media: Set file->private_data in v4l2_fh_add()

All the drivers that use v4l2_fh and call v4l2_fh_add() manually store a
pointer to the v4l2_fh instance in file->private_data in their video
device .open() file operation handler. Move the code to the
v4l2_fh_add() function to avoid direct access to file->private_data in
drivers. This requires adding a file pointer argument to the function.

Changes to drivers have been generated with the following coccinelle
semantic patch:

@@
expression fh;
identifier filp;
identifier open;
type ret;
@@
ret open(..., struct file *filp, ...)
{
	<...
-	filp->private_data = fh;
	...
-	v4l2_fh_add(fh);
+	v4l2_fh_add(fh, filp);
	...>
}

@@
expression fh;
identifier filp;
identifier open;
type ret;
@@
ret open(..., struct file *filp, ...)
{
	<...
-	v4l2_fh_add(fh);
+	v4l2_fh_add(fh, filp);
	...
-	filp->private_data = fh;
	...>
}

Manual changes have been applied to Documentation/ to update the usage
patterns, to drivers/media/v4l2-core/v4l2-fh.c to update the
v4l2_fh_add() prototype set file->private_data, and to
include/media/v4l2-fh.h to update the v4l2_fh_add() function prototype
and its documentation.

Additionally, white space issues have been fixed manually in
drivers/media/platform/nvidia/tegra-vde/v4l2.c,
drivers/media/platform/rockchip/rkvdec/rkvdec.c,
drivers/media/v4l2-core/v4l2-fh.c and
drivers/staging/most/video/video.c.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

Documentation/driver-api/media/v4l2-fh.rst

@@ -11,25 +11,22 @@ data that is used by the V4L2 framework.
 	since it is also used to implement priority handling
 	(:ref:`VIDIOC_G_PRIORITY`).
 
-The users of :c:type:`v4l2_fh` (in the V4L2 framework, not the driver) know
-whether a driver uses :c:type:`v4l2_fh` as its ``file->private_data`` pointer
-by testing the ``V4L2_FL_USES_V4L2_FH`` bit in :c:type:`video_device`->flags.
-This bit is set whenever :c:func:`v4l2_fh_init` is called.
+struct v4l2_fh is allocated in the driver's ``open()`` file operation handler.
+It is typically embedded in a larger driver-specific structure. The
+:c:type:`v4l2_fh` must be initialized with a call to :c:func:`v4l2_fh_init`,
+and added to the video device with :c:func:`v4l2_fh_add`. This associates the
+:c:type:`v4l2_fh` with the :c:type:`file` by setting ``file->private_data`` to
+point to the :c:type:`v4l2_fh`.
 
-struct v4l2_fh is allocated as a part of the driver's own file handle
-structure and ``file->private_data`` is set to it in the driver's ``open()``
-function by the driver. The :c:type:`v4l2_fh` file handle can be retrieved
-from the :c:type:`file` using :c:func:`file_to_v4l2_fh`. Drivers must not
-access ``file->private_data`` directly.
+Similarly, the struct v4l2_fh is freed in the driver's ``release()`` file
+operation handler. It must be removed from the video device with
+:c:func:`v4l2_fh_del` and cleaned up with :c:func:`v4l2_fh_exit` before being
+freed.
 
-In many cases the struct v4l2_fh will be embedded in a larger
-structure. In that case you should call:
-
-#) :c:func:`v4l2_fh_init` and :c:func:`v4l2_fh_add` in ``open()``
-#) :c:func:`v4l2_fh_del` and :c:func:`v4l2_fh_exit` in ``release()``
-
-Drivers can extract their own file handle structure by using the container_of
-macro.
+Drivers must not access ``file->private_data`` directly. They can retrieve the
+:c:type:`v4l2_fh` associated with a :c:type:`file` by calling
+:c:func:`file_to_v4l2_fh`. Drivers can extract their own file handle structure
+by using the container_of macro.
 
 Example:
 
@@ -58,8 +55,7 @@ Example:
 
 		...
 
-		file->private_data = &my_fh->fh;
-		v4l2_fh_add(&my_fh->fh);
+		v4l2_fh_add(&my_fh->fh, file);
 		return 0;
 	}
 
@@ -84,7 +80,7 @@ Below is a short description of the :c:type:`v4l2_fh` functions used:
   :c:type:`v4l2_file_operations`->open() handler.
 
