Hi all,
this small series introduces a per socket refcount to increase the
efficiency on socket release operations, and makes releasing passive
sockets safe.
Cheers,
Stefano
Stefano Stabellini (2):
pvcalls-front: introduce a per sock_mapping refcount
pvcalls-front: wait for other operations to return when release passive sockets
drivers/xen/pvcalls-front.c | 196 +++++++++++++++++++-------------------------
1 file changed, 84 insertions(+), 112 deletions(-)
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 <[email protected]>
---
drivers/xen/pvcalls-front.c | 190 ++++++++++++++++++--------------------------
1 file changed, 78 insertions(+), 112 deletions(-)
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 4c789e6..164d3ad 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -60,6 +60,7 @@ struct sock_mapping {
bool active_socket;
struct list_head list;
struct socket *sock;
+ atomic_t refcount;
union {
struct {
int irq;
@@ -93,6 +94,33 @@ struct sock_mapping {
};
};
+static inline struct sock_mapping *pvcalls_enter_sock(struct socket *sock)
+{
+ struct sock_mapping *map = NULL;
+
+ if (!pvcalls_front_dev || &pvcalls_front_dev->dev == NULL)
+ return ERR_PTR(-ENOTCONN);
+
+ pvcalls_enter();
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
+ if (map == NULL) {
+ pvcalls_exit()
+ return ERR_PTR(-ENOTSOCK);
+ }
+
+ atomic_inc(&map->refcount);
+ return map;
+}
+
+static inline void pvcalls_exit_sock(struct socket *sock)
+{
+ struct sock_mapping *map = NULL;
+
+ map = (struct sock_mapping *) sock->sk->sk_send_head;
+ atomic_dec(&map->refcount);
+ pvcalls_exit();
+}
+
static inline int get_request(struct pvcalls_bedata *bedata, int *req_id)
{
*req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1);
@@ -369,31 +397,23 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
return -EOPNOTSUPP;
- pvcalls_enter();
- if (!pvcalls_front_dev) {
- pvcalls_exit();
- return -ENOTCONN;
- }
+ map = pvcalls_enter_sock(sock);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
- map = (struct sock_mapping *)sock->sk->sk_send_head;
- if (!map) {
- pvcalls_exit();
- return -ENOTSOCK;
- }
-
spin_lock(&bedata->socket_lock);
ret = get_request(bedata, &req_id);
if (ret < 0) {
spin_unlock(&bedata->socket_lock);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
ret = create_active(map, &evtchn);
if (ret < 0) {
spin_unlock(&bedata->socket_lock);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
@@ -423,7 +443,7 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
smp_rmb();
ret = bedata->rsp[req_id].ret;
bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
@@ -488,23 +508,15 @@ int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg,
if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB))
return -EOPNOTSUPP;
- pvcalls_enter();
- if (!pvcalls_front_dev) {
- pvcalls_exit();
- return -ENOTCONN;
- }
+ map = pvcalls_enter_sock(sock);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
- map = (struct sock_mapping *) sock->sk->sk_send_head;
- if (!map) {
- pvcalls_exit();
- return -ENOTSOCK;
- }
-
mutex_lock(&map->active.out_mutex);
if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) {
mutex_unlock(&map->active.out_mutex);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -EAGAIN;
}
if (len > INT_MAX)
@@ -526,7 +538,7 @@ int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg,
tot_sent = sent;
mutex_unlock(&map->active.out_mutex);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return tot_sent;
}
@@ -591,19 +603,11 @@ int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC))
return -EOPNOTSUPP;
- pvcalls_enter();
- if (!pvcalls_front_dev) {
- pvcalls_exit();
- return -ENOTCONN;
- }
+ map = pvcalls_enter_sock(sock);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
- map = (struct sock_mapping *) sock->sk->sk_send_head;
- if (!map) {
- pvcalls_exit();
- return -ENOTSOCK;
- }
-
mutex_lock(&map->active.in_mutex);
if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER))
len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
@@ -623,7 +627,7 @@ int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
ret = 0;
mutex_unlock(&map->active.in_mutex);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
@@ -637,24 +641,16 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
return -EOPNOTSUPP;
- pvcalls_enter();
- if (!pvcalls_front_dev) {
- pvcalls_exit();
- return -ENOTCONN;
- }
+ map = pvcalls_enter_sock(sock);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
- map = (struct sock_mapping *) sock->sk->sk_send_head;
- if (map == NULL) {
- pvcalls_exit();
- return -ENOTSOCK;
- }
-
spin_lock(&bedata->socket_lock);
ret = get_request(bedata, &req_id);
if (ret < 0) {
spin_unlock(&bedata->socket_lock);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
req = RING_GET_REQUEST(&bedata->ring, req_id);
@@ -684,7 +680,7 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
map->passive.status = PVCALLS_STATUS_BIND;
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return 0;
}
@@ -695,21 +691,13 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
struct xen_pvcalls_request *req;
