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-rw-r--r--net/sunrpc/xprtrdma/fmr_ops.c2
-rw-r--r--net/sunrpc/xprtrdma/frwr_ops.c2
-rw-r--r--net/sunrpc/xprtrdma/physical_ops.c2
-rw-r--r--net/sunrpc/xprtrdma/verbs.c22
-rw-r--r--net/sunrpc/xprtrdma/xprt_rdma.h21
5 files changed, 23 insertions, 26 deletions
diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
index b289e106540b..4aeb104d0696 100644
--- a/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/net/sunrpc/xprtrdma/fmr_ops.c
@@ -48,7 +48,7 @@ static size_t
fmr_op_maxpages(struct rpcrdma_xprt *r_xprt)
{
return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
- rpcrdma_max_segments(r_xprt) * RPCRDMA_MAX_FMR_SGES);
+ RPCRDMA_MAX_HDR_SEGS * RPCRDMA_MAX_FMR_SGES);
}
static int
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index c250924a9fd3..2f375982abf4 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -243,7 +243,7 @@ frwr_op_maxpages(struct rpcrdma_xprt *r_xprt)
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
- rpcrdma_max_segments(r_xprt) * ia->ri_max_frmr_depth);
+ RPCRDMA_MAX_HDR_SEGS * ia->ri_max_frmr_depth);
}
static void
diff --git a/net/sunrpc/xprtrdma/physical_ops.c b/net/sunrpc/xprtrdma/physical_ops.c
index 481b9b6f4a15..e16ed54d24ed 100644
--- a/net/sunrpc/xprtrdma/physical_ops.c
+++ b/net/sunrpc/xprtrdma/physical_ops.c
@@ -47,7 +47,7 @@ static size_t
physical_op_maxpages(struct rpcrdma_xprt *r_xprt)
{
return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
- rpcrdma_max_segments(r_xprt));
+ RPCRDMA_MAX_HDR_SEGS);
}
static int
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index f5ed9f982cd7..9f8d6c1dc7c6 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1271,25 +1271,3 @@ out_rc:
rpcrdma_recv_buffer_put(rep);
return rc;
}
-
-/* How many chunk list items fit within our inline buffers?
- */
-unsigned int
-rpcrdma_max_segments(struct rpcrdma_xprt *r_xprt)
-{
- struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
- int bytes, segments;
-
- bytes = min_t(unsigned int, cdata->inline_wsize, cdata->inline_rsize);
- bytes -= RPCRDMA_HDRLEN_MIN;
- if (bytes < sizeof(struct rpcrdma_segment) * 2) {
- pr_warn("RPC: %s: inline threshold too small\n",
- __func__);
- return 0;
- }
-
- segments = 1 << (fls(bytes / sizeof(struct rpcrdma_segment)) - 1);
- dprintk("RPC: %s: max chunk list size = %d segments\n",
- __func__, segments);
- return segments;
-}
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 7723e5faff4d..00287486c62c 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -144,6 +144,26 @@ rdmab_to_msg(struct rpcrdma_regbuf *rb)
#define RPCRDMA_DEF_GFP (GFP_NOIO | __GFP_NOWARN)
+/* To ensure a transport can always make forward progress,
+ * the number of RDMA segments allowed in header chunk lists
+ * is capped at 8. This prevents less-capable devices and
+ * memory registrations from overrunning the Send buffer
+ * while building chunk lists.
+ *
+ * Elements of the Read list take up more room than the
+ * Write list or Reply chunk. 8 read segments means the Read
+ * list (or Write list or Reply chunk) cannot consume more
+ * than
+ *
+ * ((8 + 2) * read segment size) + 1 XDR words, or 244 bytes.
+ *
+ * And the fixed part of the header is another 24 bytes.
+ *
+ * The smallest inline threshold is 1024 bytes, ensuring that
+ * at least 750 bytes are available for RPC messages.
+ */
+#define RPCRDMA_MAX_HDR_SEGS (8)
+
/*
* struct rpcrdma_rep -- this structure encapsulates state required to recv
* and complete a reply, asychronously. It needs several pieces of
@@ -456,7 +476,6 @@ struct rpcrdma_regbuf *rpcrdma_alloc_regbuf(struct rpcrdma_ia *,
void rpcrdma_free_regbuf(struct rpcrdma_ia *,
struct rpcrdma_regbuf *);
-unsigned int rpcrdma_max_segments(struct rpcrdma_xprt *);
int rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *, unsigned int);
int frwr_alloc_recovery_wq(void);