 :c:func:`v4l2_fh_add <v4l2_fh_add>`
-(:c:type:`fh <v4l2_fh>`)
+(:c:type:`fh <v4l2_fh>`, struct file \*filp)
 
 - Add a :c:type:`v4l2_fh` to :c:type:`video_device` file handle list.
   Must be called once the file handle is completely initialized.
@@ -138,6 +134,12 @@ associated device node:
 
 - Same, but it calls v4l2_fh_is_singular with filp->private_data.
 
+.. note::
+        The V4L2 framework knows whether a driver uses :c:type:`v4l2_fh` as its
+        ``file->private_data`` pointer by testing the ``V4L2_FL_USES_V4L2_FH``
+        bit in :c:type:`video_device`->flags. This bit is set whenever
+        :c:func:`v4l2_fh_init` is called.
+
 
 V4L2 fh functions and data structures
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Documentation/translations/zh_CN/video4linux/v4l2-framework.txt

@@ -812,8 +812,7 @@ int my_open(struct file *file)
 
 	...
 
-	file->private_data = &my_fh->fh;
-	v4l2_fh_add(&my_fh->fh);
+	v4l2_fh_add(&my_fh->fh, file);
 	return 0;
 }
 
@@ -836,7 +835,7 @@ void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
   初始化文件句柄。这*必须*在驱动的 v4l2_file_operations->open()
   函数中执行。
 
-void v4l2_fh_add(struct v4l2_fh *fh)
+void v4l2_fh_add(struct v4l2_fh *fh, struct file *filp)
 
   添加一个 v4l2_fh 到 video_device 文件句柄列表。一旦文件句柄
   初始化完成就必须调用。

drivers/media/pci/cx18/cx18-fileops.c

@@ -743,8 +743,7 @@ static int cx18_serialized_open(struct cx18_stream *s, struct file *filp)
 	item->type = s->type;
 
 	item->open_id = cx->open_id++;
-	filp->private_data = &item->fh;
-	v4l2_fh_add(&item->fh);
+	v4l2_fh_add(&item->fh, filp);
 
 	if (item->type == CX18_ENC_STREAM_TYPE_RAD &&
 			v4l2_fh_is_singular_file(filp)) {

drivers/media/pci/ivtv/ivtv-fileops.c

@@ -998,9 +998,7 @@ static int ivtv_open(struct file *filp)
 	v4l2_fh_init(&item->fh, &s->vdev);
 	item->itv = itv;
 	item->type = s->type;
-
-	filp->private_data = &item->fh;
-	v4l2_fh_add(&item->fh);
+	v4l2_fh_add(&item->fh, filp);
 
 	if (item->type == IVTV_ENC_STREAM_TYPE_RAD &&
 			v4l2_fh_is_singular_file(filp)) {

drivers/media/pci/saa7164/saa7164-encoder.c

@@ -725,8 +725,7 @@ static int fops_open(struct file *file)
 
 	fh->port = port;
 	v4l2_fh_init(&fh->fh, video_devdata(file));
-	v4l2_fh_add(&fh->fh);
-	file->private_data = &fh->fh;
+	v4l2_fh_add(&fh->fh, file);
 
 	return 0;
 }

drivers/media/pci/saa7164/saa7164-vbi.c

@@ -428,8 +428,7 @@ static int fops_open(struct file *file)
 
 	fh->port = port;
 	v4l2_fh_init(&fh->fh, video_devdata(file));
-	v4l2_fh_add(&fh->fh);
-	file->private_data = &fh->fh;
+	v4l2_fh_add(&fh->fh, file);
 
 	return 0;
 }

drivers/media/platform/allegro-dvt/allegro-core.c

@@ -3219,8 +3219,7 @@ static int allegro_open(struct file *file)
 	}
 
 	list_add(&channel->list, &dev->channels);
-	file->private_data = &channel->fh;
-	v4l2_fh_add(&channel->fh);
+	v4l2_fh_add(&channel->fh, file);
 
 	allegro_channel_adjust(channel);
 

drivers/media/platform/amlogic/meson-ge2d/ge2d.c

@@ -860,8 +860,7 @@ static int ge2d_open(struct file *file)
 		return ret;
 	}
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ge2d_setup_ctrls(ctx);
 

