v4.19.13 snapshot.
diff --git a/fs/xfs/xfs_trans_rmap.c b/fs/xfs/xfs_trans_rmap.c
new file mode 100644
index 0000000..05b00e4
--- /dev/null
+++ b/fs/xfs/xfs_trans_rmap.c
@@ -0,0 +1,265 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_trans.h"
+#include "xfs_trans_priv.h"
+#include "xfs_rmap_item.h"
+#include "xfs_alloc.h"
+#include "xfs_rmap.h"
+
+/* Set the map extent flags for this reverse mapping. */
+static void
+xfs_trans_set_rmap_flags(
+	struct xfs_map_extent		*rmap,
+	enum xfs_rmap_intent_type	type,
+	int				whichfork,
+	xfs_exntst_t			state)
+{
+	rmap->me_flags = 0;
+	if (state == XFS_EXT_UNWRITTEN)
+		rmap->me_flags |= XFS_RMAP_EXTENT_UNWRITTEN;
+	if (whichfork == XFS_ATTR_FORK)
+		rmap->me_flags |= XFS_RMAP_EXTENT_ATTR_FORK;
+	switch (type) {
+	case XFS_RMAP_MAP:
+		rmap->me_flags |= XFS_RMAP_EXTENT_MAP;
+		break;
+	case XFS_RMAP_MAP_SHARED:
+		rmap->me_flags |= XFS_RMAP_EXTENT_MAP_SHARED;
+		break;
+	case XFS_RMAP_UNMAP:
+		rmap->me_flags |= XFS_RMAP_EXTENT_UNMAP;
+		break;
+	case XFS_RMAP_UNMAP_SHARED:
+		rmap->me_flags |= XFS_RMAP_EXTENT_UNMAP_SHARED;
+		break;
+	case XFS_RMAP_CONVERT:
+		rmap->me_flags |= XFS_RMAP_EXTENT_CONVERT;
+		break;
+	case XFS_RMAP_CONVERT_SHARED:
+		rmap->me_flags |= XFS_RMAP_EXTENT_CONVERT_SHARED;
+		break;
+	case XFS_RMAP_ALLOC:
+		rmap->me_flags |= XFS_RMAP_EXTENT_ALLOC;
+		break;
+	case XFS_RMAP_FREE:
+		rmap->me_flags |= XFS_RMAP_EXTENT_FREE;
+		break;
+	default:
+		ASSERT(0);
+	}
+}
+
+struct xfs_rud_log_item *
+xfs_trans_get_rud(
+	struct xfs_trans		*tp,
+	struct xfs_rui_log_item		*ruip)
+{
+	struct xfs_rud_log_item		*rudp;
+
+	rudp = xfs_rud_init(tp->t_mountp, ruip);
+	xfs_trans_add_item(tp, &rudp->rud_item);
+	return rudp;
+}
+
+/*
+ * Finish an rmap update and log it to the RUD. Note that the transaction is
+ * marked dirty regardless of whether the rmap update succeeds or fails to
+ * support the RUI/RUD lifecycle rules.
+ */
+int
+xfs_trans_log_finish_rmap_update(
+	struct xfs_trans		*tp,
+	struct xfs_rud_log_item		*rudp,
+	enum xfs_rmap_intent_type	type,
+	uint64_t			owner,
+	int				whichfork,
+	xfs_fileoff_t			startoff,
+	xfs_fsblock_t			startblock,
+	xfs_filblks_t			blockcount,
+	xfs_exntst_t			state,
+	struct xfs_btree_cur		**pcur)
+{
+	int				error;
+
+	error = xfs_rmap_finish_one(tp, type, owner, whichfork, startoff,
+			startblock, blockcount, state, pcur);
+
+	/*
+	 * Mark the transaction dirty, even on error. This ensures the
+	 * transaction is aborted, which:
+	 *
+	 * 1.) releases the RUI and frees the RUD
+	 * 2.) shuts down the filesystem
+	 */
+	tp->t_flags |= XFS_TRANS_DIRTY;
+	set_bit(XFS_LI_DIRTY, &rudp->rud_item.li_flags);
+
+	return error;
+}
+
+/* Sort rmap intents by AG. */
+static int
+xfs_rmap_update_diff_items(
+	void				*priv,
+	struct list_head		*a,
+	struct list_head		*b)
+{
+	struct xfs_mount		*mp = priv;
+	struct xfs_rmap_intent		*ra;
+	struct xfs_rmap_intent		*rb;
+
+	ra = container_of(a, struct xfs_rmap_intent, ri_list);
+	rb = container_of(b, struct xfs_rmap_intent, ri_list);
+	return  XFS_FSB_TO_AGNO(mp, ra->ri_bmap.br_startblock) -
+		XFS_FSB_TO_AGNO(mp, rb->ri_bmap.br_startblock);
+}
+
+/* Get an RUI. */
+STATIC void *
+xfs_rmap_update_create_intent(
+	struct xfs_trans		*tp,
+	unsigned int			count)
+{
+	struct xfs_rui_log_item		*ruip;
+
+	ASSERT(tp != NULL);
+	ASSERT(count > 0);
+
+	ruip = xfs_rui_init(tp->t_mountp, count);
+	ASSERT(ruip != NULL);
+
+	/*
+	 * Get a log_item_desc to point at the new item.