int notify, req_id, ret;
- pvcalls_enter();
- if (!pvcalls_front_dev) {
- pvcalls_exit();
- return -ENOTCONN;
- }
+ map = pvcalls_enter_sock(sock);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
- map = (struct sock_mapping *) sock->sk->sk_send_head;
- if (!map) {
- pvcalls_exit();
- return -ENOTSOCK;
- }
-
if (map->passive.status != PVCALLS_STATUS_BIND) {
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -EOPNOTSUPP;
}
@@ -717,7 +705,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
ret = get_request(bedata, &req_id);
if (ret < 0) {
spin_unlock(&bedata->socket_lock);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
req = RING_GET_REQUEST(&bedata->ring, req_id);
@@ -741,7 +729,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
map->passive.status = PVCALLS_STATUS_LISTEN;
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
@@ -753,21 +741,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
struct xen_pvcalls_request *req;
int notify, req_id, ret, evtchn, nonblock;
- pvcalls_enter();
- if (!pvcalls_front_dev) {
- pvcalls_exit();
- return -ENOTCONN;
- }
+ map = pvcalls_enter_sock(sock);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
- map = (struct sock_mapping *) sock->sk->sk_send_head;
- if (!map) {
- pvcalls_exit();
- return -ENOTSOCK;
- }
-
if (map->passive.status != PVCALLS_STATUS_LISTEN) {
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -EINVAL;
}
@@ -785,13 +765,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
goto received;
}
if (nonblock) {
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -EAGAIN;
}
if (wait_event_interruptible(map->passive.inflight_accept_req,
!test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
(void *)&map->passive.flags))) {
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -EINTR;
}
}
@@ -802,7 +782,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
(void *)&map->passive.flags);
spin_unlock(&bedata->socket_lock);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
map2 = kzalloc(sizeof(*map2), GFP_ATOMIC);
@@ -810,7 +790,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
(void *)&map->passive.flags);
spin_unlock(&bedata->socket_lock);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -ENOMEM;
}
ret = create_active(map2, &evtchn);
@@ -819,7 +799,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
(void *)&map->passive.flags);
spin_unlock(&bedata->socket_lock);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
list_add_tail(&map2->list, &bedata->socket_mappings);
@@ -841,13 +821,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
/* We could check if we have received a response before returning. */
if (nonblock) {
WRITE_ONCE(map->passive.inflight_req_id, req_id);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -EAGAIN;
}
if (wait_event_interruptible(bedata->inflight_req,
READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) {
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -EINTR;
}
/* read req_id, then the content */
@@ -862,7 +842,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
(void *)&map->passive.flags);
pvcalls_front_free_map(bedata, map2);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return -ENOMEM;
}
newsock->sk->sk_send_head = (void *)map2;
@@ -874,7 +854,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags);
wake_up(&map->passive.inflight_accept_req);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
@@ -965,23 +945,16 @@ unsigned int pvcalls_front_poll(struct file *file, struct socket *sock,
struct sock_mapping *map;
int ret;
- pvcalls_enter();
- if (!pvcalls_front_dev) {
- pvcalls_exit();
+ map = pvcalls_enter_sock(sock);
+ if (IS_ERR(map))
return POLLNVAL;
- }
bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
- map = (struct sock_mapping *) sock->sk->sk_send_head;
- if (!map) {
- pvcalls_exit();
- return POLLNVAL;
- }
if (map->active_socket)
ret = pvcalls_front_poll_active(file, bedata, map, wait);
else
ret = pvcalls_front_poll_passive(file, bedata, map, wait);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
@@ -995,25 +968,18 @@ int pvcalls_front_release(struct socket *sock)
if (sock->sk == NULL)
return 0;
- pvcalls_enter();
- if (!pvcalls_front_dev) {
- pvcalls_exit();
+ map = pvcalls_enter_sock(sock);
+ if (IS_ERR(map) && PTR_ERR(map) == -ENOTCONN)
return -EIO;
- }
-
- bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
-
- map = (struct sock_mapping *) sock->sk->sk_send_head;
- if (map == NULL) {
- pvcalls_exit();
+ if (IS_ERR(map) && PTR_ERR(map) == -ENOTSOCK)
return 0;
- }
+ bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
spin_lock(&bedata->socket_lock);
ret = get_request(bedata, &req_id);
if (ret < 0) {
spin_unlock(&bedata->socket_lock);
- pvcalls_exit();
+ pvcalls_exit_sock(sock);
return ret;
}
sock->sk->sk_send_head = NULL;
@@ -1043,10 +1009,10 @@ int pvcalls_front_release(struct socket *sock)
/*
* We need to make sure that sendmsg/recvmsg on this socket have
* not started before we've cleared sk_send_head here. The
- * easiest (though not optimal) way to guarantee this is to see
- * that no pvcall (other than us) is in progress.