drivers/media/platform/amphion/vpu_v4l2.c

@@ -760,7 +760,7 @@ int vpu_v4l2_open(struct file *file, struct vpu_inst *inst)
 	inst->min_buffer_cap = 2;
 	inst->min_buffer_out = 2;
 	v4l2_fh_init(&inst->fh, func->vfd);
-	v4l2_fh_add(&inst->fh);
+	v4l2_fh_add(&inst->fh, file);
 
 	ret = call_vop(inst, ctrl_init);
 	if (ret)
@@ -774,7 +774,6 @@ int vpu_v4l2_open(struct file *file, struct vpu_inst *inst)
 	}
 
 	inst->fh.ctrl_handler = &inst->ctrl_handler;
-	file->private_data = &inst->fh;
 	inst->state = VPU_CODEC_STATE_DEINIT;
 	inst->workqueue = alloc_ordered_workqueue("vpu_inst", WQ_MEM_RECLAIM);
 	if (inst->workqueue) {

drivers/media/platform/chips-media/coda/coda-common.c

@@ -2642,8 +2642,7 @@ static int coda_open(struct file *file)
 	if (ctx->ops->seq_end_work)
 		INIT_WORK(&ctx->seq_end_work, ctx->ops->seq_end_work);
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	ctx->dev = dev;
 	ctx->idx = idx;
 

drivers/media/platform/chips-media/wave5/wave5-vpu-dec.c

@@ -1761,8 +1761,7 @@ static int wave5_vpu_open_dec(struct file *filp)
 		return -ENOMEM;
 
 	v4l2_fh_init(&inst->v4l2_fh, vdev);
-	filp->private_data = &inst->v4l2_fh;
-	v4l2_fh_add(&inst->v4l2_fh);
+	v4l2_fh_add(&inst->v4l2_fh, filp);
 
 	INIT_LIST_HEAD(&inst->list);
 

drivers/media/platform/chips-media/wave5/wave5-vpu-enc.c

@@ -1587,8 +1587,7 @@ static int wave5_vpu_open_enc(struct file *filp)
 		return -ENOMEM;
 
 	v4l2_fh_init(&inst->v4l2_fh, vdev);
-	filp->private_data = &inst->v4l2_fh;
-	v4l2_fh_add(&inst->v4l2_fh);
+	v4l2_fh_add(&inst->v4l2_fh, filp);
 
 	INIT_LIST_HEAD(&inst->list);
 

drivers/media/platform/imagination/e5010-jpeg-enc.c

@@ -742,8 +742,7 @@ static int e5010_open(struct file *file)
 	}
 
 	v4l2_fh_init(&ctx->fh, vdev);
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ctx->e5010 = e5010;
 	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(e5010->m2m_dev, ctx, queue_init);

drivers/media/platform/m2m-deinterlace.c

@@ -847,7 +847,6 @@ static int deinterlace_open(struct file *file)
 		return -ENOMEM;
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = pcdev;
 
 	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(pcdev->m2m_dev, ctx, &queue_init);
@@ -866,7 +865,7 @@ static int deinterlace_open(struct file *file)
 	}
 
 	ctx->colorspace = V4L2_COLORSPACE_REC709;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	dprintk(pcdev, "Created instance %p, m2m_ctx: %p\n",
 		ctx, ctx->fh.m2m_ctx);

drivers/media/platform/mediatek/jpeg/mtk_jpeg_core.c

@@ -1176,8 +1176,7 @@ static int mtk_jpeg_open(struct file *file)
 	INIT_LIST_HEAD(&ctx->dst_done_queue);
 	spin_lock_init(&ctx->done_queue_lock);
 	v4l2_fh_init(&ctx->fh, vfd);
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ctx->jpeg = jpeg;
 	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(jpeg->m2m_dev, ctx,

drivers/media/platform/mediatek/mdp/mtk_mdp_m2m.c

@@ -1070,14 +1070,13 @@ static int mtk_mdp_m2m_open(struct file *file)
 	mutex_init(&ctx->slock);
 	ctx->id = mdp->id_counter++;
 	v4l2_fh_init(&ctx->fh, vfd);
-	file->private_data = &ctx->fh;
 	ret = mtk_mdp_ctrls_create(ctx);
 	if (ret)
 		goto error_ctrls;
 
