| Message ID | 1501017730-12797-7-git-send-email-sstabellini@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/25/2017 05:22 PM, Stefano Stabellini wrote: > Send PVCALLS_ACCEPT to the backend. Allocate a new active socket. Make > sure that only one accept command is executed at any given time by > setting PVCALLS_FLAG_ACCEPT_INFLIGHT and waiting on the > inflight_accept_req waitqueue. > > sock->sk->sk_send_head is not used for ip sockets: reuse the field to > store a pointer to the struct sock_mapping corresponding to the socket. > > Convert the new struct socket pointer into an uint64_t and use it as id > for the new socket to pass to the backend. > > Signed-off-by: Stefano Stabellini <stefano@aporeto.com> > CC: boris.ostrovsky@oracle.com > CC: jgross@suse.com > --- > drivers/xen/pvcalls-front.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ > drivers/xen/pvcalls-front.h | 3 ++ > 2 files changed, 82 insertions(+) > > diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c > index 3b5d50e..b8c4538 100644 > --- a/drivers/xen/pvcalls-front.c > +++ b/drivers/xen/pvcalls-front.c > @@ -413,6 +413,85 @@ int pvcalls_front_listen(struct socket *sock, int backlog) > return ret; > } > > +int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags) > +{ > + struct pvcalls_bedata *bedata; > + struct sock_mapping *map; > + struct sock_mapping *map2 = NULL; > + struct xen_pvcalls_request *req; > + int notify, req_id, ret, evtchn; > + > + if (!pvcalls_front_dev) > + return -ENOTCONN; > + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); > + > + map = (struct sock_mapping *) READ_ONCE(sock->sk->sk_send_head); > + if (!map) > + return -ENOTSOCK; > + > + if (map->passive.status != PVCALLS_STATUS_LISTEN) > + return -EINVAL; > + > + /* > + * Backend only supports 1 inflight accept request, will return > + * errors for the others > + */ > + if (test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, > + (void *)&map->passive.flags)) { > + if (wait_event_interruptible(map->passive.inflight_accept_req, > + !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, > + (void *)&map->passive.flags)) > + != 0) Unnecessary "!=0". -boris > + return -EINTR; > + } > + > + > + newsock->sk = kzalloc(sizeof(*newsock->sk), GFP_KERNEL); > + if (newsock->sk == NULL) > + return -ENOMEM; > + > + spin_lock(&bedata->pvcallss_lock); > + req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1); > + if (RING_FULL(&bedata->ring) || > + READ_ONCE(bedata->rsp[req_id].req_id) != PVCALLS_INVALID_ID) { > + kfree(newsock->sk); > + spin_unlock(&bedata->pvcallss_lock); > + return -EAGAIN; > + } > + > + map2 = create_active(&evtchn); > + > + req = RING_GET_REQUEST(&bedata->ring, req_id); > + req->req_id = req_id; > + req->cmd = PVCALLS_ACCEPT; > + req->u.accept.id = (uint64_t) sock; > + req->u.accept.ref = map2->active.ref; > + req->u.accept.id_new = (uint64_t) newsock; > + req->u.accept.evtchn = evtchn; > + > + list_add_tail(&map2->list, &bedata->socket_mappings); > + WRITE_ONCE(newsock->sk->sk_send_head, (void *)map2); > + map2->sock = newsock; > + > + bedata->ring.req_prod_pvt++; > + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); > + spin_unlock(&bedata->pvcallss_lock); > + if (notify) > + notify_remote_via_irq(bedata->irq); > + > + wait_event(bedata->inflight_req, > + READ_ONCE(bedata->rsp[req_id].req_id) == req_id); > + > + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags); > + wake_up(&map->passive.inflight_accept_req); > + > + ret = bedata->rsp[req_id].ret; > + /* read ret, then set this rsp slot to be reused */ > + smp_mb(); > + WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); > + return ret; > +} > + > static const struct xenbus_device_id pvcalls_front_ids[] = { > { "pvcalls" }, > { "" } > diff --git a/drivers/xen/pvcalls-front.h b/drivers/xen/pvcalls-front.h > index aa8fe10..ab4f1da 100644 > --- a/drivers/xen/pvcalls-front.h > +++ b/drivers/xen/pvcalls-front.h > @@ -10,5 +10,8 @@ int pvcalls_front_bind(struct socket *sock, > struct sockaddr *addr, > int addr_len); > int pvcalls_front_listen(struct socket *sock, int backlog); > +int pvcalls_front_accept(struct socket *sock, > + struct socket *newsock, > + int flags); > > #endif
