NFSv4.1: file layout must consider pg_bsize for coalescing

Otherwise we end up overflowing the rpc buffer size on the receive end.
Signed-off-by: Benny Halevy <benny@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4filelayout.c

@@ -30,6 +30,7 @@
  */
 
 #include <linux/nfs_fs.h>
+#include <linux/nfs_page.h>
 
 #include "internal.h"
 #include "nfs4filelayout.h"
@@ -666,8 +667,9 @@ filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 	u64 p_stripe, r_stripe;
 	u32 stripe_unit;
 
-	if (!pnfs_generic_pg_test(pgio, prev, req))
-		return 0;
+	if (!pnfs_generic_pg_test(pgio, prev, req) ||
+	    !nfs_generic_pg_test(pgio, prev, req))
+		return false;
 
 	if (!pgio->pg_lseg)
 		return 1;

fs/nfs/pagelist.c

@@ -204,7 +204,7 @@ nfs_wait_on_request(struct nfs_page *req)
 			TASK_UNINTERRUPTIBLE);
 }
 
-static bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
+bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req)
 {
 	/*
 	 * FIXME: ideally we should be able to coalesce all requests
@@ -218,6 +218,7 @@ static bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_p
 
 	return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
 }
+EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
 
 /**
  * nfs_pageio_init - initialise a page io descriptor

include/linux/nfs_page.h

@@ -92,6 +92,9 @@ extern	int nfs_pageio_add_request(struct nfs_pageio_descriptor *,
 				   struct nfs_page *);
 extern	void nfs_pageio_complete(struct nfs_pageio_descriptor *desc);
 extern	void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *, pgoff_t);
+extern bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
+				struct nfs_page *prev,
+				struct nfs_page *req);
 extern  int nfs_wait_on_request(struct nfs_page *);
 extern	void nfs_unlock_request(struct nfs_page *req);
 extern	int nfs_set_page_tag_locked(struct nfs_page *req);