+ * easiest way to guarantee this is to see that no pvcalls
+ * (other than us) is in progress on this socket.
*/
- while (atomic_read(&pvcalls_refcount) > 1)
+ while (atomic_read(&map->refcount) > 1)
cpu_relax();
pvcalls_front_free_map(bedata, map);
--
1.9.1
Passive sockets can have ongoing operations on them, specifically, we
have two wait_event_interruptable calls in pvcalls_front_accept.
Add two wake_up calls in pvcalls_front_release, then wait for the
potential waiters to return and release the sock_mapping refcount.
Signed-off-by: Stefano Stabellini <[email protected]>
---
drivers/xen/pvcalls-front.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
index 164d3ad..d32cac5 100644
--- a/drivers/xen/pvcalls-front.c
+++ b/drivers/xen/pvcalls-front.c
@@ -1017,6 +1017,12 @@ int pvcalls_front_release(struct socket *sock)
pvcalls_front_free_map(bedata, map);
} else {
+ wake_up(&bedata->inflight_req);
+ wake_up(&map->passive.inflight_accept_req);
+
+ while (atomic_read(&map->refcount) > 1)
+ cpu_relax();
+
spin_lock(&bedata->socket_lock);
list_del(&map->list);
spin_unlock(&bedata->socket_lock);
--
1.9.1
On 05/02/18 23:51, Stefano Stabellini wrote:
> Passive sockets can have ongoing operations on them, specifically, we
> have two wait_event_interruptable calls in pvcalls_front_accept.
>
> Add two wake_up calls in pvcalls_front_release, then wait for the
> potential waiters to return and release the sock_mapping refcount.
>
> Signed-off-by: Stefano Stabellini <[email protected]>
Acked-by: Juergen Gross <[email protected]>
Juergen
On 05/02/18 23:51, Stefano Stabellini wrote:
> 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 <[email protected]>
> ---
> drivers/xen/pvcalls-front.c | 190 ++++++++++++++++++--------------------------
> 1 file changed, 78 insertions(+), 112 deletions(-)
>
> diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
> index 4c789e6..164d3ad 100644
> --- a/drivers/xen/pvcalls-front.c
> +++ b/drivers/xen/pvcalls-front.c
> @@ -60,6 +60,7 @@ struct sock_mapping {
> bool active_socket;
> struct list_head list;
> struct socket *sock;
> + atomic_t refcount;
> union {
> struct {
> int irq;
> @@ -93,6 +94,33 @@ struct sock_mapping {
> };
> };
>
> +static inline struct sock_mapping *pvcalls_enter_sock(struct socket *sock)
> +{
> + struct sock_mapping *map = NULL;
> +
> + if (!pvcalls_front_dev || &pvcalls_front_dev->dev == NULL)
Did you mean:
if (!pvcalls_front_dev || !pvcalls_front_dev->dev)
> + return ERR_PTR(-ENOTCONN);
> +
> + pvcalls_enter();
> + map = (struct sock_mapping *) sock->sk->sk_send_head;
Style: no blank after the cast, please (multiple times).