On Wed, 26 Jul 2017, Boris Ostrovsky wrote: > On 07/25/2017 05:22 PM, Stefano Stabellini wrote: > > Send PVCALLS_ACCEPT to the backend. Allocate a new active socket. Make > > sure that only one accept command is executed at any given time by > > setting PVCALLS_FLAG_ACCEPT_INFLIGHT and waiting on the > > inflight_accept_req waitqueue. > > > > sock->sk->sk_send_head is not used for ip sockets: reuse the field to > > store a pointer to the struct sock_mapping corresponding to the socket. > > > > Convert the new struct socket pointer into an uint64_t and use it as id > > for the new socket to pass to the backend. > > > > Signed-off-by: Stefano Stabellini <stefano@aporeto.com> > > CC: boris.ostrovsky@oracle.com > > CC: jgross@suse.com > > --- > > drivers/xen/pvcalls-front.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ > > drivers/xen/pvcalls-front.h | 3 ++ > > 2 files changed, 82 insertions(+) > > > > diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c > > index 3b5d50e..b8c4538 100644 > > --- a/drivers/xen/pvcalls-front.c > > +++ b/drivers/xen/pvcalls-front.c > > @@ -413,6 +413,85 @@ int pvcalls_front_listen(struct socket *sock, int backlog) > > return ret; > > } > > > > +int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags) > > +{ > > + struct pvcalls_bedata *bedata; > > + struct sock_mapping *map; > > + struct sock_mapping *map2 = NULL; > > + struct xen_pvcalls_request *req; > > + int notify, req_id, ret, evtchn; > > + > > + if (!pvcalls_front_dev) > > + return -ENOTCONN; > > + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); > > + > > + map = (struct sock_mapping *) READ_ONCE(sock->sk->sk_send_head); > > + if (!map) > > + return -ENOTSOCK; > > + > > + if (map->passive.status != PVCALLS_STATUS_LISTEN) > > + return -EINVAL; > > + > > + /* > > + * Backend only supports 1 inflight accept request, will return > > + * errors for the others > > + */ > > + if (test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, > > + (void *)&map->passive.flags)) { > > + if (wait_event_interruptible(map->passive.inflight_accept_req, > > + !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, > > + (void *)&map->passive.flags)) > > + != 0) > > Unnecessary "!=0". OK > > + return -EINTR; > > + } > > + > > + > > + newsock->sk = kzalloc(sizeof(*newsock->sk), GFP_KERNEL); > > + if (newsock->sk == NULL) > > + return -ENOMEM; > > + > > + spin_lock(&bedata->pvcallss_lock); > > + req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1); > > + if (RING_FULL(&bedata->ring) || > > + READ_ONCE(bedata->rsp[req_id].req_id) != PVCALLS_INVALID_ID) { > > + kfree(newsock->sk); > > + spin_unlock(&bedata->pvcallss_lock); > > + return -EAGAIN; > > + } > > + > > + map2 = create_active(&evtchn); > > + > > + req = RING_GET_REQUEST(&bedata->ring, req_id); > > + req->req_id = req_id; > > + req->cmd = PVCALLS_ACCEPT; > > + req->u.accept.id = (uint64_t) sock; > > + req->u.accept.ref = map2->active.ref; > > + req->u.accept.id_new = (uint64_t) newsock; > > + req->u.accept.evtchn = evtchn; > > + > > + list_add_tail(&map2->list, &bedata->socket_mappings); > > + WRITE_ONCE(newsock->sk->sk_send_head, (void *)map2); > > + map2->sock = newsock; > > + > > + bedata->ring.req_prod_pvt++; > > + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); > > + spin_unlock(&bedata->pvcallss_lock); > > + if (notify) > > + notify_remote_via_irq(bedata->irq); > > + > > + wait_event(bedata->inflight_req, > > + READ_ONCE(bedata->rsp[req_id].req_id) == req_id); > > + > > + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags); > > + wake_up(&map->passive.inflight_accept_req); > > + > > + ret = bedata->rsp[req_id].ret; > > + /* read ret, then set this rsp slot to be reused */ > > + smp_mb(); > > + WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); > > + return ret; > > +} > > + > > static const struct xenbus_device_id pvcalls_front_ids[] = { > > { "pvcalls" }, > > { "" } > > diff --git a/drivers/xen/pvcalls-front.h b/drivers/xen/pvcalls-front.h > > index aa8fe10..ab4f1da 100644 > > --- a/drivers/xen/pvcalls-front.h > > +++ b/drivers/xen/pvcalls-front.h > > @@ -10,5 +10,8 @@ int pvcalls_front_bind(struct socket *sock, > > struct sockaddr *addr, > > int addr_len); > > int pvcalls_front_listen(struct socket *sock, int backlog); > > +int pvcalls_front_accept(struct socket *sock, > > + struct socket *newsock, > > + int flags); > > > > #endif >
