There will be a memory leak in the function alloc_ring when the parameter
sw_size is nonzero and metadata is NULL. I don't know if that can happen.

Here is the code, taken from the latest git tree.

static void *alloc_ring(struct pci_dev *pdev, size_t nelem, size_t elem_size,
                        size_t sw_size, dma_addr_t * phys, void *metadata)

It might make sense to stick a WARN_ON(sw_size && !metadata) in that
function or something like that, but a quick audit of the current code
(there are only 4 callers of alloc_ring() in that file -- and it's
static so we know those are all of them -- all in t3_sge_alloc_qset())
shows that all callers pass non-NULL metadata if sw_size != 0.

 - R.