diff --git a/fs/iomap.c b/fs/iomap.c
index 0342254646e3..706270f21b35 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -428,9 +428,12 @@ static int iomap_to_fiemap(struct fiemap_extent_info *fi,
 		break;
 	}
 
+	if (iomap->flags & IOMAP_F_MERGED)
+		flags |= FIEMAP_EXTENT_MERGED;
+
 	return fiemap_fill_next_extent(fi, iomap->offset,
 			iomap->blkno != IOMAP_NULL_BLOCK ? iomap->blkno << 9: 0,
-			iomap->length, flags | FIEMAP_EXTENT_MERGED);
+			iomap->length, flags);
 
 }
 
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 3dd8f1d54498..05b5243d89f6 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2278,6 +2278,8 @@ xfs_alloc_log_agf(
 		offsetof(xfs_agf_t, agf_btreeblks),
 		offsetof(xfs_agf_t, agf_uuid),
 		offsetof(xfs_agf_t, agf_rmap_blocks),
+		/* needed so that we don't log the whole rest of the structure: */
+		offsetof(xfs_agf_t, agf_spare64),
 		sizeof(xfs_agf_t)
 	};
 
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index b5c213a051cd..08569792fe20 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -1814,6 +1814,10 @@ xfs_btree_lookup(
 
 	XFS_BTREE_STATS_INC(cur, lookup);
 
+	/* No such thing as a zero-level tree. */
+	if (cur->bc_nlevels == 0)
+		return -EFSCORRUPTED;
+
 	block = NULL;
 	keyno = 0;
 
@@ -4554,15 +4558,22 @@ xfs_btree_simple_query_range(
 	if (error)
 		goto out;
 
+	/* Nothing?  See if there's anything to the right. */
+	if (!stat) {
+		error = xfs_btree_increment(cur, 0, &stat);
+		if (error)
+			goto out;
+	}
+
 	while (stat) {
 		/* Find the record. */
 		error = xfs_btree_get_rec(cur, &recp, &stat);
 		if (error || !stat)
 			break;
-		cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
 
 		/* Skip if high_key(rec) < low_key. */
 		if (firstrec) {
+			cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
 			firstrec = false;
 			diff = cur->bc_ops->diff_two_keys(cur, low_key,
 					&rec_key);
@@ -4571,6 +4582,7 @@ xfs_btree_simple_query_range(
 		}
 
 		/* Stop if high_key < low_key(rec). */
+		cur->bc_ops->init_key_from_rec(&rec_key, recp);
 		diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
 		if (diff > 0)
 			break;
diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
index 054a2032fdb3..c221d0ecd52e 100644
--- a/fs/xfs/libxfs/xfs_defer.c
+++ b/fs/xfs/libxfs/xfs_defer.c
@@ -194,7 +194,7 @@ xfs_defer_trans_abort(
 	/* Abort intent items. */
 	list_for_each_entry(dfp, &dop->dop_pending, dfp_list) {
 		trace_xfs_defer_pending_abort(tp->t_mountp, dfp);
-		if (dfp->dfp_committed)
+		if (!dfp->dfp_done)
 			dfp->dfp_type->abort_intent(dfp->dfp_intent);
 	}
 
@@ -290,7 +290,6 @@ xfs_defer_finish(
 	struct xfs_defer_pending	*dfp;
 	struct list_head		*li;
 	struct list_head		*n;
-	void				*done_item = NULL;
 	void				*state;
 	int				error = 0;
 	void				(*cleanup_fn)(struct xfs_trans *, void *, int);
@@ -309,19 +308,11 @@ xfs_defer_finish(
 		if (error)
 			goto out;
 
-		/* Mark all pending intents as committed. */
-		list_for_each_entry_reverse(dfp, &dop->dop_pending, dfp_list) {
-			if (dfp->dfp_committed)
-				break;
-			trace_xfs_defer_pending_commit((*tp)->t_mountp, dfp);
-			dfp->dfp_committed = true;
-		}
-
 		/* Log an intent-done item for the first pending item. */
 		dfp = list_first_entry(&dop->dop_pending,
 				struct xfs_defer_pending, dfp_list);
 		trace_xfs_defer_pending_finish((*tp)->t_mountp, dfp);
-		done_item = dfp->dfp_type->create_done(*tp, dfp->dfp_intent,
+		dfp->dfp_done = dfp->dfp_type->create_done(*tp, dfp->dfp_intent,
 				dfp->dfp_count);
 		cleanup_fn = dfp->dfp_type->finish_cleanup;
 
