| Message ID | 1501541855-7354-12-git-send-email-sstabellini@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/31/2017 06:57 PM, Stefano Stabellini wrote: > Send PVCALLS_RELEASE to the backend and wait for a reply. Take both > in_mutex and out_mutex to avoid concurrent accesses. Then, free the > socket. > > For passive sockets, check whether we have already pre-allocated an > active socket for the purpose of being accepted. If so, free that as > well. > > Signed-off-by: Stefano Stabellini <stefano@aporeto.com> > CC: boris.ostrovsky@oracle.com > CC: jgross@suse.com > --- > drivers/xen/pvcalls-front.c | 88 +++++++++++++++++++++++++++++++++++++++++++++ > drivers/xen/pvcalls-front.h | 1 + > 2 files changed, 89 insertions(+) > > diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c > index 1c975d6..775a6d2 100644 > --- a/drivers/xen/pvcalls-front.c > +++ b/drivers/xen/pvcalls-front.c > @@ -192,6 +192,23 @@ static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map) > return IRQ_HANDLED; > } > > +static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, > + struct sock_mapping *map) > +{ > + int i; > + > + spin_lock(&bedata->pvcallss_lock); > + if (!list_empty(&map->list)) > + list_del_init(&map->list); > + spin_unlock(&bedata->pvcallss_lock); > + > + for (i = 0; i < (1 << map->active.ring->ring_order); i++) > + gnttab_end_foreign_access(map->active.ring->ref[i], 0, 0); > + gnttab_end_foreign_access(map->active.ref, 0, 0); > + free_page((unsigned long)map->active.ring); > + unbind_from_irqhandler(map->active.irq, map); Would it better to first unbind the handler? Any chance an interrupt might come in? > +} > + > int pvcalls_front_socket(struct socket *sock) > { > struct pvcalls_bedata *bedata; > @@ -853,6 +870,77 @@ unsigned int pvcalls_front_poll(struct file *file, struct socket *sock, > return pvcalls_front_poll_passive(file, bedata, map, wait); > } > > +int pvcalls_front_release(struct socket *sock) > +{ > + struct pvcalls_bedata *bedata; > + struct sock_mapping *map; > + int req_id, notify, ret; > + struct xen_pvcalls_request *req; > + > + if (!pvcalls_front_dev) > + return -EIO; > + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); > + > + if (sock->sk == NULL) > + return 0; This can go above bedata access. (You are going to address locking here so I won't review the rest) -boris > + > + map = (struct sock_mapping *) READ_ONCE(sock->sk->sk_send_head); > + if (map == NULL) > + return 0; > + > + spin_lock(&bedata->pvcallss_lock); > + ret = get_request(bedata, &req_id); > + if (ret < 0) { > + spin_unlock(&bedata->pvcallss_lock); > + return ret; > + } > + WRITE_ONCE(sock->sk->sk_send_head, NULL); > + > + req = RING_GET_REQUEST(&bedata->ring, req_id); > + req->req_id = req_id; > + req->cmd = PVCALLS_RELEASE; > + req->u.release.id = (uint64_t)map; > + > + 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); > + > + if (map->active_socket) { > + /* > + * Set in_error and wake up inflight_conn_req to force > + * recvmsg waiters to exit. > + */ > + map->active.ring->in_error = -EBADF; > + wake_up_interruptible(&map->active.inflight_conn_req); > + > + mutex_lock(&map->active.in_mutex); > + mutex_lock(&map->active.out_mutex); > + pvcalls_front_free_map(bedata, map); > + mutex_unlock(&map->active.out_mutex); > + mutex_unlock(&map->active.in_mutex); > + kfree(map); > + } else { > + spin_lock(&bedata->pvcallss_lock); > + if (READ_ONCE(map->passive.inflight_req_id) != > + PVCALLS_INVALID_ID) { > + pvcalls_front_free_map(bedata, > + map->passive.accept_map); > + kfree(map->passive.accept_map); > + } > + list_del_init(&map->list); > + kfree(map); > + spin_unlock(&bedata->pvcallss_lock); > + } > + WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); > + > + return 0; > +} > + > 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 25e05b8..3332978 100644 > --- a/drivers/xen/pvcalls-front.h > +++ b/drivers/xen/pvcalls-front.h > @@ -23,5 +23,6 @@ int pvcalls_front_recvmsg(struct socket *sock, > unsigned int pvcalls_front_poll(struct file *file, > struct socket *sock, > poll_table *wait); > +int pvcalls_front_release(struct socket *sock); > > #endif
On Tue, 15 Aug 2017, Boris Ostrovsky wrote: > On 07/31/2017 06:57 PM, Stefano Stabellini wrote: > > Send PVCALLS_RELEASE to the backend and wait for a reply. Take both > > in_mutex and out_mutex to avoid concurrent accesses. Then, free the > > socket. > > > > For passive sockets, check whether we have already pre-allocated an > > active socket for the purpose of being accepted. If so, free that as > > well. > > > > Signed-off-by: Stefano Stabellini <stefano@aporeto.com> > > CC: boris.ostrovsky@oracle.com > > CC: jgross@suse.com > > --- > > drivers/xen/pvcalls-front.c | 88 +++++++++++++++++++++++++++++++++++++++++++++ > > drivers/xen/pvcalls-front.h | 1 + > > 2 files changed, 89 insertions(+) > > > > diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c > > index 1c975d6..775a6d2 100644 > > --- a/drivers/xen/pvcalls-front.c > > +++ b/drivers/xen/pvcalls-front.c > > @@ -192,6 +192,23 @@ static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map) > > return