> + if (map == NULL) {
> + pvcalls_exit()
> + return ERR_PTR(-ENOTSOCK);
> + }
> +
> + atomic_inc(&map->refcount);
> + return map;
> +}
> +
> +static inline void pvcalls_exit_sock(struct socket *sock)
> +{
> + struct sock_mapping *map = NULL;
> +
> + map = (struct sock_mapping *) sock->sk->sk_send_head;
> + atomic_dec(&map->refcount);
> + pvcalls_exit();
> +}
> +
> static inline int get_request(struct pvcalls_bedata *bedata, int *req_id)
> {
> *req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1);
> @@ -369,31 +397,23 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
> if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
> return -EOPNOTSUPP;
>
> - pvcalls_enter();
> - if (!pvcalls_front_dev) {
> - pvcalls_exit();
> - return -ENOTCONN;
> - }
> + map = pvcalls_enter_sock(sock);
> + if (IS_ERR(map))
> + return PTR_ERR(map);
>
> bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
>
> - map = (struct sock_mapping *)sock->sk->sk_send_head;
> - if (!map) {
> - pvcalls_exit();
> - return -ENOTSOCK;
> - }
> -
> spin_lock(&bedata->socket_lock);
> ret = get_request(bedata, &req_id);
> if (ret < 0) {
> spin_unlock(&bedata->socket_lock);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
> ret = create_active(map, &evtchn);
> if (ret < 0) {
> spin_unlock(&bedata->socket_lock);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
>
> @@ -423,7 +443,7 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
> smp_rmb();
> ret = bedata->rsp[req_id].ret;
> bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
>
> @@ -488,23 +508,15 @@ int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg,
> if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB))
> return -EOPNOTSUPP;
>
> - pvcalls_enter();
> - if (!pvcalls_front_dev) {
> - pvcalls_exit();
> - return -ENOTCONN;
> - }
> + map = pvcalls_enter_sock(sock);
> + if (IS_ERR(map))
> + return PTR_ERR(map);
> bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
>
> - map = (struct sock_mapping *) sock->sk->sk_send_head;
> - if (!map) {
> - pvcalls_exit();
> - return -ENOTSOCK;
> - }
> -
> mutex_lock(&map->active.out_mutex);
> if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) {
> mutex_unlock(&map->active.out_mutex);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -EAGAIN;
> }
> if (len > INT_MAX)
> @@ -526,7 +538,7 @@ int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg,
> tot_sent = sent;
>
> mutex_unlock(&map->active.out_mutex);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return tot_sent;
> }
>
> @@ -591,19 +603,11 @@ int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC))
> return -EOPNOTSUPP;
>
> - pvcalls_enter();
> - if (!pvcalls_front_dev) {
> - pvcalls_exit();
> - return -ENOTCONN;
> - }
> + map = pvcalls_enter_sock(sock);
> + if (IS_ERR(map))
> + return PTR_ERR(map);
> bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
>
> - map = (struct sock_mapping *) sock->sk->sk_send_head;
> - if (!map) {
> - pvcalls_exit();
> - return -ENOTSOCK;
> - }
> -
> mutex_lock(&map->active.in_mutex);
> if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER))
> len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
> @@ -623,7 +627,7 @@ int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> ret = 0;
>
> mutex_unlock(&map->active.in_mutex);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
>
> @@ -637,24 +641,16 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
> return -EOPNOTSUPP;
>
> - pvcalls_enter();
> - if (!pvcalls_front_dev) {
> - pvcalls_exit();
> - return -ENOTCONN;
> - }
> + map = pvcalls_enter_sock(sock);
> + if (IS_ERR(map))
> + return PTR_ERR(map);
> bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
>
> - map = (struct sock_mapping *) sock->sk->sk_send_head;
> - if (map == NULL) {
> - pvcalls_exit();
> - return -ENOTSOCK;
> - }
> -
> spin_lock(&bedata->socket_lock);
> ret = get_request(bedata, &req_id);
> if (ret < 0) {
> spin_unlock(&bedata->socket_lock);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
> req = RING_GET_REQUEST(&bedata->ring, req_id);
> @@ -684,7 +680,7 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
>
> map->passive.status = PVCALLS_STATUS_BIND;
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return 0;
> }
>
> @@ -695,21 +691,13 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
> struct xen_pvcalls_request *req;