+	 */
+	xfs_trans_add_item(tp, &ruip->rui_item);
+	return ruip;
+}
+
+/* Log rmap updates in the intent item. */
+STATIC void
+xfs_rmap_update_log_item(
+	struct xfs_trans		*tp,
+	void				*intent,
+	struct list_head		*item)
+{
+	struct xfs_rui_log_item		*ruip = intent;
+	struct xfs_rmap_intent		*rmap;
+	uint				next_extent;
+	struct xfs_map_extent		*map;
+
+	rmap = container_of(item, struct xfs_rmap_intent, ri_list);
+
+	tp->t_flags |= XFS_TRANS_DIRTY;
+	set_bit(XFS_LI_DIRTY, &ruip->rui_item.li_flags);
+
+	/*
+	 * atomic_inc_return gives us the value after the increment;
+	 * we want to use it as an array index so we need to subtract 1 from
+	 * it.
+	 */
+	next_extent = atomic_inc_return(&ruip->rui_next_extent) - 1;
+	ASSERT(next_extent < ruip->rui_format.rui_nextents);
+	map = &ruip->rui_format.rui_extents[next_extent];
+	map->me_owner = rmap->ri_owner;
+	map->me_startblock = rmap->ri_bmap.br_startblock;
+	map->me_startoff = rmap->ri_bmap.br_startoff;
+	map->me_len = rmap->ri_bmap.br_blockcount;
+	xfs_trans_set_rmap_flags(map, rmap->ri_type, rmap->ri_whichfork,
+			rmap->ri_bmap.br_state);
+}
+
+/* Get an RUD so we can process all the deferred rmap updates. */
+STATIC void *
+xfs_rmap_update_create_done(
+	struct xfs_trans		*tp,
+	void				*intent,
+	unsigned int			count)
+{
+	return xfs_trans_get_rud(tp, intent);
+}
+
+/* Process a deferred rmap update. */
+STATIC int
+xfs_rmap_update_finish_item(
+	struct xfs_trans		*tp,
+	struct list_head		*item,
+	void				*done_item,
+	void				**state)
+{
+	struct xfs_rmap_intent		*rmap;
+	int				error;
+
+	rmap = container_of(item, struct xfs_rmap_intent, ri_list);
+	error = xfs_trans_log_finish_rmap_update(tp, done_item,
+			rmap->ri_type,
+			rmap->ri_owner, rmap->ri_whichfork,
+			rmap->ri_bmap.br_startoff,
+			rmap->ri_bmap.br_startblock,
+			rmap->ri_bmap.br_blockcount,
+			rmap->ri_bmap.br_state,
+			(struct xfs_btree_cur **)state);
+	kmem_free(rmap);
+	return error;
+}
+
+/* Clean up after processing deferred rmaps. */
+STATIC void
+xfs_rmap_update_finish_cleanup(
+	struct xfs_trans	*tp,
+	void			*state,
+	int			error)
+{
+	struct xfs_btree_cur	*rcur = state;
+
+	xfs_rmap_finish_one_cleanup(tp, rcur, error);
+}
+
+/* Abort all pending RUIs. */
+STATIC void
+xfs_rmap_update_abort_intent(
+	void				*intent)
+{
+	xfs_rui_release(intent);
+}
+
+/* Cancel a deferred rmap update. */
+STATIC void
+xfs_rmap_update_cancel_item(
+	struct list_head		*item)
+{
+	struct xfs_rmap_intent		*rmap;
+
+	rmap = container_of(item, struct xfs_rmap_intent, ri_list);
+	kmem_free(rmap);
+}
+
+static const struct xfs_defer_op_type xfs_rmap_update_defer_type = {
+	.type		= XFS_DEFER_OPS_TYPE_RMAP,
+	.max_items	= XFS_RUI_MAX_FAST_EXTENTS,
+	.diff_items	= xfs_rmap_update_diff_items,
+	.create_intent	= xfs_rmap_update_create_intent,
+	.abort_intent	= xfs_rmap_update_abort_intent,
+	.log_item	= xfs_rmap_update_log_item,
+	.create_done	= xfs_rmap_update_create_done,
+	.finish_item	= xfs_rmap_update_finish_item,
+	.finish_cleanup = xfs_rmap_update_finish_cleanup,
+	.cancel_item	= xfs_rmap_update_cancel_item,
+};
+
+/* Register the deferred op type. */
+void
+xfs_rmap_update_init_defer_op(void)
+{
+	xfs_defer_init_op_type(&xfs_rmap_update_defer_type);
+}