound, sk); @@ -1134,9 +1135,6 @@ restart: /* take ten and and send info to listening sock */ spin_lock(&other->sk_receive_queue.lock); __skb_queue_tail(&other->sk_receive_queue, skb); - /* Undo artificially decreased inflight after embrion - * is installed to listening socket. */ - atomic_inc(&newu->inflight); spin_unlock(&other->sk_receive_queue.lock); unix_state_unlock(other); other->sk_data_ready(other, 0); -- cgit v1.2.3