[RFC PATCH 3/6] virtio/console: Wait until the port is ready on splice
From: Yoshihiro YUNOMAE <hidden>
Date: 2012-07-24 02:39:54
Also in:
lkml, qemu-devel
Subsystem:
char and misc drivers, the rest, virtio console driver · Maintainers:
Arnd Bergmann, Greg Kroah-Hartman, Linus Torvalds, Amit Shah
From: Masami Hiramatsu <redacted> Wait if the port is not connected or full on splice like as write is doing. Signed-off-by: Masami Hiramatsu <redacted> Cc: Amit Shah <redacted> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/char/virtio_console.c | 39 +++++++++++++++++++++++++++------------ 1 files changed, 27 insertions(+), 12 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 911cb3e..e49d435 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c@@ -724,6 +724,26 @@ static ssize_t port_fops_read(struct file *filp, char __user *ubuf, return fill_readbuf(port, ubuf, count, true); } +static int wait_port_writable(struct port *port, bool nonblock) +{ + int ret; + + if (will_write_block(port)) { + if (nonblock) + return -EAGAIN; + + ret = wait_event_freezable(port->waitqueue, + !will_write_block(port)); + if (ret < 0) + return ret; + } + /* Port got hot-unplugged. */ + if (!port->guest_connected) + return -ENODEV; + + return 0; +} + static ssize_t port_fops_write(struct file *filp, const char __user *ubuf, size_t count, loff_t *offp) {
@@ -740,18 +760,9 @@ static ssize_t port_fops_write(struct file *filp, const char __user *ubuf, nonblock = filp->f_flags & O_NONBLOCK; - if (will_write_block(port)) { - if (nonblock) - return -EAGAIN; - - ret = wait_event_freezable(port->waitqueue, - !will_write_block(port)); - if (ret < 0) - return ret; - } - /* Port got hot-unplugged. */ - if (!port->guest_connected) - return -ENODEV; + ret = wait_port_writable(port, nonblock); + if (ret < 0) + return ret; count = min((size_t)(32 * 1024), count);
@@ -851,6 +862,10 @@ static ssize_t port_fops_splice_write(struct pipe_inode_info *pipe, .u.data = &sgl, }; + ret = wait_port_writable(port, filp->f_flags & O_NONBLOCK); + if (ret < 0) + return ret; + sgl.n = 0; sgl.len = 0; sgl.sg = kmalloc(sizeof(struct scatterlist) * MAX_SPLICE_PAGES,