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index 3b5d50e..b8c4538 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -413,6 +413,85 @@ int pvcalls_front_listen(struct socket *sock, int backlog) return ret; } +int pvcalls_front_accept(struct socket *sock, struct socket *newsock, int flags) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map; + struct sock_mapping *map2 = NULL; + struct xen_pvcalls_request *req; + int notify, req_id, ret, evtchn; + + if (!pvcalls_front_dev) + return -ENOTCONN; + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) READ_ONCE(sock->sk->sk_send_head); + if (!map) + return -ENOTSOCK; + + if (map->passive.status != PVCALLS_STATUS_LISTEN) + return -EINVAL; + + /* + * Backend only supports 1 inflight accept request, will return + * errors for the others + */ + if (test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags)) { + if (wait_event_interruptible(map->passive.inflight_accept_req, + !test_and_set_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, + (void *)&map->passive.flags)) + != 0) + return -EINTR; + } + + + newsock->sk = kzalloc(sizeof(*newsock->sk), GFP_KERNEL); + if (newsock->sk == NULL) + return -ENOMEM; + + spin_lock(&bedata->pvcallss_lock); + req_id = bedata->ring.req_prod_pvt & (RING_SIZE(&bedata->ring) - 1); + if (RING_FULL(&bedata->ring) || + READ_ONCE(bedata->rsp[req_id].req_id) != PVCALLS_INVALID_ID) { + kfree(newsock->sk); + spin_unlock(&bedata->pvcallss_lock); + return -EAGAIN; + } + + map2 = create_active(&evtchn); + + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + req->cmd = PVCALLS_ACCEPT; + req->u.accept.id = (uint64_t) sock; + req->u.accept.ref = map2->active.ref; + req->u.accept.id_new = (uint64_t) newsock; + req->u.accept.evtchn = evtchn; + + list_add_tail(&map2->list, &bedata->socket_mappings); + WRITE_ONCE(newsock->sk->sk_send_head, (void *)map2); + map2->sock = newsock; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->pvcallss_lock); + if (notify) + notify_remote_via_irq(bedata->irq); + + wait_event(bedata->inflight_req, + READ_ONCE(bedata->rsp[req_id].req_id) == req_id); + + clear_bit(PVCALLS_FLAG_ACCEPT_INFLIGHT, (void *)&map->passive.flags); + wake_up(&map->passive.inflight_accept_req); + + ret = bedata->rsp[req_id].ret; + /* read ret, then set this rsp slot to be reused */ + smp_mb(); + WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); + return ret; +} + static const struct xenbus_device_id pvcalls_front_ids[] = { { "pvcalls" }, { "" } diff --git a/drivers/xen/pvcalls-front.h b/drivers/xen/pvcalls-front.h index aa8fe10..ab4f1da 100644 --- a/drivers/xen/pvcalls-front.h +++ b/drivers/xen/pvcalls-front.h @@ -10,5 +10,8 @@ int pvcalls_front_bind(struct socket *sock, struct sockaddr *addr, int addr_len); int pvcalls_front_listen(struct socket *sock, int backlog); +int pvcalls_front_accept(struct socket *sock, + struct socket *newsock, + int flags); #endif
Send PVCALLS_ACCEPT to the backend. Allocate a new active socket. Make sure that only one accept command is executed at any given time by setting PVCALLS_FLAG_ACCEPT_INFLIGHT and waiting on the inflight_accept_req waitqueue. sock->sk->sk_send_head is not used for ip sockets: reuse the field to store a pointer to the struct sock_mapping corresponding to the socket. Convert the new struct socket pointer into an uint64_t and use it as id for the new socket to pass to the backend. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-front.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ drivers/xen/pvcalls-front.h | 3 ++ 2 files changed, 82 insertions(+)