ext3: Use bitops to read/modify EXT3_I(inode)->i_state

At several places we modify EXT3_I(inode)->i_state without holding i_mutex
(ext3_release_file, ext3_bmap, ext3_journalled_writepage, ext3_do_update_inode,
...). These modifications are racy and we can lose updates to i_state. So
convert handling of i_state to use bitops which are atomic.

Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext3/file.c b/fs/ext3/file.c
index 388bbdf..a86d330 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -33,9 +33,9 @@
  */
 static int ext3_release_file (struct inode * inode, struct file * filp)
 {
-	if (EXT3_I(inode)->i_state & EXT3_STATE_FLUSH_ON_CLOSE) {
+	if (ext3_test_inode_state(inode, EXT3_STATE_FLUSH_ON_CLOSE)) {
 		filemap_flush(inode->i_mapping);
-		EXT3_I(inode)->i_state &= ~EXT3_STATE_FLUSH_ON_CLOSE;
+		ext3_clear_inode_state(inode, EXT3_STATE_FLUSH_ON_CLOSE);
 	}
 	/* if we are the last writer on the inode, drop the block reservation */
 	if ((filp->f_mode & FMODE_WRITE) &&