From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
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@xxxxxxxxx>
---
drivers/media/video/em28xx/em28xx-video.c | 52 +++++++++++++++++++----------
1 file changed, 35 insertions(+), 17 deletions(-)
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index 50f5f4f..ecb23df 100644
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -2146,9 +2146,12 @@ static int em28xx_v4l2_open(struct file *filp)
dev->users);
+ if (mutex_lock_interruptible(&dev->lock))
+ return -ERESTARTSYS;
fh = kzalloc(sizeof(struct em28xx_fh), GFP_KERNEL);
if (!fh) {
em28xx_errdev("em28xx-video.c: Out of memory?!\n");
+ mutex_unlock(&dev->lock);
return -ENOMEM;
}
fh->dev = dev;
@@ -2189,6 +2192,7 @@ static int em28xx_v4l2_open(struct file *filp)
V4L2_BUF_TYPE_VBI_CAPTURE,
V4L2_FIELD_SEQ_TB,
sizeof(struct em28xx_buffer), fh, &dev->lock);
+ mutex_unlock(&dev->lock);
return errCode;
}
@@ -2243,6 +2247,7 @@ static int em28xx_v4l2_close(struct file *filp)
em28xx_videodbg("users=%d\n", dev->users);
+ mutex_lock(&dev->lock);
if (res_check(fh, EM28XX_RESOURCE_VIDEO)) {
videobuf_stop(&fh->vb_vidq);
res_free(fh, EM28XX_RESOURCE_VIDEO);
@@ -2261,6 +2266,7 @@ static int em28xx_v4l2_close(struct file *filp)
kfree(dev->alt_max_pkt_size);
kfree(dev);
kfree(fh);
+ mutex_unlock(&dev->lock);
return 0;
}
@@ -2285,6 +2291,7 @@ static int em28xx_v4l2_close(struct file *filp)
videobuf_mmap_free(&fh->vb_vbiq);
kfree(fh);
dev->users--;
+ mutex_unlock(&dev->lock);
return 0;
}
@@ -2304,35 +2311,35 @@ em28xx_v4l2_read(struct file *filp, char __user *buf, size_t count,
if (rc < 0)
return rc;
+ if (mutex_lock_interruptible(&dev->lock))
+ return -ERESTARTSYS;
/* FIXME: read() is not prepared to allow changing the video
resolution while streaming. Seems a bug at em28xx_set_fmt
*/
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
if (res_locked(dev, EM28XX_RESOURCE_VIDEO))
- return -EBUSY;
-
- return videobuf_read_stream(&fh->vb_vidq, buf, count, pos, 0,
+ rc = -EBUSY;
+ else
+ rc = videobuf_read_stream(&fh->vb_vidq, buf, count, pos, 0,
filp->f_flags & O_NONBLOCK);
- }
-
-
- if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) {
+ } else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE) {
if (!res_get(fh, EM28XX_RESOURCE_VBI))
- return -EBUSY;
-
- return videobuf_read_stream(&fh->vb_vbiq, buf, count, pos, 0,
+ rc = -EBUSY;
+ else
+ rc = videobuf_read_stream(&fh->vb_vbiq, buf, count, pos, 0,
filp->f_flags & O_NONBLOCK);
}
+ mutex_unlock(&dev->lock);
- return 0;
+ return rc;
}
/*
- * em28xx_v4l2_poll()
+ * em28xx_poll()
* will allocate buffers when called for the first time
*/
-static unsigned int em28xx_v4l2_poll(struct file *filp, poll_table *wait)
+static unsigned int em28xx_poll(struct file *filp, poll_table *wait)
{
struct em28xx_fh *fh = filp->private_data;
struct em28xx *dev = fh->dev;
@@ -2355,6 +2362,18 @@ static unsigned int em28xx_v4l2_poll(struct file *filp, poll_table *wait)
}
}
+static unsigned int em28xx_v4l2_poll(struct file *filp, poll_table *wait)
+{
+ struct em28xx_fh *fh = filp->private_data;
+ struct em28xx *dev = fh->dev;
+ unsigned int res;
+
+ mutex_lock(&dev->lock);
+ res = em28xx_poll(filp, wait);
+ mutex_unlock(&dev->lock);
+ return res;
+}
+
/*
* em28xx_v4l2_mmap()
*/
@@ -2368,10 +2387,13 @@ static int em28xx_v4l2_mmap(struct file *filp, struct vm_area_struct *vma)
if (rc < 0)
return rc;
+ if (mutex_lock_interruptible(&dev->lock))
+ return -ERESTARTSYS;
if (fh->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
rc = videobuf_mmap_mapper(&fh->vb_vidq, vma);
else if (fh->type == V4L2_BUF_TYPE_VBI_CAPTURE)
rc = videobuf_mmap_mapper(&fh->vb_vbiq, vma);
+ mutex_unlock(&dev->lock);
em28xx_videodbg("vma start=0x%08lx, size=%ld, ret=%d\n",
(unsigned long)vma->vm_start,
@@ -2495,10 +2517,6 @@ static struct video_device *em28xx_vdev_init(struct em28xx *dev,
vfd->release = video_device_release;
vfd->debug = video_debug;
vfd->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, &vfd->flags);
snprintf(vfd->name, sizeof(vfd->name), "%s %s",
dev->name, type_name);
--
1.7.10
--
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