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[media] v4l2-dev: use mutex_lock_interruptible instead of plain mutex_lock

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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>
This commit is contained in:
Hans Verkuil 2010-11-26 06:43:51 -03:00 committed by Mauro Carvalho Chehab
parent 78b055be27
commit 2877842de8
1 changed files with 17 additions and 14 deletions
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31
drivers/media/video/v4l2-dev.c
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@ -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);