gfs2: Minor gfs2_page_add_databufs cleanup

The to parameter of gfs2_page_add_databufs is passed inconsistently:
once as from + len, once as from + len - 1.  Just pass len instead.

In addition, once we're past the end, we can immediately break out of
the loop.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 38e403a9e543..ac4a1e89da1e 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -39,18 +39,21 @@
 
 
 static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
-                                   unsigned int from, unsigned int to)
+                                   unsigned int from, unsigned int len)
 {
         struct buffer_head *head = page_buffers(page);
         unsigned int bsize = head->b_size;
         struct buffer_head *bh;
+        unsigned int to = from + len;
         unsigned int start, end;
 
         for (bh = head, start = 0; bh != head || !start;
              bh = bh->b_this_page, start = end) {
                 end = start + bsize;
-                if (end <= from || start >= to)
+                if (end <= from)
                         continue;
+                if (start >= to)
+                        break;
                 if (gfs2_is_jdata(ip))
                         set_buffer_uptodate(bh);
                 gfs2_trans_add_data(ip->i_gl, bh);
@@ -189,7 +192,7 @@ static int __gfs2_jdata_writepage(struct page *page, struct writeback_control *w
                         create_empty_buffers(page, inode->i_sb->s_blocksize,
                                              BIT(BH_Dirty)|BIT(BH_Uptodate));
                 }
-                gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize-1);
+                gfs2_page_add_databufs(ip, page, 0, sdp->sd_vfs->s_blocksize);
         }
         return gfs2_write_full_page(page, gfs2_get_block_noalloc, wbc);
 }
@@ -889,8 +892,6 @@ static int gfs2_write_end(struct file *file, struct address_space *mapping,
         struct gfs2_sbd *sdp = GFS2_SB(inode);
         struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
         struct buffer_head *dibh;
-        unsigned int from = pos & (PAGE_SIZE - 1);
-        unsigned int to = from + len;
         int ret;
         struct gfs2_trans *tr = current->journal_info;
         BUG_ON(!tr);
@@ -908,7 +909,7 @@ static int gfs2_write_end(struct file *file, struct address_space *mapping,
                 return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page);
 
         if (!gfs2_is_writeback(ip))
-                gfs2_page_add_databufs(ip, page, from, to);
+                gfs2_page_add_databufs(ip, page, pos & ~PAGE_MASK, len);
 
         ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
         if (tr->tr_num_buf_new)