svcrdma: Change DMA mapping logic to avoid the page_address kernel API
There was logic in the send path that assumed that a page containing data
to send to the client has a KVA. This is not always the case and can result
in data corruption when page_address returns zero and we end up DMA mapping
zero.
This patch changes the bus mapping logic to avoid page_address() where
necessary and converts all calls from ib_dma_map_single to ib_dma_map_page
in order to keep the map/unmap calls symmetric.
Signed-off-by: Tom Tucker <tom@ogc.us>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 0194de8..926bdb4 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -263,9 +263,9 @@
frmr->page_list_len = PAGE_ALIGN(byte_count) >> PAGE_SHIFT;
for (page_no = 0; page_no < frmr->page_list_len; page_no++) {
frmr->page_list->page_list[page_no] =
- ib_dma_map_single(xprt->sc_cm_id->device,
- page_address(rqstp->rq_arg.pages[page_no]),
- PAGE_SIZE, DMA_FROM_DEVICE);
+ ib_dma_map_page(xprt->sc_cm_id->device,
+ rqstp->rq_arg.pages[page_no], 0,
+ PAGE_SIZE, DMA_FROM_DEVICE);
if (ib_dma_mapping_error(xprt->sc_cm_id->device,
frmr->page_list->page_list[page_no]))
goto fatal_err;
@@ -309,17 +309,21 @@
int count)
{
int i;
+ unsigned long off;
ctxt->count = count;
ctxt->direction = DMA_FROM_DEVICE;
for (i = 0; i < count; i++) {
ctxt->sge[i].length = 0; /* in case map fails */
if (!frmr) {
+ BUG_ON(0 == virt_to_page(vec[i].iov_base));
+ off = (unsigned long)vec[i].iov_base & ~PAGE_MASK;
ctxt->sge[i].addr =
- ib_dma_map_single(xprt->sc_cm_id->device,
- vec[i].iov_base,
- vec[i].iov_len,
- DMA_FROM_DEVICE);
+ ib_dma_map_page(xprt->sc_cm_id->device,
+ virt_to_page(vec[i].iov_base),
+ off,
+ vec[i].iov_len,
+ DMA_FROM_DEVICE);
if (ib_dma_mapping_error(xprt->sc_cm_id->device,
ctxt->sge[i].addr))
return -EINVAL;