Commit 2877842d authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
Browse files

[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: default avatarHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 78b055be

drivers/media/video/v4l2-dev.c

+17 −14
Original line number Diff line number Diff line
@@ -186,12 +186,12 @@ static ssize_t v4l2_read(struct file *filp, char __user *buf, 
		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 @@ static ssize_t v4l2_write(struct file *filp, const char __user *buf, 
		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 ssize_t v4l2_write(struct file *filp, const char __user *buf, 
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 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 
	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 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm) 


	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 @@ static int v4l2_open(struct inode *inode, struct file *filp) 
	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 @@ static int v4l2_open(struct inode *inode, struct file *filp) 
			mutex_unlock(vdev->lock);

	}



err:

	/* decrease the refcount in case of an error */

	if (ret)

		video_put(vdev);

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