IRQ_HANDLED; > > } > > > > +static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, > > + struct sock_mapping *map) > > +{ > > + int i; > > + > > + spin_lock(&bedata->pvcallss_lock); > > + if (!list_empty(&map->list)) > > + list_del_init(&map->list); > > + spin_unlock(&bedata->pvcallss_lock); > > + > > + for (i = 0; i < (1 << map->active.ring->ring_order); i++) > > + gnttab_end_foreign_access(map->active.ring->ref[i], 0, 0); > > + gnttab_end_foreign_access(map->active.ref, 0, 0); > > + free_page((unsigned long)map->active.ring); > > + unbind_from_irqhandler(map->active.irq, map); > > Would it better to first unbind the handler? Any chance an interrupt > might come in? Fair enough, I'll do that. > > +} > > + > > int pvcalls_front_socket(struct socket *sock) > > { > > struct pvcalls_bedata *bedata; > > @@ -853,6 +870,77 @@ unsigned int pvcalls_front_poll(struct file *file, struct socket *sock, > > return pvcalls_front_poll_passive(file, bedata, map, wait); > > } > > > > +int pvcalls_front_release(struct socket *sock) > > +{ > > + struct pvcalls_bedata *bedata; > > + struct sock_mapping *map; > > + int req_id, notify, ret; > > + struct xen_pvcalls_request *req; > > + > > + if (!pvcalls_front_dev) > > + return -EIO; > > + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); > > + > > + if (sock->sk == NULL) > > + return 0; > > This can go above bedata access. Yes, good idea. > (You are going to address locking here so I won't review the rest) Yes, I will. Thanks for the review! And sorry for taking so long to come back to you.
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index 1c975d6..775a6d2 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -192,6 +192,23 @@ static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map) return IRQ_HANDLED; } +static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, + struct sock_mapping *map) +{ + int i; + + spin_lock(&bedata->pvcallss_lock); + if (!list_empty(&map->list)) + list_del_init(&map->list); + spin_unlock(&bedata->pvcallss_lock); + + for (i = 0; i < (1 << map->active.ring->ring_order); i++) + gnttab_end_foreign_access(map->active.ring->ref[i], 0, 0); + gnttab_end_foreign_access(map->active.ref, 0, 0); + free_page((unsigned long)map->active.ring); + unbind_from_irqhandler(map->active.irq, map); +} + int pvcalls_front_socket(struct socket *sock) { struct pvcalls_bedata *bedata; @@ -853,6 +870,77 @@ unsigned int pvcalls_front_poll(struct file *file, struct socket *sock, return pvcalls_front_poll_passive(file, bedata, map, wait); } +int pvcalls_front_release(struct socket *sock) +{ + struct pvcalls_bedata *bedata; + struct sock_mapping *map; + int req_id, notify, ret; + struct xen_pvcalls_request *req; + + if (!pvcalls_front_dev) + return -EIO; + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + if (sock->sk == NULL) + return 0; + + map = (struct sock_mapping *) READ_ONCE(sock->sk->sk_send_head); + if (map == NULL) + return 0; + + spin_lock(&bedata->pvcallss_lock); + ret = get_request(bedata, &req_id); + if (ret < 0) { + spin_unlock(&bedata->pvcallss_lock); + return ret; + } + WRITE_ONCE(sock->sk->sk_send_head, NULL); + + req = RING_GET_REQUEST(&bedata->ring, req_id); + req->req_id = req_id; + req->cmd = PVCALLS_RELEASE; + req->u.release.id = (uint64_t)map; + + 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); + + if (map->active_socket) { + /* + * Set in_error and wake up inflight_conn_req to force + * recvmsg waiters to exit. + */ + map->active.ring->in_error = -EBADF; + wake_up_interruptible(&map->active.inflight_conn_req); + + mutex_lock(&map->active.in_mutex); + mutex_lock(&map->active.out_mutex); + pvcalls_front_free_map(bedata, map); + mutex_unlock(&map->active.out_mutex); + mutex_unlock(&map->active.in_mutex); + kfree(map); + } else { + spin_lock(&bedata->pvcallss_lock); + if (READ_ONCE(map->passive.inflight_req_id) != + PVCALLS_INVALID_ID) { + pvcalls_front_free_map(bedata, + map->passive.accept_map); + kfree(map->passive.accept_map); + } + list_del_init(&map->list); + kfree(map); + spin_unlock(&bedata->pvcallss_lock); + } + WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); + + return 0; +} + 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 25e05b8..3332978 100644 --- a/drivers/xen/pvcalls-front.h +++ b/drivers/xen/pvcalls-front.h @@ -23,5 +23,6 @@ int pvcalls_front_recvmsg(struct socket *sock, unsigned int pvcalls_front_poll(struct file *file, struct socket *sock, poll_table *wait); +int pvcalls_front_release(struct socket *sock); #endif
Send PVCALLS_RELEASE to the backend and wait for a reply. Take both in_mutex and out_mutex to avoid concurrent accesses. Then, free the socket. For passive sockets, check whether we have already pre-allocated an active socket for the purpose of being accepted. If so, free that as well. Signed-off-by: Stefano Stabellini <stefano@aporeto.com> CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-front.c | 88 +++++++++++++++++++++++++++++++++++++++++++++ drivers/xen/pvcalls-front.h | 1 + 2 files changed, 89 insertions(+)