> int notify, req_id, ret;
>
> - pvcalls_enter();
> - if (!pvcalls_front_dev) {
> - pvcalls_exit();
> - return -ENOTCONN;
> - }
> + map = pvcalls_enter_sock(sock);
> + if (IS_ERR(map))
> + return PTR_ERR(map);
> bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
>
> - map = (struct sock_mapping *) sock->sk->sk_send_head;
> - if (!map) {
> - pvcalls_exit();
> - return -ENOTSOCK;
> - }
> -
> if (map->passive.status != PVCALLS_STATUS_BIND) {
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -EOPNOTSUPP;
> }
>
> @@ -717,7 +705,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
> ret = get_request(bedata, &req_id);
> if (ret < 0) {
> spin_unlock(&bedata->socket_lock);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
> req = RING_GET_REQUEST(&bedata->ring, req_id);
> @@ -741,7 +729,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
> bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
>
> map->passive.status = PVCALLS_STATUS_LISTEN;
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
>
> @@ -753,21 +741,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> struct xen_pvcalls_request *req;
> int notify, req_id, ret, evtchn, nonblock;
>
> - pvcalls_enter();
> - if (!pvcalls_front_dev) {
> - pvcalls_exit();
> - return -ENOTCONN;
> - }
> + map = pvcalls_enter_sock(sock);
> + if (IS_ERR(map))
> + return PTR_ERR(map);
> bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
>
> - map = (struct sock_mapping *) sock->sk->sk_send_head;
> - if (!map) {
> - pvcalls_exit();
> - return -ENOTSOCK;
> - }
> -
> if (map->passive.status != PVCALLS_STATUS_LISTEN) {
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -EINVAL;
> }
>
> @@ -785,13 +765,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> goto received;
> }
> if (nonblock) {
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -EAGAIN;
> }
> if (wait_event_interruptible(map->passive.inflight_accept_req,
> !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> (void *)&map->passive.flags))) {
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -EINTR;
> }
> }
> @@ -802,7 +782,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> (void *)&map->passive.flags);
> spin_unlock(&bedata->socket_lock);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
> map2 = kzalloc(sizeof(*map2), GFP_ATOMIC);
> @@ -810,7 +790,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> (void *)&map->passive.flags);
> spin_unlock(&bedata->socket_lock);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -ENOMEM;
> }
> ret = create_active(map2, &evtchn);
> @@ -819,7 +799,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> (void *)&map->passive.flags);
> spin_unlock(&bedata->socket_lock);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
> list_add_tail(&map2->list, &bedata->socket_mappings);
> @@ -841,13 +821,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> /* We could check if we have received a response before returning. */
> if (nonblock) {
> WRITE_ONCE(map->passive.inflight_req_id, req_id);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -EAGAIN;
> }
>
> if (wait_event_interruptible(bedata->inflight_req,
> READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) {
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -EINTR;
> }
> /* read req_id, then the content */
> @@ -862,7 +842,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> (void *)&map->passive.flags);
> pvcalls_front_free_map(bedata, map2);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return -ENOMEM;
> }
> newsock->sk->sk_send_head = (void *)map2;
> @@ -874,7 +854,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags);
> wake_up(&map->passive.inflight_accept_req);
>
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
>
> @@ -965,23 +945,16 @@ unsigned int pvcalls_front_poll(struct file *file, struct socket *sock,
> struct sock_mapping *map;
> int ret;
>
> - pvcalls_enter();
> - if (!pvcalls_front_dev) {
> - pvcalls_exit();
> + map = pvcalls_enter_sock(sock);
> + if (IS_ERR(map))
> return POLLNVAL;
> - }
> bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
>
> - map = (struct sock_mapping *) sock->sk->sk_send_head;
> - if (!map) {
> - pvcalls_exit();
> - return POLLNVAL;
> - }
> if (map->active_socket)
> ret = pvcalls_front_poll_active(file, bedata, map, wait);
> else
> ret = pvcalls_front_poll_passive(file, bedata, map, wait);
