[media] v4l2-dev: use mutex_lock_interruptible instead of plain mutex_lock
Where reasonable use mutex_lock_interruptible instead of mutex_lock.
Also fix the poll, read and write error codes when called with an unregistered
device (e.g. after a USB device was disconnected). Poll must return
POLLERR|POLLHUP and read/write must return -ENODEV.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 03f7f46..bfd392e 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -186,12 +186,12 @@
size_t sz, loff_t *off)
{
struct video_device *vdev = video_devdata(filp);
- int ret = -EIO;
+ int ret = -ENODEV;
if (!vdev->fops->read)
return -EINVAL;
- if (vdev->lock)
- mutex_lock(vdev->lock);
+ if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+ return -ERESTARTSYS;
if (video_is_registered(vdev))
ret = vdev->fops->read(filp, buf, sz, off);
if (vdev->lock)
@@ -203,12 +203,12 @@
size_t sz, loff_t *off)
{
struct video_device *vdev = video_devdata(filp);
- int ret = -EIO;
+ int ret = -ENODEV;
if (!vdev->fops->write)
return -EINVAL;
- if (vdev->lock)
- mutex_lock(vdev->lock);
+ if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+ return -ERESTARTSYS;
if (video_is_registered(vdev))
ret = vdev->fops->write(filp, buf, sz, off);
if (vdev->lock)
@@ -219,10 +219,10 @@
static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
{
struct video_device *vdev = video_devdata(filp);
- int ret = DEFAULT_POLLMASK;
+ int ret = POLLERR | POLLHUP;
if (!vdev->fops->poll)
- return ret;
+ return DEFAULT_POLLMASK;
if (vdev->lock)
mutex_lock(vdev->lock);
if (video_is_registered(vdev))
@@ -238,8 +238,8 @@
int ret = -ENODEV;
if (vdev->fops->unlocked_ioctl) {
- if (vdev->lock)
- mutex_lock(vdev->lock);
+ if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+ return -ERESTARTSYS;
if (video_is_registered(vdev))
ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
if (vdev->lock)
@@ -265,8 +265,8 @@
if (!vdev->fops->mmap)
return ret;
- if (vdev->lock)
- mutex_lock(vdev->lock);
+ if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+ return -ERESTARTSYS;
if (video_is_registered(vdev))
ret = vdev->fops->mmap(filp, vm);
if (vdev->lock)
@@ -292,8 +292,10 @@
video_get(vdev);
mutex_unlock(&videodev_lock);
if (vdev->fops->open) {
- if (vdev->lock)
- mutex_lock(vdev->lock);
+ if (vdev->lock && mutex_lock_interruptible(vdev->lock)) {
+ ret = -ERESTARTSYS;
+ goto err;
+ }
if (video_is_registered(vdev))
ret = vdev->fops->open(filp);
else
@@ -302,6 +304,7 @@
mutex_unlock(vdev->lock);
}
+err:
/* decrease the refcount in case of an error */
if (ret)
video_put(vdev);