diff options
author | Stefano Stabellini <sstabellini@kernel.org> | 2017-10-30 15:41:02 -0700 |
---|---|---|
committer | Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2017-10-31 09:05:53 -0400 |
commit | 235a71c5390316429e2c7823119c5ea439816beb (patch) | |
tree | 20ab8b2a3827d6dbce43bf026121e4bb36cfc908 /drivers/xen | |
parent | 5842c83596fcfa742978ec2840440ab56c7fdf79 (diff) | |
download | linux-235a71c5390316429e2c7823119c5ea439816beb.tar.bz2 |
xen/pvcalls: implement release command
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>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
CC: boris.ostrovsky@oracle.com
CC: jgross@suse.com
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r-- | drivers/xen/pvcalls-front.c | 98 | ||||
-rw-r--r-- | drivers/xen/pvcalls-front.h | 1 |
2 files changed, 99 insertions, 0 deletions
diff --git a/drivers/xen/pvcalls-front.c b/drivers/xen/pvcalls-front.c index c7d4251c3678..0c1ec6894cc4 100644 --- a/drivers/xen/pvcalls-front.c +++ b/drivers/xen/pvcalls-front.c @@ -199,6 +199,21 @@ again: static void pvcalls_front_free_map(struct pvcalls_bedata *bedata, struct sock_mapping *map) { + int i; + + unbind_from_irqhandler(map->active.irq, map); + + spin_lock(&bedata->socket_lock); + if (!list_empty(&map->list)) + list_del_init(&map->list); + spin_unlock(&bedata->socket_lock); + + for (i = 0; i < (1 << PVCALLS_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); + + kfree(map); } static irqreturn_t pvcalls_front_conn_handler(int irq, void *sock_map) @@ -972,6 +987,89 @@ unsigned int pvcalls_front_poll(struct file *file, struct socket *sock, return ret; } +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 (sock->sk == NULL) + return 0; + + pvcalls_enter(); + if (!pvcalls_front_dev) { + pvcalls_exit(); + return -EIO; + } + + bedata = dev_get_drvdata(&pvcalls_front_dev->dev); + + map = (struct sock_mapping *) sock->sk->sk_send_head; + if (map == NULL) { + pvcalls_exit(); + return 0; + } + + spin_lock(&bedata->socket_lock); + ret = get_request(bedata, &req_id); + if (ret < 0) { + spin_unlock(&bedata->socket_lock); + pvcalls_exit(); + return ret; + } + 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 = (uintptr_t)map; + + bedata->ring.req_prod_pvt++; + RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&bedata->ring, notify); + spin_unlock(&bedata->socket_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); + + /* + * Wait until there are no more waiters on the mutexes. + * We know that no new waiters can be added because sk_send_head + * is set to NULL -- we only need to wait for the existing + * waiters to return. + */ + while (!mutex_trylock(&map->active.in_mutex) || + !mutex_trylock(&map->active.out_mutex)) + cpu_relax(); + + pvcalls_front_free_map(bedata, map); + } else { + spin_lock(&bedata->socket_lock); + list_del(&map->list); + spin_unlock(&bedata->socket_lock); + if (READ_ONCE(map->passive.inflight_req_id) != + PVCALLS_INVALID_ID) { + pvcalls_front_free_map(bedata, + map->passive.accept_map); + } + kfree(map); + } + WRITE_ONCE(bedata->rsp[req_id].req_id, PVCALLS_INVALID_ID); + + pvcalls_exit(); + 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 25e05b8f2d72..3332978f4fcd 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 |