[media] cpia2: 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>

1 files changed, 28 insertions, 11 deletions

diff --git a/drivers/media/video/cpia2/cpia2_v4l.c b/drivers/media/video/cpia2/cpia2_v4l.c
index a62a7b739991..5ca6f44b4c63 100644
--- a/drivers/media/video/cpia2/cpia2_v4l.c
+++ b/drivers/media/video/cpia2/cpia2_v4l.c
@@ -84,21 +84,26 @@ MODULE_VERSION(CPIA_VERSION);
 static int cpia2_open(struct file *file)
 {
         struct camera_data *cam = video_drvdata(file);
-        int retval = v4l2_fh_open(file);
+        int retval;
 
+        if (mutex_lock_interruptible(&cam->v4l2_lock))
+                return -ERESTARTSYS;
+        retval = v4l2_fh_open(file);
         if (retval)
-                return retval;
+                goto open_unlock;
 
         if (v4l2_fh_is_singular_file(file)) {
                 if (cpia2_allocate_buffers(cam)) {
                         v4l2_fh_release(file);
-                        return -ENOMEM;
+                        retval = -ENOMEM;
+                        goto open_unlock;
                 }
 
                 /* reset the camera */
                 if (cpia2_reset_camera(cam) < 0) {
                         v4l2_fh_release(file);
-                        return -EIO;
+                        retval = -EIO;
+                        goto open_unlock;
                 }
 
                 cam->APP_len = 0;
@@ -106,7 +111,9 @@ static int cpia2_open(struct file *file)
         }
 
         cpia2_dbg_dump_registers(cam);
-        return 0;
+open_unlock:
+        mutex_unlock(&cam->v4l2_lock);
+        return retval;
 }
 
 /******************************************************************************
@@ -119,6 +126,7 @@ static int cpia2_close(struct file *file)
         struct video_device *dev = video_devdata(file);
         struct camera_data *cam = video_get_drvdata(dev);
 
+        mutex_lock(&cam->v4l2_lock);
         if (video_is_registered(&cam->vdev) && v4l2_fh_is_singular_file(file)) {
                 cpia2_usb_stream_stop(cam);
 
@@ -133,6 +141,7 @@ static int cpia2_close(struct file *file)
                 cam->stream_fh = NULL;
                 cam->mmapped = 0;
         }
+        mutex_unlock(&cam->v4l2_lock);
         return v4l2_fh_release(file);
 }
 
@@ -146,11 +155,16 @@ static ssize_t cpia2_v4l_read(struct file *file, char __user *buf, size_t count,
 {
         struct camera_data *cam = video_drvdata(file);
         int noblock = file->f_flags&O_NONBLOCK;
+        ssize_t ret;
 
         if(!cam)
                 return -EINVAL;
 
-        return cpia2_read(cam, buf, count, noblock);
+        if (mutex_lock_interruptible(&cam->v4l2_lock))
+                return -ERESTARTSYS;
+        ret = cpia2_read(cam, buf, count, noblock);
+        mutex_unlock(&cam->v4l2_lock);
+        return ret;
 }
 
 
@@ -162,8 +176,12 @@ static ssize_t cpia2_v4l_read(struct file *file, char __user *buf, size_t count,
 static unsigned int cpia2_v4l_poll(struct file *filp, struct poll_table_struct *wait)
 {
         struct camera_data *cam = video_drvdata(filp);
+        unsigned int res;
 
-        return cpia2_poll(cam, filp, wait);
+        mutex_lock(&cam->v4l2_lock);
+        res = cpia2_poll(cam, filp, wait);
+        mutex_unlock(&cam->v4l2_lock);
+        return res;
 }
 
 
@@ -987,10 +1005,13 @@ static int cpia2_mmap(struct file *file, struct vm_area_struct *area)
         struct camera_data *cam = video_drvdata(file);
         int retval;
 
+        if (mutex_lock_interruptible(&cam->v4l2_lock))
+                return -ERESTARTSYS;
         retval = cpia2_remap_buffer(cam, area);
 
         if(!retval)
                 cam->stream_fh = file->private_data;
+        mutex_unlock(&cam->v4l2_lock);
         return retval;
 }
 
@@ -1147,10 +1168,6 @@ int cpia2_register_camera(struct camera_data *cam)
         cam->vdev.ctrl_handler = hdl;
         cam->vdev.v4l2_dev = &cam->v4l2_dev;
         set_bit(V4L2_FL_USE_FH_PRIO, &cam->vdev.flags);
-        /* 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, &cam->vdev.flags);
 
         reset_camera_struct_v4l(cam);