> - pvcalls_exit();
> + pvcalls_exit_sock(sock);
> return ret;
> }
>
> @@ -995,25 +968,18 @@ int pvcalls_front_release(struct socket *sock)
> if (sock->sk == NULL)
> return 0;
>
> - pvcalls_enter();
> - if (!pvcalls_front_dev) {
> - pvcalls_exit();
> + map = pvcalls_enter_sock(sock);
> + if (IS_ERR(map) && PTR_ERR(map) == -ENOTCONN)
> return -EIO;
> - }
> -
> - bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> -
> - map = (struct sock_mapping *) sock->sk->sk_send_head;
> - if (map == NULL) {
> - pvcalls_exit();
> + if (IS_ERR(map) && PTR_ERR(map) == -ENOTSOCK)
> return 0;
Hmm, what about:
if (IS_ERR(map)) {
if (PTR_ERR(map) == -ENOTCONN)
return -EIO;
else
return 0;
}
Juergen
On Mon, 12 Feb 2018, Juergen Gross wrote:
> On 05/02/18 23:51, Stefano Stabellini wrote:
> > 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 <[email protected]>
> > ---
> > drivers/xen/pvcalls-front.c | 190 ++++++++++++++++++--------------------------
> > 1 file changed, 78 insertions(+), 112 deletions(-)
> >
> > diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c
> > index 4c789e6..164d3ad 100644
> > --- a/drivers/xen/pvcalls-front.c
> > +++ b/drivers/xen/pvcalls-front.c
> > @@ -60,6 +60,7 @@ struct sock_mapping {
> > bool active_socket;
> > struct list_head list;
> > struct socket *sock;
> > + atomic_t refcount;
> > union {
> > struct {
> > int irq;
> > @@ -93,6 +94,33 @@ struct sock_mapping {
> > };
> > };
> >
> > +static inline struct sock_mapping *pvcalls_enter_sock(struct socket *sock)
> > +{
> > + struct sock_mapping *map = NULL;
> > +
> > + if (!pvcalls_front_dev || &pvcalls_front_dev->dev == NULL)
>
> Did you mean:
> if (!pvcalls_front_dev || !pvcalls_front_dev->dev)
I actually meant:
if (!pvcalls_front_dev || dev_get_drvdata(&pvcalls_front_dev->dev) == NULL)
> > + return ERR_PTR(-ENOTCONN);
> > +
> > + pvcalls_enter();
> > + map = (struct sock_mapping *) sock->sk->sk_send_head;
>
> Style: no blank after the cast, please (multiple times).
OK, I'll fix them all
> > + if (map == NULL) {
> > + pvcalls_exit()
> > + return ERR_PTR(-ENOTSOCK);
> > + }
> > +
> > + atomic_inc(&map->refcount);
> > + return map;
> > +}
> > +
> > +static inline void pvcalls_exit_sock(struct socket *sock)
> > +{
> > + struct sock_mapping *map = NULL;
> > +
> > + map = (struct sock_mapping *) sock->sk->sk_send_head;
> > + atomic_dec(&map->refcount);
> > + pvcalls_exit();
> > +}
> > +
> > static inline int get_request(struct pvcalls_bedata *bedata, int *req_id)
> > {
> > *req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1);
> > @@ -369,31 +397,23 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
> > if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
> > return -EOPNOTSUPP;
> >
> > - pvcalls_enter();
> > - if (!pvcalls_front_dev) {
> > - pvcalls_exit();
> > - return -ENOTCONN;
> > - }
> > + map = pvcalls_enter_sock(sock);
> > + if (IS_ERR(map))
> > + return PTR_ERR(map);
> >
> > bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> >
> > - map = (struct sock_mapping *)sock->sk->sk_send_head;
> > - if (!map) {
> > - pvcalls_exit();
> > - return -ENOTSOCK;
> > - }
> > -
> > spin_lock(&bedata->socket_lock);
> > ret = get_request(bedata, &req_id);
> > if (ret < 0) {
> > spin_unlock(&bedata->socket_lock);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> > ret = create_active(map, &evtchn);
> > if (ret < 0) {
> > spin_unlock(&bedata->socket_lock);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> >
> > @@ -423,7 +443,7 @@ int pvcalls_front_connect(struct socket *sock, struct sockaddr *addr,
> > smp_rmb();
> > ret = bedata->rsp[req_id].ret;
> > bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> >
> > @@ -488,23 +508,15 @@ int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg,
> > if (flags & (MSG_CONFIRM|MSG_DONTROUTE|MSG_EOR|MSG_OOB))
> > return -EOPNOTSUPP;
> >
> > - pvcalls_enter();
> > - if (!pvcalls_front_dev) {
> > - pvcalls_exit();
> > - return -ENOTCONN;
> > - }
> > + map = pvcalls_enter_sock(sock);
> > + if (IS_ERR(map))
> > + return PTR_ERR(map);
> > bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> >
> > - map = (struct sock_mapping *) sock->sk->sk_send_head;
> > - if (!map) {
> > - pvcalls_exit();
> > - return -ENOTSOCK;
> > - }
> > -
> > mutex_lock(&map->active.out_mutex);
> > if ((flags & MSG_DONTWAIT) && !pvcalls_front_write_todo(map)) {
