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/journal.c b/fs/ocfs2/journal.c
index a126cb3..44fc3e5 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -836,14 +836,14 @@
 	inode_lock = 1;
 	di = (struct ocfs2_dinode *)bh->b_data;
 
-	if (inode->i_size <  OCFS2_MIN_JOURNAL_SIZE) {
+	if (i_size_read(inode) <  OCFS2_MIN_JOURNAL_SIZE) {
 		mlog(ML_ERROR, "Journal file size (%lld) is too small!\n",
-		     inode->i_size);
+		     i_size_read(inode));
 		status = -EINVAL;
 		goto done;
 	}
 
-	trace_ocfs2_journal_init(inode->i_size,
+	trace_ocfs2_journal_init(i_size_read(inode),
 				 (unsigned long long)inode->i_blocks,
 				 OCFS2_I(inode)->ip_clusters);
 
@@ -1131,7 +1131,7 @@
 
 	memset(bhs, 0, sizeof(struct buffer_head *) * CONCURRENT_JOURNAL_FILL);
 
-	num_blocks = ocfs2_blocks_for_bytes(inode->i_sb, inode->i_size);
+	num_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
 	v_blkno = 0;
 	while (v_blkno < num_blocks) {
 		status = ocfs2_extent_map_get_blocks(inode, v_blkno,