From 6736f4e948817ca8385bdc6feb5475cdf1eb1ec8 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Mon, 27 Aug 2018 11:10:38 -0400 Subject: media: media-request: add media_request_(un)lock_for_access Add helper functions to prevent a completed request from being re-inited while it is being accessed. Signed-off-by: Hans Verkuil Reviewed-by: Tomasz Figa Acked-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/media-request.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/media/media-request.c') diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c index 4cee67e6657e..414197645e09 100644 --- a/drivers/media/media-request.c +++ b/drivers/media/media-request.c @@ -43,6 +43,7 @@ static void media_request_clean(struct media_request *req) /* Just a sanity check. No other code path is allowed to change this. */ WARN_ON(req->state != MEDIA_REQUEST_STATE_CLEANING); WARN_ON(req->updating_count); + WARN_ON(req->access_count); list_for_each_entry_safe(obj, obj_safe, &req->objects, list) { media_request_object_unbind(obj); @@ -50,6 +51,7 @@ static void media_request_clean(struct media_request *req) } req->updating_count = 0; + req->access_count = 0; WARN_ON(req->num_incomplete_objects); req->num_incomplete_objects = 0; wake_up_interruptible_all(&req->poll_wait); @@ -198,6 +200,13 @@ static long media_request_ioctl_reinit(struct media_request *req) spin_unlock_irqrestore(&req->lock, flags); return -EBUSY; } + if (req->access_count) { + dev_dbg(mdev->dev, + "request: %s is being accessed, cannot reinit\n", + req->debug_str); + spin_unlock_irqrestore(&req->lock, flags); + return -EBUSY; + } req->state = MEDIA_REQUEST_STATE_CLEANING; spin_unlock_irqrestore(&req->lock, flags); @@ -313,6 +322,7 @@ int media_request_alloc(struct media_device *mdev, int *alloc_fd) spin_lock_init(&req->lock); init_waitqueue_head(&req->poll_wait); req->updating_count = 0; + req->access_count = 0; *alloc_fd = fd; -- cgit v1.2.3