From: Chuck Lever <chuck.lever@oracle.com>
Date: Wed, 26 Aug 2015 20:27:00 +0000 (-0600)
Subject: svcrdma: Add svc_rdma_get_context() API that is allowed to fail
X-Git-Tag: v4.1.12-92~278^2^2~3
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=15b3ea37334ca66abb9106168cdc761538847cde;p=users%2Fjedix%2Flinux-maple.git

svcrdma: Add svc_rdma_get_context() API that is allowed to fail

[ Proposed for v4.4 ]

To support backward direction calls, I'm going to add an
svc_rdma_get_context() call in the client RDMA transport.

Called from ->buf_alloc(), we can't sleep waiting for memory.
So add an API that can get a server op_ctxt but won't sleep.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index a91f760254d9e..ae58283775228 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -223,6 +223,8 @@ extern void svc_rdma_send_error(struct svcxprt_rdma *, struct rpcrdma_msg *,
 extern int svc_rdma_post_recv(struct svcxprt_rdma *);
 extern int svc_rdma_create_listen(struct svc_serv *, int, struct sockaddr *);
 extern struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *);
+extern struct svc_rdma_op_ctxt *svc_rdma_get_context_gfp(struct svcxprt_rdma *,
+							 gfp_t);
 extern void svc_rdma_put_context(struct svc_rdma_op_ctxt *, int);
 extern void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt);
 extern struct svc_rdma_req_map *svc_rdma_get_req_map(void);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index e35cf9c5fe813..bc8b46e49638d 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -153,17 +153,35 @@ static void svc_rdma_bc_free(struct svc_xprt *xprt)
 }
 #endif	/* CONFIG_SUNRPC_BACKCHANNEL */
 
-struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
+static void svc_rdma_init_context(struct svcxprt_rdma *xprt,
+				  struct svc_rdma_op_ctxt *ctxt)
 {
-	struct svc_rdma_op_ctxt *ctxt;
-
-	ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep,
-				GFP_KERNEL | __GFP_NOFAIL);
 	ctxt->xprt = xprt;
 	INIT_LIST_HEAD(&ctxt->dto_q);
 	ctxt->count = 0;
 	ctxt->frmr = NULL;
 	atomic_inc(&xprt->sc_ctxt_used);
+}
+
+struct svc_rdma_op_ctxt *svc_rdma_get_context_gfp(struct svcxprt_rdma *xprt,
+						  gfp_t flags)
+{
+	struct svc_rdma_op_ctxt *ctxt;
+
+	ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep, flags);
+	if (!ctxt)
+		return NULL;
+	svc_rdma_init_context(xprt, ctxt);
+	return ctxt;
+}
+
+struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
+{
+	struct svc_rdma_op_ctxt *ctxt;
+
+	ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep,
+				GFP_KERNEL | __GFP_NOFAIL);
+	svc_rdma_init_context(xprt, ctxt);
 	return ctxt;
 }