Clean up data when last reference goes away

In particular, don't free hash context until both master and slave are
closed.

1 files changed, 32 insertions, 26 deletions

diff --git a/cryptodev_main.c b/cryptodev_main.c
index f90dd45..c52210d 100644
--- a/cryptodev_main.c
+++ b/cryptodev_main.c
@@ -97,7 +97,7 @@ int __get_userbuf(uint8_t __user * addr, uint32_t len, int write,
 /* A socket merely used for I/O. */
 struct data_sock {
 	struct sock sk;
-	struct alg_sock *master; /* See below for reference counting */
+	struct alg_sock *master; /* NULL until master's accept() */
 	unsigned index;
 };
 
@@ -235,6 +235,15 @@ static struct proto alg_proto = {
 	.name = "ALG",
 };
 
+/* We only call sock_put() from task context, so this is running in task
+   context as well. */
+static void data_destruct(struct sock *sk)
+{
+	local_bh_disable();
+	sock_prot_inuse_add(sock_net(sk), &data_proto, -1);
+	local_bh_enable();
+}
+
 static int data_release(struct socket *sock)
 {
 	struct sock *sk;
@@ -247,10 +256,6 @@ static int data_release(struct socket *sock)
 	dsk = data_sk(sk);
 	DUMP_DSK(dsk);
 
-	local_bh_disable();
-	sock_prot_inuse_add(sock_net(sk), &data_proto, -1);
-	local_bh_enable();
-
 	BUG_ON(dsk->master == NULL);
 	sock_put(&dsk->master->sk);
 	DUMP_DSK(dsk);
@@ -271,7 +276,8 @@ static int do_data_sendmsg(struct kiocb *iocb, struct alg_sock *ask,
 	BUG_ON(index != 0);
 	BUG_ON(ask->hash.init == 0);
 
-	// FIXME: limit size, or use socket buffer
+	// FIXME: limit size, or use socket buffer, or refer to userspace
+	// pages directly
 	buf = kmalloc(total_len, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
@@ -372,6 +378,22 @@ static const struct proto_ops data_proto_ops = {
 	.splice_read = NULL,
 };
 
+/* We only call sock_put() from task context, so this is running in task
+   context as well. */
+static void alg_destruct(struct sock *sk)
+{
+	struct alg_sock *ask;
+
+	ask = alg_sk(sk);
+
+	if (ask->hash.init != 0)
+		cryptodev_hash_deinit(&ask->hash);
+
+	local_bh_disable();
+	sock_prot_inuse_add(sock_net(sk), &alg_proto, -1);
+	local_bh_enable();
+}
+
 static int alg_release(struct socket *sock)
 {
 	struct sock *sk;
@@ -396,24 +418,10 @@ static int alg_release(struct socket *sock)
 
 		BUG_ON(dsk == NULL);
 		DUMP_DSK(dsk);
-		if (i >= ask->accept_idx) { // FIXME: cleaner - on last sock_put
-			local_bh_disable();
-			sock_prot_inuse_add(sock_net(&dsk->sk), &data_proto,
-					    -1);
-			local_bh_enable();
-		}
 		sock_put(&dsk->sk);
 		DUMP_DSK(dsk);
 	}
 
-	if (ask->hash.init != 0)
-		cryptodev_hash_deinit(&ask->hash);
-
-	// FIXME: on last sock_put
-	local_bh_disable();
-	sock_prot_inuse_add(sock_net(sk), &alg_proto, -1);
-	local_bh_enable();
-
 	sock_put(sk);
 
 	return 0;
@@ -509,6 +517,8 @@ static int alg_listen(struct socket *sock, int len)
 		sock_prot_inuse_add(net, &data_proto, 1);
 		local_bh_enable();
 
+		newsk->sk_destruct = data_destruct;
+
 		dsk = data_sk(newsk);
 		dsk->index = i;
 		DUMP_DSK(dsk);
@@ -529,12 +539,6 @@ err_partial:
 
 		BUG_ON(dsk == NULL);
 		DUMP_DSK(dsk);
-
-		// FIXME: cleaner - on last sock_put
-		local_bh_disable();
-		sock_prot_inuse_add(sock_net(&dsk->sk), &data_proto, -1);
-		local_bh_enable();
-
 		sock_put(&dsk->sk);
 		DUMP_DSK(dsk);
 	}
@@ -617,6 +621,8 @@ static int alg_create(struct net *net, struct socket *sock, int protocol,
 	sock_prot_inuse_add(net, &alg_proto, 1);
 	local_bh_enable();
 
+	sk->sk_destruct = alg_destruct;
+
 	return 0;
 }