svcrdma: Return error from rdma_read_xdr so caller knows to free context
The rdma_read_xdr function did not discriminate between no read-list and
an error posting the read-list. This results in a leak of a page if there
is an error posting the read-list.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index f3a108a..5e03d95 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -260,11 +260,16 @@
* On our side, we need to read into a pagelist. The first page immediately
* follows the RPC header.
*
- * This function returns 1 to indicate success. The data is not yet in
+ * This function returns:
+ * 0 - No error and no read-list found.
+ *
+ * 1 - Successful read-list processing. The data is not yet in
* the pagelist and therefore the RPC request must be deferred. The
* I/O completion will enqueue the transport again and
* svc_rdma_recvfrom will complete the request.
*
+ * <0 - Error processing/posting read-list.
+ *
* NOTE: The ctxt must not be touched after the last WR has been posted
* because the I/O completion processing may occur on another
* processor and free / modify the context. Ne touche pas!
@@ -398,7 +403,7 @@
svc_rdma_put_context(head, 1);
head = ctxt;
}
- return 0;
+ return err;
}
return 1;
@@ -532,14 +537,18 @@
goto close_out;
}
- /* Read read-list data. If we would need to wait, defer
- * it. Not that in this case, we don't return the RQ credit
- * until after the read completes.
- */
- if (rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt)) {
+ /* Read read-list data. */
+ ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt);
+ if (ret > 0) {
+ /* read-list posted, defer until data received from client. */
svc_xprt_received(xprt);
return 0;
}
+ if (ret < 0) {
+ /* Post of read-list failed, free context. */
+ svc_rdma_put_context(ctxt, 1);
+ return 0;
+ }
ret = rqstp->rq_arg.head[0].iov_len
+ rqstp->rq_arg.page_len