[RFC PATCH 23/26] fimc-capture.c: 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/s5p-fimc/fimc-capture.c |   36 +++++++++++++++++++--------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/media/video/s5p-fimc/fimc-capture.c 
b/drivers/media/video/s5p-fimc/fimc-capture.c
index 62ce539..62045dc 100644
--- a/drivers/media/video/s5p-fimc/fimc-capture.c
+++ b/drivers/media/video/s5p-fimc/fimc-capture.c
@@ -479,17 +479,22 @@ static int fimc_capture_set_default_format(struct 
fimc_dev *fimc);
 static int fimc_capture_open(struct file *file)
 {
        struct fimc_dev *fimc = video_drvdata(file);
-       int ret = v4l2_fh_open(file);
+       int ret;
+
+       /* Return if the corresponding video mem2mem node is already opened. */
+       if (fimc_m2m_active(fimc))
+               return -EBUSY;
 
+       ret = v4l2_fh_open(file);
        if (ret)
                return ret;
 
        dbg("pid: %d, state: 0x%lx", task_pid_nr(current), fimc->state);
 
-       /* Return if the corresponding video mem2mem node is already opened. */
-       if (fimc_m2m_active(fimc))
-               return -EBUSY;
-
+       if (mutex_lock_interruptible(&fimc->lock)) {
+               v4l2_fh_release(file);
+               return -ERESTARTSYS;
+       }
        set_bit(ST_CAPT_BUSY, &fimc->state);
        pm_runtime_get_sync(&fimc->pdev->dev);
 
@@ -503,6 +508,7 @@ static int fimc_capture_open(struct file *file)
                        fimc->vid_cap.refcnt--;
                        v4l2_fh_release(file);
                        clear_bit(ST_CAPT_BUSY, &fimc->state);
+                       mutex_unlock(&fimc->lock);
                        return ret;
                }
                ret = fimc_capture_ctrls_create(fimc);
@@ -510,6 +516,7 @@ static int fimc_capture_open(struct file *file)
                if (!ret && !fimc->vid_cap.user_subdev_api)
                        ret = fimc_capture_set_default_format(fimc);
        }
+       mutex_unlock(&fimc->lock);
        return ret;
 }
 
@@ -519,6 +526,7 @@ static int fimc_capture_close(struct file *file)
 
        dbg("pid: %d, state: 0x%lx", task_pid_nr(current), fimc->state);
 
+       mutex_lock(&fimc->lock);
        if (--fimc->vid_cap.refcnt == 0) {
                clear_bit(ST_CAPT_BUSY, &fimc->state);
                fimc_stop_capture(fimc, false);
@@ -532,6 +540,7 @@ static int fimc_capture_close(struct file *file)
                vb2_queue_release(&fimc->vid_cap.vbq);
                fimc_ctrls_delete(fimc->vid_cap.ctx);
        }
+       mutex_unlock(&fimc->lock);
        return v4l2_fh_release(file);
 }
 
@@ -539,15 +548,24 @@ static unsigned int fimc_capture_poll(struct file *file,
                                      struct poll_table_struct *wait)
 {
        struct fimc_dev *fimc = video_drvdata(file);
+       unsigned res;
 
-       return vb2_poll(&fimc->vid_cap.vbq, file, wait);
+       mutex_lock(&fimc->lock);
+       res = vb2_poll(&fimc->vid_cap.vbq, file, wait);
+       mutex_unlock(&fimc->lock);
+       return res;
 }
 
 static int fimc_capture_mmap(struct file *file, struct vm_area_struct *vma)
 {
        struct fimc_dev *fimc = video_drvdata(file);
+       int ret;
 
-       return vb2_mmap(&fimc->vid_cap.vbq, vma);
+       if (mutex_lock_interruptible(&fimc->lock))
+               return -ERESTARTSYS;
+       ret = vb2_mmap(&fimc->vid_cap.vbq, vma);
+       mutex_unlock(&fimc->lock);
+       return ret;
 }
 
 static const struct v4l2_file_operations fimc_capture_fops = {
@@ -1590,10 +1608,6 @@ static int fimc_register_capture_device(struct fimc_dev 
*fimc,
        vfd->minor      = -1;
        vfd->release    = video_device_release;
        vfd->lock       = &fimc->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);
        video_set_drvdata(vfd, fimc);
 
        vid_cap = &fimc->vid_cap;
-- 
1.7.10

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