From: Hans Verkuil <hans.verk...@cisco.com>
Add media_request_find() to find a request based on the file
descriptor.
The caller has to call media_request_put() for the returned
request since this function increments the refcount.
Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
---
drivers/media/media-request.c | 47 +++++++++++++++++++++++++++++++++++++++++++
include/media/media-request.h | 9 +++++++++
2 files changed, 56 insertions(+)
diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
index 3ee3b27fd644..d54fd353d8a6 100644
--- a/drivers/media/media-request.c
+++ b/drivers/media/media-request.c
@@ -194,6 +194,53 @@ static const struct file_operations request_fops = {
.release = media_request_close,
};
+/**
+ * media_request_find - Find a request based on the file descriptor
+ * @mdev: The media device
+ * @request: The request file handle
+ *
+ * Find and return the request associated with the given file descriptor, or
+ * an error if no such request exists.
+ *
+ * When the function returns a request it increases its reference count. The
+ * caller is responsible for releasing the reference by calling
+ * media_request_put() on the request.
+ */
+struct media_request *
+media_request_find(struct media_device *mdev, int request_fd)
+{
+ struct file *filp;
+ struct media_request *req;
+
+ if (!mdev || !mdev->ops || !mdev->ops->req_queue)
+ return ERR_PTR(-ENOENT);
+
+ filp = fget(request_fd);
+ if (!filp)
+ return ERR_PTR(-ENOENT);
+
+ if (filp->f_op != &request_fops)
+ goto err_fput;
+ req = filp->private_data;
+ media_request_get(req);
+
+ if (req->mdev != mdev)
+ goto err_kref_put;
+
+ fput(filp);
+
+ return req;
+
+err_kref_put:
+ media_request_put(req);
+
+err_fput:
+ fput(filp);
+
+ return ERR_PTR(-EBADF);
+}
+EXPORT_SYMBOL_GPL(media_request_find);
+
int media_request_alloc(struct media_device *mdev,
struct media_request_alloc *alloc)
{
diff --git a/include/media/media-request.h b/include/media/media-request.h
index baed99eb1279..c01b05570a31 100644
--- a/include/media/media-request.h
+++ b/include/media/media-request.h
@@ -57,6 +57,9 @@ static inline void media_request_get(struct media_request
*req)
void media_request_put(struct media_request *req);
+struct media_request *
+media_request_find(struct media_device *mdev, int request_fd);
+
int media_request_alloc(struct media_device *mdev,
struct media_request_alloc *alloc);
#else
@@ -67,6 +70,12 @@ static inline void media_request_get(struct media_request
*req)
static inline void media_request_put(struct media_request *req)
{
}
+
+static inline struct media_request *
+media_request_find(struct media_device *mdev, int request_fd)
+{
+ return ERR_PTR(-ENOENT);
+}
#endif
struct media_request_object_ops {
--
2.16.1
