diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3cccf0f05666..fd3084feb4b5 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2779,10 +2779,11 @@ enum btrfs_flush_state {
 	FLUSH_DELAYED_REFS	=	4,
 	FLUSH_DELALLOC		=	5,
 	FLUSH_DELALLOC_WAIT	=	6,
-	ALLOC_CHUNK		=	7,
-	ALLOC_CHUNK_FORCE	=	8,
-	RUN_DELAYED_IPUTS	=	9,
-	COMMIT_TRANS		=	10,
+	FLUSH_DELALLOC_FULL	=	7,
+	ALLOC_CHUNK		=	8,
+	ALLOC_CHUNK_FORCE	=	9,
+	RUN_DELAYED_IPUTS	=	10,
+	COMMIT_TRANS		=	11,
 };
 
 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index fbd492fe87f9..eb90a262563f 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -493,6 +493,11 @@ static void shrink_delalloc(struct btrfs_fs_info *fs_info,
 	long time_left;
 	int loops;
 
+	delalloc_bytes = percpu_counter_sum_positive(&fs_info->delalloc_bytes);
+	ordered_bytes = percpu_counter_sum_positive(&fs_info->ordered_bytes);
+	if (delalloc_bytes == 0 && ordered_bytes == 0)
+		return;
+
 	/* Calc the number of the pages we need flush for space reservation */
 	if (to_reclaim == U64_MAX) {
 		items = U64_MAX;
@@ -500,22 +505,21 @@ static void shrink_delalloc(struct btrfs_fs_info *fs_info,
 		/*
 		 * to_reclaim is set to however much metadata we need to
 		 * reclaim, but reclaiming that much data doesn't really track
-		 * exactly, so increase the amount to reclaim by 2x in order to
-		 * make sure we're flushing enough delalloc to hopefully reclaim
-		 * some metadata reservations.
+		 * exactly.  What we really want to do is reclaim full inode's
+		 * worth of reservations, however that's not available to us
+		 * here.  We will take a fraction of the delalloc bytes for our
+		 * flushing loops and hope for the best.  Delalloc will expand
+		 * the amount we write to cover an entire dirty extent, which
+		 * will reclaim the metadata reservation for that range.  If
+		 * it's not enough subsequent flush stages will be more
+		 * aggressive.
 		 */
+		to_reclaim = max(to_reclaim, delalloc_bytes >> 3);
 		items = calc_reclaim_items_nr(fs_info, to_reclaim) * 2;
-		to_reclaim = items * EXTENT_SIZE_PER_ITEM;
 	}
 
 	trans = (struct btrfs_trans_handle *)current->journal_info;
 
-	delalloc_bytes = percpu_counter_sum_positive(
-						&fs_info->delalloc_bytes);
-	ordered_bytes = percpu_counter_sum_positive(&fs_info->ordered_bytes);
-	if (delalloc_bytes == 0 && ordered_bytes == 0)
-		return;
-
 	/*
 	 * If we are doing more ordered than delalloc we need to just wait on
 	 * ordered extents, otherwise we'll waste time trying to flush delalloc
@@ -595,8 +599,11 @@ static void flush_space(struct btrfs_fs_info *fs_info,
 		break;
 	case FLUSH_DELALLOC:
 	case FLUSH_DELALLOC_WAIT:
+	case FLUSH_DELALLOC_FULL:
+		if (state == FLUSH_DELALLOC_FULL)
+			num_bytes = U64_MAX;
 		shrink_delalloc(fs_info, space_info, num_bytes,
-				state == FLUSH_DELALLOC_WAIT, for_preempt);
+				state != FLUSH_DELALLOC, for_preempt);
 		break;
 	case FLUSH_DELAYED_REFS_NR:
 	case FLUSH_DELAYED_REFS:
@@ -906,6 +913,14 @@ static void btrfs_async_reclaim_metadata_space(struct work_struct *work)
 				commit_cycles--;
 		}
 
+		/*
+		 * We do not want to empty the system of delalloc unless we're
+		 * under heavy pressure, so allow one trip through the flushing
+		 * logic before we start doing a FLUSH_DELALLOC_FULL.
+		 */
+		if (flush_state == FLUSH_DELALLOC_FULL && !commit_cycles)
+			flush_state++;
+
 		/*
 		 * We don't want to force a chunk allocation until we've tried
 		 * pretty hard to reclaim space.  Think of the case where we
@@ -1069,7 +1084,7 @@ static void btrfs_preempt_reclaim_metadata_space(struct work_struct *work)
  *   so if we now have space to allocate do the force chunk allocation.
  */
 static const enum btrfs_flush_state data_flush_states[] = {
-	FLUSH_DELALLOC_WAIT,
+	FLUSH_DELALLOC_FULL,
 	RUN_DELAYED_IPUTS,
 	COMMIT_TRANS,
 	ALLOC_CHUNK_FORCE,
@@ -1158,6 +1173,7 @@ static const enum btrfs_flush_state evict_flush_states[] = {
 	FLUSH_DELAYED_REFS,
 	FLUSH_DELALLOC,
 	FLUSH_DELALLOC_WAIT,
+	FLUSH_DELALLOC_FULL,
 	ALLOC_CHUNK,
 	COMMIT_TRANS,
 };
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index c7d19eadecc5..8f58fd95efc7 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -94,6 +94,7 @@ struct btrfs_space_info;
 	EM( FLUSH_DELAYED_ITEMS,	"FLUSH_DELAYED_ITEMS")		\
 	EM( FLUSH_DELALLOC,		"FLUSH_DELALLOC")		\
 	EM( FLUSH_DELALLOC_WAIT,	"FLUSH_DELALLOC_WAIT")		\
+	EM( FLUSH_DELALLOC_FULL,	"FLUSH_DELALLOC_FULL")		\
 	EM( FLUSH_DELAYED_REFS_NR,	"FLUSH_DELAYED_REFS_NR")	\
 	EM( FLUSH_DELAYED_REFS,		"FLUSH_ELAYED_REFS")		\
 	EM( ALLOC_CHUNK,		"ALLOC_CHUNK")			\