Re: [Linaro-mm-sig] [PATCH v3] dma-buf: add ref counting for module as exporter

On Fri, May 08, 2015 at 07:12:43PM +0530, Sumit Semwal wrote:

Add reference counting on a kernel module that exports dma-buf and implements its operations. This prevents the module from being unloaded while DMABUF file is in use.

The original patch [1] was submitted by Tomasz Stanislawski, but this is a simpler way to do it.

v3: call module_put() as late as possible, per gregkh's comment. v2: move owner to struct dma_buf, and use DEFINE_DMA_BUF_EXPORT_INFO macro to simplify the change.

Signed-off-by: Sumit Semwal sumit.semwal@linaro.org

[1]: https://lkml.org/lkml/2012/8/8/163

drivers/dma-buf/dma-buf.c | 10 +++++++++- include/linux/dma-buf.h | 10 ++++++++-- 2 files changed, 17 insertions(+), 3 deletions(-)

Acked-by: Greg Kroah-Hartman gregkh@linuxfoundation.org