On Mon, Nov 11, 2013 at 12:57:47AM -0800, Thomas Hellstrom wrote: > Resending since it appears this RFC never got to the dri-devel lkml lists. > > In this context, a "doomed" object is an object whose refcount has reached > zero, but that has not yet been freed. > > To avoid mutual refcounting vmwgfx need to have a non-refcounted pointer to > a dma-buf in a lookup structure. The pointer is removed in the dma-buf > destructor. To allow lookup-structure private locks we need > get_dma_buf_unless_doomed(). This common refcounting scenario is described > with examples in detail in the kref documentaion. > The solution with local locks is under kref_get_unless_zero(). > See also kobject_get_unless_zero() and its commit message. > Since dma-bufs are using the attached file for refcounting, > get_dma_buf_unless_doomed maps directly to a get_file_unless_doomed.
NAK for struct file. This kind of stuff is for implementing primitives, not as a public API. BTW, as for dmabuf... dma_buf_fd() calling conventions are seriously misguided - we are trying to transfer the reference we hold into something (in this case - descriptor table), so the failure exit should be dropping the reference, not leaving that to caller. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
