[PATCH v2] sync_file: Return consistent status in SYNC_IOC_FILE_INFO

[Chris Wilson]

Quoting John Einar Reitan (2017-10-09 14:49:36)
> sync_file_ioctl_fence_info has a race between filling the status
> of the underlying fences and the overall status of the sync_file.
> If fence transitions in the time frame between its sync_fill_fence_info
> and the later dma_fence_is_signaled for the sync_file, the returned
> information is inconsistent showing non-signaled underlying fences but
> an overall signaled state.
> 
> This patch changes sync_file_ioctl_fence_info to track what has been
> encoded and using that as the overall sync_file status.
> 
> Tested-by: Vamsidhar Reddy Gaddam <vamsidhar.gaddam at arm.com>
> Signed-off-by: John Einar Reitan <john.reitan at arm.com>
> Cc: Sumit Semwal <sumit.semwal at linaro.org>
> Cc: Gustavo Padovan <gustavo at padovan.org>
> Cc: dri-devel at lists.freedesktop.org
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris