[XFS] Add ail pointer into log items

Add an xfs_ail pointer to log items so that the log items can reference
the AIL directly during callbacks without needed a struct xfs_mount.

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32352a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index ae2ae3e..0df5154 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -768,6 +768,7 @@
 	xfs_lsn_t			li_lsn;		/* last on-disk lsn */
 	struct xfs_log_item_desc	*li_desc;	/* ptr to current desc*/
 	struct xfs_mount		*li_mountp;	/* ptr to fs mount */
+	struct xfs_ail			*li_ailp;	/* ptr to AIL */
 	uint				li_type;	/* item type */
 	uint				li_flags;	/* misc flags */
 	struct xfs_log_item		*li_bio_list;	/* buffer item list */