 	/* Use separate control handler per file handle */
 	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	INIT_LIST_HEAD(&ctx->list);
 
 	ctx->mdp_dev = mdp;

drivers/media/platform/mediatek/mdp3/mtk-mdp3-m2m.c

@@ -590,14 +590,13 @@ static int mdp_m2m_open(struct file *file)
 	ctx->mdp_dev = mdp;
 
 	v4l2_fh_init(&ctx->fh, vdev);
-	file->private_data = &ctx->fh;
 	ret = mdp_m2m_ctrls_create(ctx);
 	if (ret)
 		goto err_exit_fh;
 
 	/* Use separate control handler per file handle */
 	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	mutex_init(&ctx->ctx_lock);
 	ctx->m2m_ctx = v4l2_m2m_ctx_init(mdp->m2m_dev, ctx, mdp_m2m_queue_init);

drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.c

@@ -206,8 +206,7 @@ static int fops_vcodec_open(struct file *file)
 	mutex_lock(&dev->dev_mutex);
 	ctx->id = dev->id_counter++;
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	INIT_LIST_HEAD(&ctx->list);
 	ctx->dev = dev;
 	if (ctx->dev->vdec_pdata->is_subdev_supported) {

drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.c

@@ -129,8 +129,7 @@ static int fops_vcodec_open(struct file *file)
 	 */
 	ctx->id = dev->id_counter++;
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	INIT_LIST_HEAD(&ctx->list);
 	ctx->dev = dev;
 	init_waitqueue_head(&ctx->queue[0]);

drivers/media/platform/nvidia/tegra-vde/v4l2.c

@@ -832,8 +832,7 @@ static int tegra_open(struct file *file)
 		goto free_ctrls;
 	}
 
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	tegra_reset_coded_fmt(ctx);
 	tegra_try_coded_fmt(file, &ctx->fh, &ctx->coded_fmt);

drivers/media/platform/nxp/dw100/dw100.c

@@ -607,7 +607,6 @@ static int dw100_open(struct file *file)
 
 	mutex_init(&ctx->vq_mutex);
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dw_dev = dw_dev;
 
 	ctx->q_data[DW100_QUEUE_SRC].fmt = &formats[0];
@@ -651,7 +650,7 @@ static int dw100_open(struct file *file)
 		goto err;
 	}
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	return 0;
 

drivers/media/platform/nxp/imx-jpeg/mxc-jpeg.c

@@ -2205,8 +2205,7 @@ static int mxc_jpeg_open(struct file *file)
 	}
 
 	v4l2_fh_init(&ctx->fh, mxc_vfd);
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ctx->mxc_jpeg = mxc_jpeg;
 

drivers/media/platform/nxp/imx-pxp.c

@@ -1660,7 +1660,6 @@ static int pxp_open(struct file *file)
 	}
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = dev;
 	hdl = &ctx->hdl;
 	v4l2_ctrl_handler_init(hdl, 4);
@@ -1699,7 +1698,7 @@ static int pxp_open(struct file *file)
 		goto open_unlock;
 	}
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	atomic_inc(&dev->num_inst);
 
 	dprintk(dev, "Created instance: %p, m2m_ctx: %p\n",

drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c

@@ -673,7 +673,6 @@ static int mxc_isi_m2m_open(struct file *file)
 	mutex_init(&ctx->vb2_lock);
 
 	v4l2_fh_init(&ctx->fh, vdev);
-	file->private_data = &ctx->fh;
 
 	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(m2m->m2m_dev, ctx,
 					    &mxc_isi_m2m_queue_init);
@@ -694,7 +693,7 @@ static int mxc_isi_m2m_open(struct file *file)
 	if (ret)
 		goto err_ctrls;
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	return 0;
 

drivers/media/platform/nxp/mx2_emmaprp.c

@@ -730,7 +730,6 @@ static int emmaprp_open(struct file *file)
 		return -ENOMEM;
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = pcdev;
 
