media: Reset file->private_data to NULL in v4l2_fh_del()

Multiple drivers that use v4l2_fh and call v4l2_fh_del() manually reset
the file->private_data pointer to NULL in their video device .release()
file operation handler. Move the code to the v4l2_fh_del() 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 release;
type ret;
@@
ret release(..., struct file *filp, ...)
{
	<...
-	filp->private_data = NULL;
	...
-	v4l2_fh_del(fh);
+	v4l2_fh_del(fh, filp);
	...>
}

@@
expression fh;
identifier filp;
identifier release;
type ret;
@@
ret release(..., struct file *filp, ...)
{
	<...
-	v4l2_fh_del(fh);
+	v4l2_fh_del(fh, filp);
	...
-	filp->private_data = NULL;
	...>
}

@@
expression fh;
identifier filp;
identifier release;
type ret;
@@
ret release(..., struct file *filp, ...)
{
	<...
-	v4l2_fh_del(fh);
+	v4l2_fh_del(fh, filp);
	...>
}

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_del() prototype and reset file->private_data, and to
include/media/v4l2-fh.h to update the v4l2_fh_del() function prototype
and its documentation.

Additionally, white space issues have been fixed manually in
drivers/usb/gadget/function/uvc_v4l2.c

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

4 files changed, 6 insertions, 6 deletions

diff --git a/drivers/staging/media/imx/imx-media-csc-scaler.c b/drivers/staging/media/imx/imx-media-csc-scaler.c
index 7fedb33dda34..dc7f9a77cbe6 100644
--- a/drivers/staging/media/imx/imx-media-csc-scaler.c
+++ b/drivers/staging/media/imx/imx-media-csc-scaler.c
@@ -792,7 +792,7 @@ static int ipu_csc_scaler_open(struct file *file)
 err_ctrls:
 	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
 err_ctx:
-	v4l2_fh_del(&ctx->fh);
+	v4l2_fh_del(&ctx->fh, file);
 	v4l2_fh_exit(&ctx->fh);
 	kfree(ctx);
 	return ret;
@@ -807,7 +807,7 @@ static int ipu_csc_scaler_release(struct file *file)
 
 	v4l2_ctrl_handler_free(&ctx->ctrl_hdlr);
 	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
-	v4l2_fh_del(&ctx->fh);
+	v4l2_fh_del(&ctx->fh, file);
 	v4l2_fh_exit(&ctx->fh);
 	kfree(ctx);
 
diff --git a/drivers/staging/media/meson/vdec/vdec.c b/drivers/staging/media/meson/vdec/vdec.c
index b92666ff50a1..49e497a32973 100644
--- a/drivers/staging/media/meson/vdec/vdec.c
+++ b/drivers/staging/media/meson/vdec/vdec.c
@@ -926,7 +926,7 @@ static int vdec_close(struct file *file)
 
 	v4l2_m2m_ctx_release(sess->m2m_ctx);
 	v4l2_m2m_release(sess->m2m_dev);
-	v4l2_fh_del(&sess->fh);
+	v4l2_fh_del(&sess->fh, file);
 	v4l2_fh_exit(&sess->fh);
 
 	mutex_destroy(&sess->lock);
diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/media/sunxi/cedrus/cedrus.c
index ebefd646dbdb..bff42ea1871f 100644
--- a/drivers/staging/media/sunxi/cedrus/cedrus.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
@@ -404,7 +404,7 @@ static int cedrus_release(struct file *file)
 
 	mutex_lock(&dev->dev_mutex);
 
-	v4l2_fh_del(&ctx->fh);
+	v4l2_fh_del(&ctx->fh, file);
 	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
 
 	v4l2_ctrl_handler_free(&ctx->hdl);
diff --git a/drivers/staging/most/video/video.c b/drivers/staging/most/video/video.c
index 24a68e3e5419..32f71d9a9cf7 100644
--- a/drivers/staging/most/video/video.c
+++ b/drivers/staging/most/video/video.c
@@ -107,7 +107,7 @@ static int comp_vdev_open(struct file *filp)
 	return 0;
 
 err_rm:
-	v4l2_fh_del(&fh->fh);
+	v4l2_fh_del(&fh->fh, filp);
 	v4l2_fh_exit(&fh->fh);
 
 err_dec:
@@ -143,7 +143,7 @@ static int comp_vdev_close(struct file *filp)
 	most_stop_channel(mdev->iface, mdev->ch_idx, &comp);
 	mdev->mute = false;
 
-	v4l2_fh_del(&fh->fh);
+	v4l2_fh_del(&fh->fh, filp);
 	v4l2_fh_exit(&fh->fh);
 
 	atomic_dec(&mdev->access_ref);