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https://github.com/torvalds/linux.git
synced 2024-11-10 22:21:40 +00:00
pvcalls-front: introduce a per sock_mapping refcount
Introduce a per sock_mapping refcount, in addition to the existing global refcount. Thanks to the sock_mapping refcount, we can safely wait for it to be 1 in pvcalls_front_release before freeing an active socket, instead of waiting for the global refcount to be 1. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> Acked-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Stefano Stabellini
Juergen Gross
parent
63e708f826
commit
64d6871827
@ -60,6 +60,7 @@ struct sock_mapping {
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bool active_socket;
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struct list_head list;
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struct socket *sock;
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atomic_t refcount;
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union {
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struct {
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int irq;
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@ -93,6 +94,32 @@ struct sock_mapping {
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};
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};
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static inline struct sock_mapping *pvcalls_enter_sock(struct socket *sock)
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{
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struct sock_mapping *map;
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if (!pvcalls_front_dev ||
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dev_get_drvdata(&pvcalls_front_dev->dev) == NULL)
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return ERR_PTR(-ENOTCONN);
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map = (struct sock_mapping *)sock->sk->sk_send_head;
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if (map == NULL)
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return ERR_PTR(-ENOTSOCK);
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pvcalls_enter();
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atomic_inc(&map->refcount);
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return map;
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}
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static inline void pvcalls_exit_sock(struct socket *sock)
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{
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struct sock_mapping *map;
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map = (struct sock_mapping *)sock->sk->sk_send_head;
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atomic_dec(&map->refcount);
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pvcalls_exit();
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}
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static inline int get_request(struct pvcalls_bedata *bedata, int *req_id)
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{
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*req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1);
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@ -369,31 +396,23 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
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if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
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return -EOPNOTSUPP;
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pvcalls_enter();
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if (!pvcalls_front_dev) {
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pvcalls_exit();
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return -ENOTCONN;
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}
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map = pvcalls_enter_sock(sock);
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if (IS_ERR(map))
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return PTR_ERR(map);
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bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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map = (struct sock_mapping *)sock->sk->sk_send_head;
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if (!map) {
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pvcalls_exit();
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return -ENOTSOCK;
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}
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spin_lock(&bedata->socket_lock);
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ret = get_request(bedata, &req_id);
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if (ret < 0) {
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spin_unlock(&bedata->socket_lock);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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ret = create_active(map, &evtchn);
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if (ret < 0) {
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spin_unlock(&bedata->socket_lock);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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@ -423,7 +442,7 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
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smp_rmb();
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ret = bedata->rsp[req_id].ret;
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bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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@ -488,23 +507,15 @@ int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg,
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if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB))
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return -EOPNOTSUPP;
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pvcalls_enter();
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if (!pvcalls_front_dev) {
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pvcalls_exit();
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return -ENOTCONN;
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}
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map = pvcalls_enter_sock(sock);
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if (IS_ERR(map))
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return PTR_ERR(map);
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bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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map = (struct sock_mapping *) sock->sk->sk_send_head;
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if (!map) {
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pvcalls_exit();
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return -ENOTSOCK;
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}
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mutex_lock(&map->active.out_mutex);
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if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) {
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mutex_unlock(&map->active.out_mutex);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -EAGAIN;
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}
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if (len > INT_MAX)
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@ -526,7 +537,7 @@ again:
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tot_sent = sent;
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mutex_unlock(&map->active.out_mutex);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return tot_sent;
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}
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@ -591,19 +602,11 @@ int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
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if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC))
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return -EOPNOTSUPP;
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pvcalls_enter();
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if (!pvcalls_front_dev) {
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pvcalls_exit();
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return -ENOTCONN;
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}
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map = pvcalls_enter_sock(sock);
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if (IS_ERR(map))
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return PTR_ERR(map);
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bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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map = (struct sock_mapping *) sock->sk->sk_send_head;
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if (!map) {
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pvcalls_exit();
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return -ENOTSOCK;
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}
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mutex_lock(&map->active.in_mutex);
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if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER))
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len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
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@ -623,7 +626,7 @@ int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
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ret = 0;
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mutex_unlock(&map->active.in_mutex);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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@ -637,24 +640,16 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
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if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
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return -EOPNOTSUPP;
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pvcalls_enter();
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if (!pvcalls_front_dev) {
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pvcalls_exit();
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return -ENOTCONN;
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}
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map = pvcalls_enter_sock(sock);
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if (IS_ERR(map))
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return PTR_ERR(map);
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bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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map = (struct sock_mapping *) sock->sk->sk_send_head;
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if (map == NULL) {
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pvcalls_exit();
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return -ENOTSOCK;
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}
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spin_lock(&bedata->socket_lock);
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ret = get_request(bedata, &req_id);
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if (ret < 0) {
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spin_unlock(&bedata->socket_lock);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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req = RING_GET_REQUEST(&bedata->ring, req_id);
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@ -684,7 +679,7 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
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bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
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map->passive.status = PVCALLS_STATUS_BIND;
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return 0;
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}
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@ -695,21 +690,13 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
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struct xen_pvcalls_request *req;
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int notify, req_id, ret;
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pvcalls_enter();
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if (!pvcalls_front_dev) {
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pvcalls_exit();
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return -ENOTCONN;
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}
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map = pvcalls_enter_sock(sock);
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if (IS_ERR(map))
