[media] s2255drv: remove V4L2_FL_LOCK_ALL_FOPS

Add proper locking to the file operations, allowing for the removal
of the V4L2_FL_LOCK_ALL_FOPS flag.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/s2255drv.c b/drivers/media/video/s2255drv.c
index 95007dd..6c7960c 100644 (file)
--- a/drivers/media/video/s2255drv.c
+++ b/drivers/media/video/s2255drv.c
@@ -258,7 +258,6 @@ struct s2255_dev {
        atomic_t                num_channels;
        int                     frames;
        struct mutex            lock;   /* channels[].vdev.lock */
-       struct mutex            open_lock;
        struct usb_device       *udev;
        struct usb_interface    *interface;
        u8                      read_endpoint;
@@ -1684,7 +1683,7 @@ static int vidioc_enum_frameintervals(struct file *file, void *priv,
        return 0;
 }
 
-static int s2255_open(struct file *file)
+static int __s2255_open(struct file *file)
 {
        struct video_device *vdev = video_devdata(file);
        struct s2255_channel *channel = video_drvdata(file);
@@ -1694,16 +1693,9 @@ static int s2255_open(struct file *file)
        int state;
        dprintk(1, "s2255: open called (dev=%s)\n",
                video_device_node_name(vdev));
-       /*
-        * open lock necessary to prevent multiple instances
-        * of v4l-conf (or other programs) from simultaneously
-        * reloading firmware.
-        */
-       mutex_lock(&dev->open_lock);
        state = atomic_read(&dev->fw_data->fw_state);
        switch (state) {
        case S2255_FW_DISCONNECTING:
-               mutex_unlock(&dev->open_lock);
                return -ENODEV;
        case S2255_FW_FAILED:
                s2255_dev_err(&dev->udev->dev,
@@ -1742,11 +1734,9 @@ static int s2255_open(struct file *file)
                break;
        case S2255_FW_FAILED:
                printk(KERN_INFO "2255 firmware load failed.\n");
-               mutex_unlock(&dev->open_lock);
                return -ENODEV;
        case S2255_FW_DISCONNECTING:
                printk(KERN_INFO "%s: disconnecting\n", __func__);
-               mutex_unlock(&dev->open_lock);
                return -ENODEV;
        case S2255_FW_LOADED_DSPWAIT:
        case S2255_FW_NOTLOADED:
@@ -1760,14 +1750,11 @@ static int s2255_open(struct file *file)
                 */
                atomic_set(&dev->fw_data->fw_state,
                           S2255_FW_FAILED);
-               mutex_unlock(&dev->open_lock);
                return -EAGAIN;
        default:
                printk(KERN_INFO "%s: unknown state\n", __func__);
-               mutex_unlock(&dev->open_lock);
                return -EFAULT;
        }
-       mutex_unlock(&dev->open_lock);
        /* allocate + initialize per filehandle data */
        fh = kzalloc(sizeof(*fh), GFP_KERNEL);
        if (NULL == fh)
@@ -1798,16 +1785,30 @@ static int s2255_open(struct file *file)
        return 0;
 }
 
+static int s2255_open(struct file *file)
+{
+       struct video_device *vdev = video_devdata(file);
+       int ret;
+
+       if (mutex_lock_interruptible(vdev->lock))
+               return -ERESTARTSYS;
+       ret = __s2255_open(file);
+       mutex_unlock(vdev->lock);
+       return ret;
+}
 
 static unsigned int s2255_poll(struct file *file,
                               struct poll_table_struct *wait)
 {
        struct s2255_fh *fh = file->private_data;
+       struct s2255_dev *dev = fh->dev;
        int rc;
        dprintk(100, "%s\n", __func__);
        if (V4L2_BUF_TYPE_VIDEO_CAPTURE != fh->type)
                return POLLERR;
+       mutex_lock(&dev->lock);
        rc = videobuf_poll_stream(file, &fh->vb_vidq, wait);
+       mutex_unlock(&dev->lock);
        return rc;
 }
 
@@ -1827,7 +1828,6 @@ static void s2255_destroy(struct s2255_dev *dev)
        kfree(dev->fw_data);
        /* reset the DSP so firmware can be reloaded next time */
        s2255_reset_dsppower(dev);
-       mutex_destroy(&dev->open_lock);
        mutex_destroy(&dev->lock);
        usb_put_dev(dev->udev);
        v4l2_device_unregister(&dev->v4l2_dev);
@@ -1843,6 +1843,7 @@ static int s2255_release(struct file *file)
        struct s2255_channel *channel = fh->channel;
        if (!dev)
                return -ENODEV;
+       mutex_lock(&dev->lock);
        /* turn off stream */
        if (res_check(fh)) {
                if (channel->b_acquire)
@@ -1851,6 +1852,7 @@ static int s2255_release(struct file *file)
                res_free(fh);
        }
        videobuf_mmap_free(&fh->vb_vidq);
+       mutex_unlock(&dev->lock);
        dprintk(1, "%s (dev=%s)\n", __func__, video_device_node_name(vdev));
        kfree(fh);
        return 0;
@@ -1859,12 +1861,16 @@ static int s2255_release(struct file *file)
 static int s2255_mmap_v4l(struct file *file, struct vm_area_struct *vma)
 {
        struct s2255_fh *fh = file->private_data;
+       struct s2255_dev *dev = fh->dev;
        int ret;
 
        if (!fh)
                return -ENODEV;
        dprintk(4, "%s, vma=0x%08lx\n", __func__, (unsigned long)vma);
+       if (mutex_lock_interruptible(&dev->lock))
+               return -ERESTARTSYS;
        ret = videobuf_mmap_mapper(&fh->vb_vidq, vma);
+       mutex_unlock(&dev->lock);
        dprintk(4, "%s vma start=0x%08lx, size=%ld, ret=%d\n", __func__,
                (unsigned long)vma->vm_start,
                (unsigned long)vma->vm_end - (unsigned long)vma->vm_start, ret);
@@ -1944,10 +1950,6 @@ static int s2255_probe_v4l(struct s2255_dev *dev)
                /* register 4 video devices */
                channel->vdev = template;
                channel->vdev.lock = &dev->lock;
-               /* Locking in file operations other than ioctl should be done
-                  by the driver, not the V4L2 core.
-                  This driver needs auditing so that this flag can be removed. */
-               set_bit(V4L2_FL_LOCK_ALL_FOPS, &channel->vdev.flags);
                channel->vdev.v4l2_dev = &dev->v4l2_dev;
                video_set_drvdata(&channel->vdev, channel);
                if (video_nr == -1)
@@ -2535,7 +2537,6 @@ static int s2255_probe(struct usb_interface *interface,
        if (!dev->fw_data)
                goto errorFWDATA1;
        mutex_init(&dev->lock);
-       mutex_init(&dev->open_lock);
        /* grab usb_device and save it */
        dev->udev = usb_get_dev(interface_to_usbdev(interface));
        if (dev->udev == NULL) {
@@ -2637,7 +2638,6 @@ errorEP:
        usb_put_dev(dev->udev);
 errorUDEV:
        kfree(dev->fw_data);
-       mutex_destroy(&dev->open_lock);
        mutex_destroy(&dev->lock);
 errorFWDATA1:
        kfree(dev);