diff options
| -rw-r--r-- | include/linux/net.h | 1 | ||||
| -rw-r--r-- | net/socket.c | 48 |
2 files changed, 44 insertions, 5 deletions
diff --git a/include/linux/net.h b/include/linux/net.h index 2248a052061d..3fd9d8c16581 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -147,6 +147,7 @@ struct proto_ops { int (*getname) (struct socket *sock, struct sockaddr *addr, int peer); + __poll_t (*poll_mask) (struct socket *sock, __poll_t events); __poll_t (*poll) (struct file *file, struct socket *sock, struct poll_table_struct *wait); int (*ioctl) (struct socket *sock, unsigned int cmd, diff --git a/net/socket.c b/net/socket.c index 571ee4005192..2d752e9eb3f9 100644 --- a/net/socket.c +++ b/net/socket.c @@ -117,8 +117,10 @@ static ssize_t sock_write_iter(struct kiocb *iocb, struct iov_iter *from); static int sock_mmap(struct file *file, struct vm_area_struct *vma); static int sock_close(struct inode *inode, struct file *file); -static __poll_t sock_poll(struct file *file, - struct poll_table_struct *wait); +static struct wait_queue_head *sock_get_poll_head(struct file *file, + __poll_t events); +static __poll_t sock_poll_mask(struct file *file, __poll_t); +static __poll_t sock_poll(struct file *file, struct poll_table_struct *wait); static long sock_ioctl(struct file *file, unsigned int cmd, unsigned long arg); #ifdef CONFIG_COMPAT static long compat_sock_ioctl(struct file *file, @@ -141,6 +143,8 @@ static const struct file_operations socket_file_ops = { .llseek = no_llseek, .read_iter = sock_read_iter, .write_iter = sock_write_iter, + .get_poll_head = sock_get_poll_head, + .poll_mask = sock_poll_mask, .poll = sock_poll, .unlocked_ioctl = sock_ioctl, #ifdef CONFIG_COMPAT @@ -1114,14 +1118,48 @@ out_release: } EXPORT_SYMBOL(sock_create_lite); +static struct wait_queue_head *sock_get_poll_head(struct file *file, + __poll_t events) +{ + struct socket *sock = file->private_data; + + if (!sock->ops->poll_mask) + return NULL; + sock_poll_busy_loop(sock, events); + return sk_sleep(sock->sk); +} + +static __poll_t sock_poll_mask(struct file *file, __poll_t events) +{ + struct socket *sock = file->private_data; + + /* + * We need to be sure we are in sync with the socket flags modification. + * + * This memory barrier is paired in the wq_has_sleeper. + */ + smp_mb(); + + /* this socket can poll_ll so tell the system call */ + return sock->ops->poll_mask(sock, events) | + (sk_can_busy_loop(sock->sk) ? POLL_BUSY_LOOP : 0); +} + /* No kernel lock held - perfect */ static __poll_t sock_poll(struct file *file, poll_table *wait) { struct socket *sock = file->private_data; - __poll_t events = poll_requested_events(wait); + __poll_t events = poll_requested_events(wait), mask = 0; - sock_poll_busy_loop(sock, events); - return sock->ops->poll(file, sock, wait) | sock_poll_busy_flag(sock); + if (sock->ops->poll) { + sock_poll_busy_loop(sock, events); + mask = sock->ops->poll(file, sock, wait); + } else if (sock->ops->poll_mask) { + sock_poll_wait(file, sock_get_poll_head(file, events), wait); + mask = sock->ops->poll_mask(sock, events); + } + + return mask | sock_poll_busy_flag(sock); } static int sock_mmap(struct file *file, struct vm_area_struct *vma) |