 	if (mutex_lock_interruptible(&pcdev->dev_mutex)) {
@@ -752,7 +751,7 @@ static int emmaprp_open(struct file *file)
 	clk_prepare_enable(pcdev->clk_emma_ahb);
 	ctx->q_data[V4L2_M2M_SRC].fmt = &formats[1];
 	ctx->q_data[V4L2_M2M_DST].fmt = &formats[0];
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	mutex_unlock(&pcdev->dev_mutex);
 
 	dprintk(pcdev, "Created instance %p, m2m_ctx: %p\n", ctx, ctx->fh.m2m_ctx);

drivers/media/platform/qcom/iris/iris_vidc.c

@@ -25,8 +25,7 @@ static void iris_v4l2_fh_init(struct iris_inst *inst, struct file *filp)
 {
 	v4l2_fh_init(&inst->fh, inst->core->vdev_dec);
 	inst->fh.ctrl_handler = &inst->ctrl_handler;
-	v4l2_fh_add(&inst->fh);
-	filp->private_data = &inst->fh;
+	v4l2_fh_add(&inst->fh, filp);
 }
 
 static void iris_v4l2_fh_deinit(struct iris_inst *inst, struct file *filp)

drivers/media/platform/qcom/venus/vdec.c

@@ -1732,9 +1732,8 @@ static int vdec_open(struct file *file)
 	v4l2_fh_init(&inst->fh, core->vdev_dec);
 
 	inst->fh.ctrl_handler = &inst->ctrl_handler;
-	v4l2_fh_add(&inst->fh);
+	v4l2_fh_add(&inst->fh, file);
 	inst->fh.m2m_ctx = inst->m2m_ctx;
-	file->private_data = &inst->fh;
 
 	return 0;
 

drivers/media/platform/qcom/venus/venc.c

@@ -1515,9 +1515,8 @@ static int venc_open(struct file *file)
 	v4l2_fh_init(&inst->fh, core->vdev_enc);
 
 	inst->fh.ctrl_handler = &inst->ctrl_handler;
-	v4l2_fh_add(&inst->fh);
+	v4l2_fh_add(&inst->fh, file);
 	inst->fh.m2m_ctx = inst->m2m_ctx;
-	file->private_data = &inst->fh;
 
 	return 0;
 

drivers/media/platform/renesas/rcar_fdp1.c

@@ -2093,7 +2093,6 @@ static int fdp1_open(struct file *file)
 	}
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->fdp1 = fdp1;
 
 	/* Initialise Queues */
@@ -2142,7 +2141,7 @@ static int fdp1_open(struct file *file)
 	if (ret < 0)
 		goto error_pm;
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	dprintk(fdp1, "Created instance: %p, m2m_ctx: %p\n",
 		ctx, ctx->fh.m2m_ctx);

drivers/media/platform/renesas/rcar_jpu.c

@@ -1231,8 +1231,7 @@ static int jpu_open(struct file *file)
 
 	v4l2_fh_init(&ctx->fh, vfd);
 	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ctx->jpu = jpu;
 	ctx->encoder = vfd == &jpu->vfd_encoder;

drivers/media/platform/renesas/vsp1/vsp1_video.c

@@ -1079,9 +1079,7 @@ static int vsp1_video_open(struct file *file)
 		return -ENOMEM;
 
 	v4l2_fh_init(vfh, &video->video);
-	v4l2_fh_add(vfh);
-
-	file->private_data = vfh;
+	v4l2_fh_add(vfh, file);
 
 	ret = vsp1_device_get(video->vsp1);
 	if (ret < 0) {

drivers/media/platform/rockchip/rga/rga.c

@@ -395,8 +395,7 @@ static int rga_open(struct file *file)
 		return ret;
 	}
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	rga_setup_ctrls(ctx);
 

drivers/media/platform/rockchip/rkvdec/rkvdec.c

@@ -938,8 +938,7 @@ static int rkvdec_open(struct file *filp)
 	if (ret)
 		goto err_cleanup_m2m_ctx;
 
-	filp->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, filp);
 
 	return 0;
 

drivers/media/platform/samsung/exynos-gsc/gsc-m2m.c

@@ -625,8 +625,7 @@ static int gsc_m2m_open(struct file *file)
 
 	/* Use separate control handler per file handle */
 	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ctx->gsc_dev = gsc;
 	/* Default color format */

drivers/media/platform/samsung/exynos4-is/fimc-m2m.c

@@ -634,8 +634,7 @@ static int fimc_m2m_open(struct file *file)
 