> > mutex_unlock(&map->active.out_mutex);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -EAGAIN;
> > }
> > if (len > INT_MAX)
> > @@ -526,7 +538,7 @@ int pvcalls_front_sendmsg(struct socket *sock, struct msghdr *msg,
> > tot_sent = sent;
> >
> > mutex_unlock(&map->active.out_mutex);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return tot_sent;
> > }
> >
> > @@ -591,19 +603,11 @@ int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> > if (flags & (MSG_CMSG_CLOEXEC|MSG_ERRQUEUE|MSG_OOB|MSG_TRUNC))
> > return -EOPNOTSUPP;
> >
> > - pvcalls_enter();
> > - if (!pvcalls_front_dev) {
> > - pvcalls_exit();
> > - return -ENOTCONN;
> > - }
> > + map = pvcalls_enter_sock(sock);
> > + if (IS_ERR(map))
> > + return PTR_ERR(map);
> > bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> >
> > - map = (struct sock_mapping *) sock->sk->sk_send_head;
> > - if (!map) {
> > - pvcalls_exit();
> > - return -ENOTSOCK;
> > - }
> > -
> > mutex_lock(&map->active.in_mutex);
> > if (len > XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER))
> > len = XEN_FLEX_RING_SIZE(PVCALLS_RING_ORDER);
> > @@ -623,7 +627,7 @@ int pvcalls_front_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
> > ret = 0;
> >
> > mutex_unlock(&map->active.in_mutex);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> >
> > @@ -637,24 +641,16 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> > if (addr->sa_family != AF_INET || sock->type != SOCK_STREAM)
> > return -EOPNOTSUPP;
> >
> > - pvcalls_enter();
> > - if (!pvcalls_front_dev) {
> > - pvcalls_exit();
> > - return -ENOTCONN;
> > - }
> > + map = pvcalls_enter_sock(sock);
> > + if (IS_ERR(map))
> > + return PTR_ERR(map);
> > bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> >
> > - map = (struct sock_mapping *) sock->sk->sk_send_head;
> > - if (map == NULL) {
> > - pvcalls_exit();
> > - return -ENOTSOCK;
> > - }
> > -
> > spin_lock(&bedata->socket_lock);
> > ret = get_request(bedata, &req_id);
> > if (ret < 0) {
> > spin_unlock(&bedata->socket_lock);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> > req = RING_GET_REQUEST(&bedata->ring, req_id);
> > @@ -684,7 +680,7 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
> > bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
> >
> > map->passive.status = PVCALLS_STATUS_BIND;
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return 0;
> > }
> >
> > @@ -695,21 +691,13 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
> > struct xen_pvcalls_request *req;
> > int notify, req_id, ret;
> >
> > - pvcalls_enter();
> > - if (!pvcalls_front_dev) {
> > - pvcalls_exit();
> > - return -ENOTCONN;
> > - }
> > + map = pvcalls_enter_sock(sock);
> > + if (IS_ERR(map))
> > + return PTR_ERR(map);
> > bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> >
> > - map = (struct sock_mapping *) sock->sk->sk_send_head;
> > - if (!map) {
> > - pvcalls_exit();
> > - return -ENOTSOCK;
> > - }
> > -
> > if (map->passive.status != PVCALLS_STATUS_BIND) {
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -EOPNOTSUPP;
> > }
> >
> > @@ -717,7 +705,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
> > ret = get_request(bedata, &req_id);
> > if (ret < 0) {
> > spin_unlock(&bedata->socket_lock);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> > req = RING_GET_REQUEST(&bedata->ring, req_id);
> > @@ -741,7 +729,7 @@ int pvcalls_front_listen(struct socket *sock, int backlog)
> > bedata->rsp[req_id].req_id = PVCALLS_INVALID_ID;
> >
> > map->passive.status = PVCALLS_STATUS_LISTEN;
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> >
> > @@ -753,21 +741,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> > struct xen_pvcalls_request *req;
> > int notify, req_id, ret, evtchn, nonblock;
> >
> > - pvcalls_enter();
> > - if (!pvcalls_front_dev) {
> > - pvcalls_exit();
> > - return -ENOTCONN;
> > - }
> > + map = pvcalls_enter_sock(sock);
> > + if (IS_ERR(map))
> > + return PTR_ERR(map);
> > bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> >
> > - map = (struct sock_mapping *) sock->sk->sk_send_head;
> > - if (!map) {
> > - pvcalls_exit();
> > - return -ENOTSOCK;
> > - }
> > -
> > if (map->passive.status != PVCALLS_STATUS_LISTEN) {
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -EINVAL;
> > }
> >
