diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 4637ae1ae91ca8ef6007c05ba060dd9fb208fdf1..356ebd1cbe82518c9898c2bb1a2befa0f5206c5b 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -2009,6 +2009,9 @@ xfs_bmap_add_extent_delay_real(
 			goto done;
 	}
 
+	if (da_new != da_old)
+		xfs_mod_delalloc(mp, (int64_t)da_new - da_old);
+
 	if (bma->cur) {
 		da_new += bma->cur->bc_private.b.allocated;
 		bma->cur->bc_private.b.allocated = 0;
@@ -2640,6 +2643,7 @@ xfs_bmap_add_extent_hole_delay(
 		/*
 		 * Nothing to do for disk quota accounting here.
 		 */
+		xfs_mod_delalloc(ip->i_mount, (int64_t)newlen - oldlen);
 	}
 }
 
@@ -3352,8 +3356,10 @@ xfs_bmap_btalloc_accounting(
 		 * already have quota reservation and there's nothing to do
 		 * yet.
 		 */
-		if (ap->wasdel)
+		if (ap->wasdel) {
+			xfs_mod_delalloc(ap->ip->i_mount, -(int64_t)args->len);
 			return;
+		}
 
 		/*
 		 * Otherwise, we've allocated blocks in a hole. The transaction
@@ -3372,8 +3378,10 @@ xfs_bmap_btalloc_accounting(
 	/* data/attr fork only */
 	ap->ip->i_d.di_nblocks += args->len;
 	xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
-	if (ap->wasdel)
+	if (ap->wasdel) {
 		ap->ip->i_delayed_blks -= args->len;
+		xfs_mod_delalloc(ap->ip->i_mount, -(int64_t)args->len);
+	}
 	xfs_trans_mod_dquot_byino(ap->tp, ap->ip,
 		ap->wasdel ? XFS_TRANS_DQ_DELBCOUNT : XFS_TRANS_DQ_BCOUNT,
 		args->len);
@@ -3969,6 +3977,7 @@ xfs_bmapi_reserve_delalloc(
 
 
 	ip->i_delayed_blks += alen;
+	xfs_mod_delalloc(ip->i_mount, alen + indlen);
 
 	got->br_startoff = aoff;
 	got->br_startblock = nullstartblock(indlen);
@@ -4840,8 +4849,10 @@ xfs_bmap_del_extent_delay(
 	da_diff = da_old - da_new;
 	if (!isrt)
 		da_diff += del->br_blockcount;
-	if (da_diff)
+	if (da_diff) {
 		xfs_mod_fdblocks(mp, da_diff, false);
+		xfs_mod_delalloc(mp, -da_diff);
+	}
 	return error;
 }
 
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index eff8b4c3eb3e68e917d393c6f9fa02853cc0c828..4cedf6f8565b174db2cef394d4286a66b5a89f5e 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1451,3 +1451,24 @@ xfs_force_summary_recalc(
 
 	xfs_fs_mark_sick(mp, XFS_SICK_FS_COUNTERS);
 }
+
+/*
+ * Update the in-core delayed block counter.
+ *
+ * We prefer to update the counter without having to take a spinlock for every
+ * counter update (i.e. batching).  Each change to delayed allocation
+ * reservations can change can easily exceed the default percpu counter
+ * batching, so we use a larger batch factor here.
+ *
+ * Note that we don't currently have any callers requiring fast summation
+ * (e.g. percpu_counter_read) so we can use a big batch value here.
+ */
+#define XFS_DELALLOC_BATCH	(4096)
+void
+xfs_mod_delalloc(
+	struct xfs_mount	*mp,
+	int64_t			delta)
+{
+	percpu_counter_add_batch(&mp->m_delalloc_blks, delta,
+			XFS_DELALLOC_BATCH);
+}
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 14fba76ab8118bb8669b5a624388be46d9cf2622..c81a5cd7c2288014da00c994d58f9d9fa2caede3 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -81,6 +81,12 @@ typedef struct xfs_mount {
 	struct percpu_counter	m_icount;	/* allocated inodes counter */
 	struct percpu_counter	m_ifree;	/* free inodes counter */
 	struct percpu_counter	m_fdblocks;	/* free block counter */
+	/*
+	 * Count of data device blocks reserved for delayed allocations,
+	 * including indlen blocks.  Does not include allocated CoW staging
+	 * extents or anything related to the rt device.
+	 */
+	struct percpu_counter	m_delalloc_blks;
 
 	struct xfs_buf		*m_sb_bp;	/* buffer for superblock */
 	char			*m_fsname;	/* filesystem name */
@@ -475,5 +481,6 @@ int	xfs_zero_extent(struct xfs_inode *ip, xfs_fsblock_t start_fsb,
 struct xfs_error_cfg * xfs_error_get_cfg(struct xfs_mount *mp,
 		int error_class, int error);
 void xfs_force_summary_recalc(struct xfs_mount *mp);
+void xfs_mod_delalloc(struct xfs_mount *mp, int64_t delta);
 
 #endif	/* __XFS_MOUNT_H__ */
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index df917f41ca466d6c60ae999586eced839e1375fd..3a870a194cd9d37700d2e04c56d270b9bf904aec 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1538,8 +1538,14 @@ xfs_init_percpu_counters(
 	if (error)
 		goto free_ifree;
 
+	error = percpu_counter_init(&mp->m_delalloc_blks, 0, GFP_KERNEL);
+	if (error)
+		goto free_fdblocks;
+
 	return 0;
 
+free_fdblocks:
+	percpu_counter_destroy(&mp->m_fdblocks);
 free_ifree:
 	percpu_counter_destroy(&mp->m_ifree);
 free_icount:
@@ -1563,6 +1569,9 @@ xfs_destroy_percpu_counters(
 	percpu_counter_destroy(&mp->m_icount);
 	percpu_counter_destroy(&mp->m_ifree);
 	percpu_counter_destroy(&mp->m_fdblocks);
+	ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
+	       percpu_counter_sum(&mp->m_delalloc_blks) == 0);
+	percpu_counter_destroy(&mp->m_delalloc_blks);
 }
 
 static struct xfs_mount *