1 files changed, 20 insertions, 12 deletions

diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index b1f0923212e6..2c4feffa4939 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -274,11 +274,12 @@ static ssize_t v4l2_read(struct file *filp, char __user *buf,
 
         if (!vdev->fops->read)
                 return -EINVAL;
-        if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+        if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags) &&
+            mutex_lock_interruptible(vdev->lock))
                 return -ERESTARTSYS;
         if (video_is_registered(vdev))
                 ret = vdev->fops->read(filp, buf, sz, off);
-        if (vdev->lock)
+        if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags))
                 mutex_unlock(vdev->lock);
         return ret;
 }
@@ -291,11 +292,12 @@ static ssize_t v4l2_write(struct file *filp, const char __user *buf,
 
         if (!vdev->fops->write)
                 return -EINVAL;
-        if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+        if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags) &&
+            mutex_lock_interruptible(vdev->lock))
                 return -ERESTARTSYS;
         if (video_is_registered(vdev))
                 ret = vdev->fops->write(filp, buf, sz, off);
-        if (vdev->lock)
+        if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags))
                 mutex_unlock(vdev->lock);
         return ret;
 }
@@ -307,11 +309,11 @@ static unsigned int v4l2_poll(struct file *filp, struct poll_table_struct *poll)
 
         if (!vdev->fops->poll)
                 return DEFAULT_POLLMASK;
-        if (vdev->lock)
+        if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags))
                 mutex_lock(vdev->lock);
         if (video_is_registered(vdev))
                 ret = vdev->fops->poll(filp, poll);
-        if (vdev->lock)
+        if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags))
                 mutex_unlock(vdev->lock);
         return ret;
 }
@@ -399,11 +401,12 @@ static int v4l2_mmap(struct file *filp, struct vm_area_struct *vm)
 
         if (!vdev->fops->mmap)
                 return ret;
-        if (vdev->lock && mutex_lock_interruptible(vdev->lock))
+        if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags) &&
+            mutex_lock_interruptible(vdev->lock))
                 return -ERESTARTSYS;
         if (video_is_registered(vdev))
                 ret = vdev->fops->mmap(filp, vm);
-        if (vdev->lock)
+        if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags))
                 mutex_unlock(vdev->lock);
         return ret;
 }
@@ -426,7 +429,8 @@ 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_interruptible(vdev->lock)) {
+                if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags) &&
+                    mutex_lock_interruptible(vdev->lock)) {
                         ret = -ERESTARTSYS;
                         goto err;
                 }
@@ -434,7 +438,7 @@ static int v4l2_open(struct inode *inode, struct file *filp)
                         ret = vdev->fops->open(filp);
                 else
                         ret = -ENODEV;
-                if (vdev->lock)
+                if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags))
                         mutex_unlock(vdev->lock);
         }
 
@@ -452,10 +456,10 @@ static int v4l2_release(struct inode *inode, struct file *filp)
         int ret = 0;
 
         if (vdev->fops->release) {
-                if (vdev->lock)
+                if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags))
                         mutex_lock(vdev->lock);
                 vdev->fops->release(filp);
-                if (vdev->lock)
+                if (test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags))
                         mutex_unlock(vdev->lock);
         }
         /* decrease the refcount unconditionally since the release()
@@ -831,6 +835,10 @@ int __video_register_device(struct video_device *vdev, int type, int nr,
         WARN_ON(video_device[vdev->minor] != NULL);
         vdev->index = get_index(vdev);
         mutex_unlock(&videodev_lock);
+        /* if no lock was passed, then make sure the LOCK_ALL_FOPS bit is
+           clear and warn if it wasn't. */
+        if (vdev->lock == NULL)
+                WARN_ON(test_and_clear_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags));
 
         if (vdev->ioctl_ops)
                 determine_valid_ioctls(vdev);