nfs: modify pg_test interface to return size_t
This is a step toward allowing pg_test to inform the the
coalescing code to reduce the size of requests so they may fit in
whatever scheme the pg_test callback wants to define.
For now, just return the size of the request if there is space, or 0
if there is not. This shouldn't change any behavior as it acts
the same as when the pg_test functions returned bool.
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/objlayout/objio_osd.c b/fs/nfs/objlayout/objio_osd.c
index 426b366..71b9c69 100644
--- a/fs/nfs/objlayout/objio_osd.c
+++ b/fs/nfs/objlayout/objio_osd.c
@@ -564,14 +564,19 @@
return 0;
}
-static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
+/*
+ * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
+ * of bytes (maximum @req->wb_bytes) that can be coalesced.
+ */
+static size_t objio_pg_test(struct nfs_pageio_descriptor *pgio,
struct nfs_page *prev, struct nfs_page *req)
{
- if (!pnfs_generic_pg_test(pgio, prev, req))
- return false;
+ if (!pnfs_generic_pg_test(pgio, prev, req) ||
+ pgio->pg_count + req->wb_bytes >
+ (unsigned long)pgio->pg_layout_private)
+ return 0;
- return pgio->pg_count + req->wb_bytes <=
- (unsigned long)pgio->pg_layout_private;
+ return req->wb_bytes;
}
static void objio_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)