staging/lustre/llite: clip page correctly for vvp_io_commit_sync

The original code was wrong which clipped page incorrectly for
partial pages started with zero.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-on: http://review.whamcloud.com/8531
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4201
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: wangdi <di.wang@intel.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lustre/llite/vvp_io.c b/drivers/staging/lustre/lustre/llite/vvp_io.c
index fb6f932..e44ef21 100644 (file)
--- a/drivers/staging/lustre/lustre/llite/vvp_io.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_io.c
@@ -595,15 +595,17 @@ static int vvp_io_commit_sync(const struct lu_env *env, struct cl_io *io,
        if (plist->pl_nr == 0)
                return 0;
 
-       if (from != 0) {
+       if (from > 0 || to != PAGE_SIZE) {
                page = cl_page_list_first(plist);
-               cl_page_clip(env, page, from,
-                            plist->pl_nr == 1 ? to : PAGE_SIZE);
-       }
-       if (to != PAGE_SIZE && plist->pl_nr > 1) {
+               if (plist->pl_nr == 1) {
+                       cl_page_clip(env, page, from, to);
+               } else if (from > 0) {
+                       cl_page_clip(env, page, from, PAGE_SIZE);
+               } else {
                page = cl_page_list_last(plist);
                cl_page_clip(env, page, 0, to);
        }
+       }
 
        cl_2queue_init(queue);
        cl_page_list_splice(plist, &queue->c2_qin);