[PATCH 4/4] dma-buf: document fd flags and O_CLOEXEC requirement

[Daniel Vetter <daniel.vetter@ffwll.ch>]

Otherwise subsystems will get this wrong and end up with and second
export ioctl with the flag and O_CLOEXEC support added.

Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 Documentation/dma-buf-sharing.txt |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt
index 9f3aeef..087e261 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -319,6 +319,11 @@ Miscellaneous notes
 - Any exporters or users of the dma-buf buffer sharing framework must have
   a 'select DMA_SHARED_BUFFER' in their respective Kconfigs.
 
+- To avoid the wrath of userspace library writers exporting subsystems must have
+  a flag parameter in the ioctl that creates the dma-buf fd which needs to
+  support at least the O_CLOEXEC fd flag. This needs to be passed in the flag
+  parameter of dma_buf_export.
+
 References:
 [1] struct dma_buf_ops in include/linux/dma-buf.h
 [2] All interfaces mentioned above defined in include/linux/dma-buf.h
-- 
1.7.7.5