 	/* Use separate control handler per file handle */
 	ctx->fh.ctrl_handler = &ctx->ctrls.handler;
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	/* Setup the device context for memory-to-memory mode */
 	ctx->state = FIMC_CTX_M2M;

drivers/media/platform/samsung/s5p-g2d/g2d.c

@@ -257,8 +257,7 @@ static int g2d_open(struct file *file)
 		return ret;
 	}
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	g2d_setup_ctrls(ctx);
 

drivers/media/platform/samsung/s5p-jpeg/jpeg-core.c

@@ -970,8 +970,7 @@ static int s5p_jpeg_open(struct file *file)
 	v4l2_fh_init(&ctx->fh, vfd);
 	/* Use separate control handler per file handle */
 	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ctx->jpeg = jpeg;
 	if (vfd == jpeg->vfd_encoder) {

drivers/media/platform/samsung/s5p-mfc/s5p_mfc.c

@@ -801,8 +801,7 @@ static int s5p_mfc_open(struct file *file)
 	}
 	init_waitqueue_head(&ctx->queue);
 	v4l2_fh_init(&ctx->fh, vdev);
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	ctx->dev = dev;
 	INIT_LIST_HEAD(&ctx->src_queue);
 	INIT_LIST_HEAD(&ctx->dst_queue);

drivers/media/platform/st/sti/bdisp/bdisp-v4l2.c

@@ -608,8 +608,7 @@ static int bdisp_open(struct file *file)
 
 	/* Use separate control handler per file handle */
 	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	/* Default format */
 	ctx->src = bdisp_dflt_fmt;

drivers/media/platform/st/sti/delta/delta-v4l2.c

@@ -1639,8 +1639,7 @@ static int delta_open(struct file *file)
 	ctx->dev = delta;
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	INIT_WORK(&ctx->run_work, delta_run_work);
 	mutex_init(&ctx->lock);

drivers/media/platform/st/sti/hva/hva-v4l2.c

@@ -1174,8 +1174,7 @@ static int hva_open(struct file *file)
 
 	INIT_WORK(&ctx->run_work, hva_run_work);
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ret = hva_ctrls_setup(ctx);
 	if (ret) {

drivers/media/platform/st/stm32/dma2d/dma2d.c

@@ -304,8 +304,7 @@ static int dma2d_open(struct file *file)
 	}
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	dma2d_setup_ctrls(ctx);
 

drivers/media/platform/sunxi/sun8i-di/sun8i-di.c

@@ -730,7 +730,6 @@ static int deinterlace_open(struct file *file)
 	deinterlace_prepare_format(&ctx->dst_fmt);
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = dev;
 
 	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx,
@@ -740,7 +739,7 @@ static int deinterlace_open(struct file *file)
 		goto err_free;
 	}
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	mutex_unlock(&dev->dev_mutex);
 

drivers/media/platform/sunxi/sun8i-rotate/sun8i_rotate.c

@@ -659,7 +659,6 @@ static int rotate_open(struct file *file)
 	rotate_set_cap_format(ctx, &ctx->dst_fmt, ctx->rotate);
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = dev;
 
 	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx,
@@ -669,7 +668,7 @@ static int rotate_open(struct file *file)
 		goto err_free;
 	}
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	ret = rotate_setup_ctrls(ctx);
 	if (ret)

drivers/media/platform/ti/omap3isp/ispvideo.c

@@ -1297,7 +1297,7 @@ static int isp_video_open(struct file *file)
 		return -ENOMEM;
 
 	v4l2_fh_init(&handle->vfh, &video->video);
-	v4l2_fh_add(&handle->vfh);
+	v4l2_fh_add(&handle->vfh, file);
 