> > @@ -785,13 +765,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> > goto received;
> > }
> > if (nonblock) {
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -EAGAIN;
> > }
> > if (wait_event_interruptible(map->passive.inflight_accept_req,
> > !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> > (void *)&map->passive.flags))) {
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -EINTR;
> > }
> > }
> > @@ -802,7 +782,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> > clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> > (void *)&map->passive.flags);
> > spin_unlock(&bedata->socket_lock);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> > map2 = kzalloc(sizeof(*map2), GFP_ATOMIC);
> > @@ -810,7 +790,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> > clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> > (void *)&map->passive.flags);
> > spin_unlock(&bedata->socket_lock);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -ENOMEM;
> > }
> > ret = create_active(map2, &evtchn);
> > @@ -819,7 +799,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> > clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> > (void *)&map->passive.flags);
> > spin_unlock(&bedata->socket_lock);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> > list_add_tail(&map2->list, &bedata->socket_mappings);
> > @@ -841,13 +821,13 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> > /* We could check if we have received a response before returning. */
> > if (nonblock) {
> > WRITE_ONCE(map->passive.inflight_req_id, req_id);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -EAGAIN;
> > }
> >
> > if (wait_event_interruptible(bedata->inflight_req,
> > READ_ONCE(bedata->rsp[req_id].req_id) == req_id)) {
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -EINTR;
> > }
> > /* read req_id, then the content */
> > @@ -862,7 +842,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> > clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT,
> > (void *)&map->passive.flags);
> > pvcalls_front_free_map(bedata, map2);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return -ENOMEM;
> > }
> > newsock->sk->sk_send_head = (void *)map2;
> > @@ -874,7 +854,7 @@ int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags)
> > clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags);
> > wake_up(&map->passive.inflight_accept_req);
> >
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> >
> > @@ -965,23 +945,16 @@ unsigned int pvcalls_front_poll(struct file *file, struct socket *sock,
> > struct sock_mapping *map;
> > int ret;
> >
> > - pvcalls_enter();
> > - if (!pvcalls_front_dev) {
> > - pvcalls_exit();
> > + map = pvcalls_enter_sock(sock);
> > + if (IS_ERR(map))
> > return POLLNVAL;
> > - }
> > bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> >
> > - map = (struct sock_mapping *) sock->sk->sk_send_head;
> > - if (!map) {
> > - pvcalls_exit();
> > - return POLLNVAL;
> > - }
> > if (map->active_socket)
> > ret = pvcalls_front_poll_active(file, bedata, map, wait);
> > else
> > ret = pvcalls_front_poll_passive(file, bedata, map, wait);
> > - pvcalls_exit();
> > + pvcalls_exit_sock(sock);
> > return ret;
> > }
> >
> > @@ -995,25 +968,18 @@ int pvcalls_front_release(struct socket *sock)
> > if (sock->sk == NULL)
> > return 0;
> >
> > - pvcalls_enter();
> > - if (!pvcalls_front_dev) {
> > - pvcalls_exit();
> > + map = pvcalls_enter_sock(sock);
> > + if (IS_ERR(map) && PTR_ERR(map) == -ENOTCONN)
> > return -EIO;
> > - }
> > -
> > - bedata = dev_get_drvdata(&pvcalls_front_dev->dev);
> > -
> > - map = (struct sock_mapping *) sock->sk->sk_send_head;
> > - if (map == NULL) {
> > - pvcalls_exit();
> > + if (IS_ERR(map) && PTR_ERR(map) == -ENOTSOCK)
> > return 0;
>
> Hmm, what about:
>
> if (IS_ERR(map)) {
> if (PTR_ERR(map) == -ENOTCONN)
> return -EIO;
> else
> return 0;
> }
Sounds good.
On Mon, 12 Feb 2018, Juergen Gross wrote:
> On 05/02/18 23:51, Stefano Stabellini wrote:
> > Passive sockets can have ongoing operations on them, specifically, we
> > have two wait_event_interruptable calls in pvcalls_front_accept.
> >
> > Add two wake_up calls in pvcalls_front_release, then wait for the
> > potential waiters to return and release the sock_mapping refcount.
> >
> > Signed-off-by: Stefano Stabellini <[email protected]>
>
> Acked-by: Juergen Gross <[email protected]>
Thanks!