@@ -331,7 +322,7 @@ xfs_defer_finish(
 			list_del(li);
 			dfp->dfp_count--;
 			error = dfp->dfp_type->finish_item(*tp, dop, li,
-					done_item, &state);
+					dfp->dfp_done, &state);
 			if (error) {
 				/*
 				 * Clean up after ourselves and jump out.
@@ -428,8 +419,8 @@ xfs_defer_add(
 		dfp = kmem_alloc(sizeof(struct xfs_defer_pending),
 				KM_SLEEP | KM_NOFS);
 		dfp->dfp_type = defer_op_types[type];
-		dfp->dfp_committed = false;
 		dfp->dfp_intent = NULL;
+		dfp->dfp_done = NULL;
 		dfp->dfp_count = 0;
 		INIT_LIST_HEAD(&dfp->dfp_work);
 		list_add_tail(&dfp->dfp_list, &dop->dop_intake);
diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h
index cc3981c48296..e96533d178cf 100644
--- a/fs/xfs/libxfs/xfs_defer.h
+++ b/fs/xfs/libxfs/xfs_defer.h
@@ -30,8 +30,8 @@ struct xfs_defer_op_type;
 struct xfs_defer_pending {
 	const struct xfs_defer_op_type	*dfp_type;	/* function pointers */
 	struct list_head		dfp_list;	/* pending items */
-	bool				dfp_committed;	/* committed trans? */
 	void				*dfp_intent;	/* log intent item */
+	void				*dfp_done;	/* log done item */
 	struct list_head		dfp_work;	/* work items */
 	unsigned int			dfp_count;	/* # extent items */
 };
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index e6a8bea0f7ba..270fb5cf4fa1 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -674,7 +674,8 @@ typedef struct xfs_agf {
 #define	XFS_AGF_BTREEBLKS	0x00000800
 #define	XFS_AGF_UUID		0x00001000
 #define	XFS_AGF_RMAP_BLOCKS	0x00002000
-#define	XFS_AGF_NUM_BITS	14
+#define	XFS_AGF_SPARE64		0x00004000
+#define	XFS_AGF_NUM_BITS	15
 #define	XFS_AGF_ALL_BITS	((1 << XFS_AGF_NUM_BITS) - 1)
 
 #define XFS_AGF_FLAGS \
@@ -691,7 +692,8 @@ typedef struct xfs_agf {
 	{ XFS_AGF_LONGEST,	"LONGEST" }, \
 	{ XFS_AGF_BTREEBLKS,	"BTREEBLKS" }, \
 	{ XFS_AGF_UUID,		"UUID" }, \
-	{ XFS_AGF_RMAP_BLOCKS,	"RMAP_BLOCKS" }
+	{ XFS_AGF_RMAP_BLOCKS,	"RMAP_BLOCKS" }, \
+	{ XFS_AGF_SPARE64,	"SPARE64" }
 
 /* disk block (xfs_daddr_t) in the AG */
 #define XFS_AGF_DADDR(mp)	((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index 0e3d4f5ec33c..4aecc5fefe96 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -583,7 +583,8 @@ xfs_sb_verify(
 	 * Only check the in progress field for the primary superblock as
 	 * mkfs.xfs doesn't clear it from secondary superblocks.
 	 */
-	return xfs_mount_validate_sb(mp, &sb, bp->b_bn == XFS_SB_DADDR,
+	return xfs_mount_validate_sb(mp, &sb,
+				     bp->b_maps[0].bm_bn == XFS_SB_DADDR,
 				     check_version);
 }
 
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 607cc29bba21..b5b9bffe3520 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1611,7 +1611,7 @@ xfs_wait_buftarg(
 	 */
 	while (percpu_counter_sum(&btp->bt_io_count))
 		delay(100);
-	drain_workqueue(btp->bt_mount->m_buf_workqueue);
+	flush_workqueue(btp->bt_mount->m_buf_workqueue);
 
 	/* loop until there is nothing left on the lru list. */
 	while (list_lru_count(&btp->bt_lru)) {
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 24ef83ef04de..fd6be45b3a1e 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1574,9 +1574,16 @@ xfs_fs_fill_super(
 		}
 	}
 
-	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+		if (mp->m_sb.sb_rblocks) {
+			xfs_alert(mp,
+	"EXPERIMENTAL reverse mapping btree not compatible with realtime device!");
+			error = -EINVAL;
+			goto out_filestream_unmount;
+		}
 		xfs_alert(mp,
 	"EXPERIMENTAL reverse mapping btree feature enabled. Use at your own risk!");
+	}
 
 	error = xfs_mountfs(mp);
 	if (error)
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 7e88bec3f359..d303a665dba9 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -2295,7 +2295,7 @@ DECLARE_EVENT_CLASS(xfs_defer_pending_class,
 		__entry->dev = mp ? mp->m_super->s_dev : 0;
 		__entry->type = dfp->dfp_type->type;
 		__entry->intent = dfp->dfp_intent;
-		__entry->committed = dfp->dfp_committed;
+		__entry->committed = dfp->dfp_done != NULL;
 		__entry->nr = dfp->dfp_count;
 	),
 	TP_printk("dev %d:%d optype %d intent %p committed %d nr %d\n",
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 3267df461012..3d70ece10313 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -18,6 +18,11 @@ struct vm_fault;
 #define IOMAP_MAPPED	0x03	/* blocks allocated @blkno */
 #define IOMAP_UNWRITTEN	0x04	/* blocks allocated @blkno in unwritten state */
 
+/*
+ * Flags for iomap mappings:
+ */
+#define IOMAP_F_MERGED	0x01	/* contains multiple blocks/extents */
+
 /*
  * Magic value for blkno:
  */
@@ -27,7 +32,8 @@ struct iomap {
 	sector_t		blkno;	/* 1st sector of mapping, 512b units */
 	loff_t			offset;	/* file offset of mapping, bytes */
 	u64			length;	/* length of mapping, bytes */
-	int			type;	/* type of mapping */
+	u16			type;	/* type of mapping */
+	u16			flags;	/* flags for mapping */
 	struct block_device	*bdev;	/* block device for I/O */
 };