 	/* If this is the first user, initialise the pipeline. */
 	if (omap3isp_get(video->isp) == NULL) {
@@ -1333,7 +1333,6 @@ static int isp_video_open(struct file *file)
 	handle->timeperframe.denominator = 1;
 
 	handle->video = video;
-	file->private_data = &handle->vfh;
 
 done:
 	if (ret < 0) {

drivers/media/platform/ti/vpe/vpe.c

@@ -2310,7 +2310,6 @@ static int vpe_open(struct file *file)
 	init_adb_hdrs(ctx);
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 
 	hdl = &ctx->hdl;
 	v4l2_ctrl_handler_init(hdl, 1);
@@ -2364,7 +2363,7 @@ static int vpe_open(struct file *file)
 		goto exit_fh;
 	}
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	/*
 	 * for now, just report the creation of the first instance, we can later

drivers/media/platform/verisilicon/hantro_drv.c

@@ -663,8 +663,7 @@ static int hantro_open(struct file *filp)
 	}
 
 	v4l2_fh_init(&ctx->fh, vdev);
-	filp->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, filp);
 
 	hantro_reset_fmts(ctx);
 

drivers/media/test-drivers/vicodec/vicodec-core.c

@@ -1848,7 +1848,6 @@ static int vicodec_open(struct file *file)
 		ctx->is_stateless = true;
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = dev;
 	hdl = &ctx->hdl;
 	v4l2_ctrl_handler_init(hdl, 5);
@@ -1932,7 +1931,7 @@ static int vicodec_open(struct file *file)
 		goto open_unlock;
 	}
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 open_unlock:
 	mutex_unlock(vfd->lock);

drivers/media/test-drivers/vim2m.c

@@ -1389,7 +1389,6 @@ static int vim2m_open(struct file *file)
 	}
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = dev;
 	hdl = &ctx->hdl;
 	v4l2_ctrl_handler_init(hdl, 4);
@@ -1433,7 +1432,7 @@ static int vim2m_open(struct file *file)
 		goto open_unlock;
 	}
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	atomic_inc(&dev->num_inst);
 
 	dprintk(dev, 1, "Created instance: %p, m2m_ctx: %p\n",

drivers/media/test-drivers/visl/visl-core.c

@@ -341,7 +341,6 @@ static int visl_open(struct file *file)
 	ctx->tpg_str_buf = kzalloc(TPG_STR_BUF_SZ, GFP_KERNEL);
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = dev;
 
 	rc = visl_init_ctrls(ctx);
@@ -361,7 +360,7 @@ static int visl_open(struct file *file)
 	if (rc)
 		goto free_m2m_ctx;
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	dprintk(dev, "Created instance: %p, m2m_ctx: %p\n",
 		ctx, ctx->fh.m2m_ctx);

drivers/media/usb/hdpvr/hdpvr-video.c

@@ -380,8 +380,7 @@ static int hdpvr_open(struct file *file)
 		return -ENOMEM;
 	fh->legacy_mode = true;
 	v4l2_fh_init(&fh->fh, video_devdata(file));
-	v4l2_fh_add(&fh->fh);
-	file->private_data = &fh->fh;
+	v4l2_fh_add(&fh->fh, file);
 	return 0;
 }
 

drivers/media/usb/pvrusb2/pvrusb2-v4l2.c

@@ -1003,10 +1003,9 @@ static int pvr2_v4l2_open(struct file *file)
 	}
 
 	fhp->file = file;
-	file->private_data = &fhp->fh;
 
 	fhp->fw_mode_flag = pvr2_hdw_cpufw_get_enabled(hdw);
-	v4l2_fh_add(&fhp->fh);
+	v4l2_fh_add(&fhp->fh, file);
 
 	return 0;
 }

drivers/media/usb/uvc/uvc_v4l2.c

@@ -600,10 +600,9 @@ static int uvc_v4l2_open(struct file *file)
 		return -ENOMEM;
 
 	v4l2_fh_init(&handle->vfh, &stream->vdev);
-	v4l2_fh_add(&handle->vfh);
+	v4l2_fh_add(&handle->vfh, file);
 	handle->chain = stream->chain;
 	handle->stream = stream;
-	file->private_data = &handle->vfh;
 
 	return 0;
 }

drivers/media/v4l2-core/v4l2-fh.c

@@ -41,10 +41,12 @@ void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev)
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_init);
 
-void v4l2_fh_add(struct v4l2_fh *fh)
+void v4l2_fh_add(struct v4l2_fh *fh, struct file *filp)
 {
 	unsigned long flags;
 
