[PATCH v2 02/10] sunrpc: Add a helper to derive maxpages from sv_max_mesg

[cel@kernel.org]

From: Chuck Lever <chuck.lever@oracle.com>

This page count is to be used to allocate various arrays of pages,
bio_vecs, and kvecs, replacing the fixed RPCSVC_MAXPAGES value.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 include/linux/sunrpc/svc.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 74658cca0f38..5b879c31d7b8 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -159,6 +159,18 @@ extern u32 svc_max_payload(const struct svc_rqst *rqstp);
 #define RPCSVC_MAXPAGES		((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \
 				+ 2 + 1)
 
+/**
+ * svc_serv_maxpages - maximum pages/kvecs needed for one RPC message
+ * @serv: RPC service context
+ *
+ * Returns a count of pages or vectors that can hold the maximum
+ * size RPC message for @serv.
+ */
+static inline unsigned long svc_serv_maxpages(const struct svc_serv *serv)
+{
+	return ((serv->sv_max_mesg + PAGE_SIZE - 1) >> PAGE_SHIFT) + 2 + 1;
+}
+
 /*
  * The context of a single thread, including the request currently being
  * processed.
-- 
2.49.0