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return PTR_ERR(map);
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bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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map = (struct sock_mapping *) sock->sk->sk_send_head;
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if (!map) {
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pvcalls_exit();
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return -ENOTSOCK;
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}
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if (map->passive.status != PVCALLS_STATUS_BIND) {
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -EOPNOTSUPP;
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}
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@ -717,7 +704,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
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ret = get_request(bedata, &req_id);
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if (ret < 0) {
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spin_unlock(&bedata->socket_lock);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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req = RING_GET_REQUEST(&bedata->ring, req_id);
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@ -741,7 +728,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
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bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
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map->passive.status = PVCALLS_STATUS_LISTEN;
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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@ -753,21 +740,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
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struct xen_pvcalls_request *req;
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int notify, req_id, ret, evtchn, nonblock;
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pvcalls_enter();
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if (!pvcalls_front_dev) {
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pvcalls_exit();
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return -ENOTCONN;
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}
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map = pvcalls_enter_sock(sock);
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if (IS_ERR(map))
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return PTR_ERR(map);
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bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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map = (struct sock_mapping *) sock->sk->sk_send_head;
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if (!map) {
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pvcalls_exit();
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return -ENOTSOCK;
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}
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if (map->passive.status != PVCALLS_STATUS_LISTEN) {
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -EINVAL;
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}
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@ -785,13 +764,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
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goto received;
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}
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if (nonblock) {
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -EAGAIN;
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}
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if (wait_event_interruptible(map->passive.inflight_accept_req,
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!test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
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(void *)&map->passive.flags))) {
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -EINTR;
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}
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}
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@ -802,7 +781,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
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clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
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(void *)&map->passive.flags);
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spin_unlock(&bedata->socket_lock);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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map2 = kzalloc(sizeof(*map2), GFP_ATOMIC);
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@ -810,7 +789,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
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clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
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(void *)&map->passive.flags);
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spin_unlock(&bedata->socket_lock);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -ENOMEM;
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}
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ret = create_active(map2, &evtchn);
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@ -819,7 +798,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
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clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
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(void *)&map->passive.flags);
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spin_unlock(&bedata->socket_lock);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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list_add_tail(&map2->list, &bedata->socket_mappings);
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@ -841,13 +820,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
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/* We could check if we have received a response before returning. */
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if (nonblock) {
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WRITE_ONCE(map->passive.inflight_req_id, req_id);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -EAGAIN;
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}
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if (wait_event_interruptible(bedata->inflight_req,
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READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) {
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -EINTR;
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}
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/* read req_id, then the content */
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@ -862,7 +841,7 @@ received:
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clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
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(void *)&map->passive.flags);
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pvcalls_front_free_map(bedata, map2);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return -ENOMEM;
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}
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newsock->sk->sk_send_head = (void *)map2;
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@ -874,7 +853,7 @@ received:
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clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags);
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wake_up(&map->passive.inflight_accept_req);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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@ -965,23 +944,16 @@ __poll_t pvcalls_front_poll(struct file *file, struct socket *sock,
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struct sock_mapping *map;
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__poll_t ret;
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pvcalls_enter();
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if (!pvcalls_front_dev) {
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pvcalls_exit();
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map = pvcalls_enter_sock(sock);
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if (IS_ERR(map))
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return EPOLLNVAL;
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}
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bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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map = (struct sock_mapping *) sock->sk->sk_send_head;
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if (!map) {
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pvcalls_exit();
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return EPOLLNVAL;
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}
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if (map->active_socket)
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ret = pvcalls_front_poll_active(file, bedata, map, wait);
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else
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ret = pvcalls_front_poll_passive(file, bedata, map, wait);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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@ -995,25 +967,20 @@ int pvcalls_front_release(struct socket *sock)
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if (sock->sk == NULL)
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return 0;
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pvcalls_enter();
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if (!pvcalls_front_dev) {
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pvcalls_exit();
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return -EIO;
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map = pvcalls_enter_sock(sock);
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if (IS_ERR(map)) {
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if (PTR_ERR(map) == -ENOTCONN)
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return -EIO;
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else
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return 0;
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}
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bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
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map = (struct sock_mapping *) sock->sk->sk_send_head;
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if (map == NULL) {
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pvcalls_exit();
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return 0;
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}
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spin_lock(&bedata->socket_lock);
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ret = get_request(bedata, &req_id);
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if (ret < 0) {
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spin_unlock(&bedata->socket_lock);
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pvcalls_exit();
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pvcalls_exit_sock(sock);
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return ret;
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}
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sock->sk->sk_send_head = NULL;
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@ -1043,10 +1010,10 @@ int pvcalls_front_release(struct socket *sock)
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/*
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* We need to make sure that sendmsg/recvmsg on this socket have
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* not started before we've cleared sk_send_head here. The
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* easiest (though not optimal) way to guarantee this is to see
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* that no pvcall (other than us) is in progress.
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* easiest way to guarantee this is to see that no pvcalls
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* (other than us) is in progress on this socket.
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*/
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while (atomic_read(&pvcalls_refcount) > 1)
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while (atomic_read(&map->refcount) > 1)
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cpu_relax();
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pvcalls_front_free_map(bedata, map);
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