+	filp->private_data = fh;
+
 	v4l2_prio_open(fh->vdev->prio, &fh->prio);
 	spin_lock_irqsave(&fh->vdev->fh_lock, flags);
 	list_add(&fh->list, &fh->vdev->fh_list);
@@ -57,11 +59,10 @@ int v4l2_fh_open(struct file *filp)
 	struct video_device *vdev = video_devdata(filp);
 	struct v4l2_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
 
-	filp->private_data = fh;
 	if (fh == NULL)
 		return -ENOMEM;
 	v4l2_fh_init(fh, vdev);
-	v4l2_fh_add(fh);
+	v4l2_fh_add(fh, filp);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(v4l2_fh_open);

drivers/media/v4l2-core/v4l2-subdev.c

@@ -86,8 +86,7 @@ static int subdev_open(struct file *file)
 	}
 
 	v4l2_fh_init(&subdev_fh->vfh, vdev);
-	v4l2_fh_add(&subdev_fh->vfh);
-	file->private_data = &subdev_fh->vfh;
+	v4l2_fh_add(&subdev_fh->vfh, file);
 
 	if (sd->v4l2_dev->mdev && sd->entity.graph_obj.mdev->dev) {
 		struct module *owner;

drivers/staging/media/imx/imx-media-csc-scaler.c

@@ -765,8 +765,7 @@ static int ipu_csc_scaler_open(struct file *file)
 	ctx->rot_mode = IPU_ROTATE_NONE;
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 	ctx->priv = priv;
 
 	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(priv->m2m_dev, ctx,

drivers/staging/media/meson/vdec/vdec.c

@@ -908,9 +908,8 @@ static int vdec_open(struct file *file)
 
 	v4l2_fh_init(&sess->fh, core->vdev_dec);
 	sess->fh.ctrl_handler = &sess->ctrl_handler;
-	v4l2_fh_add(&sess->fh);
+	v4l2_fh_add(&sess->fh, file);
 	sess->fh.m2m_ctx = sess->m2m_ctx;
-	file->private_data = &sess->fh;
 
 	return 0;
 

drivers/staging/media/sunxi/cedrus/cedrus.c

@@ -366,7 +366,6 @@ static int cedrus_open(struct file *file)
 	}
 
 	v4l2_fh_init(&ctx->fh, video_devdata(file));
-	file->private_data = &ctx->fh;
 	ctx->dev = dev;
 	ctx->bit_depth = 8;
 
@@ -383,7 +382,7 @@ static int cedrus_open(struct file *file)
 	if (ret)
 		goto err_m2m_release;
 
-	v4l2_fh_add(&ctx->fh);
+	v4l2_fh_add(&ctx->fh, file);
 
 	mutex_unlock(&dev->dev_mutex);
 

drivers/staging/most/video/video.c

@@ -96,9 +96,7 @@ static int comp_vdev_open(struct file *filp)
 
 	fh->mdev = mdev;
 	v4l2_fh_init(&fh->fh, vdev);
-	filp->private_data = &fh->fh;
-
-	v4l2_fh_add(&fh->fh);
+	v4l2_fh_add(&fh->fh, filp);
 
 	ret = most_start_channel(mdev->iface, mdev->ch_idx, &comp);
 	if (ret) {

drivers/usb/gadget/function/uvc_v4l2.c

@@ -672,10 +672,9 @@ uvc_v4l2_open(struct file *file)
 		return -ENOMEM;
 
 	v4l2_fh_init(&handle->vfh, vdev);
-	v4l2_fh_add(&handle->vfh);
+	v4l2_fh_add(&handle->vfh, file);
 
 	handle->device = &uvc->video;
-	file->private_data = &handle->vfh;
 
 	return 0;
 }

include/media/v4l2-fh.h

@@ -87,11 +87,14 @@ void v4l2_fh_init(struct v4l2_fh *fh, struct video_device *vdev);
  * v4l2_fh_add - Add the fh to the list of file handles on a video_device.
  *
  * @fh: pointer to &struct v4l2_fh
+ * @filp: pointer to &struct file associated with @fh
+ *
+ * The function sets filp->private_data to point to @fh.
  *
  * .. note::
  *    The @fh file handle must be initialised first.
  */
-void v4l2_fh_add(struct v4l2_fh *fh);
+void v4l2_fh_add(struct v4l2_fh *fh, struct file *filp);
 
 /**
  * v4l2_fh_open - Ancillary routine that can be used as the open\(\) op