To support device hotplug and migrating a connection between devices
of different capabilities, we have to guarantee that all in-kernel
devices can support the same max NFS payload size (1 megabyte).
This means that possibly one or two in-tree devices are no longer
supported for NFS/RDMA because they cannot support 1MB rsize/wsize.
The only one I confirmed was cxgb3, but it has already been removed
from the kernel.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
net/sunrpc/xprtrdma/frwr_ops.c | 40 +++++++++++++++------------------------
net/sunrpc/xprtrdma/rpc_rdma.c | 2 +-
net/sunrpc/xprtrdma/transport.c | 14 ++++----------
net/sunrpc/xprtrdma/verbs.c | 4 ++--
net/sunrpc/xprtrdma/xprt_rdma.h | 3 +--
5 files changed, 23 insertions(+), 40 deletions(-)
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index 24b8b75d0d49..f31ff54bb266 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -171,7 +171,7 @@ int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr)
* ep->rep_attr.cap.max_send_wr
* ep->rep_attr.cap.max_recv_wr
* ep->rep_max_requests
- * ia->ri_max_segs
+ * ia->ri_max_rdma_segs
*
* And these FRWR-related fields:
* ia->ri_max_frwr_depth
@@ -202,14 +202,12 @@ int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep)
* capability, but perform optimally when the MRs are not larger
* than a page.
*/
- if (attrs->max_sge_rd > 1)
+ if (attrs->max_sge_rd > RPCRDMA_MAX_HDR_SEGS)
ia->ri_max_frwr_depth = attrs->max_sge_rd;
else
ia->ri_max_frwr_depth = attrs->max_fast_reg_page_list_len;
if (ia->ri_max_frwr_depth > RPCRDMA_MAX_DATA_SEGS)
ia->ri_max_frwr_depth = RPCRDMA_MAX_DATA_SEGS;
- dprintk("RPC: %s: max FR page list depth = %u\n",
- __func__, ia->ri_max_frwr_depth);
/* Add room for frwr register and invalidate WRs.
* 1. FRWR reg WR for head
@@ -253,30 +251,22 @@ int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep)
ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
ep->rep_attr.cap.max_recv_wr += 1; /* for ib_drain_rq */
- ia->ri_max_segs =
+ ia->ri_max_rdma_segs =
DIV_ROUND_UP(RPCRDMA_MAX_DATA_SEGS, ia->ri_max_frwr_depth);
/* Reply chunks require segments for head and tail buffers */
- ia->ri_max_segs += 2;
- if (ia->ri_max_segs > RPCRDMA_MAX_HDR_SEGS)
- ia->ri_max_segs = RPCRDMA_MAX_HDR_SEGS;
- return 0;
-}
-
-/**
- * frwr_maxpages - Compute size of largest payload
- * @r_xprt: transport
- *
- * Returns maximum size of an RPC message, in pages.
- *
- * FRWR mode conveys a list of pages per chunk segment. The
- * maximum length of that list is the FRWR page list depth.
- */
-size_t frwr_maxpages(struct rpcrdma_xprt *r_xprt)
-{
- struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+ ia->ri_max_rdma_segs += 2;
+ if (ia->ri_max_rdma_segs > RPCRDMA_MAX_HDR_SEGS)
+ ia->ri_max_rdma_segs = RPCRDMA_MAX_HDR_SEGS;
+
+ /* Ensure the underlying device is capable of conveying the
+ * largest r/wsize NFS will ask for. This guarantees that
+ * failing over from one RDMA device to another will not
+ * break NFS I/O.
+ */
+ if ((ia->ri_max_rdma_segs * ia->ri_max_frwr_depth) < RPCRDMA_MAX_SEGS)
+ return -ENOMEM;
- return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
- (ia->ri_max_segs - 2) * ia->ri_max_frwr_depth);
+ return 0;
}
/**
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 520323ddc930..c6dcea06c754 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -111,7 +111,7 @@ static unsigned int rpcrdma_max_reply_header_size(unsigned int maxsegs)
*/
void rpcrdma_set_max_header_sizes(struct rpcrdma_xprt *r_xprt)
{
- unsigned int maxsegs = r_xprt->rx_ia.ri_max_segs;
+ unsigned int maxsegs = r_xprt->rx_ia.ri_max_rdma_segs;
struct rpcrdma_ep *ep = &r_xprt->rx_ep;
ep->rep_max_inline_send =
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index f868a75057ad..3cfeba68ee9a 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -359,19 +359,13 @@ xprt_setup_rdma(struct xprt_create *args)
if (rc)
goto out3;
- INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
- xprt_rdma_connect_worker);
-
- xprt->max_payload = frwr_maxpages(new_xprt);
- if (xprt->max_payload == 0)
- goto out4;
- xprt->max_payload <<= PAGE_SHIFT;
- dprintk("RPC: %s: transport data payload maximum: %zu bytes\n",
- __func__, xprt->max_payload);
-
if (!try_module_get(THIS_MODULE))
goto out4;
+ INIT_DELAYED_WORK(&new_xprt->rx_connect_worker,
+ xprt_rdma_connect_worker);
+ xprt->max_payload = RPCRDMA_MAX_DATA_SEGS << PAGE_SHIFT;
+
dprintk("RPC: %s: %s:%s\n", __func__,
xprt->address_strings[RPC_DISPLAY_ADDR],
xprt->address_strings[RPC_DISPLAY_PORT]);
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 4f9595b72888..601a1bd56260 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -935,7 +935,7 @@ rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
unsigned int count;
- for (count = 0; count < ia->ri_max_segs; count++) {
+ for (count = 0; count < ia->ri_max_rdma_segs; count++) {
struct rpcrdma_mr *mr;
int rc;
@@ -1017,7 +1017,7 @@ struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
/* Compute maximum header buffer size in bytes */
maxhdrsize = rpcrdma_fixed_maxsz + 3 +
- r_xprt->rx_ia.ri_max_segs * rpcrdma_readchunk_maxsz;
+ r_xprt->rx_ia.ri_max_rdma_segs * rpcrdma_readchunk_maxsz;
maxhdrsize *= sizeof(__be32);
rb = rpcrdma_regbuf_alloc(__roundup_pow_of_two(maxhdrsize),
DMA_TO_DEVICE, flags);
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 0fde694144f5..aac4cf959c3a 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -71,7 +71,7 @@ struct rpcrdma_ia {
struct rdma_cm_id *ri_id;
struct ib_pd *ri_pd;
int ri_async_rc;
- unsigned int ri_max_segs;
+ unsigned int ri_max_rdma_segs;
unsigned int ri_max_frwr_depth;
bool ri_implicit_roundup;
enum ib_mr_type ri_mrtype;
@@ -539,7 +539,6 @@ void frwr_reset(struct rpcrdma_req *req);
int frwr_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep);
int frwr_init_mr(struct rpcrdma_ia *ia, struct rpcrdma_mr *mr);
void frwr_release_mr(struct rpcrdma_mr *mr);
-size_t frwr_maxpages(struct rpcrdma_xprt *r_xprt);
struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt,
struct rpcrdma_mr_seg *seg,
int nsegs, bool writing, __be32 xid,
