xfs: add log item method to return related intents

To apply a whiteout to an intent item when an intent done item is
committed, we need to be able to retrieve the intent item from the
the intent done item. Add a log item op method for doing this, and
wire all the intent done items up to it.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_bmap_item.c

@@ -203,12 +203,20 @@ xfs_bud_item_release(
 	kmem_cache_free(xfs_bud_cache, budp);
 }
 
+static struct xfs_log_item *
+xfs_bud_item_intent(
+	struct xfs_log_item	*lip)
+{
+	return &BUD_ITEM(lip)->bud_buip->bui_item;
+}
+
 static const struct xfs_item_ops xfs_bud_item_ops = {
 	.flags		= XFS_ITEM_RELEASE_WHEN_COMMITTED |
 			  XFS_ITEM_INTENT_DONE,
 	.iop_size	= xfs_bud_item_size,
 	.iop_format	= xfs_bud_item_format,
 	.iop_release	= xfs_bud_item_release,
+	.iop_intent	= xfs_bud_item_intent,
 };
 
 static struct xfs_bud_log_item *

fs/xfs/xfs_extfree_item.c

@@ -306,12 +306,20 @@ xfs_efd_item_release(
 	xfs_efd_item_free(efdp);
 }
 
+static struct xfs_log_item *
+xfs_efd_item_intent(
+	struct xfs_log_item	*lip)
+{
+	return &EFD_ITEM(lip)->efd_efip->efi_item;
+}
+
 static const struct xfs_item_ops xfs_efd_item_ops = {
 	.flags		= XFS_ITEM_RELEASE_WHEN_COMMITTED |
 			  XFS_ITEM_INTENT_DONE,
 	.iop_size	= xfs_efd_item_size,
 	.iop_format	= xfs_efd_item_format,
 	.iop_release	= xfs_efd_item_release,
+	.iop_intent	= xfs_efd_item_intent,
 };
 
 /*

fs/xfs/xfs_refcount_item.c

@@ -209,12 +209,20 @@ xfs_cud_item_release(
 	kmem_cache_free(xfs_cud_cache, cudp);
 }
 
+static struct xfs_log_item *
+xfs_cud_item_intent(
+	struct xfs_log_item	*lip)
+{
+	return &CUD_ITEM(lip)->cud_cuip->cui_item;
+}
+
 static const struct xfs_item_ops xfs_cud_item_ops = {
 	.flags		= XFS_ITEM_RELEASE_WHEN_COMMITTED |
 			  XFS_ITEM_INTENT_DONE,
 	.iop_size	= xfs_cud_item_size,
 	.iop_format	= xfs_cud_item_format,
 	.iop_release	= xfs_cud_item_release,
+	.iop_intent	= xfs_cud_item_intent,
 };
 
 static struct xfs_cud_log_item *

fs/xfs/xfs_rmap_item.c

@@ -232,12 +232,20 @@ xfs_rud_item_release(
 	kmem_cache_free(xfs_rud_cache, rudp);
 }
 
+static struct xfs_log_item *
+xfs_rud_item_intent(
+	struct xfs_log_item	*lip)
+{
+	return &RUD_ITEM(lip)->rud_ruip->rui_item;
+}
+
 static const struct xfs_item_ops xfs_rud_item_ops = {
 	.flags		= XFS_ITEM_RELEASE_WHEN_COMMITTED |
 			  XFS_ITEM_INTENT_DONE,
 	.iop_size	= xfs_rud_item_size,
 	.iop_format	= xfs_rud_item_format,
 	.iop_release	= xfs_rud_item_release,
+	.iop_intent	= xfs_rud_item_intent,
 };
 
 static struct xfs_rud_log_item *

fs/xfs/xfs_trans.h

@@ -78,6 +78,7 @@ struct xfs_item_ops {
 	bool (*iop_match)(struct xfs_log_item *item, uint64_t id);
 	struct xfs_log_item *(*iop_relog)(struct xfs_log_item *intent,
 			struct xfs_trans *tp);
+	struct xfs_log_item *(*iop_intent)(struct xfs_log_item *intent_done);
 };
 
 /*