ocfs2: use i_size_read() to access i_size

Though ocfs2 uses inode->i_mutex to protect i_size, there are both
i_size_read/write() and direct accesses.  Clean up all direct access to
eliminate confusion.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 452068b..4159285 100644
--- a/fs/ocfs2/move_extents.c
+++ b/fs/ocfs2/move_extents.c
@@ -845,7 +845,7 @@
 	struct ocfs2_move_extents *range = context->range;
 	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 
-	if ((inode->i_size == 0) || (range->me_len == 0))
+	if ((i_size_read(inode) == 0) || (range->me_len == 0))
 		return 0;
 
 	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)