[PATCH 6/8] NFSv4.1: define nfs_generic_pg_test

[Boaz Harrosh <bharrosh@panasas.com>]

By default, unless pnfs is used coalesce pages until pg_bsize
(rsize or wsize) is reached.

pnfs layout drivers define their own pg_test methods that use
pnfs_generic_pg_test and need to define their own I/O size
limits (e.g. based on the file stripe size).

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
---
 fs/nfs/pagelist.c |   17 +++++++----------
 1 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 5344371..36bb67f 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -204,6 +204,11 @@ 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)
+{
+	return desc->pg_count + req->wb_bytes <= desc->pg_bsize;
+}
+
 /**
  * nfs_pageio_init - initialise a page io descriptor
  * @desc: pointer to descriptor
@@ -229,7 +234,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
 	desc->pg_ioflags = io_flags;
 	desc->pg_error = 0;
 	desc->pg_lseg = NULL;
-	desc->pg_test = NULL;
+	desc->pg_test = nfs_generic_pg_test;
 	pnfs_pageio_init(desc, inode);
 }
 
@@ -260,13 +265,7 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev,
 		return false;
 	if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE)
 		return false;
-	/*
-	 * Non-whole file layouts need to check that req is inside of
-	 * pgio->pg_lseg.
-	 */
-	if (pgio->pg_test && !pgio->pg_test(pgio, prev, req))
-		return false;
-	return true;
+	return pgio->pg_test(pgio, prev, req);
 }
 
 /**
@@ -295,8 +294,6 @@ static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc,
 		if (desc->pg_bsize < PAGE_SIZE)
 			return 0;
 		newlen += desc->pg_count;
-		if (newlen > desc->pg_bsize)
-			return 0;
 		prev = nfs_list_entry(desc->pg_list.prev);
 		if (!nfs_can_coalesce_requests(prev, req, desc))
 			return 0;
-- 
1.7.2.3