[RFC PATCH 13/26] vpif_capture: remove V4L2_FL_LOCK_ALL_FOPS

[Hans Verkuil]

From: Hans Verkuil <hans.verk...@cisco.com>

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.verk...@cisco.com>
---
 drivers/media/video/davinci/vpif_capture.c |   28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/drivers/media/video/davinci/vpif_capture.c 
b/drivers/media/video/davinci/vpif_capture.c
index 9604695..425f6d8 100644
--- a/drivers/media/video/davinci/vpif_capture.c
+++ b/drivers/media/video/davinci/vpif_capture.c
@@ -713,10 +713,15 @@ static int vpif_mmap(struct file *filep, struct 
vm_area_struct *vma)
        struct vpif_fh *fh = filep->private_data;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &(ch->common[VPIF_VIDEO_INDEX]);
+       int ret;
 
        vpif_dbg(2, debug, "vpif_mmap\n");
 
-       return videobuf_mmap_mapper(&common->buffer_queue, vma);
+       if (mutex_lock_interruptible(&common->lock))
+               return -ERESTARTSYS;
+       ret = videobuf_mmap_mapper(&common->buffer_queue, vma);
+       mutex_unlock(&common->lock);
+       return ret;
 }
 
 /**
@@ -729,12 +734,16 @@ static unsigned int vpif_poll(struct file *filep, 
poll_table * wait)
        struct vpif_fh *fh = filep->private_data;
        struct channel_obj *channel = fh->channel;
        struct common_obj *common = &(channel->common[VPIF_VIDEO_INDEX]);
+       unsigned int res = 0;
 
        vpif_dbg(2, debug, "vpif_poll\n");
 
-       if (common->started)
-               return videobuf_poll_stream(filep, &common->buffer_queue, wait);
-       return 0;
+       if (common->started) {
+               mutex_lock(&common->lock);
+               res = videobuf_poll_stream(filep, &common->buffer_queue, wait);
+               mutex_unlock(&common->lock);
+       }
+       return res;
 }
 
 /**
@@ -788,6 +797,10 @@ static int vpif_open(struct file *filep)
                return -ENOMEM;
        }
 
+       if (mutex_lock_interruptible(&common->lock)) {
+               kfree(fh);
+               return -ERESTARTSYS;
+       }
        /* store pointer to fh in private_data member of filep */
        filep->private_data = fh;
        fh->channel = ch;
@@ -805,6 +818,7 @@ static int vpif_open(struct file *filep)
        /* Initialize priority of this instance to default priority */
        fh->prio = V4L2_PRIORITY_UNSET;
        v4l2_prio_open(&ch->prio, &fh->prio);
+       mutex_unlock(&common->lock);
        return 0;
 }
 
@@ -825,6 +839,7 @@ static int vpif_release(struct file *filep)
 
        common = &ch->common[VPIF_VIDEO_INDEX];
 
+       mutex_lock(&common->lock);
        /* if this instance is doing IO */
        if (fh->io_allowed[VPIF_VIDEO_INDEX]) {
                /* Reset io_usrs member of channel object */
@@ -854,6 +869,7 @@ static int vpif_release(struct file *filep)
        if (fh->initialized)
                ch->initialized = 0;
 
+       mutex_unlock(&common->lock);
        filep->private_data = NULL;
        kfree(fh);
        return 0;
@@ -2228,10 +2244,6 @@ static __init int vpif_probe(struct platform_device 
*pdev)
                common = &(ch->common[VPIF_VIDEO_INDEX]);
                spin_lock_init(&common->irqlock);
                mutex_init(&common->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, &ch->video_dev->flags);
                ch->video_dev->lock = &common->lock;
                /* Initialize prio member of channel object */
                v4l2_prio_init(&ch->prio);
-- 
1.7.10

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